Influence of environmental, anthropogenic, and climatic changes on vector-borne disease transmission: a comprehensive framework and critical review

1 Introduction

Vector-borne diseases (VBDs) represent one of humanity’s most persistent and escalating public health challenges. This review synthesizes evidence from both foundational studies (dating to the early 2000s) and the most recent publications (through early 2026), reflecting the long history of research on VBD drivers as well as rapid new developments. Transmitted through the bites of blood-feeding arthropods—principally mosquitoes, ticks, sandflies, and triatomine bugs—these diseases place a disproportionate burden on tropical and subtropical populations, particularly in low- and middle-income countries (1). Yet the boundaries of their geographical distribution are no longer static. Over the past three decades, dengue, chikungunya, Zika, West Nile virus, Lyme disease, and leishmaniasis have all recorded dramatic expansions into previously non-endemic regions, signaling a systemic reorganization of the conditions that sustain VBD transmission.

The factors driving this reorganization are multiple and deeply interlocking. Climate change—through warming temperatures, shifting precipitation patterns, and increasingly frequent extreme weather events—alters the survival, reproduction, biting rates, and geographic range of arthropod vectors (2, 3). Simultaneously, human activities such as deforestation, agricultural intensification, dam construction, and rapid urbanization fragment natural habitats, create new vector breeding sites, and bring human populations into closer contact with wildlife reservoirs (4). Globalization and mass international travel further accelerate the introduction of novel pathogens and vectors into regions with existing or expanding competent vector populations (5).

The Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (6) confirmed with high confidence that climate change has already increased the transmission potential of several VBDs, and projects further expansion under all emissions scenarios. The World Health Organization (1) estimates that over 3.9 billion people are currently at risk of dengue alone, while malaria caused an estimated 249 million cases in 2023, an increase of 5 million compared to 2021. These trends are not coincidental; they reflect the compounding effects of planetary change on the ecological systems that govern pathogen transmission.

This manuscript synthesizes current evidence within a unified conceptual framework, organized around three interacting axes: climatic drivers, anthropogenic drivers, and ecological/environmental mediators. It examines disease-specific impacts, discusses how these drivers interact across biological scales, and highlights priorities for surveillance, modeling, and public health action. The main goal is to provide researchers, epidemiologists, and policymakers with an integrated, up-to-date reference that reflects both the complexity and urgency of the VBD challenge. The depth of discussion for each disease reflects the availability of well quantified empirical evidence on its climatic, anthropogenic, and ecological drivers; diseases with fewer mechanistic or large-scale observational studies are reviewed more concisely.

1.1 Literature search strategy and methodology

This review was developed through a structured and comprehensive search of the scientific literature to synthesize current evidence on the influence of climatic, anthropogenic, and ecological drivers on vector-borne disease (VBD) transmission. The literature search covered publications from January 2019 to June 2026. The initial search was conducted in May 2025 and subsequently updated to incorporate key studies published during 2026, ensuring that the review reflects the latest advances in this rapidly evolving field.

The primary databases searched were PubMed (MEDLINE), Web of Science Core Collection, Scopus, and Google Scholar, with the latter limited to the first 200 results ranked by relevance. In addition, authoritative reports and technical documents were retrieved from the World Health Organization (WHO) Institutional Repository and other major international agencies when appropriate.

The search strategy combined three groups of keywords using Boolean operators (AND and OR): (i) vector-borne diseases and their principal vectors (e.g., malaria, dengue, Zika, chikungunya, Lyme disease, leishmaniasis, mosquitoes, ticks, and sandflies); (ii) environmental and anthropogenic drivers (e.g., climate change, global warming, precipitation, urbanization, deforestation, land-use change, travel, trade, and insecticide resistance); and (iii) transmission dynamics and analytical approaches (e.g., transmission, risk, modeling, surveillance, early warning systems, and One Health).

Studies were included if they were peer-reviewed original research articles, systematic reviews, meta-analyses, or authoritative reports published by recognized organizations such as the WHO, the Intergovernmental Panel on Climate Change (IPCC), and the Centers for Disease Control and Prevention (CDC). Eligible studies examined at least one vector-borne disease together with one or more climatic, anthropogenic, or ecological drivers. Publications were restricted to English-language articles or those providing sufficiently detailed English abstracts. Although the primary focus was on literature published between 2019 and 2026, seminal studies published before 2019 were retained where necessary to provide historical context or describe foundational concepts.

Editorials, opinion pieces, conference abstracts without full-text publications, studies focused exclusively on non-vector-borne infectious diseases, and publications lacking empirical or mechanistic evidence were excluded from the review.

Titles and abstracts were initially screened to determine relevance, followed by full-text evaluation of all potentially eligible articles. To assess the consistency of the screening process, a randomly selected 20% subset of records was independently reviewed, demonstrating excellent agreement (Cohen’s κ = 0.89).

The database search identified 4,872 records. After removing 1,103 duplicate records and excluding 2,968 studies during title and abstract screening, 801 full-text articles were assessed for eligibility. Ultimately, 312 publications met the inclusion criteria and form the evidence base for this review, including 28 reports from international organizations such as the WHO and IPCC. Although a formal PRISMA systematic review was not undertaken, the literature selection process followed the core principles of transparent identification, screening, eligibility assessment, and inclusion to ensure methodological rigor and reproducibility.

2 Conceptual framework: a triaxial model of VBD drivers

Understanding the influence of global change on VBDs requires moving beyond single-factor explanations. This review proposes a triaxial framework in which three broad categories of drivers interact dynamically at multiple biological and geographical scales (Figure 1).

Unlike additive multi-stimulus frameworks, which treat climatic, anthropogenic, and ecological drivers as independent and summable contributors to disease risk (effectively modeling transmission potential as Risk ≈ f(climate) + f (land use) + f(ecology)), the triaxial framework proposed here is defined by its explicit two-way and three-way interaction structure. Each axis is hypothesized to modify the marginal effect of the other two: the effect of warming on vector breeding depends on the degree of forest fragmentation already present (Axis I × Axis II), the effect of deforestation on transmission depends on prevailing host biodiversity (Axis II × Axis III), and the effect of biodiversity loss on the dilution effect is itself modulated by climatic suitability for vector survival (Axis III × Axis I). This interaction-based formulation has two practical advantages over additive taxonomies. First, it generates falsifiable, quantitatively testable predictions — specifically, that statistical models including climate × land-use or climate × biodiversity product terms (or equivalent tensor-product smooths in generalized additive models) should outperform models containing only main effects, a prediction we substantiate with empirical evidence in Section 7. Second, it provides a structural template for future mechanistic and statistical modeling efforts, in which the three axes can be operationalized as covariate blocks with explicit interaction terms rather than as an unordered checklist of risk factors. In this sense, the triaxial model is intended not merely as a descriptive taxonomy but as a generative framework for hypothesis-driven, interaction-explicit VBD risk modeling.

These axes do not operate independently. A rise in temperature (Axis I) interacts with deforestation (Axis II) to create edge habitats with elevated temperatures and increased vector breeding (Axis III). Similarly, urbanization (Axis II) concentrates human populations in heat islands that amplify local warming (Axis I) and create abundant artificial vector breeding sites (Axis III). Recognizing these interactions is fundamental to predicting future VBD dynamics and designing effective interventions (Table 1).

Table 1. Triaxial driver framework with components, mechanisms, and example diseases.

EIP, extrinsic incubation period; WNV, West Nile virus; Ae., Aedes.

Recent modeling efforts increasingly employ ensemble frameworks that integrate climatic variables, land-use change, biodiversity metrics, socioeconomic indicators, remote sensing products, and machine-learning algorithms to improve prediction of vector-borne disease risk. Compared with traditional single-driver models, these integrated approaches better capture non-linear interactions, quantify uncertainty, and generate more robust spatial predictions under future climate scenarios. Continued development of hybrid mechanistic-statistical models capable of assimilating real-time surveillance and Earth-observation data represents a promising direction for operational early-warning systems.

3 Climatic drivers of vector-borne disease transmission

Discrepancies in Thermal Optimum Estimates Across Methods Recent studies reveal notable discrepancies in thermal optimum and threshold estimates derived from laboratory experiments, field observations, and modeling efforts for various vector–pathogen systems. Laboratory experiments, conducted under highly controlled temperature regimes, often report thermal suitability ranges that do not fully correspond to field data where microclimatic heterogeneity, behavioral thermoregulation, and biotic interactions modulate vector ecology (7, 8). Mordecai et al. (7) found that optimal transmission temperatures of mosquito-borne diseases such as dengue and Zika derived from lab experiments tended to differ from field estimates, partly because field conditions introduce variability not replicable in lab settings. Additionally, different modeling approaches yield varying threshold estimates depending on assumptions about temperature effects on vector and pathogen life-history traits (9). Furthermore, certain models may underestimate upper thermal limits by neglecting vector acclimation or adaptation potential (10). Similarly, low-temperature thresholds show species- and pathogen-specific variability (11). Addressing these discrepancies calls for integrative, multi-scale approaches combining empirical field data, controlled experiments, and improved mechanistic models to better capture thermal dependencies in diverse ecological contexts.

