Isolation of Cryptosporidium parvum and Cyclospora cayetanensis from vegetables collected in markets of an endemic region in Peru

Am J Trop Med Hyg. 1997 Dec;57(6):683-6. doi: 10.4269/ajtmh.1997.57.683.

Abstract

Cryptosporidium parvum and Cyclospora cayetanensis are protozoan pathogens that cause prolonged diarrhea in both immunocompetent and immunocompromised hosts. Cryptosporidium parvum can be transmitted via the fecal-oral route, while the exact mechanisms of transmission of Cyclospora cayetanensis have not been fully determined. Humans appear to be the sole host for the latter and a distinct seasonality has been observed in endemic areas around the world. Samples of vegetables were collected at several small markets in a periurban slum in Peru during the seasons of high and low incidence. The vegetables were washed, the supernatants were collected and centrifuged, and the pellets were resuspended in a solution of 2.5% potassium dichromate. Pellets were examined using direct microscopic observation, acid-fast staining, and immunofluorescent assays for C. parvum and Cyclospora cayetanensis oocysts. Samples were collected during three time periods: the season of low incidence, the beginning of the season of high incidence, and end of the season of high incidence. Of the total vegetables examined, 14.5% contained C. parvum oocysts and 1.8% had Cyclospora oocysts. Thus, market vegetables may provide a route by which Cryptosporidium and Cyclospora can be transmitted. Our study also suggests that washing vegetables does not completely remove Cryptosporidium and Cyclospora oocysts.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Animals, Domestic / parasitology
  • Coccidiosis / epidemiology
  • Coccidiosis / transmission
  • Cryptosporidiosis / epidemiology
  • Cryptosporidiosis / transmission
  • Cryptosporidium parvum / isolation & purification*
  • Cryptosporidium parvum / ultrastructure
  • Eucoccidiida / isolation & purification*
  • Eucoccidiida / ultrastructure
  • Feces / parasitology
  • Fluorescent Antibody Technique
  • Humans
  • Incidence
  • Insecta / parasitology
  • Microscopy, Electron, Scanning
  • Peru / epidemiology
  • Poverty Areas
  • Seasons
  • Staining and Labeling
  • Vegetables / parasitology*