%0 Journal Article
%T Dynamics of asymptomatic Plasmodium falciparum and Plasmodium vivax infections and their infectiousness to mosquitoes in a low transmission setting of Ethiopia: a longitudinal observational study.
%A Hailemeskel E
%A Tebeje SK
%A Ramjith J
%A Ashine T
%A Lanke K
%A Behaksra SW
%A Emiru T
%A Tsegaye T
%A Gashaw A
%A Kedir S
%A Chali W
%A Esayas E
%A Tafesse T
%A Abera H
%A Bulto MG
%A Shumie G
%A Petros B
%A Mamo H
%A Drakeley C
%A Gadisa E
%A Bousema T
%A Tadesse FG
%J Int J Infect Dis
%V 143
%N 0
%D 2024 Jun 14
%M 38490637
%F 12.074
%R 10.1016/j.ijid.2024.107010
%X OBJECTIVE: A 15-month longitudinal study was conducted to determine the duration and infectivity of asymptomatic qPCR-detected Plasmodium falciparum and Plasmodium vivax infections in Ethiopia.
METHODS: Total parasite and gametocyte kinetics were determined by molecular methods; infectivity to Anopheles arabiensis mosquitoes by repeated membrane feeding assays. Infectivity results were contrasted with passively recruited symptomatic malaria cases.
RESULTS: For P. falciparum and P. vivax infections detected at enrolment, median durations of infection were 37 days (95% confidence interval [CI], 15-93) and 60 days (95% CI, 18-213), respectively. P. falciparum and P. vivax parasite densities declined over the course of infections. From 47 feeding assays on 22 asymptomatic P. falciparum infections, 6.4% (3/47) were infectious and these infected 1.8% (29/1579) of mosquitoes. No transmission was observed in feeding assays on asymptomatic P. vivax mono-infections (0/56); one mixed-species infection was highly infectious. Among the symptomatic cases, 4.3% (2/47) of P. falciparum and 73.3% (53/86) of P. vivax patients were infectious to mosquitoes.
CONCLUSIONS: The majority of asymptomatic infections were of short duration and low parasite density. Only a minority of asymptomatic individuals were infectious to mosquitoes. This contrasts with earlier findings and is plausibly due to the low parasite densities in this population.