3.1 Temperature

Temperature is arguably the most extensively studied climatic determinant of VBD transmission. Because arthropod vectors are ectothermic, their physiological processes—including larval development time, adult survival, biting frequency, gonotrophic cycle duration, and the extrinsic incubation period (EIP) of the pathogen within the vector—are all temperature dependent (2). Transmission potential follows a unimodal, non-linear response to temperature, rising sharply across a lower thermal threshold and declining above an upper threshold as enzymes denature and adult survival plummets. For malaria (Plasmodium falciparum transmitted by Anopheles mosquitoes), the optimal transmission temperature range is approximately 25–30 °C, with a lower threshold near 16 °C and cessation above ~34 °C (12). Rising temperatures in highland regions of sub-Saharan Africa and the Andes have allowed malaria transmission to occur at progressively higher altitudes, exposing immunologically naive populations (13). For dengue, the optimal transmission range for Aedes aegypti is approximately 21–34 °C, and models project a 35% rise in dengue incidence globally by 2050 under moderate warming scenarios (14). West Nile virus transmission peaks at 23–26 °C, and warming of temperate summers has been associated with intensified WNV epidemics in North America and Europe (8) (Table 2; Figure 2).

Table 2. Thermal optima and climate projections for major vector-borne diseases.

DENV, dengue virus; WNV, West Nile virus; ZIKV, Zika virus; CHIKV, chikungunya virus. Lower and upper thermal limits refer to thresholds for vector activity or pathogen transmission; optimal range denotes the temperature interval of peak transmission potential (R₀).

A critical but often underappreciated dimension is the effect of diurnal temperature range (DTR) on transmission dynamics. Even when mean temperatures remain within optimal ranges, large daily fluctuations can reduce mosquito survival and lengthen the EIP, while small fluctuations in an already optimal range can accelerate pathogen development (15). Climate models projecting reduced DTR under greenhouse warming may therefore have important implications for transmission intensity beyond mean temperature effects.

Most mechanistic thermal suitability models remain simplified representations of field conditions because they often exclude diurnal temperature variation, humidity co-variation, vector adaptation, and microclimatic heterogeneity, highlighting important sources of uncertainty.

Beyond mosquitoes, temperature also strongly structures transmission potential in sandflies, ticks, and triatomines, although the responses are often more heterogeneous and context dependent. In phlebotomine sandflies, temperature affects both vector life-history traits and Leishmania development within the insect, while moisture-linked microhabitats constrain where these thermal effects can be realized. In ixodid ticks, warming can extend seasonal activity and facilitate poleward and altitudinal expansion, but changes in phenology and disease incidence must be interpreted alongside host dynamics, land use, and surveillance intensity. For triatomines, climate change may shift species ranges unevenly, with some vectors such as Rhodnius prolixus projected to expand into newly suitable areas while others such as Triatoma infestans may contract under some scenarios, underscoring that warming does not produce uniform outcomes across vector taxa (16–18).

The rapid development of insecticide resistance is another temperature-mediated phenomenon of concern. Rising temperatures boost the activity of cytochrome P450 and other detoxification enzymes in Anopheles, Aedes, and Culex mosquitoes, accelerating the selection of resistance alleles and undermining standard vector control programs (19–22). For Lyme disease, transmission intensity peaks within a narrow thermal band of 17.0–20.5 °C; as surface temperatures rise, this optimal ‘sweet spot’ shifts geographically, causing risk to decline in areas that warm above the optimum while emerging in newly suitable cooler regions (23).

3.2 Precipitation and humidity

Rainfall and humidity exert direct and indirect effects on vector populations. Most mosquito species require standing water for larval development; therefore, precipitation creates and replenishes breeding habitats, leading to population surges that can precede epidemic events by weeks. However, the relationship is non-linear: moderate rainfall increases breeding sites, whereas intense flooding can flush larval habitats, temporarily reducing vector populations before creating abundant new pools as floodwaters recede (2).

Relative humidity influences adult mosquito survival by affecting desiccation risk. High humidity prolongs adult lifespan, increasing the probability that a mosquito survives the EIP and becomes infectious. Conversely, drought conditions concentrate animal and human populations around diminishing water sources, increasing contact between hosts and vectors. In East Africa, drought-related clustering around water holes has been associated with intensified malaria and Rift Valley fever transmission cycles (24).

El Niño–Southern Oscillation (ENSO) cycles represent a particularly powerful modulator of precipitation-driven VBD dynamics. El Niño events warm the central and eastern Pacific, triggering droughts in parts of Southeast Asia, Australia, and East Africa while increasing rainfall in the Americas. La Niña brings the opposite pattern. These large-scale oscillations create multi-year cycles of heightened malaria, dengue, and leishmaniasis risk. In Bangladesh, dengue cases surged by 317% in 2023 compared to 2019, with observed links to ENSO and Indian Ocean Dipole dynamics (25). Integrating ENSO forecasts into early warning systems represents a promising avenue for proactive VBD surveillance. Recent research has further demonstrated that rising ENSO amplitude and teleconnections are intensifying dengue risk globally (26) (Table 3).

Table 3. ENSO phase effects on regional vector-borne disease risk.

IOD, Indian Ocean Dipole; SST, sea surface temperature; VL, visceral leishmaniasis. [Source: de Souza & Weaver (2); Baidya et al. (25); Paz (24)].

Precipitation and humidity are especially important for sandfly-borne transmission because moisture conditions influence the availability of breeding and resting sites, while rainfall and temperature variability can alter transmission seasonality. In Panama, cutaneous leishmaniasis cycles were associated with ENSO, rainfall, and temperature, with a measurable lag between sandfly abundance and human cases, indicating that climate variability can propagate through vector population dynamics into epidemic timing. Comparable moisture dependence is also relevant for ticks because humidity regulates questing activity and desiccation risk, meaning that warming effects may be amplified or suppressed depending on local hydrological conditions (16, 27, 28). Importantly, precipitation–VBD relationships remain highly context-dependent, with both positive and negative associations reported across regions owing to differences in hydrology, vector ecology, and human behaviors.

3.3 Extreme weather events and climate variability

Beyond secular warming trends, the increasing frequency and intensity of extreme weather events predicted under climate change scenarios introduce episodic disruptions to VBD transmission cycles. Flooding events can destroy vector control infrastructure, displace populations, and create vast new larval breeding opportunities, as observed during the 2022 Pakistan floods that precipitated a major malaria resurgence (29). Conversely, prolonged heatwaves can drive vectors indoors, alter biting behavior toward nocturnal or dawn patterns, and shift peak transmission season.

Tropical cyclones, whose intensity is projected to increase under climate change, can spread vectors and pathogens across new territories through wind-assisted dispersal of adult mosquitoes and through the creation of standing water habitats in their aftermath. Post-hurricane dengue outbreaks have been documented across the Caribbean and Gulf Coast of the United States, illustrating the capacity of extreme events to trigger acute epidemics in partially endemic or non-endemic settings (3).

3.4 Sea level rise and coastal habitat changes

Sea level rise, a major consequence of global warming, will progressively inundate coastal zones, expand brackish water habitats, and alter the hydrology of coastal wetlands. Several Anopheles and Culex species breed productively in brackish water, and the expansion of such habitats could introduce VBDs into coastal urban centers. Saltwater intrusion into freshwater systems may also alter the composition of aquatic communities, potentially remove predators and competitors of larval mosquitoes, and facilitate population expansion (24).

Sea level rise (SLR) is a slow onset but irreversible consequence of climate change, driven primarily by thermal expansion of ocean water and melting of land-based ice (glaciers and ice sheets). Global mean sea level has risen by approximately 0.20 m (1901–2018) and is projected to rise by 0.43–0.84 m by 2100 under SSP5 8.5, with higher local rates in tropical and low latitude regions (30). Although often overshadowed by temperature and rainfall effects, SLR alters vector borne disease dynamics through several interrelated mechanisms:

3.4.1 Mechanisms

3.4.1.1 Saltwater intrusion into coastal freshwater habitats

Rising sea levels push saline water into coastal aquifers, rivers, and wetlands, creating new brackish water environments. Many mosquito species, most notably Anopheles sundaicus (a major malaria vector in Southeast Asia) and Ochlerotatus (Aedes) vigilax (a vector of Ross River virus and Barmah Forest virus in Australia), breed preferentially in brackish water. SLR expands the geographic extent of suitable breeding sites, potentially increasing vector abundance.

