2002-10-01
Evaluation of the patterns of Schistosoma mansoni infection and re-infection in Senegal, from faecal egg counts and serum concentrations of circulating anodic antigen
Publication
Publication
Annals of Tropical Medicine and Parasitology , Volume 96 - Issue 7 p. 679- 689
Infection and re-infection patterns were evaluated in a recent Schistosoma mansoni focus in northern Senegal, by determining concentrations of serum circulating anodic antigen (CAA), as a measure of worm burden, and counting eggs in faeces before, 6 or 12 weeks and 1 year after praziquantel treatment in two subsequent cohorts (cohort A and B). No differences in egg counts and CAA concentrations or their relationship were found between the cohorts, which were examined 2 years apart. Within both cohorts, CAA concentrations showed the same, typical, age-related patterns as egg counts, with a peak in children and a strong decline in adults. These trends were apparent both before and 1 year after treatment. The results indicate that an age-related resistance to infection and to re-infection has been firmly established, at a steady level, in the recent S. mansoni focus investigated, with no indication of a gradual development of immunity or anti-fecundity immunity over a period of 2 years. Both shortly and 1 year after treatment, the decrease in egg counts was stronger than that in CAA concentrations, indicating that that there had been a reduction in worm fecundity after treatment. The possibility that praziquantel may induce anti-fecundity immunity has important implications for the use and interpretation of the results of (egg-count-based) re-infection studies designed to follow the development of naturally acquired immunity.
Additional Metadata | |
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doi.org/10.1179/000349802125001708, hdl.handle.net/1765/55609 | |
Annals of Tropical Medicine and Parasitology | |
Organisation | Erasmus MC: University Medical Center Rotterdam |
Polman, K., Stelma, F., le Cessie, S., de Vlas, S., Falcão Ferreira, S. T. M., Talla, I., … Gryseels, B. (2002). Evaluation of the patterns of Schistosoma mansoni infection and re-infection in Senegal, from faecal egg counts and serum concentrations of circulating anodic antigen. Annals of Tropical Medicine and Parasitology, 96(7), 679–689. doi:10.1179/000349802125001708 |