2026-04-17T02:22:39Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/1227242025-12-05T01:19:35Zcom_2072_1057col_2072_478917

00925njm 22002777a 4500 dc Martins Campos, Keillen M. author Kuehn, Andrea author Almeida, Anne Cristine Gomes author Duarte, Ana Paula M. author Sampaio, Vanderson Souza author Rodriguez, Íria C. author Silva, Sara G. M. da author Rios Velasquez, Claudia María author Lima, José Bento Pereira author Pimenta, Paulo F. P. author Bassat Orellana, Quique author Mueller, Ivo author Lacerda, Marcus Vinícius Guimarães author Monteiro, Wuelton Marcelo author Barbosa Guerra, Maria G. author 2018-06-01T13:37:38Z 2018-06-01T13:37:38Z 2018-05-04 2018-05-23T17:59:53Z BACKGROUND: Asymptomatic individuals are one of the major challenges for malaria elimination programs in endemic areas. In the absence of clinical symptoms and with a lower parasite density they constitute silent reservoirs considered important for maintaining transmission of human malaria. Studies from Brazil have shown that infected individuals may carry these parasites for long periods. RESULTS: Patients were selected from three periurban endemic areas of the city of Manaus, in the western Brazilian Amazon. Symptomatic and asymptomatic patients with positive thick blood smear and quantitative real-time PCR (qPCR) positive for Plasmodium vivax were invited to participate in the study. A standardised pvs25 gene amplification by qPCR was used for P. vivax gametocytes detection. Anopheles aquasalis were fed using membrane feeding assays (MFA) containing blood from malaria patients. Parasitemia of 42 symptomatic and 25 asymptomatic individuals was determined by microscopic examination of blood smears and qPCR. Parasitemia density and gametocyte density were assessed as determinants of infection rates and oocysts densities. A strong correlation between gametocyte densities (microscopy and molecular techniques) and mosquito infectivity (P < 0.001) and oocysts median numbers (P < 0.05) was found in both groups. The ability to infect mosquitoes was higher in the symptomatic group (41%), but infectivity in the asymptomatic group was also seen (1.42%). CONCLUSIONS: Although their infectivity to mosquitoes is relatively low, given the high prevalence of P. vivax asymptomatic carriers they are likely to play and important role in malaria transmission in the city of Manaus. The role of asymptomatic infections therefore needs to be considered in future malaria elimination programs in Brazil. Anopheles Plasmodium vivax Anopheles Plasmodium vivax Infection of Anopheles aquasalis from symptomatic and asymptomatic Plasmodium vivax infections in Manaus, western Brazilian Amazon