The tragedy of viral diagnosis.

The shortcomings of the methods commonly recommended for the diagnosis of viral infections are emphasized. Most of them are laborious and expensive, and are of very little practical value to the clinician. Nine years' experience has confirmed that the use of a single swab, obtained during the acute stage of the illness, for bacterial culture and viral isolation (looking for cytopathic effects or haemadsorption) provides the diagnosis quickly in the great majority of viral infections.