INFLUENZA Causes of influenza: Influenza viruses A, and B RSV and adenovirus Mycoplasma pneumoniae Chlamydia species.

Influenza Influenza virus is the main human pathogen of the Orthomyxoviruses It has an enveloped, helical capsid and a linear, single, stranded Spherical in shape, with capsid projecting spikes

Classification of influenza Classified into 3 types A, B or A – causes epidemic influenza in Man and influenza in birds, pigs, and B – causes mild winter C – not sure to cause influenza in Man. * Influenza A viruses are subdivided into 9 H subtypes and 13 N subtypes.

Antigenic S or soluble antigen, found inside the core of H or haemagglutinin antigen in the envelope projecting N or neuraminidase antigen in the envelope projecting spikes

Antigenic Variations: Called antigenic drift and antigenic shift. Antigenic Occurs in both influenza A and The antigenic drift is due to mutation of the virus This is due to production of new strains each This leads to epidemics only inside countries.

Antigenic Occurs only in influenza A It is due to the production of new subtypes every 20 years causing pandemics all over the In 1957: Asian In 1968: Hong Kong pandemic.

Fever and Productive Runny Muscle Watery and painful Difficulty in breathing through nose

Complications of Viral pneumonia: by influenza Bacterial pneumonia: by Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus Encephalitis.

Lab. Diagnosis of Nasopharyngeal swab or throat swab in a viral transport medium for Isolation in monkey kidney cell Serology using ELISA and Sputum collected for both bacterial and viral Blood culture to diagnose Bronchoalveolar lavage to identify influenza by immunofluorescence

Vaccination against By giving an inactivated vaccine contains: * Influenza A, subtypes: H1N1 and H3N2 * Influenza Vaccine is given IM & it is 70% It is effective for only one year because antigens change from year to year.

@ Vaccination is given to people with:  Asthma  Chronic heart disease  Chronic renal failure  Diabetes mellitus  Immunosuppression.  Old people above 70 years.