The Global Enterics Multi-Center Study (GEMS), funded by the Bill and Melinda Gates Foundation, was a prospective, multi-center, case-control study of acute diarrhea in children 0-59 months of age. It was conducted at seven sites in Africa and Asia, representing developing countries with moderate or high infant mortality rates; rural or urban settings; and high or low HIV and malaria prevalences. Each site recruited up to 880 children with severe diarrhea from hospitals or ambulatory facilities and 880 matched community controls in each of three age strata: 0-11 months, 12-23 months and 24-59 months.
Participants provided clinical and epidemiological data and a fecal sample for identification and antigenic characterization of various bacterial, viral and protozoal enteropathogens. Population-based, age-specific incidences and pathogen-specific, severe diarrhea-associated attributable disease burdens was calculated using census and health care utilization surveys conducted at each site. Isolation frequencies of each pathogen will be compared among cases and controls to derive a "pathogenicity index". Deaths and sequelae attributed to pathogens will be determined acutely and at 60-day follow-up visits. In addition to the health burden, the public and private financial costs, both direct and indirect, incurred by an episode of severe diarrhea in a child 0-59 months of age was assessed.
The research consortium involved in the project represents most of the world's major players in vaccine development and the diagnosis and treatment of diarrheal diseases. Institutions and organizations participating in the project included: Centro de Investigaçao em Saude da Manhiça Manhiça, Mozambique; Medical Research Council, Basse, Gambia; CDC/Kenya Medical Research Institute Research Station, Kisumu, Kenya; Centre pour le Développement des Vaccins du Mali (CVD-Mali), Bamako, Mali, National Institute of Cholera and Enteric Diseases, Kolkata, West Bengal, India; International Center for Diarrheal Disease Research (ICDDR,B), Mirzapur, Bangladesh; Aga Khan University, Pakistan; Perry Point Veterans Administration Medical Center in Maryland; the U.S. Centers for Disease Control and Prevention; the University of Chile; the University of Virginia School of Medicine; the International Vaccine Institute in Seoul, Korea; the Institut Pasteur in Paris, France; the World Health Organization; the Center for International Health at the University of Bergen and the Institute of Public Health in Norway; the University of Goteborg in Sweden; Rollins School of Public Health at Emory University in Atlanta, and the Johns Hopkins University Bloomberg School of Public Health in Maryland.