3.4.1.2 Coastal flooding and storm surge amplification

Higher sea levels exacerbate the inland reach of storm surges and high tides, inundating coastal settlements and creating transient mosquito breeding habitats. Post flood conditions (standing water, decaying organic matter) can trigger explosive population growth of floodwater mosquitoes (Aedes and Culex species), as observed after cyclones in Bangladesh and Hurricane Katrina in the United States.

3.4.1.3 Salinization of drinking water and sanitation infrastructure

Saltwater intrusion into groundwater and surface water sources forces communities to rely on stored rainwater or trucked water, often stored in open containers that become Aedes breeding sites. This mechanism links SLR directly to dengue and chikungunya risk in coastal urban slums.

3.4.1.4 Displacement and migration

SLR driven coastal erosion and permanent inundation are projected to displace millions of people by 2100 (e.g., 13–40 million in South and Southeast Asia (31)). Displaced populations often relocate to informal settlements with poor sanitation and high vector exposure, increasing VBD transmission.

3.4.2 Regional examples

3.4.2.1 Bangladesh and the Ganges Brahmaputra delta

This region experiences the highest rate of SLR in the tropics (4–6 mm yr ¹). Salinity intrusion has already shifted the distribution of An. sundaicus landward by 15–30 km, correlating with a doubling of malaria incidence in saline affected coastal districts (32). Projections under 2 °C warming indicate that an additional 3.2 million people will be at risk of brackish water malaria by 2050 (33).

3.4.2.2 Pacific Island nations (Fiji, Tuvalu, Kiribati)

SLR of 0.5–1.0 m by 2100 will inundate low lying atolls, destroy natural Anopheles breeding grounds but simultaneously create new artificial containers (water tanks, tarpaulins) that favor Aedes vectors. Dengue outbreaks in the region are already more frequent following king tides and salinization events (34).

3.4.2.3 U.S. Gulf Coast and Chesapeake Bay

SLR of 0.3–0.6 m by 2050 is projected to increase the area of saltmarsh habitat for Ae. sollicitans and Ae. taeniorhynchus, major vectors of eastern equine encephalitis (EEE) and West Nile virus. Modeling indicates a 20–40% increase in EEE human cases in Florida and Texas under a high emission scenario (35).

3.4.2.4 Nile Delta, Egypt

The Nile Delta is one of the world’s most vulnerable coastal zones to SLR, with rates of 2.5–5.0 mm yr ¹ and a projected 1.0 m rise by 2100 threatening 12 % of Egypt’s agricultural land. Salinization of the northern delta has expanded brackish water habitats for Culex pipiens (vector of lymphatic filariasis and West Nile virus) and Anopheles pharoensis (vector of malaria). A 2022 modeling study predicted a 35 % increase in the seasonal abundance of Culex pipiens in the Kafr el Sheikh governorate under a 0.5 m SLR scenario, with a corresponding 20 % rise in filariasis transmission potential (36). Additionally, the displacement of farming communities to inland urban peripheries has been linked to increased dengue seroprevalence due to proliferation of Aedes aegypti breeding sites in stored water containers (37).

3.4.2.5 Caribbean islands (e.g., Cuba, Dominican Republic, Trinidad)

SLR in the Caribbean is accelerating at 3–5 mm yr ^-¹, with high islands and low-lying coastal zones equally affected. Saltwater intrusion into coastal aquifers has been correlated with a 50–80 % increase in Aedes aegypti container positivity in Havana’s coastal municipalities since 2010, coinciding with severe dengue outbreaks in 2012, 2019, and 2022 (38). In the Dominican Republic, a national vulnerability assessment found that a 0.6 m SLR by 2050 would place 1.2 million people in zones where, groundwater salinization forces reliance on rainwater storage, potentially doubling the number of Aedes breeding sites per household (39). Projections for Trinidad indicate that the combined effect of SLR and increased hurricane intensity could increase the suitable habitat for Ae. aegypti by 18 % by 2080, extending the geographical range of dengue and chikungunya transmission into currently cooler highland regions (40).

3.4.3 Modeling projections

Recent coupled hydrodynamic epidemiological models have begun to quantify SLR driven VBD risk. For example, a 0.5 m SLR scenario in West Africa is predicted to expand An. sundiacus habitat by 12,000 km² along the Niger Delta, potentially increasing malaria cases by 1.2 million annually (41). In the Mekong Delta, a 1.0 m SLR could triple the number of months per year with brackish water conditions suitable for An. Sundiacus breeding, shifting malaria transmission from seasonal to perennial (42).

These projections remain sensitive to assumptions about adaptation (e.g., coastal defenses, water management), demonstrating the need for integrated coastal zone and vector control planning.

3.4.4 Knowledge gaps and research needs

Despite growing evidence, the epidemiological consequences of SLR remain understudied compared to those of warming. Key gaps include: (1) quantitative relationships between salinity concentration and vector fitness (survival, fecundity, competence) across diverse mosquito species; (2) long term cohort studies linking SLR trajectories to VBD incidence in highly exposed populations; and (3) economic cost effectiveness of adaptive infrastructure (e.g., seawalls, rainwater harvesting) compared to traditional vector control.

4 Anthropogenic drivers of vector-borne disease transmission

4.1 Deforestation and land use change

Human-driven land use change is one of the most powerful drivers of emerging and re- emerging VBDs. Deforestation—the conversion of forest to agricultural land, pasture, or urban space—disrupts the ecological balance between vectors, wildlife reservoir hosts, and human populations, often dramatically increasing transmission risk (43, 44). A comprehensive synthesis of 305 studies found that deforestation/forest fragmentation and agricultural development were the most commonly reported drivers of VBD transmission change in the scientific literature (45).

The mechanisms are multiple. Deforestation eliminates canopy cover, increasing air and ground temperatures and creating sun-exposed, slow-moving water bodies that are preferred breeding habitats for malaria vectors such as Anopheles gambiae in sub-Saharan Africa. A landmark study in Amazonian Brazil demonstrated that each 1% increase in deforestation was associated with a nearly 1% increase in malaria incidence, a relationship driven by the expansion of forest edges where vector density is highest (46). Forest edges also represent spillover interfaces where wildlife reservoir hosts encounter domestic animals and humans, facilitating zoonotic pathogen transmission.

Recent evidence confirms that land-use changes including deforestation and urbanization generally increase transmission risks, particularly for diseases transmitted by mosquitoes and rodents (47). Deforestation in Southeast Asia has been closely linked to the emergence of Plasmodium knowlesi malaria—a simian malaria parasite now the leading cause of malaria in Malaysia—by increasing human encroachment into the habitat of its macaque reservoir hosts. In Africa, Ebola outbreaks have been statistically associated with forest loss events, and globally, both zoonotic and vector-borne disease outbreaks increased dramatically over the 1990–2016 period in association with deforestation (48). The construction of large hydroelectric dams creates vast artificial reservoirs with extensive shorelines and slow-moving water that are highly productive for anopheline mosquitoes, as documented extensively along the Volta River in Ghana and the Aswan Dam in Egypt.

Meta-analyses confirm that land use intensification increases VBD prevalence in a dose-response fashion, with the most pronounced effects occurring at early stages of land degradation when forest fragmentation creates high-edge habitats (47). This edge effect is particularly strong for tick-borne diseases: fragmented forest patches harbor high densities of white-tailed deer and white-footed mice—the primary reservoir hosts for Borrelia burgdorferi (Lyme disease) and its tick vector Ixodes scapularis—while simultaneously placing human recreational and residential activities adjacent to tick habitat.

Land-use change and habitat fragmentation can reshape non-mosquito vector systems by altering microclimate, host community structure, and human contact patterns. For tick-borne disease, forest configuration and fragmentation influence enzootic hazard through effects on host movement, tick survival, and human exposure across urban–rural gradients. For Chagas disease, the sylvatic–domestic interface is also sensitive to landscape disturbance: while heavy disturbance may reduce some forest-associated triatomines, intermediate disturbance can favor more generalist species and increase house invasion risk, showing that anthropogenic change can reconfigure rather than simply eliminate transmission interfaces (49–51).

4.2 Agricultural expansion and irrigation

Agricultural intensification represents a related but distinct driver of VBD dynamics. Irrigated rice cultivation creates extensive shallow water habitats that sustain year-round populations of Anopheles culicifacies and other malaria vectors in South and Southeast Asia. The expansion of irrigation infrastructure in arid and semi-arid regions of sub-Saharan Africa has enabled malaria transmission to persist through dry seasons in areas that were previously seasonally free of the disease (44).

