Título:
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Blood-Stage Parasitaemia and Age Determine Plasmodium falciparum
and P. vivax Gametocytaemia in Papua New Guinea
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Autor/a:
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Koepfli, Cristian; Robinson, Leanne J.; Rarau, Patricia; Salib, Mary; Sambale, Naomi; Wampfler, Rahel; Betuela, Inoni; Nuitragool, Wang; Barry, Alyssa E.; Siba, Peter; Felger, Ingrid; Mueller, Ivo
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Abstract:
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A better understanding of human-to-mosquito transmission is
crucial to control malaria. In order to assess factors
associated with gametocyte carriage, 2083 samples were collected
in a cross-sectional survey in Papua New Guinea. Plasmodium
species were detected by light microscopy and qPCR and
gametocytes by detection of pfs25 and pvs25 mRNA transcripts by
reverse-transcriptase PCR (qRT-PCR). The parasite prevalence by
PCR was 18.5% for Plasmodium falciparum and 13.0% for P. vivax.
52.5% of all infections were submicroscopic. Gametocytes were
detected in 60% of P. falciparum-positive and 51% of P.
vivax-positive samples. Each 10-fold increase in parasite
density led to a 1.8-fold and 3.3-fold increase in the odds of
carrying P. falciparum and P. vivax gametocytes. Thus the
proportion of gametocyte positive and gametocyte densities was
highest in young children carrying high asexual parasite
densities and in symptomatic individuals. Dilution series of
gametocytes allowed absolute quantification of gametocyte
densities by qRT-PCR and showed that pvs25 expression is 10-20
fold lower than pfs25 expression. Between 2006 and 2010 parasite
prevalence in the study site has decreased by half. 90% of the
remaining infections were asymptomatic and likely constitute an
important reservoir of transmission. However, mean gametocyte
densities were low (approx. 1-2 gametocyte/muL) and it remains
to be determined to what extent low-density gametocyte positive
individuals are infective to mosquitos. |
Materia(s):
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-Plasmodium falciparum -Plasmodium vivax -Malària -Mosquits -Plasmodium falciparum -Plasmodium vivax -Malaria -Mosquitoes |
Derechos:
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cc by (c) Koepfli et al., 2015
http://creativecommons.org/licenses/by/3.0/es/ |
Tipo de documento:
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Artículo Artículo - Versión publicada |
Editor:
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Public Library of Science (PLoS)
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Compartir:
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