Epidemiology and control of virus infections in the laboratory.

Viruses cause some of the most dangerous infections. Laboratory work with viruses entails hazards which should be faced rationally. Data are scarce but studies, particularly of hepatitis, are in progress and are extended to cover other infections also. Surveillance can provide facts with which to correct theories and guide control measures. A simple and informal surveillance scheme operated through membership of a professional association has proved useful and is commended as a model.