Livestock agriculture influences VBD transmission through zooprophylaxis (dilution of vector biting on less competent non-human hosts) and zoo-potentiation (provision of blood meals that sustain large vector populations). The net direction of effect depends on vector host preferences and the competence of livestock as pathogen reservoirs. Dense livestock populations around human settlements have been associated with elevated Rift Valley fever, Crimean-Congo Hemorrhagic Fever (CCHF), and certain arboviral transmission risks (2).

4.3 Urbanization

Urbanization—one of the most significant demographic transitions of the 21st century—profoundly reshapes VBD transmission dynamics. By 2050, it is projected that 68% of the world’s population will live in urban areas, with the majority of growth concentrated in tropical and subtropical cities already endemic for dengue, chikungunya, and Zika (52). Rapid, unplanned urbanization creates ideal ecological conditions for Aedes aegypti, the primary vector of all four Aedes-borne arboviruses: the proliferation of water storage containers, discarded plastic waste, blocked drains, and construction sites provides abundant breeding habitats, while high human density ensures plentiful blood meal hosts (1, 53).

A systematic review of 29 studies found clear associations between urbanization patterns, Aedes mosquito density, and arboviral disease transmission, with unplanned peri-urban expansion presenting the highest risk (53). The urban heat island effect, by which urban surfaces absorb and re-radiate heat to create temperatures 2–5 °C above surrounding rural areas, creates microclimatic conditions favorable to year-round mosquito activity even at latitudes where winters would otherwise interrupt transmission.

Critically, urbanization is also transforming the epidemiology of historically rural diseases. Visceral leishmaniasis (kala-azar), traditionally associated with poverty in rural South Asia and East Africa, has become increasingly urbanized in Brazil, where the sandfly vector Lutzomyia longipalpis has adapted to peri-urban environments. Similarly, Chagas disease, caused by Trypanosoma cruzi and transmitted by triatomine bugs, is urbanizing as rural-to-urban migration brings infected individuals and their peridomestic vectors into cities.

Urbanization has also been pivotal for sandfly- and triatomine-borne diseases. In Latin America, the urbanization of American visceral leishmaniasis has been linked to the adaptation of Lutzomyia longipalpis to domestic and peri-urban settings, aided by deforestation, human migration, infected dogs, and poor sanitary conditions. Chagas disease has likewise expanded beyond its traditional rural profile, as peri-urban settlement, synanthropic hosts, and vector adaptation bring enzootic cycles closer to households and, in some settings, favor oral and other non-classical transmission routes. These examples illustrate that urban growth can generate new ecotones and domestic interfaces rather than simply replacing natural transmission landscapes (54, 55).

4.4 Globalization, international travel, and trade

The modern era is characterized by unprecedented levels of international travel and trade, creating efficient conduits for the transcontinental spread of both vectors and pathogens. A comprehensive global analysis documented 697 first records of non-native mosquito vectors across 288 regions, with 45 species (24.5% of all known vectors) introduced and 28 successfully establishing populations. Aedes species alone accounted for 469 regional introductions, with Ae. aegypti now present in 192 regions and Ae. albopictus in 189 (56). The global spread of Aedes albopictus—the Asian tiger mosquito—from its native range in Southeast Asia to Europe, the Americas, and Africa over the past three decades has been driven largely by the international trade in used tires and lucky bamboo plants, in which desiccation-resistant eggs survive long-distance transport (5, 57).

The explosive emergence of Zika virus in the Americas between 2015 and 2017 exemplifies the role of travel in triggering VBD epidemics. Phylogenetic analyses traced the introduction of the Asian lineage Zika virus to Brazil through viremic travelers arriving at the 2014 FIFA World Cup, following which the virus spread through existing Ae. aegypti populations across 35 countries within two years (58). Returning travelers also represent the primary route by which dengue, malaria, chikungunya, and West Nile virus are introduced into non-endemic regions with competent local vectors, as demonstrated by the recurrent autochthonous dengue and chikungunya outbreaks in southern France and Italy (24, 59).

A systematic review published in 2025 confirmed that globalization, urbanization, and human mobility are key drivers of the global spread of Aedes mosquitoes, and recommended climate-resilient, internationally coordinated vector control strategies as an essential response (60).

4.5 Insecticide use and resistance

The widespread use of insecticides—in agriculture, public health programs, and household products—exerts intense selection pressure on arthropod vector populations, accelerating the evolution and spread of insecticide resistance. Three primary mechanisms have been identified: metabolic detoxification via cytochrome P-450 monooxygenases, glutathione-S-transferases, and esterases; target-site mutations in voltage-gated sodium channels (notably kdr mutations V1016I, F1534C, and G119S); and behavioral adaptations including avoidance of treated surfaces and shifts in feeding or resting behavior (19). This resistance is compounded by climate change, which boosts detoxification enzyme activity in mosquitoes, reduces insecticide persistence in the environment, and facilitates gene flow of resistance alleles between populations (19, 20, 22). In warmer regions, Aedes aegypti has demonstrated behavioral modifications—including a shift to nighttime biting and outdoor resting—that reduce exposure to daytime insecticide applications and indoor residual spraying, respectively, further challenging conventional control paradigms (Table 4).

Table 4. Summary of major anthropogenic drivers and their mechanisms of influence on vector-borne disease transmission.

CCHF, Crimean-Congo Haemorrhagic Fever; Ae., Aedes. Evidence quality ratings are based on availability of meta-analyses, systematic reviews, and longitudinal studies in the peer-reviewed literature.

5 Ecological and environmental mediators

5.1 Biodiversity loss and the dilution effect

Biodiversity loss—an accelerating consequence of both climate change and human land use—modulates VBD transmission through the dilution effect hypothesis, which posits that diverse host communities reduce transmission by including incompetent hosts that dilute the proportion of bites taken on competent reservoir hosts (61). When biodiversity declines, communities become dominated by competent reservoir species (“amplification hosts”), increasing the probability that a vector blood meal results in pathogen acquisition or transmission.

Evidence for the dilution effect has been demonstrated for Lyme disease in North America, where the white-footed mouse (a highly competent B. burgdorferi reservoir) increases in relative dominance as vertebrate diversity declines in fragmented forest patches, leading to elevated tick infection rates. The dilution effect also has implications for avian-amplified arboviruses such as West Nile virus, where diverse bird communities may buffer transmission by providing many non-amplifying dead-end hosts for Culex mosquitoes (2). The recent meta-analysis by Mahon et al. (62) confirmed that global change drivers—including biodiversity loss—are significantly associated with elevated infectious disease risk across a broad range of pathogens.

5.2 Habitat fragmentation

Forest fragmentation—the subdivision of continuous forest into smaller, isolated patches—dramatically increases the ratio of edge to interior habitat, creating the warm, sun-exposed conditions favored by many vector species. Meta-analyses confirm that VBD prevalence is highest in early-stage degraded landscapes with high edge density (47).

Forest edges generate ecotones—transition zones between different habitats—that concentrate wildlife movement and increase encounter rates between reservoir hosts, vectors, and human intruders (63). In the Amazon Basin, malaria incidence is strongly associated with proximity to recently deforested areas, reflecting the concentration of competent Anopheles vectors along forest margins.

5.3 Invasive species and vector range expansion

The introduction of invasive plant species can alter vector breeding habitats by affecting hydrology, shade, and organic matter inputs to water bodies. Conversely, the establishment of invasive vector species in new geographic areas represents a direct driver of VBD expansion. Aedes albopictus, introduced to Europe, North America, and South America through the live plant trade, is now established in over 100 countries and serves as a competent vector for dengue, chikungunya, Zika, and West Nile virus in temperate climates where Ae. Aegypti cannot persist year-round (5). Its establishment has enabled autochthonous dengue and chikungunya transmission in France, Italy, Spain, and Croatia. Beyond Aedes mosquitoes, Culex species contributed 192 introductions with 9 established across 184 regions, while Anopheles were introduced in 33 regions with 7 species established (56). This diversity of invasive vectors underscores that the threat extends far beyond the most commonly discussed Aedes species.

Tick range expansion represents an analogous threat for tick-borne diseases. The blacklegged tick (Ixodes scapularis), the vector of Lyme disease, babesiosis, anaplasmosis, and Powassan virus in North America, has expanded northward into Canada and eastward across the United States over the past 25 years as milder winters reduce overwinter tick mortality (64). The Hyalomma tick, vector of CCHF, has similarly expanded poleward beyond the 50th parallel in Europe and Asia, with Spain reporting its first human CCHF cases in 2016 and France detecting the virus in ticks for the first time in 2023 (64).

