The African continent, already disproportionately affected by malaria, with 94% of total cases and 95% of deaths recorded in 2022, is worried about the installation of a new mosquito, theAnopheles stephensi.
Originally from South Asia, this particularly effective vector of the disease could wipe out decades of fight against malaria (also called malaria), which is transmitted by bites.
Already present in certain regions of the Arabian Peninsula, theAnopheles stephensi entered Africa through Djibouti in 2012. The World Health Organization (WHO) then identified it in Ethiopia and Sudan in 2016, in Somalia (2019) and Nigeria (2020). Last year, local media reported its appearance in Ghana.
Unlike his cousin Anopheles gambiae, The most widespread malaria vector species in Africa, this mosquito is resistant to high heat, and continues to bite during the dry season, when transmission generally reaches its lowest seasonal level, underlines the WHO.
It also bites earlier in the evening, making the use of mosquito nets ineffective, the most effective prevention tool for limiting the transmission of malaria. It is also resistant to most insecticides.
Malaria eradication slips away
The adaptability of this mosquito and its progression in Africa further remove the hope of eradicating malaria. While between 2000 and 2014 “there was an overall decrease from 243 million to 230 million cases in the 108 affected countries”notes the WHO in its latest annual report, “since 2015, cases of malaria have increased”until reaching 249 million worldwide in 2022.
An increase especially localized on the African continent, where the appearance ofAnopheles stephensi comes in addition to other factors favoring the spread of the disease: climate change, which creates more favorable conditions for the life and reproduction of mosquitoes, droughts, famines, wars, etc.
Ethiopia, a country in the Horn of Africa affected by several of these ills, is experiencing a “unprecedented increase” of the number of malaria cases. 7.3 million cases were recorded by the WHO between January 1 and October 20, 2024, compared to 4.1 million the previous year. The number of deaths more than doubled, from 527 to 1,157.
Faced with these worrying prospects, several countries are focusing on vaccinating children, who are particularly vulnerable to malaria. The WHO prequalified the R21 malaria vaccine in December 2023. Since then, Unicef has distributed more than 18 million doses in 12 African countries.
