Prevalence and clinical profile of rotavirus A infection among diarrhoeal children and phylogenetic analysis with vaccine strains in Chengdu, West China, 2009-2014.

OBJECTIVES: Rotaviruses are the most common cause of severe diarrhoeal disease in young children. However, little is known about the epidemiological and clinical profile of rotavirus A (RVA) in diarrhoeal children or the efficacy of Lanzhou lamb rotavirus vaccine (LLR) in Chengdu, China. This study aimed to determine the prevalence and clinical profile of RVA in diarrhoeal children and provide gene analysis information for RVA vaccination programmes.

METHODS: A total of 1121 faecal samples were collected from outpatient children with diarrhoea between 2009 and 2014. RT-PCR was performed to detect RVA infection and other gastroenteritis viruses. VP4 and VP7 genes of 13 RVA strains were sequenced to compare their similarity with vaccine strains.

RESULTS: The overall RVA infection rate was 17.48%. G1 (54.72%) and G3 (18.87%) were the predominant G genotypes; P[8] (72.36%) and P[4] (11.38%) were the main P genotypes. Sixteen genotypes were identified; G1P[8] (57.33%) and G9P[8] (12.00%) were the most prevalent. The proportion of coinfection with RVA and other gastroenteritis viruses was 18.88%. RVA was mostly detected in winter and in diarrhoeal children 1-2 years of age. The genotypes of Rotarix and RotaTeq vaccines were consistent with RVA strains prevalent in Sichuan and shared high identity.

CONCLUSIONS: RVA was one of the major aetiological agents of diarrhoeal children in Chengdu. Genotype distribution differed within each year and the gene analysis implied low efficacy of LLR. Continuous epidemiological monitoring of RVA is essential for the national vaccination programme.