6 Disease-specific impacts of global change

The following part looks at how eight priority vector-borne diseases are affected by ecological, anthropogenic, and climatic variables. Their present worldwide burden and anticipated future course under climate change are summarized comparatively in Table 5 (Figure 3). Population-at-risk projections incorporate both current surveillance data and modeling estimates.

Table 5. Global burden and climate-change projections for priority vector-borne diseases.

Annual case estimates are drawn from WHO (1), Kraemer et al. (64), and de Souza & Weaver (2). CCHF, Crimean-Congo Hemorrhagic Fever; VL, visceral leishmaniasis; WNV, West Nile virus.

6.1 Malaria

Malaria remains the deadliest VBD globally, with 249 million cases and over 608,000 deaths in 2023, predominantly in sub-Saharan Africa (1, 65). Climate change is projected to expand the geographic and altitudinal range of malaria transmission, while intensifying existing transmission in regions where temperatures approach optimal levels. The WHO World Malaria Report (29) documented that progress toward the 2025 global reduction targets is significantly off track, with actual transmission rates 55% above target and projected to miss the goal by 89%. Deforestation-driven malaria is particularly acute in the Amazon Basin and Mekong region, where agricultural expansion continuously generates new edge habitats for efficient vector species.

6.2 Dengue

Dengue has experienced a 30-fold increase in global incidence over the past 50 years. The year 2024 marked the highest global dengue burden ever recorded, with 14.1 million cases reported worldwide—double the previous record of 7 million in 2023—and 9,508 deaths (66, 67). Brazil alone reported over 10 million cases and 6,321 deaths. Other countries with large epidemics included Argentina (581,559 cases), Mexico (558,846), Colombia (320,982), and Indonesia (257,271) (67). Climate models consistently project major expansions of dengue-suitable territory by 2050, with southern Europe, eastern China, parts of the southern United States, and high-elevation East Africa emerging as newly at-risk regions (7, 14). In Europe, autochthonous dengue transmission has shifted from a theoretical risk to an established reality, with outbreaks documented in France, Spain, and Italy driven by the northward expansion of Aedes albopictus (68). Projections suggest that by 2080, over one billion additional people in Europe and North America could be exposed to Aedes-borne arboviruses as climatic suitability expands (68). The combined effects of warming, urbanization, and the expansion of Aedes vectors position dengue as the archetypal climate-sensitive urban disease of the 21st century.

6.3 Zika and chikungunya

The rapid emergence of Zika virus across the Pacific and Americas (2013–2017) and the unprecedented chikungunya expansion into Europe and the Americas demonstrated the potential for Aedes-borne arboviruses to cause global public health emergencies within years of introduction into newly suitable environments. Between 2024 and 2025, chikungunya surged globally, with more than 400,000 cases and 155 deaths across 40 countries. The ECSA (East-Central-South-African) genotype—well adapted to Aedes mosquitoes—spread from the Indian Ocean to Europe, Asia, and the Americas (69). A 2025 analysis estimated that 5.66 billion people now live in areas environmentally suitable for dengue, chikungunya, and Zika transmission (70), reflecting the near-global distribution of competent Aedes vectors combined with favorable temperature conditions for transmission.

6.4 West Nile virus and other encephalitic arboviruses

West Nile virus (WNV), transmitted primarily by Culex mosquitoes in bird-mosquito-human transmission cycles, has become endemic across Europe and North America following its introduction into New York in 1999. European WNV epidemics have intensified markedly since 2018, with record case counts in Italy, Greece, Romania, and Serbia, driven by warming summer temperatures, altered rainfall, and changes in land use affecting bird migration and Culex habitat (71). The 2018 European season saw an unprecedented spike in WNV cases, attributed to prolonged heat, ecological degradation from wildfires, and favorable environmental conditions—patterns that have intensified in subsequent years (68). Japanese encephalitis virus continues to expand its range across Southeast and East Asia, with recent emergence in Australia’s Queensland state, while tick- borne encephalitis (TBE) has expanded northward across Scandinavia in association with milder winters and increased deer populations.

6.5 Lyme disease and other tick-borne diseases

Lyme disease is now the most commonly reported vector-borne disease in the United States and Europe. The northward range expansion of I. scapularis has brought Lyme disease to previously non-endemic areas of Canada and northern U.S. states, while I. ricinus has expanded to higher altitudes in Europe. Climate models project that Lyme-endemic territory in North America could more than double by 2080 under high-emissions scenarios (72). Recent mechanistic modeling for Maryland indicates that rising temperatures will not simply expand but redistribute Lyme risk: under moderate warming, Central Maryland will see increased burden while Western counties become newly at-risk; under high warming, the optimal thermal band shifts westward, creating new hotspots in Western Maryland while reducing transmission in Central, Southern, and Eastern counties where approximately 70% of the state’s population resides (23). This westward redistribution underscores that climate change may relocate rather than uniformly intensify VBD risk, complicating public health planning. CCHF presents a similarly alarming trend, with the Hyalomma tick now established in southern European countries where it was previously absent.

Although Lyme disease remains the dominant exemplar, warming may also favor the emergence or intensification of other tick-borne threats. In Europe, climate trends are projected to expand suitable conditions for Hyalomma marginatum, a vector of Crimean–Congo hemorrhagic fever virus (CCHF) and Rickettsia aeschlimannii, into parts of southeastern and central Europe while retaining suitability across the Mediterranean basin. This supports a broader interpretation of climate-driven tick-borne risk, in which changing temperature regimes, land use, and host movement interact to affect multiple pathogens rather than Lyme disease alone (28, 73).

6.6 Leishmaniasis and trypanosomiasis

Leishmaniasis, transmitted by phlebotomine sandflies, is highly sensitive to temperature and humidity, with warming conditions accelerating sandfly development and expanding the distribution of Phlebotomus and Lutzomyia species into previously non-endemic areas of southern Europe, North Africa, and highland regions of the Americas and Asia (24). Recent autochthonous cases have been documented in Germany and northern Italy, areas historically considered free of transmission risk. In the Mediterranean, Phlebotomus sandfly vectors have expanded into higher altitudes, including the Atlas Mountains in Morocco, while cross-sectional studies in southern Spain indicate that temperature increases may influence transmission more than vector density through enhanced biting frequency and shortened parasite incubation periods (68). African trypanosomiasis (sleeping sickness) and American trypanosomiasis (Chagas disease) are similarly influenced by land use changes that affect tsetse fly and triatomine bug habitats, respectively.

For Chagas disease, urbanization, and peridomestic adaptation of triatomine bugs (e.g., Triatoma infestans) have driven spread into cities across Latin America; however, mechanistic thermal performance data for Trypanosoma cruzi development in triatomines remain sparse, limiting quantitative projections. African trypanosomiasis, transmitted by tsetse flies (Glossina spp.), is highly sensitive to land use change — particularly deforestation and livestock expansion — which alter tsetse habitat and host availability. Recent modeling suggests that warming may expand the northern range of Glossina in sub–Saharan Africa, although the lack of laboratory derived thermal response curves for the parasite (T. brucei) constrains predictive accuracy (74, 75).

Chagas disease illustrates how climate and land-use change interact with sylvatic–domestic transitions. Climate-driven redistribution may differ among major triatomine species, while deforestation, settlement expansion, and peri-urbanization increase opportunities for contact between humans and sylvatic vectors. The resulting epidemiology is therefore shaped not only by climatic suitability but also by the reorganization of reservoirs, vectors, and domestic environments across disturbed landscapes (28, 73).

Leishmaniasis transmission is highly sensitive to coupled temperature–moisture regimes because temperature affects Leishmania development and sandfly life-history traits, whereas humidity and rainfall influence breeding and resting microhabitats. Notably, disease occurrence in the Americas has been associated with low seasonality in temperature and precipitation, while interannual climatic variability such as ENSO can modulate transmission cycles through delayed effects on vector abundance (16, 27).

7 Interactions, synergies, and feedback loops

A defining feature of the current VBD crisis is the synergistic amplification of risk through interactions between climatic, anthropogenic, and ecological drivers. Several critical feedback loops deserve particular attention (Figure 4).

7.1 The deforestation-warming feedback

Forest clearance releases stored carbon, accelerating atmospheric warming while simultaneously creating warmer, more humid microhabitats at forest edges that are favorable for vector breeding. This creates a positive feedback loop in which deforestation amplifies both global and local climate change, compounding VBD risk (4).

