Evolutionary analysis of all eleven genes of species C rotaviruses circulating in humans and domestic animals.

Species C rotaviruses (RVC) are the second most common rotavirus species known to cause gastroenteritis in humans and pigs and with occurrence documented in cattle, dogs, ferrets, and sloth bears. Despite the host-specific nature of RVC genotypes, cross-species transmission, reassortment, and recombination events are also documented. In the present study, we inferred the evolutionary history of globally circulating RVC strains, including time scale stasis, the most probable ancestral country, and the most probable source host using Bayesian methods implemented in BEAST v.1.8.4. The human-derived RVC strains were majorly monophyletic and further grouped into two lineages. The RVC strains derived from pigs were monophyletic for the VP1 and the remaining genes were classified into 2 to 4 groups based on the high posterior support. The root mean age for all the genes indicated the circulation of RVC for over 800 years. Overall, the time to Most Recent Common Ancestor of human RVC strains dated back to the beginning of the 20th century. The VP7 and NSP2 genes had the lowest rates of evolution compared to other genes. The majority of the genes of RVC showed their origin in Japan except for VP7 and VP4 genes in South Korea. The phylogeographic analysis with the country as a trait showed the role of Japan, China, and India in the dispersion of the virus. In the current study, significant transmission links between different hosts were analyzed for the first time using the host as a trait. Significant transmission links between pigs and other animal species as well as humans indicate possible transmission from the pig as a source host and suggest monitoring of proximity with animals.

Circulation of unusual and diverse enteric virus strains in adults with acute gastroenteritis: a study from Pune (Maharashtra), Western India.

In India, studies on the epidemiological and genetic characteristics of enteric viruses in adults with acute gastroenteritis (AGE) are lacking. In this study, fecal samples (n = 110) from adults with acute gastroenteritis in Pune, Western India, were tested for six enteric viruses, and the prevalence of these viruses was as follows: rotavirus A (RVA), 38.5%; enterovirus (EV), 23.1%; astrovirus (AstV), 23.1%; adenovirus (AdV), 7.7%; human bocavirus (HBoV), 7.7%; norovirus (NoV), 0%. Circulation of the RVA G1P[8], G3P[8], G9P[4], CVA-10, echovirus E13, EVC-116, AstV-5, AstV-2, HBoV-1, and AdVC-2 types was observed. When compared to the RotaTeq, Rotarix, and RotaVac vaccine strains, antigenic changes were found in the A, B, C, and F regions of the RVA strains. The circulation of genetically diverse, unusual enteric virus strains, reported here for the first time in adults with acute gastroenteritis, warrants multi-center hospital-based surveillance studies across the country.

Enteric and non-enteric adenoviruses in children with acute gastroenteritis in Western India.

Human adenoviruses (HAdVs) are the viral agents responsible for a wide spectrum of acute and chronic diseases. HAdVs are the most important etiological agents of acute gastroenteritis (AGE) and are identified as the major contributor to the deaths of diarrheal children globally. The significant rise in HAdV infections in rotavirus-vaccinated children documented in multiple studies demands continuous monitoring of HAdV strains. After the inclusion of rotavirus vaccines in the immunization schedule of India, public health research regarding prevalence, etiology, and risk factors is highly necessary for evidence-based policies and their implementation to sustain diarrhea prevention programs. In the present study, children admitted for AGE between 2013 and 2016 in seven different hospitals in Maharashtra and Gujrat states of Western India were subjected for investigation. HAdVs were found in 5.2% of the fecal specimens with the dominance of species-F (52.4%) strains, followed by the occurrence of non-enteric adenoviruses of species A (17.4%), C (11.4%), B (8.2%), and D (3.2%). The species-F strains were predominant in Ahmadabad (78.5%), Mumbai (61.5%), and Surat (57.1%) cities, followed by species-A strains. In Pune city, species B strains were detected in all HAdV patients, with none of the species A strains. Clinically, patients infected with enteric and non-enteric HAdV strains were indistinguishable. However, a high viral load was observed in species-F specimens as compared to non-species-F. The present study on fecal specimens collected in the pre-rotavirus vaccination era from hospitalized AGE patients will be important for future comparative analysis to know the exact impact of vaccination in children of Western India.

