イベルメクチンによるマラリア抑制可能性 （Ivermectin could help beat malaria, veterinary college researcher finds in running the numbers）

2026-05-21 バージニア工科大学（Virginia Tech）

＜関連情報＞

• https://news.vt.edu/articles/2026/05/vetmed-public-health-research.html
• https://www.thelancet.com/journals/langlo/article/PIIS2214-109X(25)00470-X/fulltext
• https://www.nejm.org/doi/10.1056/NEJMoa2411262

ケニア、クワレ郡におけるマラリア対策のためのイベルメクチン集団投与の費用と費用対効果：クラスター無作為化試験のモデリング分析 Cost and cost-effectiveness of ivermectin mass drug administration for malaria control in Kwale county, Kenya: a modelling analysis of a cluster-randomised trial

Kexin Xie, BSc ∙ Rachel Otuko, MPH ∙ Achla Marathe, PhD ∙ Almudena Sanz Gutierrez, MSc ∙ Mercy Kariuki, MSc ∙ Leah Musyoka, BSc ∙ et al.
The Lancet Global Health  Published: March 2026
DOI:https://doi.org/10.1016/S2214-109X(25)00470-X

Summary

Background

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 × 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.

マラリアを制御するためのイベルメクチン ― クラスター無作為化試験 Ivermectin to Control Malaria — A Cluster-Randomized Trial

Carlos Chaccour, M.D., Ph.D., Marta Maia, D.V.M., Ph.D., Mercy Kariuki, M.Sc., Paula Ruiz-Castillo, Ph.D., Caroline Wanjiku, Ph.D., Lydia Kasiwa, B.Sc., Aurelia Brazeal, M.D., +40 , and N. Regina Rabinovich, M.D., M.P.H.
The New England Journal of Medicine  Published July 23, 2025
DOI: 10.1056/NEJMoa2411262

Abstract

Background

Malaria control and elimination is threatened by the spread of insecticide resistance and behavioral adaptation of vectors. Whether mass administration of ivermectin, a broad-spectrum antiparasitic drug that also kills mosquitoes feeding on treated persons, can reduce malaria transmission is unclear.

Methods

We conducted a cluster-randomized trial in Kwale, a county in coastal Kenya in which malaria is highly endemic and coverage and use of insecticide-treated nets are high. Clusters of household areas were randomly assigned in a 1:1 ratio to receive mass administration of ivermectin (400 μg per kilogram of body weight) or albendazole (400 mg, active control) once a month for 3 consecutive months at the beginning of the “short rains” season. Children 5 to 15 years of age were tested for malaria infection monthly for 6 months after the first round of treatment. The two primary outcomes were the cumulative incidence of malaria infection (assessed among children 5 to 15 years of age) and of adverse events (assessed among all eligible participants). Analyses were performed with generalized estimating equations in accordance with the intention-to-treat principle.

Results

A total of 84 clusters comprising 28,932 eligible participants underwent randomization. The baseline characteristics of the participants were similar in the trial groups. Six months after the first round of treatment, the incidence of malaria infection was 2.20 per child-year at risk in the ivermectin group and 2.66 per child-year at risk in the albendazole group; the adjusted incidence rate ratio (ivermectin vs. albendazole) was 0.74 (95% confidence interval [CI], 0.58 to 0.95, P=0.02). The incidence of serious adverse events per 100 treatments did not differ significantly between the trial groups (incidence rate ratio, 0.63; 95% CI, 0.21 to 1.91).

Conclusions

Among children 5 to 15 years of age who were living in an area with high coverage and use of bed nets, ivermectin, administered once a month for 3 consecutive months, resulted in a 26% lower incidence of malaria infection than albendazole. No safety concerns were identified. (Funded by Unitaid; BOHEMIA ClinicalTrials.gov number, NCT04966702; Pan African Clinical Trial Registry number, PACTR202106695877303.)