Pandemic and seasonal influenza viruses among patients with acute respiratory illness in Kashmir (India)

Sheri-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India.
Influenza and Other Respiratory Viruses (Impact Factor: 2.2). 05/2011; 5(6):e521-7. DOI: 10.1111/j.1750-2659.2011.00261.x
Source: PubMed


With the emergence of pandemic influenza A (2009A/H1N1) virus in India, we sought to determine the prevalence and clinical presentations of seasonal and pandemic influenza viruses among acute respiratory illness (ARI) patients from Srinagar, a temperate climate area in northern India, during the peak winter season.
Combined throat and nasal swabs, obtained from 194 (108 male) presenting with ARI from January to March 2010 (Week 53-week 10), were tested by RT-PCR for influenza A and B, including 2009A/H1N1 viruses. HA1 gene of selected 2009A/H1N1-positive samples was sequenced, and phylogenetic analysis was carried out.
Twenty-one (10·8%, age 15-80 years, median age 40 years) patients tested positive for influenza viruses: 13 (62%) for 2009A/H1N1 virus, 6 (28·5%) for seasonal influenza A (H3N2), and 2 (9·5%) for influenza B. Twelve of the 13 patients with 2009A/H1N1 presented with febrile ARI, and eight had associated comorbidities. All of the patients recovered. Phylogenetic analysis of HA gene (n = 8) revealed that all strains from Srinagar clustered in 2009A/H1N1 clade seven along with the other 2009A/H1N1 strains from India. Amino acid substitutions in the HA protein defining clade seven (P83S, S203T, and I321V) were found in almost all isolates from Srinagar.
Both seasonal and 2009A/H1N1 viruses appear to be associated with ARI in Srinagar. The 2009A/H1N1 in Srinagar is genetically similar to globally circulating clade 7 strains, with unique signature sequences in the HA gene. Further investigations into ascertain the role of these mutations in possible alteration of the virulence and transmissibility of the virus are needed.

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Available from: Parvaiz A Koul, Sep 24, 2014
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    • "A medical team (consisting of 4 physicians and 5 laboratory personnel of influenza Laboratory of the SKIMS) visited the area during May 14-23, 2011. The clinical features of those fulfilling the criteria of ILI (defined by fever >38°C and a cough or sore throat) were recorded on a predefined questionnaire5. A total of 526 persons (age 1-75 yr, median 20 yr) with ARI were screened and throat/nasal swabs were obtained from 84 consecutive consenting patients (age 1-70 yr, median 7 yr) with ILI for influenza testing and transported to the Microbiology Laboratory at the All India Institute for Medical Sciences (AIIMS), New Delhi. The patients with ILI had significantly higher frequency of fever and chills (P<0.0001, "
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    ABSTRACT: Background & objectives: Community outbreaks of disease amongst nomadic populations generally remain undocumented. Following a reported increase in acute respiratory tract infections (ARI) in May 2011 in a nomadic population of Sangerwini in Jammu & Kashmir, India, we examined the patients with ARI symptoms and their nasal swabs were tested for influenza virus. Methods: Patients with ARI (n=526) were screened from May 14 to 23, 2011 and nasopharyngeal swabs collected from 84 with Influenza like illness (ILI) for bacterial cultures and influenza virus testing. Samples were tested for influenza A and influenza B by real time (RT)-PCR. Results: Twelve (14.3%) of the 84 patients tested positive for influenza B, compared to only one (0.9%) of 108 patients with ILI in a parallel survey performed in Srinagar during the same period, suggesting a localized outbreak in the isolated nomadic community. All presented with respiratory symptoms of less than seven days. Familial clustering was seen in 40 per cent (25% of influenza B positives). Average daytime temperatures ranged from 15-16°C compared to 22°C in Srinagar. Four patients developed pneumonia whereas others ran a mild course with a total recovery with oseltamivir and symptomatic therapy. Interpretation & conclusion: Our report of confirmed influenza B in this underprivileged nomadic population argues for routine surveillance with efforts to improve vaccination and infection control practices.
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    • "Our data are in concordance with published data where clade 7 viruses remain the predominant circulating strains globally [Nelson et al., 2009; Potdar et al., 2010; Graham et al., 2011]. Previous studies from India have also revealed the predominance of clade 7 viruses [Potdar et al., 2010; Koul et al., 2011; Mullick et al., 2011]. In addition, all of 22 clade 7 sequences had signature sequence S203T in the HA1 subunit [Nelson et al., 2009], whereas the single clade 6 virus had unique amino acid substitutions (K2E, Q310H) in the HA1 gene. "
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    ABSTRACT: Genetic analysis of pandemic 2009 influenza A (H1N1; H1N1pdm09) virus was undertaken to understand virus evolution during 2009 and 2010 in India. Surveillance of influenza viruses from July 2009 to December 2010 revealed major peaks of circulating H1N1pdm09 viruses in August-September and December-January 2009 and then in August-September 2010. To understand the diversity of the H1N1pdm09 virus, selected specimens (n = 23) from 2009 or 2010 were characterized by nucleotide sequence determination of the HA1 subunit of the HA gene. Phylogenetic analysis revealed that 22 clustered with clade 7 viruses characterized by S203T mutations, whereas one virus from 2010 fell within clade 6. None of the viruses from either 2009 or 2010 formed a monophyletic group, suggesting a continuum of independent introduction of circulating viral strains. Amino acid analysis revealed minor amino acid changes in the antigenic or receptor-binding domains. Importantly, we observed mutations that were also present in 1918 pandemic virus, which includes S183P in 4 and S185T mutation in 3 of 13 viruses analyzed from 2010, while none of the 2009 viruses carried these mutations. Whether antibody-mediated pressure is imposing such changes remains to be determined. Continued genetic surveillance is warranted to monitor pathogenicity as the virus evolves to acquire new features.
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