Community Based Case-Control Study of Rotavirus Gastroenteritis among Young Children during 2008-2010 Reveals Vast Genetic Diversity and Increased Prevalence of G9 Strains in Kolkata

Abstract

BackgroundGroup A Rotaviruses are a major etiologic agent of gastroenteritis in infants and young children (<5 years) worldwide. Although rotavirus vaccines have been successfully administered in many countries, in India the introduction of rotavirus vaccine in national immunization program was approved in 2014. Since high disease burden and large number of genetic variants have been reported from low income countries including India, monitoring of rotavirus was initiated prior to implementation of the vaccine in the region.MethodsA total number of 3,582 stool samples were collected from an urban slum community in Kolkata, among which 1,568 samples were obtained from children of ≤5 years of age, with moderate to severe diarrhoea and 2,014 samples were collected from age-sex matched healthy neighbourhood controls. Rotavirus positive samples were typed by multiplex semi-nested PCR and nucleotide sequencing. Circulating strains were phylogenetically analyzed.ResultsAmong 1,568 children with diarrhoea, 395 (25.2%), and among 2,014 asymptomatic children, 42 (2%) were rotavirus positive. G1P[8] was identified as the most common strain (32%) followed by G9P[8] (16.9%), G2P[4] (13.5%) and G9P[4] (10.75%). G12 strains with combinations of P[4], P[6] and P[8] comprised 11.9% of total positive strains. The rest (<10%) were rare and uncommon strains like G1P[4], G1P[6], G2P[8] and animal-like strains G4P[6], G6P[14] and G11P[25]. The 42 rotavirus positive samples from asymptomatic children revealed common genotypes like G1, G2 and G9.ConclusionThis community based case-control study showed increased predominance of genotype G9 in Kolkata. It also confirmed co-circulation of a large number of genetic variants in the community. Asymptomatic rotavirus positive children though low in number can also be a source of dispersal of infection in the community. This study provides background information to the policy makers for implementation of rotavirus vaccines in this region.

Investigation of Rotavirus with Various Methods in Children with Acute Gastroenteritis and Determination of Its Molecular Epidemiology in Kayseri Province, Turkey

“…Antunes et al (24) investigated rotavirus genotypes in an unvaccinated population in northern Portugal in 2007, and they reported the most common genotype was G2P [4] with a rate of 68.6% and it was followed by G9P [8] with a rate of 14%. In South Korea, India, Japan, and Indonesia, the most common genotype was G1P [8]; it was followed by the G4P [6] genotype in South Korea, by G9P [8], G2P [4], and G9P [4], respectively, in India, by G3P [8] and G9P [8] in Japan, and by G1P [6] and G2P [4] genotypes in Indonesia (25)(26)(27)(28). The most common genotype in Brazil was reported to be G2P [4], and it was followed by the G1P [8] genotype (28).…”

Prevalence and genotype distribution of rotaviruses in children with gastroenteritis in Rize province

“…The other common genotypes isolated in Europe were: G4P(8), G2P(4), G9P (8), and G3P(8) [4][5][11][12]. In addition, Mullick et al [13] reported the most common genotypes as G1P(8), G9P(8), G2P(4) and G9P(4) in India, while Numazaki et al [14] identified G1P(8), G3P (8) and G9P(8) as the most frequent in Japan. In Republic of Korea, the most common genotypes were G1P(8), G2P(4) and G9P (8) in the study published by Kim et al [1], while Boula et al [15] reported G9P(8), G1P(8) and G3P(6) genotypes in Cameroon.…”

Molecular epidemiology of Rotavirus causing diarrhea among children less than five years of age visiting national level children hospitals, Nepal

“…When the molecular study of Rotavirus begun from 2003 in Nepal by Uchida et al, in that first study G9 was not found, in subsequent studies by Sherchand et al and Ansari et al there were G9 genotypes occurrence comprising 2–6% [19, 20, 28]. Alike kind of increase in G9 has also been observed in neighboring country India, from 2 to 10% in 2003–2007 to around 40% in 2013 [35]. The increment of G9 can be because of the escape recognition by immune system of Nepalese children where G 12 was predominant in previous years.…”