Human caliciviruses in symptomatic and asymptomatic infections in children in Vellore, South India

Abstract

Pediatric gastroenteritis is a major cause of childhood morbidity and mortality worldwide, especially in developing countries. It has been increasingly recognised that human caliciviruses (HuCV), comprising noroviruses (NoV), and sapoviruses (SaV), are important in both outbreak and non-outbreak settings. This study aimed to characterise caliciviruses detected in the faeces of hospitalized children and children in the community in India. This study examined 350 faecal samples from children presenting to the hospital with acute gastroenteritis and 673 samples collected from children in the community, 500 from children with diarrhea, and 173 samples from children without diarrhea. Strain characterisation was performed by reverse transcriptionpolymerase chain reaction (RT-PCR) and partial sequencing of the gene encoding the RNAdependent RNA polymerase (RdRp) and/or a region spanning the open reading frames (ORFs) 1 and 2 (ORF1/ORF2) junction. A total of 68 of 350 specimens (19.4%) from hospitalized children were positive, and SaV and NoV accounted for 5.1 and 15.1% of the infections, respectively. Mixed infections of HuCVs with other enteric pathogens were seen in 9.4% of the total children tested. Sixty-eight out of 673 (10.1%) samples collected from children in the community were positive for caliciviruses, and SaV and NoV accounted for 3.4 and 6.6% of the infections. In the community cohort 55/500 (11%) and 13/173 (7.5%) were from symptomatic and asymptomatic children, respectively, and SaVs accounted for 17/500 (3.4%) and NoVs for 38/500 (7.6%) of the symptomatic infections. This is the first report of genotyping of circulating caliciviruses in both hospital and community in India and has increased the evidence for the role of these viruses in pediatric gastroenteritis in India.

Norovirus Genogroup II Gastroenteritis in Hospitalized Children in South India

“…Hospital-based studies from India between 2003 and 2009 reported a 6% prevalence of NoV associated diarrhea among children 5 years of age, [21][22][23][24] which is lower than the current study. This variation could be a result of the detection method used.…”

Acute norovirus gastroenteritis in children in a highly rotavirus-vaccinated population in Northeast Brazil

“…This is due to norovirus causing less severe diarrhoea than rotavirus and parents tend not to seek medical services [25,26]. In our study, the severity of diarrhoea episodes was similar in children with and without NoV and similar high detection rates had been reported from Chile, India and Nicaragua at that time when the vaccines had not been introduced [18][19][20].…”

“…Globally, hospital-based series in children with diarrhoea report a median of 14%, which seems lower than the proportions detected in our study [17]. Although our data suggests an annual increase in the proportion of cases, similar detection rates had been reported from Chile, India and Nicaragua prior to rotavirus vaccine introduction [18][19][20]. This relative increase may also be due to the decrease of number of rotavirus-related hospitalizations [10,11] and all-cause diarrhoea cases due to the effectiveness of the rotavirus vaccine [21] and the herd effect of the vaccine that has resulted in an overall and not a real increase in the overall number of NoV cases.…”

Epidemiological profile and genetic diversity of sapoviruses (SaVs) identified in children suffering from acute gastroenteritis in Pune, Maharashtra, Western India, 2007–2011

“…5·1-12·7% of cases hospitalized with AG [11,18,19]. In the present study, SaV was detected in 2·7% of children with AG and in 1·9% of asymptomatic children.…”