Abstract
Cost and cost-effectiveness of ivermectin mass drug administration for malaria control in Kwale county, Kenya: a modelling analysis of a cluster-randomised trial
Xie, K.
Otuko, R.
Marathe, A.
Gutierrez, A. S.
Kariuki, M.
Musyoka, L.
Yaa, E.
Mbarak, J.
Omondi, I.
Kasiwa, L.
Rabinovich, R.
Maia, M.
Chaccour, C.
Deng, X.
Rist, C.
Lancet Glob Health. 2026; 14e435-e443
Permanent descriptor
https://doi.org/10.1016/S2214-109X(25)00470-XBACKGROUND: Malaria remains a major health burden in sub-Saharan Africa, where traditional vector control methods are hindered by insecticide resistance and evolving mosquito behaviour causing residual transmission. In the BOHEMIA cluster-randomised trial in Kenya, ivermectin mass drug administration (iMDA), delivered once a month for 3 months with approximately 64% population coverage, was shown to reduce malaria incidence by 26%. We aimed to assess the cost-effectiveness of iMDA as a supplementary vector control tool using data from the BOHEMIA trial in Kenya. METHODS: We did a cost-effectiveness analysis of the BOHEMIA cluster-randomised trial done in Kwale county, Kenya, using a societal perspective to estimate the intervention costs, health system costs, direct household out-of-pocket expenses, and indirect costs from lost wages of iMDA versus a no-intervention scenario. Intervention effectiveness was measured as the number of malaria cases averted and disability-adjusted life-years (DALYs) averted. A decision tree model was developed to simulate the intervention's impact on a broader population. Deterministic and probabilistic sensitivity analyses were performed to assess the robustness of the results, and incremental cost-effectiveness ratios (ICERs) were compared with Kenya's gross domestic product (GDP)-based thresholds. FINDINGS: The intervention cost of iMDA was US$11.83 per person. Household out-of-pocket costs averaged $5.85 for uncomplicated malaria cases and $52.23 for severe cases. Productivity loss amounted to $2.18 for uncomplicated and $8.83 for severe cases. The base-case ICER was $905.23 per DALY averted, which was below the threshold of 0.5 x Kenya's GDP per capita ($974.65). In probabilistic analysis (10 000 iterations), the median ICER was $1107.51 per DALY averted (50% credible interval 770.05-1606.77). INTERPRETATION: This study demonstrates that iMDA can be a cost-effective supplementary intervention for malaria control in settings with moderate malaria transmission and good insecticide-treated net coverage, particularly when malaria reduction is greater than 23.62% for children younger than 5 years and opportunities for reducing intervention costs can be identified. FUNDING: This work was funded and supported by Unitaid through the BOHEMIA project.
