Mapping current and future thermal limits to suitability for malaria transmission by the invasive mosquitoAnopheles stephensi

Abstract

Background:Anopheles stephensiis a malaria-transmitting mosquito that has recently expanded from its primary range in Asia and the Middle East, to locations in Africa. This species is a competent vector of bothP. falciparum(PF) andP. vivax(PV) malaria. Perhaps most alarming, the characteristics ofAn. stephensi, such as container breeding and anthropophily, make it particularly adept at exploiting built environments in areas with no prior history of malaria risk. Methods: In this paper we created global maps of thermal transmission suitability and people at risk (PAR) for malaria transmission byAn. stephensi, under current and future climate. Temperature-dependent transmission suitability thresholds derived from recently published species-specific thermal curves were used to threshold gridded, monthly mean temperatures under current and future climatic conditions. These temperature driven transmission models were coupled with gridded population data for 2020 and 2050, under climate-matched scenarios for future outcomes, to compare with baseline predictions for 2020 populations. Results: Using the Global Burden of Disease regions approach, we found that heterogenous regional increases and decreases in risk did not mask the overall pattern of massive increases of PAR for malaria transmission suitability with An. stephensi presence. General patterns of poleward expansion for thermal suitability were seen for both PF and PV transmission potential. Conclusions: Understanding the potential suitability forAn. stephensitransmission in a changing climate provides a key tool for planning, given an ongoing invasion and expansion of the vector. Anticipating the potential impact of onward expansion to transmission suitable areas, and the size of population at risk under future climate scenarios, and where they occur, can serve as a large-scale call for attention, planning, and monitoring.

The historical fingerprint and future impact of climate change on childhood malaria in Africa

“…stephensi were to become a dominant vector across the continent, climate change might become an even more pressing concern 64,65 . These risks only add more urgency to the global goals of eliminating both malaria and greenhouse gas emissions.…”

Stage -Specific Antimalarial Activity of Alkaloidal Fractions of the Avicennia africana P. Beauv. (Avicenniaceae) Leaf Extract

“…However, efforts to eradicate malaria are in jeopardy due to the emergence and spread of drug-resistant clones of malarial parasites, particularly those resistant to 4-aminoquinolines such as chloroquine (CQ), sulfadoxine-pyrimethamine, and recently, artemisinin (Talisuna, et al, 2004 andWHO, 2015). Malaria control and eradication efforts are further threatened due to the invasion of Anopheles stephensi in urban environments in several endemic countries (Ahn, et al, 2023 andRyan et al, 2023). Therefore, there is a need to step up preventive measures while searching for an alternative medication from natural products.…”