Astrovirus diarrhea in Egyptian children

This study describes the epidemiology of astrovirus diarrhea among a popula tion-based cohort of 397 children aged <3 years residing in rural Egypt fro m 1995 to 1998. The age-specific incidence rates of astrovirus diarrheal ep isodes per person-year were 0.38 for infants aged <6 months, 0.40 for those aged 6-11 months, 0.16 for those aged 12-23 months, and 0.05 for those age d 24-35 months. The overall incidence rate of astrovirus diarrhea was the s ame as that of rotavirus diarrhea, 0.19 episodes per person-year. Astroviru s infection was pathogenic and associated with severe dehydration in 17% of the cases. The most frequent serotype was HAstV-1, and, in order of decrea sing frequency, HAstV-5, HAstV-8 and HAstV-3, HAstV-6, HAstV-4, and HAstV-2 . In determining whether astrovirus diarrhea was associated with a reduced incidence of subsequent disease, there was evidence to suggest HAstV-1 homo typic immunity but not heterotypic immunity. Because we observed 38% of the incidence of astrovirus diarrhea to occur in infants aged <6 months, a can didate astrovirus vaccine would have to confer immunity very early in life.