An outbreak of infectious conjunctivitis spread by microscopes.

Among the potential occupational hazards of microscope use is the transmission of infectious agents among employees. We report a large (145 cases) and costly (+647,000) epidemic of viral conjunctivitis in a microelectronics factory. Spread of the illness appeared to be through sharing of microscopes among employees. Routine handwashing instructions and safety glasses failed to prevent spread of the epidemic. Mandatory screening prior to work and temporary plant shut-down were finally successful. We discuss efforts to control this outbreak and make recommendations to prevent similar epidemics in other workplaces.