THE EPIDEMIOLOGY OF ROTAVIRUS INFECTIONS - A GLOBAL PERSPECTIVE

Rotavirus, which is the most common cause of infantile diarrhea worldw ide, mainly affects infants between the ages of 6 and 24 months. Most infections in human newborns are mild or asymptomatic, due to the inhe rently attenuated nature of the ''nursery'' rotavirus strains. Adults are also sometimes affected, especially those in families with an infe cted child; the disease also occurs in closed adult communities, HIV-i nfected persons, travelers, or as a result of water-borne epidemics. N osocomially acquired hospital infections add to morbidity and to the c ost of hospitalization. A winter predominance of rotavirus diarrhea ha s been noted in temperate climates but not in tropical areas. Group A rotavirus infections are generally more common, but human infections w ith groups B and C have also been documented. The prevalence of serum antibodies is high during the neonatal period, but it declines sharply between the ages of 3 and 6 months, then rises steeply, peaking at si milar to 2 years and remaining high into adulthood. Vaccines against r otavirus are currently under evaluation,