Infectivity of symptomatic and asymptomatic Plasmodium vivax infections to a Southeast Asian vector, Anopheles dirus

Kirakorn Kiattibutr (1) , Wanlapa Roobsoong (1) , Patchara Sriwichai (1) , Teerawat Saeseu (1) , Nattawan Rachaphaew (1) , Chayanut Suansomjit (1) , Sureemas Buates (1) , Thomas Obadia (2, 3) , Ivo Mueller (4, 2) , Liwang Cui (5) , Wang Nguitragool (1) , Jetsumon Sattabongkot (1)

1 Mahidol University [Bangkok]
2 Malaria : parasites et hôtes - Malaria : parasites and hosts
3 Hub Bioinformatique et Biostatistique - Bioinformatics and Biostatistics HUB
4 WEHI - The Walter and Eliza Hall Institute of Medical Research
5 Penn State - Pennsylvania State University

Plasmodium vivax is now the predominant species causing malarial infection and disease in most non-African areas, but little is known about its transmission efficiency from human to mosquitoes. Because the majority of Plasmodium infections in endemic areas are low density and asymptomatic, it is important to evaluate how well these infections transmit. Using membrane feeding apparatus, Anopheles dirus were fed with blood samples from 94 individuals who had natural P. vivax infections with parasitemias spanning four orders of magnitude. We found that the mosquito infection rate was positively correlated with blood parasitemia and that infection began to rise when parasitemia was >10 parasites/ll. Below this threshold, mosquito infection is rare and associated with very few oocysts. These findings provide useful information for assessing the human reservoir of transmission and for establishing diagnostic sensitivity required to identify individuals who are most infective to mosquitoes.

Keywords: Infectivity; Malaria; Membrane feeding assay; Anopheles dirus; Plasmodium vivax; Transmission

Domains: Parasitology

Kirakorn Kiattibutr, Wanlapa Roobsoong, Patchara Sriwichai, Teerawat Saeseu, Nattawan Rachaphaew, et al.. Infectivity of symptomatic and asymptomatic Plasmodium vivax infections to a Southeast Asian vector, Anopheles dirus. International Journal for Parasitology, 2017, 47 (2-3), pp.163-170. ⟨10.1016/j.ijpara.2016.10.006⟩. ⟨pasteur-02612668⟩