Flu

Influenza A and B viruses

A 22 year old medical student comes to your office complaining of sore throat, runny nose, cough, and fever for two days. Her back muscles also ache and she was unable to sleep soundly last night. She has been rotating through the pediatric department in the hospital. Her symptoms started "all of a sudden". Physical exam reveals no palpable nodes in the neck.

Labs: Helical, enveloped, ssRNA virus grown in cell culture from throat washings or identified by fluorescent-antibody staining. Rise in antibody titer of greater than 4-fold in paired serum samples taken early in the illness and 10 days later.

Discussion: The clinical presentation of the patient and serology is the primary source of information for diagnosis of influenza causes by Influenza A and B viruses. Influenza is spread by droplet infection. The incubation period is 1 to 3 days. Following the incubation period, there is onset of chills, headache, fever, muscular pain, anorexia, and malaise. Respiratory symptoms present at onset. There is a non-productive cough. As the fever decreases, the cough becomes more severe. Reye's syndrome in children should be a concern as it is sometimes a secondary complication. Children should not be given aspirin for this disease because of the potential for Reye's syndrome. It may progress to pneumonia.

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