Prenatal or early postnatal events predict infectious deaths in young adulthood in rural Africa

Background Research over the past decade has suggested that prenatal and ea rly postnatal nutrition influence the risk of developing chronic degenerati ve diseases up to 60 years later. We now present evidence that risk of deat h from infectious diseases in young adulthood is similarly programmed by ea rly life events. Methods In three rural Gambian villages, affected by a marked annual season ality in diet and disease, we have kept detailed demographic, anthropometri c and health records since 1949. Fate was known with certainty for 3162 ind ividuals (2059 alive/1103 dead, most dying in childhood). For this case-con trol analysis of antecedent predictors of premature mortality, all adult de aths (n = 61) were paired with two randomly selected controls matched for s ex and year of birth. Results Mean age at death was 25 (SD: 8) years. Adult death was associated with a profound bias in month of birth with 49 cases born in the nutritiona lly-debilitating hungry season (Jul-Dec) versus 12 in the harvest season (J an-Jun). Relative to harvest season the hazard ratio for early death in hun gry-season births rose from 3.7 (for deaths >14.5 years, P = 0.000013) to 1 0.3 (for deaths >25 years, P = 0.00002). Anthropometric and haematological status at 18 months of age was identical in cases and controls, indicating an earlier origin to the defect. Most deaths for which cause was known had a definite or possible infectious aetiology; none were from degenerative di seases of affluence. Conclusions Early life exposures, correlated with season of birth, strongly influence susceptibility to fatal infections in young adulthood. The evide nce suggests that nutritionally-mediated intrauterine growth retardation ma y permanently impair the development of immune function.