As the multi-agency effort to eliminate the threat of Legionnaires’ Disease at the Illinois Veterans’ Home, the number of dead and infected by the bacteria continues to grow.

The Illinois Department of Veterans’ Affairs reports there are now 39 confirmed cases of the disease, with seven now reported dead.

Officials say they expect additional cases and possibly additional deaths, because the incubation period for Legionnaires’ Disease can be up to two weeks.

The U.S. Centers for Disease Control and Prevention have been called in to help local and state health personnel to get the outbreak under control.

The legionella bacteria is transmitted by infected water vapor. It cannot be passed on by person-to-person contact.