Enterotoxigenic Escherichia coli (ETEC) diarrhea is hyperendemic among young Egyptian children, with a balanced distribution of toxin phenotypes from pathogenic isolates. These features make it logical to develop a field site for the evaluation of ETEC epidemiology and ETEC vaccines in Egypt. We are engaged in a collaborative program of research in lower Egypt designed to characterize ETEC diarrhea in a pediatric cohort and to test the safety and immunogenicity of a promising killed oral ETEC vaccine candidate in preparation for a field trial of vaccine efficacy. We have followed a cohort of children under 3 years with twice-weekly active surveillance in Abu Homos (Beheira governorate) to determine the age-specific incidence rate of ETEC diarrhea, by toxin and colonization factor (CFA) phenotypes. During 18 months of follow-up of 288 children in Abu Homos, ETEC was isoalted in 290 (24%) of the 1232 detected diarrheal episodes; the incidence rates of ETEC (episodes per child-year) were 1.5, 1.6, and 0.8 in the first, second, and third years of life. Concurrent with establishment of this surveillance, we conducted randomized, placebo-controlled Phase 2 studies of killed oral ETEC vaccine, administered as a two-dose regimen to 76 adults, 107 children aged 6-12 years, and and 106 children aged 2-5 years in Benha, near Cairo. Each of these studies demonstrated the vaccine to be well-tolerated and to induce significant musosal immune responses to vaccine antigens. A similarly designed trial of the vaccine, administered to infants will be launched during the coming months.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Intramural Research (Z01)
Project #
1Z01HD002500-06
Application #
6108125
Study Section
Epidemiology and Biometry Training Committee (EB)
Project Start
Project End
Budget Start
Budget End
Support Year
6
Fiscal Year
1998
Total Cost
Indirect Cost
City
State
Country
United States
Zip Code