Attentional and mnemonic deficits associated with infectious disease in humans

Infectious diseases are accompanied by behavioural and psychological changes that suggest the implication of the central nervous system. Among them, cognitive alterations have been reported, but their specificity and implication in everyday life are still largely unclear. The purpose of the present study was to evaluate and specify the everyday memory disturbances in sick human subjects and to determinate the role of fever in the appearance of these alterations.

The study was carried out in a military training centre for naval recruits. Ninety-one volunteer subjects, healthy (N = 30) or suffering from flu-like syndrome, with (N = 29) or without fever (N = 32), participated in this experiment and were administered a cognitive test (the ERBMT) according to a cross-sectional design for assessing various aspects of everyday memory.

Sick subjects were specifically impaired in daily memory tasks that require the temporary management of a large amount of information. This impairment was similar for the feverish and apyretic sick subjects who both differed from the controls.

These findings suggest that infectious disease disturbs the complex cognitive processes that might be associated with attentional functions. Moreover, these results show that fever is not a necessary condition for the appearance of these cognitive disturbances.