Clinical profile and molecular typing of viral etiological agents associated with Hand, Foot and Mouth Disease (HFMD): A study from Udhampur, Northern India.

PURPOSE: Hand, Foot and Mouth disease (HFMD) is a contagious pediatric viral disease caused due to enteroviruses (EV) of the family Picornaviridae. Cases of HFMD were reported from a tertiary care health centre, Udhampur, (Jammu and Kashmir), Northern India. The present study highlights the clinical and molecular virological aspects of HFMD cases. MATERIAL AND METHODS: Cases reported during August 2016-September 2017, and clinically diagnosed as HFMD of all age groups were included. Clinical, Biochemical and molecular virology aspects were compared. Clinical samples (n â€‹= â€‹50) such as vesicle swab, buccal and throat swabs were collected for enterovirus detection. EV-RNA was detected by 5'NCR based RT-PCR and genotyping by VP1 gene amplification and cycle sequencing. RESULTS: Of the cases of HFMD enrolled (n â€‹= â€‹50), highest (84%) were of children aged <5 years, presented either or both anathemas and exanthemas with prodromal symptoms (fever, irritability). Clinical presentations involved mainly oral ulcers on lips and tongue (48%). Oral erosions were either single or multiple in numbers. Exanthemas were seen on hand and palm, widely spread up to buttocks, legs, arms and trunk. Of these, six patients were found anemic. Complete blood count (CBC) indicated lymphocytosis and C-reactive protein (n â€‹= â€‹10) in children aged <5 years. EV-RNA was detected in 78% (39/50) of the clinical samples. VP1 gene based typing indicated the presence of CV-A16, CVA6 and EV-A71 types. CONCLUSIONS: The study highlights association of EVs in HFMD cases in the reported region. CV-A16, CV-A6 and EV-A71 types were reported for the first time from Udhampur (J&K), Northern India. No differences were observed in the clinical profile of EV strains detected. Circulation of the strains warrant and alarm outbreaks. More focused studies on HFMD and monitoring of viral strains is mandatory.

Rotavirus C infections in asymptomatic piglets in India, 2009-2013: genotyping and phylogenetic analysis of all genomic segments.

Asymptomatic infection with rotavirus C (RVC) was observed in pigs in India, with a detection rate of 20%. Sequencing of the VP6, VP7, and NSP4 genes of RVC strains identified the genotypes I7/I10, G1, and E5, respectively. Full genome sequencing of one of these strains revealed that the genotypes of the VP4, VP1, VP2, VP3, NSP1, NSP2, NSP3, and NSP5 genes were P1, R1, C1, M3, A1, N5, T5, and H1, respectively. The detection of porcine RVC strains at two different locations in India at different time points strongly suggests that they are circulating continuously in the pig population through asymptomatic infections.

Complete genomic analysis of uncommon G12P[11] rotavirus causing a nosocomial outbreak of acute diarrhea in the newborns in New Delhi, India.

Rotaviruses (RVs) are the major causative agents of acute gastroenteritis in children, but in neonates, RV infections are generally nosocomial in origin and mostly asymptomatic. However, there have been infrequent reports of nosocomial outbreaks of clinical disease in this population. In this study, we describe uncommon RV genotype; G12P[11] associated with an outbreak of acute gastroenteritis in the neonatal ward and neonatal intensive care unit (NICU) in New Delhi, North India. Full-genome analyses of the pathogenic G12P[11] strain was carried out to map the genotype constellation and further to explore the variations in the antigenic epitopes on the immunodominant VP7 and VP4 proteins, the amino acid sequences were compared with neonatal strains; ROTAVAC® (G9P[11]) and asymptomatic G12P[11] and also other G/P-type matched strains. The study revealed G12-P[11]-I1-R1-C1-M1-A1-N1-T1-E1-H1 human Wa-like genotype constellation and highlights evidence of gene reassortment. No significant differences were observed in the sequences of structural (except VP3) and nonstructural encoding genes of G12P[11] strains recovered from symptomatic and asymptomatic neonates. Presence of additional N-linked glycosylation site was noted in the G12 strains, as a consequence of a change from Asp→Asn at amino acid position 238. Interestingly, only two and four amino acids substitution within the 7-1a and 8-1 antigenic epitope were observed, respectively, compared with asymptomatic G12P[11] strain. The study emphasizes the importance of close monitoring of RV outbreaks in neonates for early alarming of novel strain.

