Infant Feeding and Risk of Severe Diarrhoea in Basrah City, Iraq: A Case-Control Study
Mahmood, D. A., Feachem, R. G., Huttly, S. R. A., Bulletin of the World Health Organization
Infant feeding and risk of severe diarrhoea in Basrah city, Iraq: a case--control study
Diarrhoeal morbidity and mortality rates are high among infants and young children in developing countries. This is also true in Iraq [1, 9]. (a,b) Biological data suggest an important protective role for breastfeeding against diarrhoea, especially early in infancy [7, 12]. Two recent reviews on the epidemiological evidence for such protectiveness support this hypothesis . (c) Our knowledge of the relationship between infant feeding and diarrhoea is not, however, as detailed and comprehensive as it should be, partly owing to the complexity of the methodological problems inherent in measuring this association .
The use of case--control methods in studies of diarrhoeal diseases has, until recently, been limited to the investigation of diarrhoea outbreaks. However, during the last few years, these methods have been increasingly applied to the investigation of diarrhoea risk factors, and to the evaluation of the impact on diarrhoea of various interventions [3, 14]. (d,e)
The present study investigated the impact of infant feeding practices on the risk of hospitalized diarrhoea in infancy in Basrah city, Iraq, using case--control methodology. The field work was conducted over a period of 9 months between September 1983 and May 1984.
Materials and methods
Basrah city, with about 750 000 inhabitants, is situated on the western bank of the Shatt-al-Arab waterway in southern Iraq. Health services in the city are mainly provided by the government health facilities, free of charge. All inpatient paediatric health services during the study period were provided by the Basrah Paediatric Hospital (BPH). There are seven maternal and child health clinics (MCHC) in Basrah city, providing preventive health care services only (immunization and monitoring of growth and development). Immunization against diphtheria, pertussis, tetanus, and poliomyelitis is compulsory in Iraq.
Cases. A case in this study was defined as an infant (below one year of age) who was admitted to the Basrah Paediatric Hospital during the study period because of diarrhoea with or without other signs or symptoms (e.g., vomiting, dehydration, fever, respiratory symptoms), with an onset of diarrhoea not more than five days before admission. Excluded from these were: (a) infants with birthweight of less than 2500 grams; (b) infants of mothers who had severe illnesses during pregnancy, delivery, and/or puerperium, and required hospitalization; (c) infants with congenital malformation, chromosomal abnormalities, and chronic debilitating diseases; (d) infants residing outside Basrah city; and (e) infants, 3 months of age and older, with no history of being taken to an MCHC for immunization. On each day of the study period the hospital was visited by one of us (DAM), and case notes of all newly admitted infants were inspected. Infants with diarrhoea as their chief complaint were chosen as potential cases and those who satisfied the above criteria were selected for the study.
Controls. Controls were selected from infants brought to any of the seven MCHCs in Basrah city for immunization and/or routine check-up during the study period. They should not have had a history of admission to hospital because of diarrhoea in the month prior to the interview, and were excluded if admitted to hospital for diarrhoea during a period of one month following selection as a control. Excluded were infants who fell in categories (a) to (d) mentioned above.
Each MCHC was visited once during each of six five-week subperiods. The initial visit to each clinic was in a randomly selected week in the first five-week subperiod, after which the visits were made systematically (every fifth week). The visits were made on one of the three days each week when the MCHCs had infant welfare clinics, randomly choosing a different day each time. …