Hans Steinsland

Hans Steinsland 2003 Steinsland, Hans. 2003. The epidemiology of enterotoxigenic Escherichia coli infections and diarrhea in early childhood. Bandim Health Project, Statens Serum Institut. Centre for Internatinoal Health and Department of Microbiology and Immunology, The Gade Institute, University of Bergen, Norway. Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark q. National Public Health Laboratory, Bissau, Guinea-Bissau. 
  We undertook a cohort study of childhood diarrheal diseases in Guinea-Bissau, West Africa. In the study, we followed 200 children from shortly after birth until up to two years of age with weekly stool specimen collection, irrespectively of whether the children had diarrhea. The present thesis is based on the epidemiological analyses of the infections with enterotoxigenic Escherichia coli (ETEC) that we identified. To contribute to the ETEC vaccine development effort, we aimed to determine which toxins and CFS were harbored by the most pathogenic and prevalent ETEC strains, and to estimate the protection that natural infections induced against new ETEC infections. We found that BTEC that were positive for the human heat-stable toxin (STh) were substantially more pathogenic than ETEC that were positive for the porcine heat-stable toxin (STp), while ETEC that only produced the heat-labile toxin (LT) seemed to comprise some strains that were substantially more pathogenic than others. We also found that natural ETEC infections induced a substantial protection against new infections with strains that carried the same Combination of toxins and colonization factors (CFS), but that the CFS did not contribute measurably to this protection. Our results indicate that, for breastfed children living in areas where ETEC infections are endemic, vaccines should primarily offer protection against STh­positive ETEC, and that the efficacy of these vaccines may be improved by including antigens other than the CFS.