More than 200 recruits at the Marine Corps Recruit Depot (MCRD) in San Diego have been sickened with diarrheal illness from an E. coli outbreak, CBS affiliate KFMB reports.

According to a press release issued by MCRD San Diego Wednesday, 26 are new cases, bringing the total to 214 recruits undergoing treatment. That's down from about 300 cases reported earlier this week. There are more than 5,500 recruits in training at the depot.

"The command's full effort is focused on caring for those recruits who are affected, ensuring we limit any spread of the illness, and identifying the source of the infection," Brig. Gen. William Jurney said in a statement.

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The cause of the outbreak is still under investigation.

E. coli is a common bacteria that easily spreads through contaminated food or from touching surfaces tainted with fecal bacteria.

Most patients recover from the severe diarrhea within about a week, but in some cases complications can become life-threatening.

Officials said they have instituted preventive measures in response to the current outbreak, including testing samples and specimens to determine the cause of the illness; inspecting facilities for cleanliness, food storage, and handling procedures; and altering food menus for those who have been affected to help them recover.

Family members will be contacted if a recruit is hospitalized or his graduation date changes due to missed training resulting from illness, MCRD said.