In a recent review published in Nature Reviews Microbiology, researchers discussed the impact of climate change, weather, and other anthropogenic factors on vector-borne illness spread globally.
Study: Effects of climate change and human activities on vector-borne diseases. Image Credit: petrmalinak/Shutterstock.com
Background
Hematophagous arthropods like ticks, mosquitoes, and sandflies transmit vector-borne infections to animals and humans, primarily affecting individuals in subtropical and tropical areas. Weather alterations can affect vectors' reproduction, survival, and ability to transfer pathogens.
Multi-scale climatic changes characterized by changing weather trends over decades may alter vector-borne illness transmission. Climate changes could lead to less predictable and stable weather patterns, with various adverse effects on humans and the environment beyond natural climatic variability.
These impacts may include ecosystem collapses, species extinctions, and extreme weather events of increased frequency and intensity.
Climate changes may also affect the risk and predictability linked to vector-borne pathogens, making the situation more complex and potentially ambiguous. Climate change can significantly impact vector-borne diseases.
About the review
In the present review, researchers explored the influence of climate changes and human activities on vector-borne diseases.
Impact of climate changes on vector growth and vector-borne pathogen transmission
Weather and environment considerably affect vector biology, including developmental rates, survival, lifespan, biting, fecundity, and replication.
Extreme weather events such as heavy rainfall, wind, floods, or temperature fluctuations can severely disrupt dipteran vectors, like mosquitoes with a brief life cycle.
Ticks have a longer life cycle, lasting months or years. Extreme weather patterns, including El Niño and La Niña, significantly affect vector activity and the likelihood of disease transmission.
The El Niño-Southern Oscillation (ENSO) predictability enables forecasting increasing vector-borne illness risks and developing mitigating solutions.
Droughts and floods cause alterations in vector-borne disease transmission, with varying timeframes, locations, and habitats. Intense precipitation can make aquatic ecosystems more conducive to vectors, increasing malaria, dengue fever, and chikungunya infection risks.
Floodwater mosquitoes, like Aedes ochraceus and Aedes vexans, can spread Dirofilaria immitis and Rift Valley fever virus (RVFV).
Drought is a primary climatic driver of West Nile virus (WNV) outbreaks in the United States, affecting transmission by increasing infection prevalence due to reduced bird reproduction or altered patterns of host-vector interaction.
Climate change can increase vector-borne illness risk, notably in mosquitoes such as Aedes albopictus and Aedes aegypti.
Temperature is the primary parameter utilized in climate change models for vector-borne infections, although other elements like precipitation and humidity influence their reproduction and survival.
Effects of land usage on climate change and vector-borne diseases
Land use changes, defined by activities like agriculture, resource extraction, and urban growth, can significantly contribute to climatic change by reducing biodiversity and carbon capture and storage.
Vector-borne illnesses are vulnerable to land utilization and cover changes since they influence vector and host populations, predators, adult and larval habitats, microclimate appropriateness for pathogens and vectors, and vector-host interaction rates.
Deforestation can interrupt vector-borne illness transmission cycles by increasing exposure to vectors in domestic animals and humans. Abiotic environmental circumstances can have varying effects on vector ecology, depending on vector species and the microclimates formed by deforestation.
Deforestation can also impact dipteran vectors by changing water quality, raising temperatures, lowering humidity, and destroying natural larval habitats.
Agricultural transformation offers various societal benefits but can also impact vector-borne infection risk. For example, irrigation equipment for rice farming alters malaria, dengue fever, and Japanese encephalitis risks.
Vector species ecology determines the impact of agricultural transformation and can negatively or positively influence the abundance and distribution of vectors and infections. Livestock agriculture can influence vector-borne illness dynamics by boosting blood meal availability and producing competent reservoir hosts for zoonotic diseases.
Inadequate waste management in urban areas can increase arthropod-borne illnesses by providing ideal larval homes for vectors.
Technical solutions for vector and disease management in agricultural settings are crucial in addressing conflicts between agricultural and population health policies in the face of fast global change.
Conclusions
Based on the study findings, climate change can considerably impact vector-borne infection risk and associated burden worldwide. Recent infection surveillance efforts and population health capacity developments may address this hazard.
However, further research is required to lessen the vector-borne disease burden in the face of climatic change. Researchers must address healthcare access inequities and vector-borne illness surveillance, especially among middle- and low-income nations.
Low-cost serological, molecular, and genomic methods should be employed to study disease dissemination and identify vulnerable populations.
Cost-effective vector control approaches such as deploying Wolbachia-infected Aedes aegypti mosquitoes can halt national disease transmission.
Affordable and effective vaccinations can influence the fight against vector-borne illnesses; however, their limited availability and administration can leave areas susceptible to disease recurrence.
Climate change drives sharp rise in fire-related mortality worldwide