ABSTRACT
Background: Rotavirus gastroenteritis is the leading cause of diarrhea in infants and young children worldwide. Although, Rotavirus vaccine has been introduced in 2017 in states like Tamil Nadu, there are reports of the role of Rotavirus as one of high disease burden agents with genetic variants arising, especially from low-income countries like India.Methods: Authors evaluated stool samples from 507 children with acute gastroenteritis Rotavirus A among the hospitalized children (>5 years) to provide baseline information on changing profile in this state. The stool samples were collected and screened for Rotaviral Antigen by Enzyme Immuno Assay and use of semi-multiplex RT PCR technique was conceded out in order to conclude the P and G genotypes of human rotavirus in rotavirus-positive samples from January 2014 to December 2016 in and around Chennai, India.Results: Of 507 samples collected 213 (42.01%) were positive for rotavirus antigen by Enzyme Immuno Assay (EIA). The maximum positivity (75%) was in the age group of one to two years. Rotavirus positives were subjected to further VP7 and VP4 molecular characterization and the predominant genotypes identified were G9P[4] followed by G9P[8], G1P[8], G3P[8], G2P[4] and mixed types of G2G9 with P[4] and G4P[6][11] with few untypable strains.Conclusions: This study had demonstrated the Rota Virus Gastro Enteritis (RVGE) is a common disease affecting the pediatric population and G9P[4], G9P[8] circulating types among the gastroenteritis cases reported in the city and its suburban area. This study in comparison to previous ones shows that the dominant serotypes and circulating genotypes changes from time to time within country. The results have reemphasized the need of rotavirus vaccines with broad serotype coverage which may help in decreasing the disease burden in this region of the country.
ABSTRACT
Background: Influenza viruses have emerged as virulent pathogens causing considerable burden across the world. A thorough understanding of the pattern in occurrence of influenza globally is the need of hour. The present study deals with analysis of the dynamics of Influenza virus, especially the influence of seasonal change on viral circulation and causation of epidemics/pandemics in the context of subtropical region. Methods: During the 7 year (2009–2015) study, 36670 specimens were subjected to influenza analysis. Nasopharyngeal swabs collected from suspected patients from Chennai, Tamil Nadu, were tested and typed by real-time polymerase chain reaction assay. Results: During 2009 pandemic, among influenza A positives 95.16% were Apdm09, indicating that there was a predominant circulation of Apdm09. During postpandemic period, there were waves in the occurrence of Apdm09 which indicates fall in immunity with buildup in the susceptible population. Conclusion: In Chennai, Tamil Nadu, influenza positivity started with the onset of monsoon and peaks during the postmonsoon months throughout the study period. The assessment of meteorological factors compounding influenza activity can help in raising alerts to the public health officials of impending disaster which suggests that Influenza vaccination can be initiated before monsoon months in South India.
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Background & objectives: Human parainfluenza virus (HPIV) accounts for a significant proportion of lower respiratory tract infections in children as well as adults. This study was done to detect the presence of different subtypes of HPIV from patients having influenza like illness (ILI). Methods: Throat and nasal swabs from 232 patients with ILI who were negative for influenza viruses were tested by multiplex reverse transcription polymerase chain reaction(mRT-PCR) for the detection of human parainfluenza virus. All samples were inoculated in rhesus monkey kidney (LLC-MK2) cell line. Results: Of the 232 samples, 26(11.2%) were positive by mRT-PCR and nine (34.6%) showed cytopathic effect with syncytium formation for HPIV and all were HPIV-3 serotype, other serotypes like 1,2,4 were negative. The HPIV-3 strains (HN gene) were sequenced and analysed. Two novel mutations were identified at amino acid residues 295 and 297. Interpretation & conclusions: The mRT-PCR assay offers a rapid, sensitive and accurate diagnostic method for detection of HPIV which enables early detection and control. In our study there was a predominance of HPIV among 1-5 yr age group and the school going age group was less affected. Further studies need to be done to characterize HPIV isolated from different parts of the country.
ABSTRACT
Group A Rotaviruses with serotypes G1-G4 and G9 are the common Rotavirus types of clinical importance. This study aimed at determining the different Rotavirus genotypes in stool sample of children below 5 years. A total of 300 children with acute gastroenteritis were tested for group specific VP6 antigen of group A Rotaviruses by Enzyme Linked Immunosorbent Assay. 47 of these samples were positive for Rotavirus antigen. Out of these, 20 positive samples were subjected to Reverse Transcriptase Polymerase Chain Reaction for genotyping. The identified genotypes were G9P8, G1P8, G2P4, G9P4 (non-vaccine genotype), G1P6, and G1 (P types not identified in 5 samples).
ABSTRACT
Background & objectives: Dengue is one of the most important Arboviral diseases in man with outbreaks in Southeast Asia and India. We report a retrospective analysis of the dengue positivity in the referred samples for three years period (2006 to 2008) at the Department of Virology, King Institute of Preventive Medicine, Chennai, Tamil Nadu, India. Methods: Serum samples from 1593 suspected cases (968 male and 625 female) were obtained. Of the 1593 cases screened, 1204 (75.5%) were paediatric cases and 389 (24.4%) adults. The samples were subjected to MAC ELISA and IgG ELISA. Results: Of the 968 patients, 686 (43.0%) were positive, of which 579 (84.0%) were in the paediatric age group (<14 yr) and 107 (15.5%) were adults. The IgM positivity being 356 (36.7%) in males and 330 (52.8%) in females. Of the 686 positives, 113 (16.47%) were positive for both IgM and IgG denoting secondary infection. There was a noticeable increased occurrence during the cooler months and during the monsoon and post-monsoon months. Interpretation & conclusions: The dengue IgM seropositivity among the suspected cases indicates active dengue virus activity. Increase in the probable secondary infections especially in a country like ours where multiple serotypes are prevalent raises concern over probable increase in the incidence of the more serious DHF/DSS. Studies need to be done to identify circulating serotypes of dengue virus to design preventive strategies.