Evidence-Based Health Behavior Interventions for Cholera: Lessons from an Outbreak Investigation in India.

In rural India, since 2014, the Swachh Bharat Abhiyan (Clean India Mission) has ensured construction of more than 100 million toilets and is now focusing on reinforcement of sanitation behaviors. We report a cholera outbreak in a remote village in western India where open defecation was implicated in causation. A water pipeline was damaged in the vicinity of a stream flowing from a site of open defecation. Despite the availability of a toilet facility in the majority of households (75%), open defecation was widely practiced (62.8%). Many reported not washing hands with soap and water before eating (78.5%) and after defecation (61.1%). The study emphasizes the need for focused health behavior studies and evidence-based interventions to reduce the occurrence of cholera outbreaks. This could be the last lap in the path toward achieving the United Nations Sustainable Development Goal 6, which aims to "ensure availability and sustainable management of water and sanitation for all."

Childhood encephalitis hospitalizations associated with virus agents in medium-endemic states in India.

BACKGROUND: Japanese encephalitis (JE) is the leading cause of childhood acute encephalitis syndrome (AES) in India. We enhanced the AES surveillance in sentinel hospitals to determine trends and virus etiologies in central India. METHODS: The neurological hospitalizations among children ≤15 years were tracked by using the AES case definition implemented by the national program. Acute and convalescent sera along with cerebrospinal fluid (CSF) specimens were collected and tested at the strengthened site hospital laboratories for anti-JE, anti-Dengue and anti-Chikungunya virus by IgM ELISA; along with Chandipura virus RT-PCR. Herpes simplex and enterovirus testing was undertaken at the reference laboratory. RESULTS: Among 1619 pediatric neurological hospitalizations reported during 2015-16, AES case definition was fulfilled in 332 (20.5%) cases. After excluding 52 non-AES cases, 280 AES cases resident from study districts were considered eligible for study. The treating physicians diagnosed non-viral causes in 90 cases, therefore 190 (67.9%) of 280 AES cases were suspected with viral etiologies. We enrolled 140 (73.7%) of 190 eligible AES cases. Viral etiologies were confirmed in 31 (22.1%) of 140 enrolled AES cases. JE (n = 22) was the leading cause. Additional non-JE viral agents included Chikungunya (5), Dengue (2) and Chandipura (2). However, only 21 (9.4%) of 222 additional AES cases referred from peripheral hospitals were confirmed as JE. CONCLUSIONS: Japanese encephalitis virus continues to be the leading cause of childhood acute encephalitis syndrome in central India despite vaccination program. Surveillance needs to be intensified for assessing the true disease burden of Japanese encephalitis following vaccination program implementation.

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.

Epidemiological and molecular characteristics of circulating CVA16, CVA6 strains and genotype distribution in hand, foot and mouth disease cases in 2017 to 2018 from Western India.

