Parasite and gametocyte dynamics and infectivity to mosquitoes during recurrent Plasmodium vivax infections: A longitudinal study from Ethiopia

OBJECTIVES: Plasmodium vivax relapses can lead to episodes of recurrent parasitemia. We longitudinally assessed parasite and gametocyte kinetics and infectivity to mosquitoes during P. vivax recurrent infections in Ethiopia. METHODS: Patients presenting with clinical P. vivax infections were enrolled at Shele health center in Arba Minch Zuria district, Ethiopia. All participants received chloroquine plus 14-day primaquine for radical cure, and were subsequently followed for one year with scheduled monthly visits. Parasite and gametocyte densities were quantified using molecular assays, and infectivity was assessed through mosquito feeding assays. RESULTS: Over the follow-up period, 54.6% (96/176) of patients experienced at least one recurrent parasitemia. Gametocyte density was similar between baseline and recurrent symptomatic episodes but lower during asymptomatic parasitemia (p