Story highlights Ten cases of Elizabethkingia infection identified in Illinois

The Illinois cluster is a different strain than an outbreak of the same infection in Wisconsin

Source of infections is still unknown

(CNN) A new cluster of Elizabethkingia infection, previously rarely seen in humans, has been found in Illinois, health officials said Wednesday.

Testing by the U.S. Centers for Disease Control and Prevention confirmed the Elizabethkingia anophelis infection in 10 Illinois residents, according to the Illinois Department of Public Health. Six of those individuals have died. Most of the infected patients had underlying health conditions, and it's unknown if they died from the infection or pre-existing conditions.

The Illinois cluster of cases is a different strain of infection from the one identified in an ongoing Elizabethkingia outbreak in Wisconsin, first reported in March . Fifty-nine cases have been confirmed in that state since November. Eighteen have died. Officials there have said all of those infected had "at least one serious underlying illness" and most are older than 65. The cases began in 2014.

Dr. Chris Braden, deputy director at the CDC's National Center for Emerging and Zoonotic Infectious Diseases, said this cluster of cases in Illinois is not surprising but it is concerning.

Federal and state health officials asked health care providers and health departments to be on the lookout for cases of Elizabethkingia last month. These bacteria are not mandated or voluntarily reported so clusters may have previously gone unnoticed.

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