In Nov. 2017, over 200 U.S. Marines-in-training were sickened by shiga-toxin producing E. coli at Marine Corps Recruit Depot San Diego and Camp Pendleton.

That outbreak was blamed on undercooked beef prepared by a civilian contractor, according to the results of an investigation.

First rule of public health (substitute military or any other organization): make public health look good.

According to Healio, the outbreak occurred in October and November among newly enlisted men at Marine Corps Recruit Depot, San Diego, and Camp Pendleton, a nearby base where recruits conduct weapons and field training, according to Amelia A. Keaton, MD, MS, EIS officer in the CDC’s Outbreak Response and Prevention Branch.

The outbreak involved Shiga toxin-producing E coli (STEC) — a major cause of foodborne illness in the United States each year and the pathogen responsible for the current multistate outbreak of E. coli linked to romaine lettuce. In all, 244 male recruits are suspected of being sickened, including 15 who developed a life-threatening complication of STEC infections called hemolytic uremic syndrome (HUS). Among those who developed HUS, six were deemed critically ill but none died, Keaton told Infectious Disease News during the CDC’s annual EIS conference.

She said the outbreak presented several challenges for investigators and highlighted some unique risk factors among military trainees living in close quarters.

“Nobody on our team had a military background, so we first wanted to understand what their training environment is like,” Keaton said. “Do they have any unique exposures that people in the general public don’t have? We wanted to get a sense of what day-to-day life was like for these guys and what risk factors for infection they were exposed to.”

Keaton and colleagues interviewed 43 case patients and 135 healthy controls, plus Marine officers, food workers and staff. They observed food preparation practices and studied recruit sleeping quarters, bathroom facilities and cafeterias where meals were served to around 2,000 to 3,000 recruits at a time, Keaton said.

Although they were unable to directly test any meat, through interviews investigators found that ill recruits were 2.4 times likelier to report consuming undercooked beef than healthy controls. Moreover, Keaton said investigators directly observed beef being undercooked.

According to Keaton, most dining facilities on military bases are run by civilian contractors, including the facilities involved in this outbreak, which offered the same menu prepared by the same company. The Navy is in charge of inspecting such facilities once a month, she said.

“A lot of people reported eating meals that were visibly undercooked,” Keaton said. “When we observed food preparation, we saw that food workers were cooking a large number of hamburger patties and a large number of meals. Because such a large number of meals are being prepared, they’re only able to check foods intermittently with a meat thermometer. In some instances, we saw there were temperature abuses where they weren’t necessarily cooking to temperatures recommended by California state law.”