New mosquito raises fear of year-round malaria in Kenya

LONDON -- Researchers from Kenya’s Medical Research Institute have detected a new species of mosquito in the East African nation that has shown resistance to locally used insecticides and the potential to transmit malaria throughout the year, unlike traditional malaria-causing mosquitoes.

The mosquito species -- named Anopheles stephensi -- was previously only known to spread malaria in South Asia and parts of the Arabian Peninsula, according to the World Health Organization.

However, it has been expanding geographically -- first being detected in Africa in Djibouti in 2012 -- and has since being found in several African nations such as Nigeria, Somalia, Ethiopia and Sudan.

This, however, is the first time the mosquito has been detected in Kenya and its arrival is raising concern among researchers who say malaria transmission may continue all year round, rather than being seasonal due to its ability to "spread very fast to new areas" regardless of climatic and environmental conditions.

“The new mosquito poses a serious threat and could reverse the gains made in the fight against malaria,” Kenya’s Medical Research Institute said in a statement sent to ABC News. “Malaria in Kenya, and Africa at large is known to occur in rural areas. Rainfall, temperature and availability of unpolluted mosquito breeding habitats in rural areas favour the breeding of malaria mosquitoes.”

“However, Anopholes stephensi is unique as it thrives in man-made containers and breeding habitats in polluted settings. The establishment of Anopheles stephensi in urban and peri-urban areas may pose a serious threat for malaria transmission in areas that have been Anopheles and malaria free.”

Recent research carried out across Kenya show that the new malaria-causing mosquito was present in Laisamis and Saku sub-counties in Marsabit, Northern Kenya, and was detected during routine surveillance from Kenya’s Medical Research Institute and the Ministry’s Division of National Malaria Program.

Data from hospitals in the area have also shown an uptick in malaria cases outside the usual malaria season.

Malaria -- which is transmitted through the infectious bite of the female Anopheles mosquito -- kills nearly one child under the age of 5 in Africa almost every minute, according to UNICEF.

“Malaria is a leading public health problem in Kenya. The disease is endemic in different parts of the country and almost 70% of the entire population is at risk,” said Kenya’s Medical Research Institute.

There were an estimated 247 million malaria cases and 619,000 deaths worldwide in 2022. Just over half of all malaria cases globally were accounted to by four African nations according to the WHO -- Nigeria, the Democratic Republic of Congo, Tanzania and Niger.

Kenya’s Medical Research Institute is conducting a “coordinated response” to the new mosquito threat -- urging people to cover all water containers to avoid mosquito breeding, utilize available malaria control tools such as mosquito nets and use personal protective measures such as the use of repellents, long-sleeved clothing.