by Navaneeth Dontuboyina (’24) | November 18, 2022
Malaria is an illness caused by parasites and most commonly passed by female Anopheles mosquitoes. The most common mosquito species in Africa within the Anopheles family is A. gambiae, which spreads the P. falciparum variant of the parasite across sub-Saharan nations, where there is the highest concentration of malaria cases on the continent. Usually, the breakout cycle for malaria is contained to the wet seasons of sub-Saharan Africa, but an unusual phenomenon is occurring where an invasive species of mosquito is terrorizing the urban cities of Ethopia, which could be potentially harmful for the entire continent.
Ethiopia is usually out of reach for major malaria outbreaks, but for the past decade, the invasive A. stephensi mosquito species from the Persian Gulf and India have been gradually making a home in North African nations. First encountered in Djibouti in 2012, the spread of A. stephensi mosquitoes has been recorded in other northeast African countries such as Yemen and Sudan. All this buildup of the new mosquito population has culminated in a breakout of P. falciparum as well as a foreign P. vivax malaria parasite. In fact, eight years after the initial spotting of the Asian mosquitos in Djibouti, the country has experienced forty times more malaria cases. And earlier this year in the urban city of Dire Dawa, Ethiopia, cases in three weeks (from 29 to 270) have exponentially grown to 2400 cases and continues to sustain such intensity.
These mosquitoes wouldn’t be as dangerous if the techniques usually used on native species worked on A. stephensi. However, the invasive species stays outdoors and relies on still water in city storage containers, rather than a moist climate, to reproduce, so the traditional control tactics such as bed nets and indoor sprays are ineffective. There is also no wet season to anticipate a surge of mosquitoes—malaria season is year-round.
However, there are solutions being implemented even with the invasive species’ unusual habits. Geneticist Martin Donnelly, in a Science magazine interview, stated that a potential solution would be to introduce pesticides into livestock feed since the A. stephensi feed on the cattle. Also, officials would have to regulate certain water storage centers to deter reproduction of the mosquitoes. But a surefire way that has been used before to combat malaria and is recommended by the WHO is to vaccinate children in urban areas with high malaria transmission rates. Another solution from Ethiopian molecular biologist, Dr. Fitsum Girma Tadesse, is to chemically attack the mosquitoes during their larval phase, which includes standard treatment to the water storage containers in the city and perhaps across the country.
The recent malaria outbreak in Ethiopia is a testament to the recurring destruction humans cause to natural ecosystems. Due to human intervention, invasive species have wreaked havoc on natural habitats and their populations for decades. Examples include lionfish that terrorized the Florida coast and the Japanese beetle that destroyed redwood forests in California. But now, invasive species are impacting humans all across a continent, and the world is finally taking notice. The outbreak is a much needed wakeup call to turn around our disastrous environmental policy before it turns on us.