Hand, Foot, and Mouth disease (HFMD) is a mild exanthematous and febrile disease occurs in children aged ≤10 years old. The present study highlights clinical, epidemiological characteristics, distribution of enterovirus (EV) types, and sub genotypes in HFMD cases reported during 2017 to 2018 in Western India. A total of 93 clinical samples collected from 68 HFMD cases were included. The presence of EV-RNA was determined by 5'UTR based nested reverse transcription polymerase chain reaction followed by molecular typing, sub genotyping by VP1/2A junction or VP1, full VP1 gene amplification, and phylogenetic analysis. The study reports 80.64% (75/93) EV positivity and 94.66% (71/75) typing rate, with a predominant circulation of CVA16 and CVA6 strains. Sequence analysis revealed the presence of coxsackievirus (CV)A16 (57.7%), CVA6 (40.8%), and Echo1 (1.4%) strains. EV infections were predominantly observed in children aged 1 to 3 years old (43.9%). Although cases were reported throughout the year, peaked in July (15.8%) and August (24.6%) months and persisted till September (19.3%). All the CVA16 and CVA6 positive strains were genotyped using full VP1 gene amplification. All CVA16 Indian strains (n = 41) were clustered with rarely reported B1c sub genotype and CVA6 strains (n = 29) with E2 sub-lineage. The study highlights the genetic characteristics of circulating CVA16, CVA6, and Echo1 strains in HFMD cases from Western India. The emergence of CVA16 B1c genotype and sub-lineage E2 of CVA6 strains and their constant circulation further demands systemic surveillance studies on HFMD from different parts of India to facilitate the rapid diagnosis of CVA16 and CVA6 strains using the molecular and serological based approach and for intervention strategies.

Clinical, epidemiological, and molecular aspects of picornaviruses (entero, parecho) in acute gastroenteritis: A study from Pune (Maharashtra), Western India.

Among enteric viruses, rotavirus A (RVA), norovirus (NoV), adenovirus, and astrovirus (AstV) are the major etiological agents associated in acute gastroenteritis. The present study highlights, clinical, epidemiological, and molecular aspects with respect to RVA, NoV, enterovirus (EV), and human parechovirus (HPeVs) in sporadic cases (n = 305) of acute gastroenteritis, Pune (Maharashtra), Western India. Detection of RVA was carried out by enzyme-linked immunosorbent assay, NoV, EV, and HPeVs by reverse transcription PCR. Prevalence of 36.06%, 20.32%, 14.09%, 3.93%, respectively was observed for RVA, EV, HPeVs, and NoV along with coinfections. Infections occurred in children less than 2 years old, with peak infections within 12 months age. The disease severity in RV infections was found high (70.90%) with severe disease, followed by EV (62.9%), NoV (58.33%), and HPeV (44.58%). Predominant strains of RV G1P[8], G2P[4] types with unusual G9P[4], NoV Genogroup II of genotype 4 strains and multiple EV types with EV-B species, E14 and E17 and two novel EV-75, EV-107 types were detected. Circulation of heterogeneous HPeV genotypes (HPeV1-5, 7, 8, 13, 14, 16) with predominance of HPeV-1 was noticed. Changing trends in circulation of a rare HPeV-2 genotype, with emerging and reemerging strains was noted. The study highlights association of RVA, NoV, EV, and HPeV and their mono-infections, genotype distribution, and changing trends in acute gastroenteritis, and added more knowledge on rota and nonrota enteric viruses in acute gastroenteritis. More such studies in rota vaccinated era are required across the country, as Indian rotavirus vaccine has been implemented under the National Immunization program.

Epidemiology of rotavirus diarrhea among children less than 5 years hospitalized with acute gastroenteritis prior to rotavirus vaccine introduction in India.

