Molecular epidemiology characteristics of group A rotavirus infection in children under 5 years old in Chengdu from the year of 2008 to 2015

Abstract

Objective To identify the epidemiological characteristics of the group A rotavirus infection of children under 5 years old in Chengdu in order to provide the objective evidences for prevention and vaccine development. Methods Fecal specimens collected from children with acute gastroenteritis between January 2008 and June 2015 in Chengdu Women and Children′s Central Hospital were sent for detection of group A rotavirus at Sichuan Disease Control and Prevention Center.Clinical data were also documented.ELISA was used to detect the antigens of rotavirus and reverse transcription(RT)-PCR was used to classify the genotypes of group A rotavirus extracted from stool samples. Results Total of 2 122 fecal specimens from children under 5 years old were collected and 1 210 were detected with virus infections(843 male and 367 female). The overall detection rate of group A rotavirus was 26.3%(558/1 210 cases). Diarrhea caused by virus decreased generally after the year of 2009.Children aged by 7 to 12 months old were the predilection population and the epidemic time was November to December.Serotype G1 was the most common serotype totally followed by G9 and G3.G1 and G2 represented with epidemic peak in 2010 and 2012, respectively.G3 showed the moderate epidemic intensity.However, G9 grew rapidly after 2011, and became predominant in 2012-2015.P[8] was the most common genotype and increased obviously after 2011 followed by P[4] which represented with moderate intensity and increased a little in 2011-2012.P[10]was only prevalence in 2009.G9P[8] was the leading combination.G1P[8] and G2P[4] were prevalent in 2008-2011 and G3P[8] was dominated in 2008.However, the dominant position was replaced by G9P[8] after 2012.Children with rotavirus were frequently companied with respiratory symptoms and were susceptible to the liver or/and the cardiac injury. Conclusions Rotavirus infection is still the common cause of acute gastroenteritis in children under 5 years old in Chengdu.G9 increased rapidly after 2012, P[8] was the most common P type in Chengdu.G9P[8] has been the predominant type of rotavirus since 2012. Key words: Group A rotavirus; Molecular epidemiology; Children under 5 years old