New data shows that an Asian species of mosquito, which transmits malaria, is spreading in Africa, posing a potential threat to hundreds of millions of African city dwellers, the researchers warned.
In Africa, where more than 95% of the 627,000 global deaths from malaria (or malaria) occurred in 2020, the disease is endemic, mainly in rural areas, via the mosquito species ‘Anopheles gambiae’, which is dominant In the continent.
However, another species, Anopheles stephensi, long the main transmitter of malaria in cities in India and Iran, has been detected in Africa since 2012, causing outbreaks in Djibouti and Ethiopia.
Unlike Anopheles gambiae, the Asian mosquito can breed in urban water reservoirs and thus multiply during dry seasons, and is also resistant to common insecticides.
If Anopheles stephensi were to spread across the entire African continent, more than 126 million people in 44 cities would be at risk of malaria, according to a 2020 scientific model.
Djibouti was the first African country to detect Anopheles stephensi, in 2012, when it was about to eradicate malaria, with only 27 cases that year.
Malaria cases have skyrocketed in that country since the arrival of the new transmitter, with around 73,000 infections registered in 2020, the World Health Organization (WHO) said.
A malaria outbreak in neighboring Ethiopia was caused by the same species of mosquito, according to a study presented Tuesday at the annual meeting of the American Society of Tropical Medicine and Hygiene.
In Dire Dawa, Ethiopia’s second-largest city, more than 2,400 cases were reported between January and May, the dry season when malaria is traditionally rare, compared with just 205 cases in all of 2019.
“Anopheles stephensi mosquitoes are responsible for the increased pollution,” said Fitsum Girma Tadesse, a molecular biologist at the Addis Ababa-based research institute Armauer Hansen.
Sudan also appears to be affected, as according to preliminary data presented at the meeting, Anopheles stephensi was identified in 64% of 60 test sites, spread over nine regions.
“In some cases, up to 94% of households have ‘stephensi’ mosquitoes” nearby, Hmooda Kafy, a medical entomologist and head of the vector control department at the Sudanese Ministry of Health, said in a statement.
The Nigerian Medical Research Institute had confirmed in July, for the first time, the presence of ‘Anopheles stephensi’ in West Africa.
The mosquito would have been detected in Somalia, according to the WHO, which launched an initiative in September to contain the spread of the species in Africa.
The threat of Anopheles stephensi in Africa is no longer potential but proven, said Sarah Zohdy, a disease ecology specialist at the US Centers for Disease Control.
Source: TSF
