Malaria experts have renewed calls for Nairobians to sleep under mosquito nets in the wake of a new species of malaria-causing mosquito in northern Kenya.

The experts also asked any person experiencing malaria symptoms to urgently test for the disease.

In late 2022, the experts drawn from the Ministry of Health’s National Malaria Programme and Kenya Medical Research Institute (Kemri) positively identified samples of the Anopheles stephensi, in parts of Marsabit county.

Yesterday, Dr Omar Ahmeddin, the National Malaria Programme’s Manager in charge of care and treatment at the MoH, told journalists at a Nairobi hotel that they suspect the vector could have crossed from the neighbouring Ethiopia, Eritrea and Djibouti where it has been reported.

“In December we reported to the World Health Organisation (WHO) that we had discovered the mosquito, Anopheles stephensi in Marsabit.

Official opening

“However, we are monitoring it, and doing close surveillance to stop it from coming into our cities,” Dr Ahameddin said ahead of today’s official opening of the 13th Kemro Annual Scientific and Health Conference (KASH) by Health Cabinet Secretary, Susan Nakhumicha.

The vector, according to Dr Ahameddin is known to bring malaria to urban conditions, unlike the previous anopheles mosquito which breeds in dirty water, more localised in rural areas.

“If this mosquito comes to Nairobi it will change the whole landscape of malaria. We are monitoring and doing surveillance for this mosquito, and we are trying to ensure that it doesn’t come to our cities to the best of our capacity,” he added.

Scientific reports indicate that this new species, first reported in Africa’s Horn region in 2012, originated from Southeast Asia and the Arabian Peninsula where it has affected urban populations for many years.

Dr Ahameddin, Dr Elvis Oyugi, a medical epidemiologist with the National Malaria Programme at the MOH and Dr Damaris Matoke, a senior research scientist at Kemri said this species  breeds in dense human urban settlements, breeds throughout the year, and has the potential to increase malaria incidences by more than 50 per cent.

“It has been found to thrive in man-made plastic containers in both clean and contaminated water. Water pots, small water containers, domestic wells, overhead water tanks, and roof gutters.

“Urban residents tend to have minimal exposure to malaria, which makes them more susceptible to this new threat,” he added.

Dr Ahameddin pointed out that this allows it to expand rapidly to urban environments.

However, on a positive note, the experts also reported that the malaria prevalence in the country has been declining in the last decade from 11 percent in 2010 to the current 6 percent.

According to Dr Oyugi, this means that for 100 persons, six people are carrying the parasite in their blood.

“However, this is not the same all over the country because there are regions in Kenya where malaria is higher than others,” he said.

The highest prevalence in the country is the Lake Endemic region which includes eight counties; namely Migori, Homa Bay, Kisumu and Siaya in Luo Nyanza, while in the Western region; Bungoma, Busia, Vihiga and Kakamega.

“In those areas, the prevalence is highest at 19 percent currently. However, this is progress from 2015 when the malaria burden was at 27 percent,” Dr Oyugi said.

In the Coast region, six counties have a 5 percent prevalence, while in the Northern and Eastern Kenya counties; the burden is estimated to be two, three percent.

In Mt Kenya region, where temperatures and environment are different, the prevalence is less than 1 percent.

The 13th KASH Conference will be held between today and Friday.

The conference will, among other things, showcase the research activities that are going-on in the areas of our mandates as well as serve as a forum for dissemination, networking, and highlight ongoing and planned activities at country level. The conference attracts an estimated 600 participants within Kenya and beyond with more than 600 research abstracts.

According to Dr Cecilia Mbae, the Conference Chair, some of the benefits of this year’s symposium include parallel sessions parallel to breakaway conference sessions where rich research findings on various health fronts will be shared.