Prevalence and genetic diversity of gastroenteritis viruses in hospitalized children < 5 years of age in Maharashtra state, Western India, 2017-2019.

Four gastroenteritis viruses were responsible for 54% of the acute gastroenteritis (AGE) cases in children hospitalized between May 2017 and December 2019 in Pune city of Maharashtra state, Western India. The majority (79%) of the children were <2 years of age. The prevalence of Rotavirus A (RVA) was 30.5% followed by 14.3% for norovirus, 8.4% for adenovirus, and 5.5% for astrovirus. The severity of the disease was highest in patients with coinfections compared with the patients with a single infection or negative for all (p = 0.024). Genotyping analysis showed that the majority of the RVA-positive samples (66%) could be typed as G3P[8], 63.6% of the norovirus as GII.4 Sydney [P16], 44% of the adenovirus as type 41%, and 56.2% of the astrovirus as astrovirus type 1. The almost equivalent prevalence of rotavirus and nonrotaviruses and acute gastroenteritis (AGE) cases without known etiology in around 46% of the cases was noted in the present study. Our data highlight that after the recent inclusion of rotavirus vaccines as a part of the National Immunization schedule in India, conducting extensive AGE surveillance in children should include nonrotaviruses such as norovirus.

Changing trends in circulating rotavirus strains in Pune, western India in 2009-2012: emergence of a rare G9P[4] rotavirus strain.

BACKGROUND: A vast diversity in rotaviruses at inter- and intra-genotypic level underscores the need for monitoring of circulating rotavirus strains. The aim of this study was to update the data on rotavirus disease and strains for the period from January 2009 to December 2012 in Pune, western India which has been one of the sites of the Indian Rotavirus Strain Surveillance Network since November 2005. METHODS: Children aged <5 years admitted for acute gastroenteritis in three different hospitals from Pune city were included in the study. The stool specimens were collected and tested for rotavirus antigen by a commercial enzyme immunoassay. The rotavirus strains were genotyped by multiplex reverse transcription polymerase chain reaction. RESULTS: During the study period, we found 35.1% of 685 stool specimens contained rotavirus antigen. Frequency of rotavirus detection was greatest (58.5%) among children aged 7-12 months. The G1P[8] (31.4%), G2P[4] (20.2%) and G9P[8] (11.8%) strains were the most common types. We noted predominance of G1P[8] strains (39.6%-46.1%) in all the years of study except 2009 wherein G9P[8] strains scored highest level (15.3%). Subsequent to this, we identified G9P[8] strains at the second highest position in 2010, their sudden decline and rise in G9P[4] strains in 2011-2012. We detected G12 strains in combination with P[6] and P[8] at variable rates (0-10.2%) and highest level (27.1%) of mixed rotavirus infections in 2009 as compared to 2010-2012 (0-3.8%). CONCLUSION: The study highlights the huge burden of rotavirus disease and changing profile of circulating rotavirus strains displaying emergence of G9P[4] reassortant strains in Pune, western India and emphasizes the need to analyze the entire genomic constellation of rotavirus strains for better evaluation of the impact of rotavirus.

Exploring the concurrent presence of hepatitis A virus genome in serum, stool, saliva, and urine samples of hepatitis A patients.

The use of saliva and urine as an alternative to serum samples for detection of anti-hepatitis A virus (HAV) IgM antibodies has been documented. However, these samples remain underreported or unexplored for shedding of HAV. To address this issue, paired serum, stool, saliva, and urine samples collected from hepatitis A patients were screened by reverse transcription polymerase chain reaction for detection of HAV RNA. HAV RNA was detected in 67.6% (44/65), 52.3% (34/65), 8.7% (5/57), and 12.3% (8/65) of the serum, stool, saliva, and urine samples, respectively. Phylogenetic analysis of nucleotide sequences obtained for partial RNA polymerase region grouped HAV strains from all of the clinical samples of the study in subgenotype IIIA. Low frequency of HAV nucleic acid in saliva and urine samples indicates limited utility of these samples in genomic studies on HAV but suggests its potential for transmission and infection of hepatitis A.

Epidemiological, clinical, and molecular features of norovirus infections in western India.

The study was conducted to investigate the molecular epidemiology of noroviruses (NoVs) from western India. A total of 830 fecal specimens were collected during July 2005-June 2007 from children, < or =7 years of age suffering from acute gastroenteritis in Pune, Nagpur, and Aurangabad cities. All the specimens were subjected to RT-PCR, sequencing and phylogenetic analysis for detection and characterization of Genogroup I (GI) and GII NoVs. NoV positivity varied between 6.3% and 12.6% in different cities with the predominance of GII (96.6%). NoV infections were very common in the patients < or =2 years of age. A majority (55%) of the patients suffered from severe disease, however, vomiting was not experienced in 35%. Coinfections with rotaviruses were found in 10% cases. Summer month seasonality supported NoV infections in western India. The phylogenetic analysis of partial RNA polymerase and VP1 (capsid) genes identified 2 GI (GI. 2 and GI.6) and 5 GII (GII.4, GII.6, GII.7, GII.8, and GII.14) genetic clusters with possible occurrence of "2007 new-variant" of GII.4. Six different combinations of RdRp and capsid genes (GII.b/GII.3, GII.b/GII.4, GII.d/GII.3, GII.b/GII.18, GII.1/GII.12 and GII.3/GII.13) were also identified. GII.4 (52%) prevailed in 2005-2006 while the predominance of probable recombinant NoV strains (58%) was noted in 2006-2007 with the contribution of GII.b/GII.3 at 79% level. GII.b/GII.18 type identified in 37% infections in 2005-2006 was completely replaced by GII.b/GII.3 type in 2006-2007. This is the first report that highlights the norovirus epidemiology and strain diversity demonstrating possible circulation of new variants in patients with acute gastroenteritis from western India.