The incidence of human cysticercosis in a rural community of Eastern Zambia

PLoS Negl Trop Dis. 2013;7(3):e2142. doi: 10.1371/journal.pntd.0002142. Epub 2013 Mar 21.

Abstract

A community-based longitudinal study was performed in the Eastern Province of Zambia, in which repeated serological samplings were done to determine the incidence of human cysticercosis. Three sampling rounds were carried out at six months intervals. A total of 867 participants presented for all three samplings. All samples were tested for the presence of cysticercus antigens using a monoclonal antibody-based enzyme-linked immunosorbent assay (sero-Ag-ELISA), while a randomly selected sub-sample of 161 samples from each sampling round was tested for specific antibodies using a commercial enzyme-linked immunoelectrotransfer blot (EITB) assay. Stool samples (n = 226) were also collected during the final round of sampling for taeniosis diagnosis by coprology and coproantigen ELISA. Cysticercosis seroprevalence varied from 12.2% to 14.5% (sero-Ag) and from 33.5% to 38.5% (sero-Ab) during the study period. A taeniosis prevalence of 11.9% was determined. Incidence rates of 6300 (sero-Ag, per 100000 persons-year) and 23600 (sero-Ab, per 100000 persons-year) were determined. Seroreversion rates of 44% for sero-Ag and 38.7% for sero-Ab were recorded over the whole period. In conclusion, this study has shown the dynamic nature of T. solium infections; many of the people at risk become (re)infected due to the high environmental contamination, with a high number turning seronegative within a year after infection. An important number of infections probably never fully establish, leading to transient antibody responses and short-term antigen presence.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Animals
  • Antibodies, Helminth / blood
  • Antigens, Helminth / blood
  • Child
  • Child, Preschool
  • Cysticercosis / epidemiology*
  • Cysticercus / immunology
  • Enzyme-Linked Immunosorbent Assay
  • Feces / parasitology
  • Female
  • Humans
  • Incidence
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Rural Population
  • Seroepidemiologic Studies
  • Young Adult
  • Zambia / epidemiology

Substances

  • Antibodies, Helminth
  • Antigens, Helminth

Grants and funding

The study received financial support from the Flemish Interuniversity Co-operation, Research Initiatives Programme, Zambia (VLIR-UOS.ZIUS2008RIP-8961). Support was also obtained from the Belgian Cooperation in the framework of the institutional collaboration between the Institute of Tropical Medicine in Antwerp, Belgium, and the University of Pretoria, Pretoria, South Africa. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.