Virological surveillance of influenza virus in acute respiratory infection

Introduction: Influenza is viral fever with the main symptom of respiratory tract like cough, fever, breathlessness, nasal discharge, sore throat. The influenza affects a large segment of the world population resulting in significant mortality, morbidity and economic loss. Objective: To monitor the trend of influenza A virus. To know the prevalence of influenza A, H1N1 and seasonal H3 subtypes of influenza virus. To study the seasonal pattern of influenza A virus. Materials and Methods: This prospective study was carried out in the department of Microbiology, B.J. Medical College, Ahmadabad from January 2014 to December 2014. Surveillance samples were taken as per ILI (Influenza like illness) case definition for out Patient department and SARI (sever acute respiratory syndrome) for indoor patients. Total 614 samples are taken and tested with PCR method. Result: Out of 614 samples total 201(32.73%) were positive for influenza. Out of 201 positive samples, 13 (2.11%) were positive for swine H1N1 and 11 (1.79%) for seasonal H3, 177 (28.82%) were positive for influenza A. Conclusion: Prevalence of influenza 201(32.73%). out of this 13 (2.11%) were positive for swine H1N1 and 11 (1.79%) for seasonal H3, 177 (28.82%) were positive for influenza A. swine H1N1 was common in winter and seasonal H3 was common in late monsoon. swine H1N1 and seasonal H3 both are more common in male than female. swine H1N1 is more in >12 age and seasonal H3 is more common in Keywords: Influenza A, Swine H1N1, Seasonal H3, Fever, cough, Breathlessness.