BACKGROUND: Rotavirus is an important cause of severe diarrhea requiring hospitalization, accounting for approximately 78,000 deaths annually in Indian children below 5 years of age. We present epidemiological data on severe rotavirus disease collected during hospital-based surveillance in India before the introduction of the oral rotavirus vaccine into the national immunization schedule. METHODS: The National Rotavirus Surveillance Network was created involving 28 hospital sites and 11 laboratories across the four geographical regions of India. From September 2012 to August 2016 children less than 5 years of age hospitalized for diarrhea for at least 6 h, were enrolled. After recording clinical details, a stool sample was collected from each enrolled child, which was tested for rotavirus antigen using enzyme immunoassay (EIA). Nearly 2/3rd of EIA positive samples were genotyped using reverse transcription polymerase chain reaction to identify the G and P types. RESULTS: Of the 21,421 children enrolled during the 4 years surveillance, 36.3% were positive for rotavirus. The eastern region had the highest proportion of rotavirus associated diarrhea (39.8%), while the southern region had the lowest (33.8%). Rotavirus detection rates were the highest in children aged 6-23 months (41.8%), and 24.7% in children aged < 6 months. Although rotavirus associated diarrhea was seen throughout the year, the highest positivity was documented between December and February across all the regions. The most common rotavirus genotype was G1P[8] (52.9%), followed by G9P4 (8.7%) and G2P4 (8.4%). CONCLUSIONS: There is high burden of rotavirus gastroenteritis among Indian children below 5 years of age hospitalized for acute diarrhea thereby highlighting the need for introduction of rotavirus vaccine into the national immunization program and also for monitoring circulating genotypes.

A real-time polymerase chain reaction-based approach for qualitative estimation of viral RNA in organ tissues of coxsackievirus A-16-infected neonatal mice.

Hand, foot and mouth disease (HFMD) is a paediatric disease associated with enteroviruses (EVs). Among EVs, coxsackievirus A-16 (CVA-16) strain is currently in circulation and causing outbreaks in India. Neonatal mice (Institute of Cancer Research) strains were infected with CVA-16 strain isolated from HFMD patients to conduct pathological and molecular studies. Infected organs were harvested as per time points. A real-time polymerase chain reaction was used for qualitative estimation of viral RNA in organ tissues of infected mice. Skeletal muscle, brain tissue and cardiac tissues were the major target sites of CVA-16 tropism. The first-ever study was conducted on CVA-16 strains using the current approach in India.

Diversity of rotavirus genotypes circulating in children < 5 years of age hospitalized for acute gastroenteritis in India from 2005 to 2016: analysis of temporal and regional genotype variation.

BACKGROUND: From 2016, the Government of India introduced the oral rotavirus vaccine into the national immunization schedule. Currently, two indigenously developed vaccines (ROTAVAC, Bharat Biotech; ROTASIIL, Serum Institute of India) are included in the Indian immunization program. We report the rotavirus disease burden and the diversity of rotavirus genotypes from 2005 to 2016 in a multi-centric surveillance study before the introduction of vaccines. METHODS: A total of 29,561 stool samples collected from 2005 to 2016 (7 sites during 2005-2009, 3 sites from 2009 to 2012, and 28 sites during 2012-2016) were included in the analysis. Stools were tested for rotavirus antigen using enzyme immunoassay (EIA). Genotyping was performed on 65.8% of the EIA positive samples using reverse transcription- polymerase chain reaction (RT-PCR) to identify the G (VP7) and P (VP4) types. Multinomial logistic regression was used to quantify the odds of detecting genotypes across the surveillance period and in particular age groups. RESULTS: Of the 29,561 samples tested, 10,959 (37.1%) were positive for rotavirus. There was a peak in rotavirus positivity during December to February across all sites. Of the 7215 genotyped samples, G1P[8] (38.7%) was the most common, followed by G2P[4] (12.3%), G9P[4] (5.8%), G12P[6] (4.2%), G9P[8] (4%), and G12P[8] (2.4%). Globally, G9P[4] and G12P[6] are less common genotypes, although these genotypes have been reported from India and few other countries. There was a variation in the geographic and temporal distribution of genotypes, and the emergence or re-emergence of new genotypes such as G3P[8] was seen. Over the surveillance period, there was a decline in the proportion of G2P[4], and an increase in the proportion of G9P[4]. A higher proportion of mixed and partially typed/untyped samples was also seen more in the age group 0-11 months. CONCLUSIONS: This 11 years surveillance highlights the high burden of severe rotavirus gastroenteritis in Indian children < 5 years of age before inclusion of rotavirus vaccines in the national programme. Regional variations in rotavirus epidemiology were seen, including the emergence of G3P[8] in the latter part of the surveillance. Having pre-introduction data is important to track changing epidemiology of rotaviruses, particularly following vaccine introduction.

