RESUMO
INTRODUCTION: Influenza is an RNA virus that belongs to the Orthomyxoviridae family. It causes a highly contagious acute respiratory illness, has been recognized since ancient times, and is a major health threat throughout the world. An outbreak of influenza-like illness (ILI) was reported from Alappuzha district of Kerala State between late June and July 2011. This investigation was conducted to determine the clinical picture, causative agents, and epidemiological characteristics of the illness. METHODOLOGY: The World Health Organization (WHO)'s case definition for ILI was followed throughout the investigation. Nasal or throat swabs were collected from 204 suspected patients. Real-time reverse transcription polymerase chain reaction (RT-PCR)-based diagnosis was performed to detect influenza A and B viruses and their subtypes. Madin-Darby canine kidney (MDCK) cell line was used for virus isolation. One-step RT-PCR was performed to amplify the HA1 gene of influenza A(H3N2). The amplicons for the HA1 gene of influenza A(H3N2) were sequenced, and phylogenetic analysis was done. RESULTS: Analysis of the data revealed that 96 (47.05%) of the 204 respiratory specimens collected were influenza A(H3N2) and only 6 (2.94%) were A(H1N1)pdm09. Phylogenetic analysis revealed that the isolated A(H3N2) was closely related to the 2012-2013 northern hemisphere vaccine strain (A/Victoria/361/2011/H3N2). CONCLUSIONS: An influenza A(H3N2) outbreak was confirmed in Alappuzha district of Kerala state with a co-circulation of A(H1N1)pdm09. No substantial difference in the sequence was observed in the etiological agent, and the virus was found to be sensitive to oseltamivir.
Assuntos
Surtos de Doenças , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Influenza Humana/epidemiologia , Influenza Humana/virologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Genótipo , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Índia/epidemiologia , Lactente , Vírus da Influenza A Subtipo H3N2/classificação , Vírus da Influenza A Subtipo H3N2/genética , Influenza Humana/patologia , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Dados de Sequência Molecular , Mucosa Nasal/virologia , Orthomyxoviridae , Faringe/virologia , Filogenia , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA , Cultura de Vírus , Adulto JovemRESUMO
West Nile virus belongs to the Flaviviridae family, transmitted by vector mosquitoes. Here, we reported the complete genome sequence of West Nile virus isolated from human samples during an acute encephalitis outbreak in Kerala, India. Phylogenetic analysis revealed that the virus genome clusters into genetic lineage 1, clade 1a.
