| The objective of this study was to examine the pattern of infant and childhood morbidity and mortality, and to analyze the determinants of observed patterns among a subgroup of the Turkana nomadic pastoralists, the Ngisonyoka. To assess the relationship between sociocultural and biological factors affecting morbidity and mortality, this study employed a proximate determinants framework, allowing for the systematic evaluation of variables which exert an influence on child survival. The framework presented here is a respecification of earlier models, unique in its assertion that the effect of nutritional status on child survival is mediated through cellular immune status.; The results of this research show that the level of immunosuppression, assessed through delayed-type hypersensitivity (DTH) testing, was extremely high, with the majority of children (56.2%) nonreactive to all administered test antigens.; Rainfall, as well as resource availability, declined dramatically between the wet and dry seasons. Despite the seasonal variation in food availability, the nutritional status of Turkana children showed only a moderate decline in the dry season. However, their nutritional status was not, on average, adequate, with 25% to 41% of children suffering from chronic mild-to-moderate malnutrition. This pattern is believed to be attributable not only to dietary stress, but also to chronic high levels of disease stress. The most frequent cause of infectious illness was acute respiratory infection (ARI), followed by gastrointestinal infection.; A multivariate analysis of determinants of morbidity showed that DTH responsiveness was a significant predictor of gastroenteritis, while no correlation between nutritional status and diarrheal disease was found. When examined separately, both nutritional status and DTH measures were significant predictors of individual attack rates of ARI. However, when the effect of nutrition and immunological status were simultaneously tested, nutrition was no longer significant. These results indicate that cellular immunocompetence is a significant predictor of gastroenteritis and ARI, and that the effect of nutritional status on the frequency of infection is mediated by CMI function.; This research concluded that nutritional and immune status are important proximate determinants of high levels of morbidity among Turkana children, and that the effect of nutritional stress is mediated through its effect on immune function. |
