Impact of seasonal variation in food availability and disease stress on the health status of nomadic Turkana children: A longitudinal analysis of morbidity, immunity, and nutritional status.

The possible influence of seasonal variations in rainfall, resource availability, and morbidity on immune function and nutritional status was examined in a longitudinal study of 54 nomadic Turkana children, 6 months to 10 years of age. The highly seasonal nature of rainfall in the arid semidesert environment of the Turkana District, northwestern Kenya, was associated with varying levels of animal milk production and meat and blood consumption. Despite significant seasonal variation in rainfall and food availability, the nutritional status of Turkana children, assessed through various anthropometric indicators, showed only moderate, if any, decline in the dry season. Rather, the data indicated that Turkana Children suffer from chronic mild-to-moderate malnutrition. In addition, analyses of cellular immunocompetence of the children, recognized to be a functional index of nutritional status, revealed extremely high levels of immunosuppression Year-round. Significant monthly variation in the levels of acute respiratory and gastrointestinal infections among children were found, although averages across seasons were not significantly different and did not correspond with fluctuations in rainfall or resources availability. Instead, periodic spikes in the prevalence of morbidity occurred against an already high level of infectious endemicity. The results indicate that food availability is not likely to be the sole determinant of nutritional status and that infection may be an important contribtor to the high levels of nutritional and immunological stress among nomadic Turkana Children. © 1995 Wiley-Liss, Inc.