Dr Stephanie Kamunya, a postdoctoral research fellow at the Centre for Epidemiological Modelling and Analysis (CEMA).
Malaria continues to be a major public health concern in
Kenya, despite decades of concerted efforts to control and eliminate the
disease.
According to researchers, malaria persists due to the complex interplay of environmental, social, and biological factors, as well as evolving challenges such as drug and insecticide resistance, emerging mosquito vectors, and shifting epidemiological patterns.
In a recent report released by the Ministry of Health, malaria
remains one of the leading causes of hospital visits and deaths in Kenya, with
an estimated 10,700 deaths attributed to the disease in 2021.
Over the last
five years, the country has reported an average of 4.9 million outpatient
malaria cases annually, and the incidence rate has increased from 96 to 105
cases per 1,000 people between 2019 and 2023.
According to Dr Stephanie Kamunya, a postdoctoral research
fellow at the Centre for Epidemiological Modelling and Analysis (CEMA), who has extensive experience in malaria research, the distribution
of malaria in Kenya is highly uneven. The highest burden is found in counties bordering Lake Victoria, including Busia, Kakamega, Kisumu, Migori, Siaya, and Vihiga.
She says, “Here, the adjusted incidence reaches an average
of 748 cases per 1,000 people. These western counties experience stable,
year-round transmission due to favourable climatic conditions like low altitude,
high rainfall and warm temperatures, all of which support mosquito breeding and
parasite survival.”
She continues, “Other high-burden counties include Bungoma,
Homa Bay, Kwale, Turkana and West Pokot, each with an average incidence of 474
cases per 1,000 people. In contrast, Nairobi is classified as malaria-free and
more than half of Kenya’s counties are now categorised as having very low or
low transmission rates.”
The persistence of malaria in specific regions is closely
linked to environmental and social factors. Dr Kamunya explains that malaria
transmission relies on the presence of three elements: the vector (mosquito),
the parasite and humans as hosts. The mosquito vector thrives in hot, wet
environments. These conditions are prevalent in the lake and coastal regions.
Dr Kamunya further says, “An emerging concern is the
detection of new mosquito species, such as Anopheles Stephensi, which prefers
urban environments and breeds in man-made containers. This species poses a
significant threat as it has the potential to bring malaria into cities where
it was previously rare, complicating control efforts.”
Traditionally, arid and semi-arid counties such as Turkana,
Marsabit, Isiolo and Mandera were not considered malaria hotspots. However,
recent surveillance has revealed a significant increase in malaria incidence in
these regions. For example, Turkana has seen its incidence nearly double,
rising from 100–200 to 200–350 cases per 1,000 people between 2019 and 2023.
Routine surveillance has also detected Plasmodium vivax, a malaria parasite
species not previously common in Kenya in these northern counties.
Dr. Kamunya associates this trend with improved surveillance
and reporting, as well as changing environmental conditions, including
increased rainfall and climate change, which are creating new breeding grounds
for mosquitoes.
A major obstacle in malaria control is the growing
resistance observed in both mosquitoes and parasites. Mosquitoes are developing
resistance to commonly used insecticides, while the malaria parasites
themselves are becoming less susceptible to standard antimalarial drugs.
“We’re seeing resistance to insecticides in vectors and to
antimalarial drugs in parasites. This means our traditional tools, like treated
bed nets and standard medications, are becoming less effective,” Dr Kamunya
explains.
In the latest Kenya Malaria Strategy,
the country has an ambitious plan to reduce malaria incidences by 80 per cent and
deaths by 90 per cent from 2023 levels by 2027/2028.
Dr Kamunya remains optimistic about the future. She says: “Malaria
elimination is possible, but it requires innovation, political will, and
collaboration. We need strong surveillance, targeted interventions and
community integration. The vaccine and new chemoprevention strategies give us
hope, but we must adapt quickly to emerging threats like new vectors and
resistance. We need to create a barrier between the vectors and the people to win
the war” With continued investment, innovation, and vigilance, Kenya stands a
real chance of achieving its malaria elimination goals.”