[Rotavirus genotypes in children with gastroenteritis assisted in two public hospitals from Chile: viral strains circulating in a country without a universal vaccination against rotavirus].

BACKGROUND Rotavirus is the main cause of severe gastroenteritis (GE) in children. Two vaccines currently available have proven efficacy against the predominant genotypes. Rotavirus genotypes vary both geographically and/or temporally. Genotype surveillance is important to monitor trends associated or not with vaccine use. AIM To update information on rotavirus genotypes circulating in two main cities of Chile. METHODOLOGY Between May 2009-March 2010, children < 5y of age receiving medical care for GE in two large hospitals were recruited; none of these children had received rotavirus vaccine previously. Epidemiological information was recorded in an ad-hoc form and stool samples were collected for rotavirus detection by a commercial ELISA. Genotyping was performed by semi-nested RT-PCR. RESULTS A total of 296/967 samples (31%) were positive for rotavirus, with a peak in November/ December mostly in children 7-24 months old (67%). G9P[8] was the predominant genotype (76%), followed for G1P[8] (6%) and G2P[4] (6%) in both cities. CONCLUSIONS Rotavirus caused one third of GE requiring emergency room care and/or hospitalization, mostly in children within an age range susceptible to benefit from rotavirus vaccines. G9P[8], a genotype against which rotavirus vaccines have demonstrated high efficacy, was by far the most frequent rotavirus variant. Continued surveillance in Chile is crucial for providing background information on disease burden and strain diversity before the introduction of rotavirus vaccines.