Food safety: the fourth pillar in the strategy to prevent infant diarrhoea.

Public health historians will hopefully clarify one day why the public health community has taken so long to recognize the link between contaminated food and diarrhoea — particularly infant diarrhoea — and why it has taken so long to integrate food safety into prevention strategies. Over two decades ago, WHO recognized that infant diarrhoea was a critical public health problem (Snyder JD, Merson HMH. Bulletin of the World Health Organization 1982;60:605-13) and that the epidemiological link between contaminated food and the resulting diarrhoea had been established and confirmed (The role of food safety in health development. Contaminated weaning food — a major risk factor in the cause of diarrhoea and associated malnutrition. The microbiological evidence was even more striking: diarrhoea is caused by pathogens that enter the body through the mouth, mainly via food or drinking-water. Food, however, contains substances that are not only nutritious for people but that also support the growth of bacterial pathogens. Herein lies the crucial difference between food and water in terms of what happens to bacteria. In water, bacterial pathogens may survive for some time but they will not increase in number. However, in many foods, and most importantly in complementary (weaning) foods, the growth of pathogens is well documented. Thus, even if food contained an originally insignificant bacterial contamination, the pathogens may multiply within a few hours to reach the minimum infective dose that is required to cause disease, particularly if food is stored at ambient temperature (between 20 °C and 40 °C) — a situation frequently observed in developing countries. A substantial number of cases of acute diarrhoea is caused by microbiologically contaminated food, and the resulting malabsorption, leading to a reduced nutritional status of the patients, is especially serious for malnourished people. On the basis of the available epidemiological and microbiological evidence, WHO concluded that food plays a much more significant role in the epidemiology of enteric diseases than previously thought, and it advocated the need to develop appropriate food safety measures to complement the three traditional strategies for preventing infant diarrhoea — namely, promotion of breastfeeding, vaccination against certain childhood diseases and improvements in the communities' drinking-water supply and sanitation. This advocacy was supported by data on infant diarrhoea morbidity. Although mortality had been successfully reduced annually from around 5 million deaths in the early 1980s to under 2 million deaths in 2000 by the widespread use of oral rehydration …