APIC 2016: Two Cases of Mystery Outbreak Acquired in Healthcare Settings

June 12th, 2016

By Gary Evans, AHC Media Senior Staff Writer

Though the common source of the outbreak remains unknown, two cases of Elizabethkingia anopheles in Wisconsin were acquired in healthcare settings, an investigator reported June 11 in Charlotte at the annual conference of the Association for Professionals in Infection Control and Epidemiology.

“Two cases were probably healthcare associated as a result of patient-to-patient transmission,” said Gwen Borlaug, MPH, CIC, coordinator of the HAI Prevention Program in Wisconsin.

The cases don’t explain the outbreak, however, as no common source has been found despite an exhaustive investigation that has reached 66 cases in three states with 20 deaths. With two cases in Illinois and one in Michigan, the remaining 63 are in Wisconsin, which reported the first six cases between Dec. 29, 2015, and Jan. 4 of this year.

The CDC has been assisting in an ongoing outbreak investigation that has included testing of water, soil, plants, food, and personal products in the search for a source of the genetically distinct strain of E. anopheles. In addition, investigators have looked for common healthcare contacts in dialysis, dental settings, long-term care and hospitals. With the exception of the two aforementioned nosocomial cases, there is no discernable pattern in healthcare contacts that would explain the majority of cases. The infections have primarily been in people with immune deficiency over the age of 65. The majority of the infections identified to date have been bloodstream infections, but some patients have had the bacteria isolated from other sites, including the respiratory tract and joints.

How exhaustive has the search been? Among the environmental sources tested have been yeti pots, bird baths, marijuana, vacuum cleaner bags, leaf cuttings and soil. Among the food sources have been fish, as fish-fries are a common social event in Wisconsin, Borlaug said. That led to questions about fish varieties and health -- leads that had to be followed like everything else in the case.

“I didn’t know we had a state Fish Health Veterinarian,” she said.