Detection and molecular characterization of porcine enterovirus G15 and teschovirus from India.

Porcine enterovirus G (EV-G) and teschovirus (PTV) generally cause asymptomatic infections. Although both viruses have been reported from various countries, they are rarely detected from India. To detect these viruses in Western India, fecal samples (n = 26) of diarrheic piglets aged below three months from private pig farms near Pune (Maharashtra) were collected. The samples were screened by reverse transcription-polymerase chain reaction using conserved enterovirus specific primers from 5' untranslated region. For genetic characterization of detected EV-G strain, nearly complete genome, and for PTV, partial VP1 gene were sequenced. EV-G strain showed the highest identity in a VP1 gene at nucleotide (78.61%) and amino acid (88.65%) level with EV-G15, prototype strain. However, its complete genome was homologous with the nucleotide (78.38% identity) and amino acid (91.24% identity) level to Ishi-Ka2 strain (LC316832), unassigned EV-G genotype detected from Japan. The nearly complete genome of EV-G15 consisted of 7398 nucleotides excluding the poly(A) tail and has an open reading frame that encodes a 2170 amino acid polyprotein. Genetic analysis of the partial VP1 gene of teschovirus identified porcine teschovirus 4 (PTV-4) and putative PTV-17 genotype. To the best of our knowledge, this is the first report on nearly full genome characterization of EV-G15, and detection of PTV-4 and putative PTV-17 genotypes from India. Further, detection and characterization of porcine enteroviruses are needed for a comprehensive understanding of their genetic diversity and their association with symptomatic infections from other geographical regions of India.

Molecular characterization of unusual G10P[33], G6P[14] genomic constellations of group A rotavirus and evidence of zooanthroponosis in bovines.

Group A rotaviruses (RVA) are a major cause of diarrhea in neonatal calves and children. The present study examined G/P combinations and genetic characteristics of RVAs in diarrheic bovine calves in Western India. RVAs were detected in 27 samples (17.64%) with a predominance of G10P[11] (51.85%), followed by previously unreported genomic constellations, G6P[14] (14.81%), and, G6P[4] (7.40%) and G10P[33] (3.70%). Sequencing and phylogenetic analysis revealed circulation of G10 (Lineage-5), G6 (Lineage-2), P[11] (Lineage-3), P[14] (proposed Lineage-8) and P[4] (Lineage-3) genotypes. The predominant G10P[11] strains were typical bovine strains and exhibited genotypic homogeneity. The rare, G10P[33] strain, had VP7 and VP4 genes of bovine origin but, a resemblance of the VP6 gene with simian strain indicated possible reassortment between bovine and simian (SA11-like) strains. The VP6 and VP7 genes of two rare strains, G6P[14] and G6P[4], were identical to those of bovine stains, but the VP4 was closely related to those of the human-bovine like and human strains, respectively. Additionally, in the VP4 gene phylogenetic tree, Indian P[14] strains constituted a closely related genetic cluster distinct from the other P[14] strains. Hence Lineage-8 was proposed for them. These findings indicated that bovines could serve as a source for anthropozoonotic transmission of G6P[14] strains while zooanthroponotic transmission followed by reassortment with human strain gave rise to G6P[4] strains. The observations of a present study reinforce the potential of rotaviruses to cross the host-species barrier and undergo reassortant to increase genetic diversity which, necessitates their continuous surveillance for development and optimization of prevention strategies against zoonotic RVAs.

Full genome based sequence and structural characterization of an unusual group A rotavirus G12P[11] isolated from neonates in Pune, western India.

