|Description:||From a date prior to 1967, this historic photograph depicted a scientist in the process of inoculating Petri dish culture plates during a plague investigation.|
Plague is caused by a bacterium called Yersinia pestis, and is transmitted from rodent to rodent by infected fleas.
At the time, this scientist was a staff member at the former San Francisco, California, Public Health Service, Communicable Disease Center, Plague Laboratory.
The Communicable Disease Center (CDC) was a branch of the U.S. Public Health Service (PHS), which was a branch of the former Department of Health, Education, and Welfare (HEW). Retaining its acronym, in 1970 the CDC was renamed to the Center for Disease Control, and in 1979, HEW was renamed the Department of Health and Human Services.