Literature Review Of Literature On Influenza

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Review of literature: Acute respiratory infections are a major cause of human disease and are one of the most important causes of child mortality throughout the globe. Though there are considerable variations in infantile mortality, according to World Health Organization, the lower respiratory tract infections are the second most important cause of death among children < 5 years of age. (Carolina et al., 2012) Respiratory syncytial virus is most frequently detected in childhood illness. Factors predisposing to severe ARI caused by RSV are well known in industrialized countries but little information exists for developing countries. Infection with human metapneumovirus (HMPV) presents similar clinical symptoms to that of RSV . Despite…show more content…
The multiplication of the virus occurs in the respiratory tract and the main site of infection occurs in the ciliated columnar epithelial cell. Crowded areas and cold climate favours the spread of the virus. Highest incidence of influenza infection is seen in young population which may be due to lack of exposure to different strains. Children are mainly affected during epidemics (Rao, 2003). The influenza virus triggers pulmonary inflammation resulting in infiltration of inflammatory cells and an immune response. The primary target and the principal host for the virus are Bronchial epithelial cells. Generally influenza viruses are recognized and destroyed by innate immune mechanisms which includes macrophages, interferon (IFN) a, b and other cytokines, natural killer (NK) cells and complement. If influenza viruses escape from these early defense mechanisms, they are captured and destroyed by adaptive immune mechanisms, where T and B cells and their antigen-specific effectors (cytotoxic T lymphocytes, cytokines such as IFNc and antibodies) target the virus. subsequent viral infection is prevented by Antigen-specific memory cells (T and B cells) (Capelozzi et al.,
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