Human immune responses that reduce the transmission of Plasmodium falciparum in African populations.
Int J Parasitol
; 41(3-4): 293-300, 2011 Mar.
Article
em En
| MEDLINE
| ID: mdl-20974145
Malaria-infected individuals can develop antibodies which reduce the infectiousness of Plasmodium gametocytes to biting Anopheles mosquitoes. When ingested in a bloodmeal together with gametocytes, these antibodies reduce or prevent subsequent parasite maturation in the insect host. This transmission-blocking immunity is usually measured in human sera by testing its effect on the infectivity of gametocytes grown in vitro. Here we evaluate evidence of transmission-blocking immunity in eight studies conducted in three African countries. Plasmodium falciparum gametocytes isolated from each individual were fed to mosquitoes in both autologous plasma collected with the parasites, and permissive serum from non-exposed donors. Evidence of transmission reducing effects of autologous plasma was found in all countries. Experiments involving 116 Gambian children (aged 0.5-15 years) were combined to determine which factors were associated with transmission reducing immune responses. The chances of infecting at least one mosquito and the average proportion of infected mosquitoes were negatively associated with recent exposure to gametocytes and sampling late in the season. These results suggest that effective malaria transmission-reducing antibodies do not commonly circulate in African children, and that recent gametocyte carriage is required to initiate and/or boost such responses.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Plasmodium falciparum
/
Anticorpos Antiprotozoários
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Malária Falciparum
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Soros Imunes
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Insetos Vetores
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Anopheles
Tipo de estudo:
Prognostic_studies
Limite:
Animals
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Child
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Child, preschool
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Humans
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Infant
País como assunto:
Africa
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article