Multiplicity of Plasmodium falciparum infection following intermittent preventive treatment in infants

Autor: Klaus Reither, Peter Ziniel, Martin P. Grobusch, Robin Kobbe, Jürgen May, Ina Danquah, Ulrike Buchholz, Philipp Zanger, Harry Hoffman Abruquah, Frank P. Mockenhaupt
Přispěvatelé: Faculteit der Geneeskunde, Amsterdam institute for Infection and Immunity, Amsterdam Public Health, Infectious diseases
Jazyk: angličtina
Rok vydání: 2010
Předmět:
Zdroj: Malaria Journal, 9. BioMed Central
Malaria Journal
Malaria journal, 9. BioMed Central
Malaria Journal, Vol 9, Iss 1, p 244 (2010)
ISSN: 1475-2875
Popis: Background Intermittent preventive treatment in infants with sulphadoxine-pyrimethamine (IPTi-SP) reduces malaria morbidity by 20% to 33%. Potentially, however, this intervention may compromise the acquisition of immunity, including the tolerance towards multiple infections with Plasmodium falciparum. Methods Plasmodium falciparum isolates were obtained from children participating in two Ghanaian IPTi-SP trials (Tamale, Afigya Sekyere) at 15 months of age, i.e., six months after they had received the second dose of IPTi-SP or placebo. By typing the polymorphic merozoite surface protein 1 (msp1) and msp2 genes, multiplicity of infection (MOI) was assessed in 389 isolates. A total of additional 133 samples were collected in Tamale at 3, 6, 9, and 12 months of age. Comparisons of MOI between groups were done by non-parametric statistical tests. Results The number of distinguishable P. falciparum clones (MOI) ranged between one and six. Mean MOI in Tamale was stable at 2.13 - 2.17 during the first year of life, and increased to 2.57 at age 15 months (P = 0.01). At no age did MOI differ between the IPTi-SP and placebo groups (each, P ≥ 0.5). At 15 months of age, i.e., six months after the second dose, MOI was very similar for children who had received IPTi or placebo (means, 2.25 vs. 2.33; P = 0.55) as was the proportion of polyclonal infections (69.6% vs. 69.7%; P = 0.99). Adjusting for study site, current and prior malaria, parasite density, and season did not change this finding. Conclusions IPTi-SP appears to have no impact on the multiplicity of infection during infancy and thereafter. This suggests that tolerance of multiple infections, a component of protective immunity in highly endemic areas, is not affected by this intervention.
Databáze: OpenAIRE
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