Establishment of the MAL-ED Birth Cohort Study Site in Vellore, Southern India

TheIndianEtiology,RiskFactorsandInteractionsofEntericInfectionsandMalnutrition andtheConsequenc-es for Child Health and Development (MAL-ED) site is in Vellore, Tamil Nadu, in south India and is coordi-nated by the Christian Medical College, Vellore, which has many years of experience in establishing andfollowingcohorts.Indiaisadiversecountry,andnosingleareacanberepresentativewithregardtomanyhealthand socioeconomic indicators. The site in Vellore is an urban semiorganized settlement or slum. In the studysite, the average family size is 5.7, adults who are gainfully employed are mostly unskilled laborers, and 51% ofthepopulationusesthefieldastheirtoiletfacility.PreviousstudiesfromVelloreslumshavereportedstuntinginwell over a third of children, comparable to national estimates. The infant mortality rate is 38 per 1000 livebirths, with deaths due mainly to perinatal and infectious causes. Rigorous staff training, monitoring, super-vision and refinement of tools have been essential to maintaining the quality of the significantly large quantityof data collected. Establishing a field clinic within the site has minimized inconvenience to participants andresearchers and enabled better rapport with the community and better follow-up. These factors contribute tothe wealth of information that will be generated from the MAL-ED multisite cohort, which will improve ourunderstanding of enteric infections and its interactions with malnutrition and development of young children.Keywords. birth cohort; India; malnutrition; MAL-ED.The Etiology, Risk Factors and Interactions of EntericInfections and Malnutrition and the Consequencesfor Child Health and Development (MAL-ED) Net-work is conducting a multicountry, longitudinal pro-spective cohort study on the etiology, risk factors, andinteractions of enteric infections and malnutrition andthe effects of these factors on child growth, cognitivedevelopment, and vaccine response. The 8 MAL-EDcohort sites are epidemiologically and geographicallydiverse and comprise low-income populations; theyarelocatedinBangladesh,Brazil,India,Nepal,Pakistan,Peru, South Africa, and Tanzania.The strengths of longitudinal studies lie in their abil-ity to document the natural history of outcomes overtime and to elucidate temporal and possibly causal re-lationships among variables. Although expensive, long,and difficult, cohort studies largely overcome the prob-lemsofrecallandcanbeusedtoinvestigatemultipleex-posures and determinants with a low possibility ofselection bias, recall bias, and confounding [1,2].MATERIALS AND METHODSThe2005–2006IndianNationalFamilyHealthSurvey3(NFHS 3), a nationally representative survey, showedthat 48% of Indian children