Examining interactions of lead and repeated Rotavirus infection on infant cognitive development

Abstract

Rotavirus is a major cause of severe childhood gastroenteritis globally. When children are frequently exposed to unsanitary conditions they are more likely to be repeatedly exposed to pathogens that cause diarrheal diseases and gut inflammation. This chronic inflammation can decrease cognitive function and generally stunt growth. Additionally, lead is well known to be neurodevelopmentally toxic, causing lower cognitive functioning at levels of 5ug/dL, the current CDC maximum acceptable blood lead level. Children in the developing world may be more likely to have a double burden of these growth stunting factors, disadvantaging them in global competition. Therefore, this project evaluated if the effects of repeated early life Rotavirus infection and elevated blood lead levels increase cognitive stunting beyond what might be expected of either threat individually. To understand these potential interactions, infants from Bangladesh, India, and Pakistan were assessed for cognition at 6 months using the Bayley’s Scales of Infant and Toddler Development. This score was evaluated in relation to the child’s blood lead level and incidence of Rotavirus infection while controlling for covariates such as home socioeconomic status, maternal reasoning abilities, nutrition, and other pathogenic burden. No relationship was found in this cohort, but it should be noted that the number of infants in this study with a non-zero Rota incidence was 43 of the 634 participants. Therefore, it is not able to be determined if the data is masking a potential reaction or if there is truly no interaction. It is possible that increased gut injury could be increasing lead uptake, as was hypothesized, but it may also be injuring the gut enough to decrease all absorption, thus decreasing lead uptake. Further study of this and other environmental health interactions are needed to evaluate if and how any stunting effects that may be seen are impacting these populations and potentially presenting a greater than additive risk.