Influenza virus has -

Ans. is 'd' i.e., 8 segments of ssRNA INFLUENZA VIRUS Belong to ohomyxoviridae --. Envelope, RNA virus Contain single stranded RNA which is segmented --4. 8 pieces There are three viral subtypes Type A Causes all pandemics and most of the epidemics Type B Can cause epidemics Type C --> Causes endemic infection Three types of influenza viruses are circulating in world -->A (H I N 1), A (H3 N2) and B A new type has been recognized -A (H5 NI ) Source of infection --> case or subclinical case Mode of transmission --> Droplet infection by respiratory route Incubation period________ _ 18-72 hours Clinical manifestations -Most infections are subclinical - Fever, headache and myalgia - Respiratory --> coughing - There is no viremia Complications - Pneumonia --> M.C. by str. pneumoniae - Worsening of COPD - Encephalitis - Reye's Syndrome with type B virus - GB. Syndrome - G I Symptoms (gastric flu) --i type B virus Laboratory diagnosis -most commonly, the diagnosis is established by the use of rapid viral tests that detect viral nucleoprotein or neuraminidase - Best specimen is nasopharyngeal secretion.