Transmission-blocking activity of tafenoquine (WR-238605) and artelinic acid against naturally circulating strains of plasmodium vivax in Thailand

• Main Authors: Narong Ponsa, Jetsumon Sattabongkot, Pattamaporn Kittayapong, Nantana Eikarat, Russell E. Coleman
• Other Authors: Mahidol University
• Format: Article
• Published: 2018
• Subjects: Immunology and Microbiology
• Online Access: https://repository.li.mahidol.ac.th/handle/123456789/20874

The sporontocidal activity of tafenoquine (WR-238605) and artelinic acid was determined against naturally circulating isolates of Plasmodium vivax in western Thailand. Primaquine was used as a negative control and a dihydroacridine-dione (WR-250547) was used as a positive control. Laboratory-reared Anopheles dirus mosquitoes were infected with P. vivax by allowing mosquitoes to feed on blood (placed in an artificial-membrane feeding apparatus) collected from gametocytemic volunteers reporting to local malaria clinics in Tak province, Thailand. Four days postinfection, mosquitoes were refed on uninfected mice treated 90 minutes earlier with a given drug. Drug activity was determined by assessing oocyst and sporozoite development. Neither primaquine nor artelinic acid affected oocyst or sporozoite development at a dose of 100 mg of base drug/kg of mouse body weight. In contrast, tafenoquine and WR-250547 affected sporogonic development at doses as low as 25.0 and 0.39 mg/kg, respectively. The potential role of these compounds in the prevention of malaria transmission is discussed, as are alternative strategies for the use of transmission-blocking antimalarial drugs.