That shift is undermining traditional defences such as bed nets, which are most effective when people are asleep. It is why IRS — which coats interior walls with long-lasting insecticides — is being pushed as a more aggressive and adaptive tool. When mosquitoes land on treated surfaces after feeding, they die, breaking the transmission cycle.
Malaria Control Coordinator Eunice Oreri said the spraying will begin in February 2026 and run until February 26, targeting every household in Siaya. She assured residents that the insecticides are safe for families, including pregnant women and young children.
“We want residents to embrace this initiative. Siaya stands to benefit immensely from it, especially because we are one of the counties that leads in malaria burden,” Oreri said.
The county is not acting on theory alone. Just across the border in Homa Bay, IRS slashed malaria prevalence from 27 per cent to just three per cent — a dramatic result that has made the strategy impossible to ignore.
IRS will complement other interventions, including the routine distribution of long-lasting insecticide-treated nets. In Siaya, pregnant women receive nets at antenatal clinics, while the entire population is covered every three years. The last mass distribution was in 2024, with the next planned for 2027.
The stakes are high. According to the Kenya Malaria Indicator Survey, if you sample 100 people in Siaya, 29 show signs of malaria. That is not just a health crisis; it is an economic and social one, draining households through lost productivity, hospital bills and school absenteeism.
As scientists in distant laboratories edge closer to new miracle drugs, Siaya’s approach is a reminder that breakthroughs only matter if the mosquitoes are first beaten back. In this county, the next battlefield is not a research lab — it is the living room wall.
Siaya County government, working with the U.S.-backed Presidential Malaria Initiative (PMI), has begun intensive capacity building of health workers ahead of a countywide Indoor Residual Spraying (IRS) rollout to destroy mosquito breeding areas | Dawan Africa