Summary Box: Foot-and-mouth outbreak highlights danger of spreading disease from labs

HIGHLY CONTAGIOUS: Foot-and-mouth disease is so easily spread that the United States won't allow researchers to work with the virus on the mainland. But in Britain, a lab making foot-and-mouth vaccines was located near herds of cattle and may have been the cause of a new outbreak.

LAB ACCIDENTS: Diseases that can kill humans have also made it out of labs. Outbreaks of everything from meningitis to SARS to Ebola have been linked to labs.

SAFETY PRECAUTIONS: To guard against accidental spread of foot-and-mouth, experts recommend that labs be located away from animal populations. Sewage should be treated to destroy infectious material and staff should shower and change clothes before leaving the lab.