title: The Global Enteric Multicenter Study (GEMS) of diarrheal disease in infants and young children in developing countries: epidemiologic and clinical methods of the case/control study.
abstract: BACKGROUND
  Diarrhea is a leading cause of illness and death among children aged <5 years in developing countries. This paper describes the clinical and epidemiological methods used to conduct the Global Enteric Multicenter Study (GEMS), a 3-year, prospective, age-stratified, case/control study to estimate the population-based burden, microbiologic etiology, and adverse clinical consequences of acute moderate-to-severe diarrhea (MSD) among a censused population of children aged 0-59 months seeking care at health centers in sub-Saharan Africa and South Asia.
  
  
  METHODS
  GEMS was conducted at 7 field sites, each serving a population whose demography and healthcare utilization practices for childhood diarrhea were documented. We aimed to enroll 220 MSD cases per year from selected health centers serving each site in each of 3 age strata (0-11, 12-23, and 24-59 months), along with 1-3 matched community controls. Cases and controls supplied clinical, epidemiologic, and anthropometric data at enrollment and again approximately 60 days later, and provided enrollment stool specimens for identification and characterization of potential diarrheal pathogens. Verbal autopsy was performed if a child died. Analytic strategies will calculate the fraction of MSD attributable to each pathogen and the incidence, financial costs, nutritional consequences, and case fatality overall and by pathogen.
  
  
  CONCLUSIONS
  When completed, GEMS will provide estimates of the incidence, etiology, and outcomes of MSD among infants and young children in sub-Saharan Africa and South Asia. This information can guide development and implementation of public health interventions to diminish morbidity and mortality from diarrheal diseases.
authors.affiliation: Department of Pediatrics, University of Maryland School of Medicine, Center for Vaccine Development, 685 W Baltimore St, HSF 480, Baltimore, MD 21201, USA. kkotloff@medicine.umaryland.edu
authors.forename: Karen L
authors.initials: KL
authors.lastname: Kotloff
authors.forename: William C
authors.initials: WC
authors.lastname: Blackwelder
authors.forename: Dilruba
authors.initials: D
authors.lastname: Nasrin
authors.forename: James P
authors.initials: JP
authors.lastname: Nataro
authors.forename: Tamer H
authors.initials: TH
authors.lastname: Farag
authors.forename: Annemieke
authors.initials: A
authors.lastname: van Eijk
authors.forename: Richard A
authors.initials: RA
authors.lastname: Adegbola
authors.forename: Pedro L
authors.initials: PL
authors.lastname: Alonso
authors.forename: Robert F
authors.initials: RF
authors.lastname: Breiman
authors.forename: Abu Syed Golam
authors.initials: AS
authors.lastname: Faruque
authors.forename: Debasish
authors.initials: D
authors.lastname: Saha
authors.forename: Samba O
authors.initials: SO
authors.lastname: Sow
authors.forename: Dipika
authors.initials: D
authors.lastname: Sur
authors.forename: Anita K M
authors.initials: AK
authors.lastname: Zaidi
authors.forename: Kousick
authors.initials: K
authors.lastname: Biswas
authors.forename: Sandra
authors.initials: S
authors.lastname: Panchalingam
authors.forename: John D
authors.initials: JD
authors.lastname: Clemens
authors.forename: Dani
authors.initials: D
authors.lastname: Cohen
authors.forename: Roger I
authors.initials: RI
authors.lastname: Glass
authors.forename: Eric D
authors.initials: ED
authors.lastname: Mintz
authors.forename: Halvor
authors.initials: H
authors.lastname: Sommerfelt
authors.forename: Myron M
authors.initials: MM
authors.lastname: Levine
mesh_terms: D017954:Africa South of the Sahara / Q000453:epidemiology; D001211:Asia, Western / Q000453:epidemiology; D016022:Case-Control Studies; D002675:Child, Preschool; D003906:Developing Countries; D003967:Diarrhea / Q000453:epidemiology*; D003968:Diarrhea, Infantile / Q000453:epidemiology*; D015340:Epidemiologic Research Design; D014943:Global Health; D006801:Humans; D007223:Infant; D015337:Multicenter Studies as Topic / Q000379:methods*; D011795:Surveys and Questionnaires