7.2 The urbanization-heat island-VBD feedback

Urban growth generates heat islands that extend mosquito activity seasons and support year-round transmission, while generating extensive artificial breeding habitats. Population concentration also creates the high human density required for epidemic dengue and Zika transmission, and places immunologically susceptible populations in proximity to airports and seaports that introduce new viral strains.

7.3 The biodiversity-dilution-disease feedback

Land use change reduces biodiversity, attenuating the dilution effect and increasing the dominance of competent reservoir hosts, which in turn drives higher transmission rates, which may further degrade ecosystems through the socioeconomic consequences of endemic disease (poverty, reduced agricultural productivity, loss of land stewardship capacity).

These three feedback loops are not solely qualitative constructs; a growing body of quantitative evidence directly demonstrates statistically significant, non-additive interaction effects between climatic and anthropogenic/ecological drivers, lending empirical support to the synergies the triaxial framework proposes. Lowe et al. (76), in a spatiotemporal modeling study of malaria re-emergence in southern Venezuela, formally tested for an interaction between environmental degradation (deforestation/mining-related land disturbance) and climate variation (ENSO-linked precipitation and temperature anomalies), and found that the effect of climate variation on malaria incidence was significantly modified by the degree of local environmental degradation — i.e., the same climatic anomaly produced markedly larger increases in malaria incidence in environmentally degraded municipalities than in intact ones, a synergistic rather than additive pattern. Similarly, Bouma and colleagues (77), in an analysis of Plasmodium vivax malaria in the Peruvian Amazon, fitted an ANCOVA model explicitly testing the interaction between ENSO phase and county-level forest cover; the ENSO × county interaction term was statistically significant (p ≈ 0.011), and the interaction-inclusive model achieved a substantially higher goodness of fit (R² = 0.85) than an equivalent model without the climate–land-use interaction term (R² = 0.26), directly demonstrating that the combined, interactive effect of climate and deforestation explains malaria incidence far better than either driver considered additively. At a broader taxonomic scale, a study of rodent-borne pathogens in central Kenya (78), found that several pathogens responded to statistically significant interactions between land-use disturbance type and climatic conditions, with the direction and magnitude of disturbance effects varying systematically across climatic gradients — again consistent with a synergistic, non-additive relationship between anthropogenic and climatic axes. Collectively, these three independents, peer-reviewed quantitative studies — spanning malaria in South America and rodent-borne zoonoses in East Africa — provide direct empirical confirmation that the interactions proposed in the triaxial framework (and illustrated qualitatively in Figure 4) are measurable, statistically testable phenomena rather than purely theoretical constructs, and that their omission from additive models produces meaningfully worse model performance.

Marcolin et al. (79) demonstrated that early-stage ecological integrity loss is a strong predictor of zoonotic disease emergence, with human footprint emerging as the most consistent predictor of epidemic cases of major VBDs including dengue, chikungunya, and Zika. These findings underscore that the boundaries between climatic, anthropogenic, and ecological drivers are artificial: they are, in reality, deeply entangled dimensions of a single planetary health crisis.

8 Surveillance, modeling, and predictive frameworks

Addressing the VBD challenge in the context of global change requires robust surveillance systems and predictive models capable of integrating climatic, ecological, and socioeconomic data streams (Figure 5). Several methodological advances have substantially improved predictive capacity in recent years (Table 6).

Table 6. Surveillance and predictive modeling approaches for vector-borne diseases under climate change.

SDM, species distribution model; ENM, ecological niche model; NDVI, normalized difference vegetation index; ENSO, El Nino-Southern Oscillation; AI, artificial intelligence. [Source: Hess et al. (95); Mordecai et al. (7); Caminade et al. (14, 57).

Mathematical and mechanistic transmission models—particularly those parameterized using empirically derived thermal performance curves for vector and pathogen traits—now provide quantitative predictions of how climate change will shift the geographic and seasonal distribution of VBDs. The Mordecai et al. (7) and Caminade et al. (57) frameworks represent landmark contributions, projecting poleward and altitudinal shifts for dengue, chikungunya, Zika, and malaria under multiple climate scenarios.

Species distribution modeling (SDM) and ecological niche modeling approaches, calibrated with occurrence data for vectors and pathogens, have been applied to project future range shifts for ticks, sandflies, and mosquitoes under IPCC emissions scenarios. The integration of remote sensing data—tracking land cover change, surface temperature, normalized difference vegetation index (NDVI), and water body dynamics—with epidemiological data enables the identification of high-risk landscapes in near-real time.

8.1 Operational early-warning systems: lessons from practice

Recent advances demonstrate that climate-informed early-warning systems (EWS) can substantially improve preparedness for vector-borne disease outbreaks when seasonal climate forecasts are integrated with epidemiological surveillance, entomological monitoring, and public health decision-making. Rather than relying solely on reactive case reporting, these systems provide several weeks to months of advance warning, enabling targeted vector control, resource allocation, and community engagement before epidemic transmission accelerates (80, 81).

One of the most mature examples is the WHO–WMO Climate-Informed Health Early Warning System (CIHEWS) framework, which integrates seasonal climate forecasts with disease surveillance to support national health agencies in forecasting climate-sensitive diseases (80). Countries in East Africa have used rainfall anomalies, vegetation indices, and seasonal forecasts to anticipate outbreaks of Rift Valley fever and malaria, facilitating pre-positioning of diagnostics, insecticides, and public health personnel before epidemic onset (80, 82).

In Latin America, the Pan American Health Organization (PAHO) has collaborated with national meteorological agencies to develop dengue early-warning systems incorporating temperature, rainfall, humidity, and ENSO forecasts (83). Brazil, Colombia, and Peru have demonstrated that combining seasonal climate predictions with vector surveillance can improve forecasting accuracy several months before dengue epidemics, allowing municipalities to intensify larval source reduction, community education, and insecticide deployment during periods of elevated climatic risk (76, 84).

Similarly, several countries in Southeast Asia have begun integrating ENSO monitoring with dengue surveillance. In Singapore, climate-based forecasting models incorporating temperature, rainfall, and mosquito abundance have enhanced prediction of dengue incidence, while Thailand and Vietnam increasingly employ satellite-derived environmental indicators alongside routine surveillance to identify emerging transmission hotspots (84, 85). Although forecasting performance varies among ecological settings, these initiatives demonstrate the operational value of combining climate services with epidemiological intelligence rather than relying on either source independently (80).

Despite these successes, important challenges remain. Forecast skill varies across regions, surveillance systems often suffer from reporting delays, and translating probabilistic climate forecasts into actionable public health decisions requires close collaboration among meteorological agencies, epidemiologists, vector-control programs, and local governments (80, 86). Future systems should therefore integrate Earth observation, genomic surveillance, real-time vector monitoring, and artificial intelligence to improve both spatial resolution and predictive accuracy (76, 80, 86).

8.2 Translating the triaxial framework into policy and practice

The triaxial framework proposed in this review offers a practical decision-support structure that can strengthen national vector-control programs by explicitly recognizing interactions among climatic, anthropogenic, and ecological drivers. Rather than addressing these drivers independently, intervention priorities can be tailored according to the dominant combination of local risk factors (1, 6, 87). For example, under India’s National Vector Borne Disease Control Programme (NVBDCP), climate information—including heat anomalies, monsoon forecasts, and extreme rainfall predictions—could be integrated with district-level surveillance and land-use data to prioritize vector-control activities before anticipated outbreaks (National Centre for Vector Borne Diseases Control (1, 88). Districts experiencing rapid urban expansion, inadequate drainage infrastructure, and forecasted above-average monsoon rainfall could receive intensified larval source management, enhanced entomological surveillance, and community awareness campaigns before peak transmission periods (1, 6). Likewise, forest fringe districts undergoing rapid land-use change could combine satellite-based deforestation monitoring with malaria surveillance to identify emerging transmission fronts requiring targeted interventions (45, 76).

Brazil provides another illustration, where malaria surveillance in the Amazon increasingly benefits from integrating satellite observations of deforestation, mining expansion, and hydrological change with routine epidemiological monitoring (2, 76). Incorporating these environmental indicators alongside seasonal climate forecasts allows earlier identification of municipalities at elevated transmission risk, thereby improving allocation of diagnostic resources, indoor residual spraying, and community health workers (76). At the global level, the proposed framework aligns closely with the WHO Global Vector Control Response (GVCR) 2017–2030, which emphasizes evidence-based decision-making, intersectoral collaboration, strengthened surveillance, and locally adapted integrated vector management (87). The triaxial model extends these principles by explicitly incorporating ecological integrity and land-use dynamics alongside climatic variability, thereby providing a more comprehensive basis for risk assessment under accelerating environmental change (6, 87).

