Exposure to Diverse Plasmodium falciparum Genotypes Shapes the Risk of Symptomatic Malaria in Incident and Persistent Infections: A Longitudinal Molecular Epidemiologic Study in Kenya.
Clin Infect Dis
; 73(7): 1176-1184, 2021 10 05.
Article
em En
| MEDLINE
| ID: mdl-33904907
ABSTRACT
BACKGROUND:
Repeated exposure to malaria infections could protect against symptomatic progression as people develop adaptive immunity to infections acquired over time.METHODS:
We investigated how new, recurrent, and persistent Plasmodium falciparum infections were associated with the odds of developing symptomatic compared with asymptomatic malaria. Using a 14-month longitudinal cohort in Western Kenya, we used amplicon deep sequencing of 2 polymorphic genes (pfama1 and pfcsp) to assess overlap of parasite genotypes (represented by haplotypes) acquired within an individual's successive infections. We hypothesized infections with novel haplotypes would increase the odds of symptomatic malaria.RESULTS:
After excluding initial infections, we observed 534 asymptomatic and 88 symptomatic infections across 186 people. We detected 109 pfcsp haplotypes, and each infection was classified as harboring novel, recurrent, or persistent haplotypes. Incident infections with only new haplotypes had higher odds of symptomatic malaria when compared with infections with only recurrent haplotypes [odds ratio (OR) 3.24; 95% confidence interval (CI), 1.20-8.78], but infections with both new and recurrent haplotypes (OR 0.64; 95% CI 0.15-2.65) did not. Assessing persistent infections, those with mixed (persistent with new or recurrent) haplotypes (OR 0.77; 95% CI 0.21-2.75) had no association with symptomatic malaria compared with infections with only persistent haplotypes. Results were similar for pfama1.CONCLUSIONS:
These results confirm that incident infections with only novel haplotypes were associated with increased odds of symptomatic malaria compared with infections with only recurrent haplotypes but this relationship was not seen when haplotypes persisted over time in consecutive infections.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
3_ND
Base de dados:
MEDLINE
Assunto principal:
Plasmodium falciparum
/
Malária Falciparum
Tipo de estudo:
Diagnostic_studies
/
Etiology_studies
/
Observational_studies
/
Risk_factors_studies
Limite:
Humans
País/Região como assunto:
Africa
Idioma:
En
Revista:
Clin Infect Dis
Ano de publicação:
2021
Tipo de documento:
Article