Prevalence and genotypes of group A rotavirus among outpatient children under five years old with diarrhea in Beijing, China, 2011–2016

Abstract

BackgroundRotavirus is a leading cause of severe diarrheal disease, and one of the common causes of death in children aged under five years old. The dominant epidemic strains may change in different years in the same area. In order to provide evidence for rotavirus epidemic control and inform vaccine development, we analyzed epidemiological patterns and genetic characteristics of rotavirus in Beijing during 2011–2016.MethodsStool specimens of outpatient children under five years old were collected from three children’s hospitals on a weekly basis. Group A rotavirus antigens were detected using enzyme-linked immunosorbent assay (ELISA) kit. The partial VP4 genes and VP7 genes of rotavirus were both amplified and sequenced. Genotyping and phylogenetic analyses were performed. Logistic regression and Chi-square tests were performed to determine differences across age groups, districts and years in rotavirus prevalence and genotype distribution.ResultsA total of 3668 stool specimens from children with acute diarrhea identified through hospital-based surveillance were collected from 2011 to 2016 in Beijing. A total of 762 (20.8%) specimens tested positive for rotavirus. The rotavirus-positive rate was highest among the 1–2 years old age group (29.0%, 310/1070). November, December and January were the highest rotavirus-positive rate months each year. G9 was the most common G genotype (64.4%, 461/716), and P [8] was the most common P genotype (87.0%, 623/716) among the 716 rotavirus-positive specimens. G9P [8], G3P [8] and G2P [4] were the most common strains. The rotavirus-positive rates of samples in 2012 and 2013 were higher than that in 2011, and the dominant genotype changed from G3P [8] to G9P [8] in 2012 and 2013. VP7 gene sequences of G9 strains in this study clustered into two main lineages. Most of the G9 strains exhibited the highest nucleotide similarity (99.1%~ 100.0%) to the strain found in Japan (MI1128). VP4 gene sequences of P [8] strains were almost P[8]b.ConclusionsRotavirus accounted for more than one fifth of childhood diarrhea in Beijing during the study period. Targeted measures such as immunization with effective rotavirus vaccines should be carried out to reduce the morbidity and mortality due to rotavirus.

Molecular epidemiology of group A rotavirus in outpatient diarrhea infants and children in Chongqing, China, 2011‐2015

“…A similar positive rate (30.46%) was also observed in our study. Understanding the distribution and variation of rotavirus infection among children under 5 years old in China can inform vaccination policy in the future . In addition, as reported in other studies, the positive rate of RVA was increased since 6‐month old, suggesting that the inoculation of rotavirus vaccines should be completed before 6‐month old.…”

“…From 2011 to 2015, the most dramatic change observed was that the previously predominant strains, G3P [8] and G1P [8] were replaced by genotype G9P [8] in recent years, increasing from 6.31% in 2011 to 61.38% in 2014. The similar conclusion was derived from other cities, such as Beijing, 35 Kunming. 36,37 However, G9P [8] became as the dominant genotype in Chongqing (since 2013) later than in Beijing (since 2012), 35 but earlier than in Kunming (since 2014).…”

“…The similar conclusion was derived from other cities, such as Beijing, 35 Kunming. 36,37 However, G9P [8] became as the dominant genotype in Chongqing (since 2013) later than in Beijing (since 2012), 35 but earlier than in Kunming (since 2014). In late 2014, G9P [8] became as the dominant genotype in neighboring country Myanmar.…”

“…The sequence analysis of the 11 gene segments of randomly selected G9P [8] strains showed that all seven strains shared the inform vaccination policy in the future. 35 In addition, as reported in other studies, the positive rate of RVA was increased since 6-month old, suggesting that the inoculation of rotavirus vaccines should be completed before 6-month old.…”

“…38 Among G9 rotaviruses, there were at least ten separated VP7 lineages globally. 35 In the present study, G9P [8] strains could be divided into two different lineages (G9-VI and G9-III) according to their phylogenetic relationships. G9-Ⅵ was the main VP7 lineage during our study period (Figure 3).…”