Abstract
Virus infections which may cause severe or life-threatening illnesses meriting chemotherapy are surveyed. Experience has shown that effective antiviral chemotherapy must be given early in the illness, and so this paper concentrates on the earliest symptoms of the various diseases and on methods leading to rapid diagnosis. This can be made by recognizing virus particles of characteristic morphology, if they occur in large numbers. e.g. rotavirus in diarrhoea. Sensitivity may be enhanced by using immune serum to trap viruses. A variety of very sensitive immunological methods is now available for detecting virus-specific proteins in secretions of the respiratory and alimentary tracts. Monoclonal antibodies help to make these more specific. Virus nucleic acids can also be detected in secretions and cells in situ by hybridization with purified radio-labelled nucleic acid. Virus diseases specifically surveyed include varicella zoster and measles, both very important in immuno-suppressed patients; epidemic influenza; and the human papilloma viruses, of which 33 different types are now known, and which cause not common warts on hands and feet, but also venereally transmitted inapparent papillomas upon the surface of the uterine cervix, often leading to cervical carcinoma. The problems of diagnosis of acquired immunodeficiency syndrome are reviewed. The aetiology of chronic non-A, non-B hepatitis is still largely obscure, but a retrovirus may be involved. The diagnosis of rabies is also considered.