Open AccessAsymptomatic Plasmodium vivax malaria in the Brazilian Amazon: Submicroscopic parasitemic blood infects Nyssorhynchus darlingi
Author(s) -
Gregório Guilherme Almeida,
Pedro Augusto Carvalho Costa,
Maísa da Silva Araújo,
Gabriela Ribeiro Gomes,
Alex F. Carvalho,
María Marta Figueiredo,
Dhélio Batista Pereira,
Mauro Shugiro Tada,
Jansen Fernandes Medeiros,
Irene da Silva Soares,
Luzia H. Carvalho,
Flora Satiko Kano,
Márcia C. Castro,
Joseph M. Vinetz,
Douglas T. Golenbock,
Lis Ribeiro do Valle Antonelli,
Ricardo T. Gazzinelli
Publication year - 2021
Publication title -
plos neglected tropical diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.99
H-Index - 135
eISSN - 1935-2735
pISSN - 1935-2727
DOI - 10.1371/journal.pntd.0009077
Subject(s) - plasmodium vivax , malaria , virology , asymptomatic , amazon rainforest , plasmodium falciparum , biology , medicine , plasmodium (life cycle) , parasite hosting , pathology , immunology , ecology , world wide web , computer science
Individuals with asymptomatic infection due to Plasmodium vivax are posited to be important reservoirs of malaria transmission in endemic regions. Here we studied a cohort of P . vivax malaria patients in a suburban area in the Brazilian Amazon. Overall 1,120 individuals were screened for P . vivax infection and 108 (9.6%) had parasitemia detected by qPCR but not by microscopy. Asymptomatic individuals had higher levels of antibodies against P . vivax and similar hematological and biochemical parameters compared to uninfected controls. Blood from asymptomatic individuals with very low parasitemia transmitted P . vivax to the main local vector, Nyssorhynchus darlingi . Lower mosquito infectivity rates were observed when blood from asymptomatic individuals was used in the membrane feeding assay. While blood from symptomatic patients infected 43.4% (199/458) of the mosquitoes, blood from asymptomatic infected 2.5% (43/1,719). However, several asymptomatic individuals maintained parasitemia for several weeks indicating their potential role as an infectious reservoir. These results suggest that asymptomatic individuals are an important source of malaria parasites and Science and Technology for Vaccines granted by Conselho Nacional de may contribute to the transmission of P . vivax in low-endemicity areas of malaria.