Contaminated Weaning Food: A Major Risk Factor for Diarrhoea and Associated Malnutrition

Article excerpt

Introduction

Contaminated weaning foods account for a substantial proportion of diarrhoeal diseases among infants and young children, especially in developing countries. Worldwide (excluding China) it is estimated that 1400 million episodes of diarrhoea occur annually in children under the age of 5 years. In 1990, over 3 million of such children died as a result.(a) Up to 70% of diarrhoeal episodes could be due to pathogens transmitted through food.[1](b) Nevertheless, the importance of food safety(c) in the prevention of diarrhoeal diseases is often overlooked or neglected. It is often observed that the strategies for prevention of diarrhoeal diseases and associated malnutrition are limited to promotion of breast-feeding or improving water supply and sanitation, neglecting the need to educate foodhandlers, particularly mothers, in food safety.[2] Not infrequently, studies of why children suffer from diarrhoea overlook the relevant factors related to food safety.

The present review provides evidence that food contamination is one of the major contributors to diarrhoeal diseases and the malnutrition associated with them and that in the prevention of diarrhoeal diseases in infants and children food safety is as important as breast-feeding or provision of safe water supplies and sanitation. Every effort should be made to improve the hygiene quality of foods. Education of foodhandlers, particularly mothers, in food safety principles, through primary health care and infant feeding programmes, should be regarded as an important strategy for the prevention of diarrhoeal diseases.[3]

Weaning age: a critical period

Breast milk is a nutritious and generally safe food for newborn infants, and exclusive breast-feeding, i.e., giving the infant no fluid or food other than breast milk, protects against diarrhoea by minimizing the infant's exposure to foodborne and waterborne pathogens. Breast-feeding may also reduce the severity of diarrhoeal illnesses and has an influential effect on preventing diarrhoea-associated deaths.[4-6] However, when the infant reaches 4-6 months of age, breast milk needs to be supplemented, and later on (>2 years of age) substituted by appropriate foods until the child is gradually introduced to family food. With the introduction of weaning foods, which in many countries are prepared under unhygienic conditions, infants who until then have only consumed breast milk may be exposed to infective doses of foodborne pathogens. Many studies report that the incidence of diarrhoeal diseases is especially high after weaning is initiated.[7] In a study of infants and children in a Guatemalan Mayan village, Mata noted that the prevalence of many infections increased during the weaning period.[8] Rowland & McCollum reported that there is particularly high incidence of diarrhoeal diseases between 7 and 18 months with a peak at 9 months of age.[9] Similarly, Black et al. found that the prevalence of diarrhoea was highest during the second 6 months of life[10, 11] and declined with increasing age thereafter. The declining incidence of foodborne illnesses with increasing age is explained by the probable acquisition of immunity from repeated exposure to the pathogens. A review by Snyder & Merson indicated that the median incidence of diarrhoeal diseases was three-to-six episodes per year, the highest incidence being during the second half of infancy.[12]

For various reasons, weaning is initiated in many cultures at an even earlier age than is nutritionally necessary, i.e., 4-6 months of age. Recent surveys indicate that exclusive breast-feeding is a very infrequent practice, and water, various infusions, rice water, and similar foods are often introduced to young infants at a very early age.(d) Consequently, contaminated weaning food may increase the risk of diarrhoeal diseases even during the very early months of life.

Foodborne pathogens

Infants and young children are very susceptible to foodborne diseases and, if they consume contaminated foods, are likely to contract infections or intoxications leading to illness and often death. …