Emerging rotavirus genotype G9P[6] in an outbreak on a neonatal medium care unit

We observed two consecutive episodes of an outbreak of rotavirus (RV) on our neonatal medium care unit in May-June 2009. We investigated the genotype of the RV; describe the spread of the virus among neonates and the measures taken to control the outbreak. Stool samples of symptomatic neonates, and during the second episode stool samples of all neonates, were tested for RV antigens. Reverse transcriptase polymerase chain reaction was performed on ten samples positive for RV, followed by genotyping. Staff members and samples of the environment were also tested for RV. An infection control advisor attended shifts on the ward to observe the daily routines. Eighteen of 44 neonates were tested positive for RV antigen and RNA. Ten samples were genotyped and revealed the G9P(6) strain. One male premature neonate developed a serious neurologic complication. None of the staff members were positive for RV. It is concluded that the RV strain G9P(6) can present as a hard to eradicate nosocomial pathogen. Since atypical RV strains can cause severe illness among neonates, surveillance and genotyping during an outbreak is recommended.