Pandemic H1N1 2009 among Pediatric Age Group in Tamilnadu, June 2009 - Aug 2010

Influenza A viruses causes recurrent outbreaks on local or global scale with potentially severe consequences on human health and the global economy. The new strain of Influenza A virus - H1N1 2009 had caused pandemic disease among human, probably owing to little or no preexisting immunity to the new strain. This is a retrospective analysis of the impact of H1N12009 on the pediatric population of Tamil Nadu during the pandemic period of June 2009- August 2010. Throat and nasal swabs were taken from the suspected cases admitted in pediatric wards and intensive care units (ICUs) and were subjected to Real time RT PCR. A total of 6245 suspected pediatric cases were screened, of which 787 (12.60 %) were found to be positive for H1N12009. A majority of cases belonged to the 6-12 age group (35.58%). Male children were more affected than female children. Despite a fall in the number of positives in 2010, there is a concern about the probability of a new reasssortment of H1N1 2009 with other viruses of either human or animal hosts during the next season that could result in a potentially pathogenic strain.