A fascinating look at how infectious disease can adversely impact cognitive development was recently published in the Journal of Infectious Diseases. In this study, cognitive function was studied in three age groups: children, adults aged 20-59, and older adults. The study assessed the effect that two herpes viruses (HSV-1 and CMV) had on performance.
The study found in children that seropositivity for HSV-1 was correlated to lower reading and spatial reasoning schools. In adults aged 20-59, seropositivity to HSV-1 and CMV was correlated to impaired coding speed and seropositivity to CMV was correlated to impaired learning and recall. In older adults, seropositivity to HSV-1 was linked to impaired immediate memory.
The implications of this study are that infection with these pathogens have wide-ranging effects that can substantially alter one's functional capacity. Indeed, both of these pathogens may have roles in Alzheimer's Disease as well. Preventing infection with these ubiquitous pathogens may prove difficult in the absence of a vaccine, however.