ABSTRACT
At the end of World War II a marked increase in infections among laboratory workers led to a survey directed to 4725 research, public health, hospital, and clinical laboratories; biological manufacturers; colleges; medical, agricultural, and veterinary schools; and experimental stations, of which 2143 responded. The sources of infection appeared to stem predominantly from working directly with the agent, exposure to an aerosolized source, and accidents which together accounted for 50 to 80% of the infections. The death rate is an indicator of the severity of laboratory infections, for which a combined case fatality rate of 4.0% was estimated in 1969. Research laboratory contact with arboviruses has been more intensively controlled than for most other infectious agents, in part because of their virulence and also because of the marked increase in their use since 1950.
