Investigation of a large waterborne acute gastroenteritis outbreak caused by group B rotavirus in Maharashtra state, India.

An acute gastroenteritis outbreak at Devli Karad village, Maharashtra, India with an attack rate of 22.6% affected mainly adolescent and adult population. The viral investigations conducted on fecal specimens of patients hospitalized indicated the presence of rotavirus B (RVB) using RNA polyacrylamide gel electrophoresis and reverse transcription polymerase chain reaction. The samples collected from the source of drinking water also showed the presence of the only RVB. Absence of other viral agents and identification of RVB of genotype G2 as the etiological agent of the acute gastroenteritis outbreak highlights, the necessity of monitoring RVB, the viral agent known for its large outbreak potential.

Identification of group B rotavirus as an etiological agent in the gastroenteritis outbreak in Maharashtra, India.

Acute gastroenteritis outbreak occurred at Pargaon, Maharashtra, India in 1789 cases with an attack rate of 32.5% between November to December 2015. The stool specimens (n = 32) were investigated for different enteric viral agents using conventional methods. Transmission electron microscopy and RNA polyacrylamide gel electrophoresis respectively identified morphologically distinct rotavirus particles in 28% and RNA migration pattern of Group B Rotavirus (GBR) in 72% of the specimens. Reverse transcription polymerase chain reaction and nucleotide sequencing confirmed presence of GBR in 97% of the samples analyzed. The predominance of GBR infections and absence or insignificant presence of other agents confirmed GBR as an etiological agent of the gastroenteritis outbreak occurred in Maharashtra, India.

Genetic characterization of enterovirus strains identified in Hand, Foot and Mouth Disease (HFMD): Emergence of B1c, C1 subgenotypes, E2 sublineage of CVA16, EV71 and CVA6 strains in India.

Hand, Foot and Mouth disease (HFMD) is a common childhood disease and caused due to Enterovirus-A (EV-A), EV-B and EV-C species worldwide. Cases of HFMD were reported from, Ahmedabad (Gujarat, 2012) and Pune (Maharashtra, 2013-2014) in India. The present study highlights the identification of EV strains (CVA16, CVA6, CVA4 and Echo12), characterization of subgenotypes of CVA16, CVA6 strains during 2012-14 and CVA16, CVA6, EV71 strains reported from the earlier study (2009-10) in HFMD cases from India. A total 158 clinical specimens collected from 64 HFMD cases (2012-2014) were included in the study. EV detection was carried out by 5'NCR based RT-PCR, molecular typing and subgenotyping was by VP1/2A junction or VP1, full VP1 gene amplification respectively followed by phylogenetic analysis. The present study reports 63.92% (101/158) EV positivity by RT-PCR. Ninety four of the 101 (93.06%) EV positive strains were amplified by VP1/2A junction or VP1 regions. Sequence analysis revealed the presence of CVA16 (61.7%), CVA6 (34.04%), CVA4 and Echo12 (4.3%). A total of 114 EV positive strains were genotyped using full and partial VP1 region. All CVA16 Indian strains (n=70) clustered with rarely reported B1c subgenotype, CVA6 (n=43) and EV71 (n=1) strains clustered with sub-lineage E2 and C1 subgenotypes respectively. In summary, the study reports genetic characterization of CVA16, CVA6, CVA4 and Echo12 strains in HFMD cases from India. Circulation of B1c subgenotype of CVA16, E2 sub-lineage of CVA6 and C1 subgenotype of EV 71 strains in HFMD cases were reported for the first time from India. This study helps to understand the genotype distribution, genetic diversity of EV strains associated with HFMD from Eastern, Western and Southern regions in India.

Identification and molecular characterization of adenovirus types (HAdV-8, HAdV-37, HAdV-4, HAdV-3) in an epidemic of keratoconjunctivitis occurred in Pune, Maharashtra, Western India.

Epidemic keratoconjunctivitis (EKC) is a highly contagious infectious disease of the ocular surface and is caused mainly due to adenoviruses species D, B, and E. The present study was carried out to identify and characterize the viral etiological agents associated with the keratoconjunctivitis cases reported from Pune (Maharashtra), Western India between November-December 2013 and January, October-November 2014. Conjunctival swab specimens (n = 23) obtained from keratoconjunctivitis patients were subjected to detection of Adenovirus (AdV) and Enterovirus (EV) by PCR/RT-PCR using hexon and 5' NCR gene specific primers, respectively. Molecular typing of AdV and EV positive specimens was carried out by amplifying penton, fiber, and VP1 genes, respectively followed by sequencing and phylogenetic analysis. In this study, human adenovirus (HAdV) was identified as an etiological agent. None of the clinical specimens were found positive for enterovirus. AdV positivity in keratoconjunctivitis cases was found to be 60.9% (14/23). Fourteen of the HAdV positive strains, all of them were amplified by hexon gene, nine strains by fiber gene, and all 14 strains by penton gene specific primers. Sequencing of all HAdV positive samples revealed the presence of HAdV-8, HAdV-37, HAdV-3, and HAdV-4. All Indian strains showed highest nucleotide identity with the reference strains reported worldwide. The study revealed the circulation of HAdV-8 (78.6%) as predominant AdV strain followed by HAdV-37, HAdV-3, and HAdV-4 (7.2%) identified in the epidemic keratoconjunctivitis. Multiple types of AdVs in EKC reported for the first time in Western India. J. Med. Virol. 88:2100-2105, 2016. © 2016 Wiley Periodicals, Inc.