title: Some epidemiologic, clinical, microbiologic, and organizational assumptions that influenced the design and performance of the Global Enteric Multicenter Study (GEMS).
abstract: The overall aim of the Global Enteric Multicenter Study-1 (GEMS-1) is to identify the etiologic agents associated with moderate-to-severe diarrhea (MSD) among children <5 years of age, and thereby the attributable pathogen-specific population-based incidence of MSD, to guide investments in research and public health interventions against diarrheal disease. To accomplish this, 9 core assumptions were vetted through widespread consultation: (1) a limited number of etiologic agents may be responsible for most MSD; (2) a definition of MSD can be crafted that encompasses cases that might otherwise be fatal in the community without treatment; (3) MSD seen at sentinel centers is a proxy for fatal diarrheal disease in the community; (4) matched case/control is the appropriate epidemiologic design; (5) methods across the sites can be standardized and rigorous quality control maintained; (6) a single 60-day postenrollment visit to case and control households creates mini-cohorts, allowing comparisons; (7) broad support for GEMS-1 messages can be achieved by incorporating advice from public health spokespersons; (8) results will facilitate the setting of investment and intervention priorities; and (9) wide acceptance and dissemination of the GEMS-1 results can be achieved.
authors.affiliation: Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD 21201, USA. tfarag@medicine.umaryland.edu
authors.forename: Tamer H
authors.initials: TH
authors.lastname: Farag
authors.forename: Dilruba
authors.initials: D
authors.lastname: Nasrin
authors.forename: Yukun
authors.initials: Y
authors.lastname: Wu
authors.forename: Khitam
authors.initials: K
authors.lastname: Muhsen
authors.forename: William C
authors.initials: WC
authors.lastname: Blackwelder
authors.forename: Halvor
authors.initials: H
authors.lastname: Sommerfelt
authors.forename: Sandra
authors.initials: S
authors.lastname: Panchalingam
authors.forename: James P
authors.initials: JP
authors.lastname: Nataro
authors.forename: Karen L
authors.initials: KL
authors.lastname: Kotloff
authors.forename: Myron M
authors.initials: MM
authors.lastname: Levine
mesh_terms: D016022:Case-Control Studies; D002675:Child, Preschool; D019411:Clinical Laboratory Techniques; D003967:Diarrhea / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D003968:Diarrhea, Infantile / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D015340:Epidemiologic Research Design; D014943:Global Health; D006761:Hospitals; D006801:Humans; D007223:Infant; D015337:Multicenter Studies as Topic / Q000379:methods*; D018571:Sentinel Surveillance