title: Clinico-Epidemiological Profile, Pandemic Influenza A H1N1/2009 and Seasonal Influenza, August 2009-March 2013, Himachal Pradesh, India.
abstract: BACKGROUND
  Novel influenza A (H1N1) virus emerged in April, 2009, spread rapidly to become pandemic by June, 2009.
  
  
  OBJECTIVE
  To study the clinco-epidemiological profile of pH1N1and seasonal influenza (SI) from 2009 to 2013.
  
  
  METHODS
  Retrospective, hospital-based study was done by reviewing medical records for collecting demographic and clinical profile of the study samples.
  
  
  RESULTS
  Out of 969 samples, positivity and case fatality for pH1N1 and SI was 9.39 and 20.87% vs 11.76 and 7.89%, respectively. Among pH1N1and SI, sex distribution, mean age, and age group involved were 54.95% females, 37.10 years, and 20-29 years (23.08%) vs 43.86% females, 40.32 years, and 20-29 years (22.81%), respectively. Mortality shift was observed from younger to older and healthier, 75% to comorbid, 100% from 2009-2010 to 2012-13 for pH1N1.
  
  
  CONCLUSIONS
  We observed seasonal variation, cocirculation, similar clinical features, decreased virulence, and community spread with respect to pH1N1 and SI from 2009-2013.
authors.affiliation: Department of Microbiology, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India.
authors.forename: Vinod Kumar
authors.initials: VK
authors.lastname: Mehta
authors.affiliation: Department of Microbiology, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India.
authors.forename: Pooja
authors.initials: P
authors.lastname: Sharma
authors.affiliation: Department of Microbiology, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India.
authors.forename: Ramesh Chand
authors.initials: RC
authors.lastname: Guleria
authors.affiliation: Department of Microbiology, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India.
authors.forename: Sunite A
authors.initials: SA
authors.lastname: Ganju
authors.affiliation: Department of Microbiology, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India.
authors.forename: Digvijay
authors.initials: D
authors.lastname: Singh
authors.affiliation: Department of Microbiology, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India.
authors.forename: Anil
authors.initials: A
authors.lastname: Kanga
keywords: Epidemic; pandemic; pandemic (H1N1); seasonal influenza