Amugongo JS, LaBeaud AD, Bosire C, Bisanzio D, Nzaro M, Ngari M, Vu DM, Ndenga BA, Mutuku FM
Malar J. 2025;24
BACKGROUND: Malaria remains a major public health issue where poverty and inadequate healthcare infrastructure intersect. This study assessed sociodemographic and ecological factors influencing malaria risk in Msambweni, Kwale County, Kenya. METHODS: A child cohort (aged 1-18 years) presenting with acute febrile illness at Msambweni County Referral Hospital from 2014 to 2018 was enrolled, supplemented by a nested case-control study. Data were collected through caregiver interviews and household observations. Malaria was diagnosed by light microscopy (Giemsa-stained thick and thin smears). Recurrent malaria was defined as ≥ 2 confirmed infections within the study period. RESULTS: There were 2610 febrile illness visits by 2371 children; 40.6% (1059/2610) had malaria parasitaemia. A single visit occurred among 2169/2371 (91.5%), while 174, 19 and 9 children made two, three and four visits, respectively. Overall, 992/2371 (41.8%, 95%CI 39.8-43.9%) children experienced malaria, and 60/2371 (2.5%, 95%CI 1.9-3.2) had recurrent malaria; 51 had one, 8 had two and 1 had three recurrent episodes. In multivariable analysis, malaria risk was associated with older age (2-5 vs. < 2 years: aRR 1.38 [95%CI 1.09-1.75]; ≥ 5 vs. < 2 years: aRR 1.57 [95%CI 1.23-2.00]). Protective factors included higher maternal education (secondary and above: aRR 0.66 [95%CI 0.50-0.87]), piped/well water inside the compound (aRR 0.78 [95%CI 0.65-0.94]), and electricity/solar lighting (aRR 0.61 [95%CI 0.50-0.74]). Recurrent malaria was linked to poor-quality housing, particularly dirt floors and proximity to mosquito breeding sites such as rice fields. Increased malaria risk was also associated with poor ventilation and limited windows. DISCUSSION: Targeted vector control near rice fields and consistent use of insecticide-treated nets remain crucial. Housing improvements, including window screening and better roofing, may reduce mosquito-human contact. The shift toward increased malaria among school-aged children highlights the need to strengthen interventions targeting this group. CONCLUSIONS: Investments in housing, maternal education, and WASH infrastructure can enhance malaria control efforts and strengthen existing interventions.
