Infectious disease burden and cognitive function in young to middle-aged adults

Prior research has suggested an association between exposure to infectious disease and neurocognitive function in humans. While most of these studies have explored individual viral, bacterial, and even parasitic sources of infection, few have considered the potential neurocognitive burden associated with multiple infections. In this study, we utilized publically available data from a large dataset produced by the Centers for Disease Control and Prevention that included measures of neurocognitive function, sociodemographic variables, and serum antibody data for several infectious diseases. Specifically, immunoglobulin G antibodies for toxocariasis, toxoplasmosis, hepatitis A, hepatitis B, and hepatitis C, cytomegalovirus, and herpes 1 and 2 were available in 5662 subjects. We calculated an overall index of infectious-disease burden to determine if an aggregate measure of exposure to infectious disease would be associated with neurocognitive function in adults aged 20-59 years. The index predicted processing speed and learning and memory but not reaction time after controlling for age, sex, race-ethnicity, immigration status, education, and the poverty-to-income ratio. Interactions between the infectious-disease index and some sociodemographic variables were also associated with neurocognitive function. In summary, an index aggregating exposure to several infectious diseases was associated with neurocognitive function in young- to middle-aged adults.