MOLECULAR EPIDMIOLOGY OF ROTAVIRUS (RV) INFECTION IN A NEWBORN CONVALESCENT ROOM

Abstract

Little is known about factors responsible for asymptomatic primary RV infection in newborns. Prior studies suggest that newborns may be infected by attenuated strains. In a prospective study, all patients admitted to a newborn convalescent unit (NCU) on an infant-toddler ward (ITW), between January and April 1985, were tested every other day for RV excretion by ELISA. RNA electropherotypes of the RV strains identified in this population were analyzed in order to determine whether specific virus strains were associated with newborn infection. RV strains infecting older symptomatic children were also available from the ITW. 39 patients admitted to the NCU were enrolled in the study (mean gestational age: 31.9 weeks; age range 2-90 days). RV was detected in the stools of 12 NCU patients, 11 of whom were asymptomatic. Three different electropherotypes were seen among the RV positive NCU patients; these were identical to the RV electropherotypes identified in the ITW from older children with community acquired and nosocomial diarrhea during the same study period. Each of the 3 strains was first identified in the ITW and subsequently detected in the NCU within 3 to 6 days. We failed to identify a particular strain infecting exclusively newborns. Our data suggest that RV strains introduced into ITW by children with acute diarrhea produced infection, usually asymptomatic, in hospitalized newborns. Host factors are important for the lack of expression of clinical disease in this population.