The framework also has important implications beyond the health sector. Urban planners can reduce vector suitability through climate-sensitive city design, including improved stormwater drainage, reduction of unmanaged water storage, preservation of urban green infrastructure that avoids fragmented edge habitats, and mitigation of urban heat-island effects through increased tree canopy and reflective building materials (6, 86).

Similarly, environmental agencies can incorporate disease risk into environmental impact assessments for dams, irrigation schemes, mining developments, and large-scale deforestation projects, while agricultural planners can promote water-management practices that minimize persistent vector breeding habitats (1, 45).

Ultimately, implementation of the triaxial framework requires coordinated governance across health, environmental, agricultural, urban development, and meteorological sectors. Such cross-sectoral integration represents one of the central objectives of the One Health approach and will become increasingly important as climate change amplifies interactions among ecological degradation, environmental variability, and infectious disease emergence (1, 6, 87).

Figure 6, demonstrates how the proposed triaxial framework can be operationalized through climate-informed surveillance, integrated predictive modeling, and coordinated One Health decision-making. By linking climatic information with environmental, entomological, and epidemiological surveillance, the framework provides a practical pathway for translating scientific evidence into adaptive vector-control strategies for vector-borne diseases.

Climatic information (temperature, precipitation, extreme weather events, and large-scale climate oscillations) is integrated with environmental monitoring, entomological surveillance, and epidemiological data to support predictive modeling and risk assessment. The resulting evidence informs decision-support systems for early warning, targeted vector control, resource allocation, and community engagement. Continuous feedback among public health, veterinary, environmental, agricultural, urban planning, and meteorological sectors strengthens adaptive management under a One Health framework.

8.3 Uncertainties and validation challenges in predictive models

Mechanistic transmission models and species distribution models (SDMs) have advanced our ability to forecast vector-borne disease risks under future climate scenarios, yet fundamental uncertainties persist. SDMs often rely on the assumption of ecological niche conservatism—that species-environment relationships are stable over time—which may not hold during rapid climate change, evolutionary adaptation, or shifts in vector behavior (89, 90). Moreover, these models depend heavily on historical occurrence and environmental data, challenging extrapolation to novel climatic conditions (91). Field validation of models is frequently constrained by insufficient long-term, spatially explicit monitoring datasets that cover vector abundance and pathogen prevalence (92). Furthermore, complex interactions between abiotic and biotic drivers are often simplified or omitted, increasing uncertainty in projections (93). To improve model reliability, interdisciplinary integration of empirical, experimental, and modeling data is essential, alongside systematic uncertainty and sensitivity analyses (94).

Early warning systems that incorporate ENSO forecasts, seasonal climate outlooks, and sentinel surveillance data have shown promise in predicting dengue and malaria epidemic seasons weeks to months in advance, enabling pre-emptive vector control and health system preparedness (95). The WHO (96) Operational Framework for Climate-Resilient Health Systems provides a policy architecture for integrating climate information into national health planning and VBD control programs.

9 Critical appraisal, uncertainties, and knowledge gaps

Although considerable progress has been made in understanding how climatic, anthropogenic, and ecological drivers shape vector-borne disease (VBD) transmission, substantial uncertainties remain regarding the magnitude, direction, and generalizability of many reported relationships. These limitations warrant careful consideration because they influence the interpretation of current evidence and the reliability of future projections.

9.1 Context-dependent effects of precipitation

Among climatic variables, precipitation exhibits one of the most heterogeneous relationships with VBD transmission (7, 9). While moderate rainfall commonly increases mosquito breeding habitats and subsequently enhances transmission of diseases such as malaria and dengue, excessive rainfall may flush immature mosquito stages from breeding sites, temporarily suppressing vector abundance before new habitats are established during flood recession (7, 97)). Conversely, prolonged drought can paradoxically increase transmission through water-storage practices that create artificial breeding habitats for Aedes mosquitoes or by concentrating humans, livestock, and wildlife around limited water resources (98, 99). Consequently, positive, negative, and non-linear precipitation–disease relationships have all been reported depending on vector species, landscape characteristics, temporal lag, and spatial scale (7, 9). Meta-analyses increasingly demonstrate that precipitation alone is an insufficient predictor unless interpreted alongside temperature, humidity, land use, and local hydrological conditions (2, 7, 9, 47).

9.2 Challenges in attributing anthropogenic drivers

Interpreting the effects of land-use change presents equally important challenges (44, 45). Deforestation, urbanization, agricultural expansion, and infrastructure development often coincide with socioeconomic changes including population growth, migration, poverty, health-care accessibility, surveillance intensity, and improvements in diagnostic capacity, all of which can independently influence disease transmission and reporting (6, 45). These factors frequently act as confounders, making causal attribution difficult (44, 45). For example, increased malaria incidence following forest clearing may partly reflect improved disease reporting associated with expanding settlements rather than ecological changes alone (44, 100). Likewise, urban dengue outbreaks are influenced not only by urban expansion but also by water management, waste disposal, housing quality, vector-control effectiveness, and human mobility (81, 101, 102). Future studies therefore require stronger causal inference approaches—including longitudinal designs, quasi-experimental analyses, counterfactual modeling, and natural experiments—to disentangle direct ecological effects from correlated socioeconomic drivers (6, 45, 103).

9.3 Limitations of current thermal suitability models

Mechanistic temperature-dependent transmission models have substantially advanced understanding of climate–vector interactions; however, many projections remain based primarily on mean air temperature and thermal estimates of the basic reproduction number (R)₀ (7, 9). Such models frequently neglect several biologically important processes, including diurnal temperature range (DTR), humidity–temperature covariance, rainfall variability, mosquito behavioral plasticity, local adaptation, evolutionary responses, insecticide resistance, and microclimatic heterogeneity generated by vegetation and urban environments (7, 8, 15). Laboratory-derived thermal performance curves may therefore overestimate or underestimate transmission potential when extrapolated to complex field conditions because environmental conditions experienced by vectors in nature differ substantially from those under controlled laboratory experiments (8, 15). Integrating microclimate observations, remotely sensed environmental variables, and evolutionary ecology into mechanistic models represents an important priority for improving predictive accuracy (6, 7, 103).

9.4 Geographic biases and evidence gaps

Current evidence is also unevenly distributed geographically. High-resolution surveillance systems, long-term epidemiological datasets, and climate observations are concentrated in North America, Europe, Australia, and a limited number of middle-income countries (6, 86). In contrast, many low-income regions that experience the highest VBD burden—including parts of sub-Saharan Africa, Central Africa, the Amazon Basin, South Asia, and Pacific Island states—remain underrepresented in longitudinal datasets (9, 86).;. Consequently, many predictive models extrapolate ecological relationships from data-rich regions to areas with substantially different vector communities, host ecology, health systems, and socioeconomic conditions. Such extrapolation introduces considerable uncertainty into estimates of future disease risk and climate vulnerability (6, 103).

9.5 Emerging research priorities

Several important knowledge gaps remain insufficiently addressed. First, relatively few studies explicitly quantify interactions among climatic, anthropogenic, and ecological drivers despite increasing evidence that these interactions are non-additive (2, 7, 47). Second, standardized longitudinal datasets integrating climate observations, land-use change, vector surveillance, pathogen genomics, biodiversity monitoring, and socioeconomic indicators remain scarce particularly in many low- and middle-income countries (6, 80, 86). Third, many vector species beyond Aedes aegypti and Anopheles gambiae remain poorly characterized with respect to thermal biology, vector competence, and adaptive capacity under climate change (7, 10). Fourth, relatively little is known about how climate adaptation policies—including urban greening, coastal protection, water management, and ecosystem restoration—may alter VBD dynamics (1, 6). Finally, future predictive frameworks should increasingly incorporate artificial intelligence, high-resolution Earth observation, genomic surveillance, and One Health monitoring to improve early-warning systems while explicitly quantifying uncertainty around projections (80, 81, 86).

Overall, the accumulated evidence strongly supports the conclusion that climatic, anthropogenic, and ecological changes jointly reshape VBD transmission. Nevertheless, considerable uncertainty remains regarding the magnitude, timing, and regional expression of these effects. Future research should therefore prioritize multidisciplinary, longitudinal, and interaction-based approaches capable of integrating ecological complexity with socioeconomic determinants, thereby producing more robust and policy-relevant predictions under accelerating global environmental change (1, 6).

10 Adaptation and mitigation strategies: a One Health approach

Effective responses to the growing VBD burden require multi-sectoral, multi-scale strategies grounded in the One Health framework—recognizing the inextricable links between human, animal, and ecosystem health (Table 7).

Table 7. One Health adaptation strategies for vector-borne diseases in the context of global change.

