The governments of Kenya and the United States have completed a major malaria prevention campaign in Siaya County, spraying more than 255,000 structures to protect over 1.1 million residents from the disease.
The 21-day Indoor Residual Spraying (IRS) campaign, supported by the U.S. government, was implemented across all six sub-counties in Siaya, marking the first time the malaria control programme has been conducted countywide.
According to officials, the initiative targeted an estimated 1,161,843 residents by spraying 255,556 houses, significantly expanding mosquito control efforts in one of Kenya’s malaria hotspots.
Persistent Malaria Burden
Health officials say malaria remains a major public health challenge in western Kenya, contributing to lost productivity, increased healthcare costs, and pressure on medical facilities.
Data from health authorities shows that Siaya recorded a malaria incidence rate of 561 cases per 1,000 people in 2025, far above the national average of 70 cases per 1,000.
By targeting mosquitoes inside homes where people sleep, indoor residual spraying is considered one of the most effective methods for reducing malaria transmission.
For residents such as Margaret Atieno Odongo, the campaign has brought relief after years of battling the disease.
“I want to thank you all for coming to my home and doing me the favour of spraying my house. Mosquitoes have troubled me for a long time,” she said, noting that repeated malaria infections had forced her family to spend large sums on treatment.
Community Health Workers Optimistic
Community health promoters say the intervention could help reverse rising infection trends in the region.
Francisca Aluoch Lunda, a community health promoter in Siaya, said malaria cases have remained a persistent challenge despite other prevention measures such as mosquito net distribution.
“Malaria has been rising over the years. We would find a lot of positive cases; however, with the net distribution, it went down slightly, but now we believe that with the IRS, the prevalence will now go down,” she said.
Long-Term U.S. Support
The United States has provided more than $500 million in support for Kenya’s malaria response since 2007, according to U.S. officials.
Previous IRS campaigns funded by the U.S. in neighbouring counties, including Homa Bay County, Migori County, and Busia County, have contributed to significant reductions in malaria cases and hospital admissions.
U.S. Embassy Charge d’Affaires Susan Burns said the programme reflects Washington’s focus on targeted foreign assistance designed to strengthen health systems while promoting long-term self-reliance.
“The fact that we provided targeted support to reduce malaria transmission in Siaya is a testament to our intention to help communities become healthier, more productive, and less dependent on foreign assistance over time,” Burns said.
Kenya’s Malaria Elimination Goals
Kenya’s Health Cabinet Secretary Aden Duale welcomed the campaign, saying it aligns with the government’s strategy to prioritise prevention and cost-effective health interventions.
“The campaign aligns with Kenya’s broader health strategy by focusing on prevention, cost-effective interventions, and country-led solutions that reduce long-term dependency on external support,” Duale said.
The spraying exercise was implemented in coordination with PMI Evolve Kenya and the Siaya County Government, with the U.S. government covering the cost of insecticides and operational logistics.
Local authorities supported the programme by mobilising communities, recruiting seasonal spray operators, and coordinating logistics through county health facilities.
Health officials say the next phase of the U.S.-funded IRS campaign has already begun in Busia County, where spraying operations started on March 9 as part of broader efforts to curb malaria transmission across western Kenya.