Background: Influenza viruses belong to Orthomyxoviridae family of viruses. Orthomyxoviridae familyviruses are negative-sense ssRNA viruses. Four genera are described; Influenza A, B, C & D. Among this,Influenza type A infects humans and is responsible for all flu pandemics. In 2009, an Influenza pandemic causedby a novel strain of H1N1 resulted in millions of infections in more than 214 countries. Since their introductionin 1968, H3N2 Influenza viruses have undergone extensive genetic and antigenic evolution leading to numerousseasonal epidemics. In the present study, patients categorized as category C under national Influenza guidelinesand admitted to hospital were screened for Influenza viruses. The aim of current study was to determine theoccurrence of Influenza virus infection, to determine circulating subtype of Influenza virus, to determinewhether the age & gender affects susceptibility to Influenza virusesMethod: In present study, rRT-PCR method was used. As per standard guidelines, received samples wereprocessed in the Molecular laboratory of Microbiology Department. Viral RNA was extracted from the sampleusing automated extraction method (GeneMag Quick Viral DNA/RNA Purification Kit). rRT-PCR reactionmixture was prepared using Tru PCR kit. The instrument used was CFX96/C1000 Touch Thermal CyclerSystem (BIO RAD).Result: Out of 728 samples received in the laboratory for influenza virus testing, 89 samples were positive forInfluenza virus.88 samples were positive for Influenza A virus and 1 for Influenza B virus from total 89 positivesamples. The most dominant subtype of Influenza A virus was H3N2 53 (60.22%) followed by H1N1 20(22.72%) and other subtype 15 (17%).Gender wise distribution of subtype does not show any significantdifference. Among 728 samples received, 347 and 381 samples from male & female patients respectively.Detection of influenza virus was found more in age group of 18 – 60 years as compared to other age group.Month wise distribution of H3N2 subtype shows that there was sudden increasing trend of this strain fromAugust 2022 to February 2023.Conclusion: In present study, an influenza A (H3N2) outbreak was confirmed with a co-circulation of A(H1N1) pdm09. Positivity rate of H3N2 is slightly higher among male patients and among age group of 18-60years. Influenza cases were maximum during winter. 

Background: Influenza viruses belong to Orthomyxoviridae family of viruses. Orthomyxoviridae familyviruses are negative-sense ssRNA viruses. Four genera are described; Influenza A, B, C & D. Among this,Influenza type A infects humans and is responsible for all flu pandemics. In 2009, an Influenza pandemic causedby a novel strain of H1N1 resulted in millions of infections in more than 214 countries. Since their introductionin 1968, H3N2 Influenza viruses have undergone extensive genetic and antigenic evolution leading to numerousseasonal epidemics. In the present study, patients categorized as category C under national Influenza guidelinesand admitted to hospital were screened for Influenza viruses. The aim of current study was to determine theoccurrence of Influenza virus infection, to determine circulating subtype of Influenza virus, to determinewhether the age & gender affects susceptibility to Influenza virusesMethod: In present study, rRT-PCR method was used. As per standard guidelines, received samples wereprocessed in the Molecular laboratory of Microbiology Department. Viral RNA was extracted from the sampleusing automated extraction method (GeneMag Quick Viral DNA/RNA Purification Kit). rRT-PCR reactionmixture was prepared using Tru PCR kit. The instrument used was CFX96/C1000 Touch Thermal CyclerSystem (BIO RAD).Result: Out of 728 samples received in the laboratory for influenza virus testing, 89 samples were positive forInfluenza virus.88 samples were positive for Influenza A virus and 1 for Influenza B virus from total 89 positivesamples. The most dominant subtype of Influenza A virus was H3N2 53 (60.22%) followed by H1N1 20(22.72%) and other subtype 15 (17%).Gender wise distribution of subtype does not show any significantdifference. Among 728 samples received, 347 and 381 samples from male & female patients respectively.Detection of influenza virus was found more in age group of 18 – 60 years as compared to other age group.Month wise distribution of H3N2 subtype shows that there was sudden increasing trend of this strain fromAugust 2022 to February 2023.Conclusion: In present study, an influenza A (H3N2) outbreak was confirmed with a co-circulation of A(H1N1) pdm09. Positivity rate of H3N2 is slightly higher among male patients and among age group of 18-60years. Influenza cases were maximum during winter.