Transmission blocking activity of low dose tafenoquine in healthy volunteers experimentally infected with Plasmodium falciparum

alexandrossfakianakis shared this article with you from Inoreader Transmission blocking activity of low dose tafenoquine in healthy volunteers experimentally infected with Plasmodium falciparum via Clinical Infectious Diseases Advance Access Abstract Background Blocking the transmission of parasites from humans to mosquitoes is a key component of malaria control. Tafenoquine exhibits activity against all stages of the malaria parasite and may have utility as a transmission blocking agent. We aimed to characterize the transmission blocking activity of low dose tafenoquine. Methods Healthy adults were inoculated with P. falciparum 3D7-infected erythrocytes on day 0. Piperaquine was administered on days 9 and 11 to clear asexual parasitemia while allowing gametocyte development. A single 50 mg oral dose of tafenoquine was administered on day 25. Transmission was determined by enriched membrane feeding assays pre-dose and at 1, 4 and 7 days post-dose. Artemether-lumefantrine was administered following the final assay. Outcomes were the reduction in mosquito infection and gametocytemia post-tafenoquine, and safety parameters. Results Six participants were enrolled, and all were infective to mosquitoes pre-tafenoquine, with a median 86% (range: 22–98) of mosquitoes positive for oocysts and 57% (range: 4–92) positive for sporozoites. By day 4 post-tafenoquine, the oocyst and sporozoite positivity rate had reduced by a median 35% (IQR: 16–46) and 52% (IQR: 40–62), respectively, and by day 7, 81% (IQR 36–92) and 77% (IQR 52–98), respectively. The decline in gametocyte density post-tafenoquine was not significant. No significant participant safety concerns were identified. Conclusion Low dose tafenoquine (50 mg) reduces P. falciparum transmission to mosquitoes, with a delay in effect. View on Web

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