Studies conducted at neonatal intensive care units in Pune, western India, suggested early exposure to rotaviruses and predominance of unusual human-bovine-like G12P[11] strains. The whole genome sequencing and phylogenetic analyses of a naturally attenuated, culture adapted neonatal strain, (NIV-1740121) revealed multiple-gene reassortment events, containing ROTAVAC® vaccine strain, 116E-like VP4, VP6, NSP3, NSP5 genes, VP7 gene of G12 origin and VP3 gene of porcine ancestry in a human Wa-like backbone. Analysis of 3D structure modeling of the VP7 and VP4 proteins with respect to 116E suggested amino acid variations in the major neutralizing epitopes of VP7, contributed to a modified charge density. Visualization of receptor-glycan interaction structures of NIV-1740121 and 116E VP8* showed type I glycan binds with a similar conformation at the same active site as represented in the available crystal structure of G10P[11] VP8*. The study adds to the knowledge of age restricted tropism of P[11] strains in neonates.

Rotavirus G9P[4], G9P[6] and G1P[6] strains isolated from children with acute gastroenteritis in Pune, western India, 2013-2015: evidence for recombination in genes encoding VP3, VP4 and NSP1.

Species A rotaviruses (RVAs) are genetically diverse pathogens. These are the most evolutionarily adaptable organisms, with a multitude of mechanisms for evolutionary change. To date, full-genome classification has been proved to be an excellent tool for studying the evolution of unusual rotavirus strains. As limited data are available from Pune (Maharashtra), western India, the current study was undertaken with the aim of understanding the genetic diversity in three (G1P[6], G9P[4] and G9P[4]) unusual RVA strains circulating in Pune, India during 2013-2015. Full-genome analysis of these strains classified them as G1-P[6]-I1-R1-C1-M1-A1-N1-T1-E1-H1, G9-P[4]-I2-R2-C2-[M1-M2_R]-[A1-A2_R]-N2-T2-E6-H2 and G9-[P4-P6_R]-I1-R1-C1-M1-A1-N1-T1-E1-H1. Sequencing and phylogenetic analysis of the structural and non-structural genes of these unusual RVA strains showed nucleotide/amino acid identities of 82.3-98.5 %/77.3-99.8 % and 86.6-97.6 %/89.6-97.8 % between the strains of the study. Evidence of recombination events was found within the genes encoding VP3, VP4 and NSP1, which showed a combination of genetic information for genogroup 1 [M1/P[6]/A1] and genogroup 2 [M2/P[4]/A2] strains. This study will facilitate future investigations into the molecular pathogenesis of such RVAs as the exchange of whole or partial genetic material between rotaviruses through recombination contributes directly to their diversification, adaptation and evolution.

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.

Changing pattern of genotypic circulation of human bocavirus variants associated with acute gastroenteritis in Pune, Western India: A 5-year retrospective study.

Human bocavirus (HBoV) has been frequently associated with acute gastroenteritis. A 5-year retrospective study was undertaken to understand the circulation pattern and genotype distribution of HBoV in acute gastroenteritis cases in Pune, Western India. A total of 985 stool samples collected from sporadic acute gastroenteritis cases and asymptomatic controls (2007-2011) from children (≤5 years) were examined for the presence of HBoV. HBoV1 was detected throughout the study period while HBoV2 during 2007-2010, HBoV3 in 2007-2009 and in 2011, and HBoV4 in 2009 and 2011. Interestingly, HBoV2 was observed to be predominant in 2007 while HBoV1 and HBoV2 were detected at an equal frequency in the year 2008. HBoV1 was predominant from 2009 onwards. The present study highlights the changing pattern of genotypic circulation, emergence, and re-emergence of HBoV variants in acute gastroenteritis cases over a 5-year study period in Western India. The severity of gastroenteritis is reported to vary with HBoV genotypes. Thus, the present study emphasizes the need for routine HBoV surveillance in acute gastroenteritis cases from other parts of the country. This data will be valuable in the current scenario because implementation of rotavirus vaccination has led to the rising of other enteric viruses associated with the disease.