Hospital officials should be aware of an unusual bacterial outbreak taking place in Wisconsin that has yet to be explained, and could pose a threat elsewhere.

Ten Illinois residents have also been diagnosed with infection caused by a strain of the bacteria that is different from the outbreak in Wisconsin, according to the Illinois Department of Public Health.

The outbreak of the unusually named Elizabethkingia anophelis bacteria in Wisconsin as of April 13 had caused at least 18 deaths out of the 59 confirmed cases and another death related to four possible cases reported since Nov. 1, 2015, according to the Wisconsin Department of Health Services, Division of Public Health.

The nature of the outbreak, which is focused in the southeastern part of the state, should invite hospital infection control specialists to act if there are any signs of an Elizabethkingia bacterial infection in a patient. “Because this [type of bacteria] isn’t necessarily on the radar of many places, if you were to get a sporadic case or two, you might just think this is unusual, but not something to worry about,” says Nasia Safdar, M.D., medical director for infection control at the University of Wisconsin Hospital and Clinics and a faculty physician at the William S. Middleton Memorial Veterans Hospital, both in Madison, Wis.

“What health care systems need to realize is that this is a much larger outbreak,” Safdar says. “If they get even a single case of Elizabethkingia, they should contact public health, retrieve the specimen that was positive and send it to the state lab in Wisconsin’s case, or the CDC, if necessary,” she says. Staffers from the Centers for Disease Control and Prevention are investigating.

The outbreak is notable for the type of bacteria involved and for the apparent lack of a common source for the reported infections. “Elizabethkingia is generally not considered to be very virulent or a highly pathogenic organism,” Safdar says.

And advancements in capabilities now allow infection control specialists to identify the species of the bacteria involved, and the one involved is relatively new, Safdar says. That means this particular strain — Elizabethkingia anophelis — could be more aggressive in humans than the broader Elizabethkingia bacteria are known to be. Plus, it is likely coming from a single source in the community.

She adds that health care is not the likely source, because although some of the affected patients have had health care exposure, many have not.

More test results are pending that could help to identify the source, she says.

The CDC, meanwhile, continues to investigate, taking the following steps, according to the Wisconsin Department of Health Services:

  • Interviewing patients with Elizabethkingia anophelis infection and/or their families' activities and exposures related to health care products, food, water, restaurants and other community settings
  • Obtaining environmental and product samples from facilities that have treated patients with Elizabethkingia anophelis infections
  • Conducting a review of medical records
  • Obtaining nose and throat swabs from individuals who receive care on the same units in health care facilities as a patient with a confirmed Elizabethkingia anophelis to determine if they are carrying the bacteria. So far, the specimens have tested negative, which suggests the bacteria is not spreading from person to person in health care settings
  • Obtaining nose and throat swabs from household contacts of patients with confirmed cases
  • Performing a “social network” analysis to examine any commonalities shared among patients including health care facilities or shared locations or activities in the community