SIT, sterile insect technique; GHG, greenhouse gas; WHO, World Health Organization; LMIC, low- and middle-income countries; UNFCCC, United Nations Framework Convention on Climate Change. [Sources: Bardosh et al. (104); Plowright et al. (109); Mordecai (4); WHO (1, 108).

10.1 Integrated vector management

Integrated Vector Management (IVM) combines biological, environmental, and chemical control methods to reduce vector populations in a manner that is sustainable and minimizes ecological harm. In response to rising insecticide resistance and behavioral adaptations by vectors, innovative approaches including the release of Wolbachia-infected mosquitoes (which suppress dengue, Zika, and chikungunya replication), sterile insect techniques (SIT), and gene-drive technologies are advancing toward large-scale deployment. Community-based approaches to eliminate Aedes breeding habitats through water management, waste removal, and housing improvements remain foundational (1, 104). The World Mosquito Program’s Wolbachia method has demonstrated remarkable success: in Niterói, Brazil, dengue cases dropped from 12,000 in 2013 to fewer than 330 cases in total between 2020 and 2023. Even after releases stopped, Wolbachia remained present in over 90% of the mosquito population, continuing to block dengue transmission (105). The program is now running in 11 sites across Brazil, with a new bio factory in Curitiba expected to produce about 100 million mosquito eggs per week.

A well-documented community-based IVM success is the “Comunidad Saludable” (Healthy Community) program in Chiapas, Mexico, which reduced dengue transmission by more than 80% through participatory elimination of Aedes breeding sites, household water storage improvements, and community health education (106). Similarly, in Sri Lanka, a community led source reduction campaign coupled with lawiciding achieved a sustained 75% reduction in Ae. aegypti indices over five years (107). These examples demonstrate that when communities are empowered with knowledge and simple tools, they can achieve vector control outcomes comparable to or exceeding those of top-down chemical spraying, while building long term resilience.

Despite these advances, the emergence of insecticide resistance—driven by metabolic detoxification, target-site mutations, and behavioral adaptations—continues to undermine chemical control programs globally (19).

10.2 Vaccine development and deployment

Vaccine development against VBDs has accelerated markedly. The WHO’s (108) recommendation of the R21/Matrix-M malaria vaccine, alongside the established RTS, S/AS01 vaccine, represents a historic breakthrough for malaria prevention. Dengue vaccines (Dengvaxia and Qdenga) are licensed in multiple countries, and Zika and chikungunya vaccines are advancing through clinical trials. Vaccination programs must be designed to account for the shifting geographic distribution of VBDs under climate change, anticipating new at-risk populations in currently non-endemic regions.

10.3 Land use planning and environmental governance

Addressing the anthropogenic drivers of VBD transmission requires transformations in land use governance. Policies that reduce deforestation, mandate environmental impact assessments for infrastructure projects, enforce sustainable agricultural practices, and promote biodiversity conservation can substantially reduce VBD emergence risk (44, 109). National 30×30 conservation commitments—pledging protection of 30% of land and ocean area by 2030—have an important co-benefit for reducing zoonotic and VBD spillover risk.

10.4 Climate mitigation and the health dividend

Ambitious climate mitigation—reducing greenhouse gas emissions to limit warming to 1.5 °C rather than 2.5–3 °C—would substantially constrain the future geographic expansion of VBDs. Mordecai (4) estimates that this temperature difference translates into hundreds of millions fewer people exposed to novel VBD transmission risk by 2100. The health co-benefits of climate action—cleaner air, reduced heat stress, lower VBD burden—provide powerful economic justification for aggressive emissions reduction policies.

10.5 Surveillance, early warning, and health system strengthening

Robust national and international surveillance systems, integrated early warning capacity using climate forecasts, and resilient health systems are essential to detecting and responding to emerging and re-emerging VBDs. The WHO’s global vector control response strategy calls for a re-alignment of vector control programs, supported by increased technical capacity, improved infrastructure, and strengthened monitoring—particularly in low-income countries that bear the greatest VBD burden while contributing least to climate change ( (1). Addressing health equity must be central to any adaptation strategy.

A flagship example of integrated One Health surveillance is the Rift Valley fever (RVF) early warning system in Kenya, which links satellite derived vegetation indices (NDVI), rainfall forecasts, sentinel livestock Sero surveillance, and human case reports. This system correctly predicted the 2018–2019 RVF outbreak three months in advance, enabling targeted livestock vaccination and movement restrictions that prevented an estimated 1,200 human cases (110). Another model is the Pacific syndromic surveillance network, which integrates human, animal, and environmental health data across 22 island countries and territories to detect arboviral outbreaks (dengue, Zika, chikungunya) weeks earlier than traditional surveillance, significantly improving response times (34).

10.6 Documented case studies of One Health implementation

Table 8 summarizes six well documented, large scale One Health initiatives that have demonstrably reduced vector borne disease burden. These examples illustrate the practical application of the principles discussed in Sections 9.1–9.5 and provide actionable models for policymakers.

Table 8. Documented case studies of successful One Health implementation against vector borne diseases.

Climate change is also a matter of health equity. Low-income tropical and subtropical countries, which have contributed relatively little to cumulative greenhouse gas emissions, continue to experience the greatest burden of malaria, dengue, leishmaniasis, and other climate-sensitive vector-borne diseases, while possessing comparatively limited adaptive capacity to respond to emerging climate risks (6, 111, 112). Limited surveillance infrastructure, constrained health-system capacity, inadequate urban services, and restricted access to climate adaptation financing further amplify vulnerability in many endemic regions (6, 112, 113).

Consequently, future adaptation strategies should prioritize equitable allocation of resources, strengthen local surveillance systems, expand climate-informed early warning systems, and support climate-resilient public health infrastructure in the most vulnerable populations, consistent with the principles of climate justice and the One Health approach (6, 87, 112, 113).

11 Conclusions and future directions

This review demonstrates that the drivers of vector-borne disease transmission are embedded in a complex, interconnected system of climatic, anthropogenic, and ecological processes. Climate change—through rising temperatures, altered precipitation, and extreme events—is expanding the geographic range and transmission intensity of VBDs across the globe. Anthropogenic land use change, urbanization, and globalization compound these climate effects by reshaping vector habitats, concentrating human populations in disease-favorable environments, and accelerating the transcontinental spread of vectors and pathogens.

Underlying both axes, the accelerating loss of biodiversity and ecological integrity erodes the natural buffering capacity of ecosystems against disease emergence. The next decade will be critical. Projections consistently show that without substantial reductions in greenhouse gas emissions and deforestation, and without major investments in VBD surveillance, vector control, and health system resilience, hundreds of millions of additional people will be exposed to novel VBD transmission risk by mid-century.

Conversely, the evidence base for effective interventions is strong, spanning technological innovations (vaccines, Wolbachia, gene drives), ecological approaches (biodiversity conservation, habitat restoration), and policy levers (climate action, land use governance).

Future research priorities include: (1) development of high-resolution, validated models that integrate climatic, land use, and socioeconomic drivers of VBD risk; (2) longitudinal surveillance studies that document actual vector range shifts and disease emergence in response to observed climate and land use change; (3) mechanistic studies of how climate change interacts with insecticide resistance evolution; (4) socioecological research on community-level vulnerability and adaptation; and (5) rigorous evaluations of integrated VBD control programs that incorporate climate projections into program design. A planetary health approach that recognizes the co-dependence of human health, biodiversity, and climate stability is the only framework equal to the scale of the challenge.

Future research should move beyond single-driver analyses toward integrated modeling frameworks that simultaneously incorporate climatic variability, land-use dynamics, biodiversity change, socioeconomic determinants, and surveillance data. Equally important is ensuring that advances in prediction and adaptation translate into equitable public health action, particularly for low- and middle-income countries that bear a disproportionate burden of climate-sensitive vector-borne diseases despite contributing least to global climate change.

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Footnotes

Edited by: Martial Ndeffo, Texas A and M University, United States

Reviewed by: Nirmal Kumar Ganguly, Apollo Hospitals Educational Research Foundation, India

Ronaldo Figueiró, Rio de Janeiro State University, Brazil

Footnotes

VBD, Vector-borne disease; EIP, Extrinsic incubation period; ENSO, El Niño–Southern Oscillation; IOD, Indian Ocean Dipole; SDM, Species Distribution Model; ENM, Ecological Niche Model; NDVI, Normalized Difference Vegetation Index; AI, Artificial Intelligence; IVM, Integrated Vector Management; SIT, Sterile Insect Technique; WNV, West Nile virus; DENV, Dengue virus; CHIKV, Chikungunya virus; ZIKV, Zika virus; VL, Visceral leishmaniasis; CCHF, Crimean-Congo hemorrhagic fever.