Health officials are testing water, skin care products and over-the-counter medications, and interviewing patients and families, to try to identify the source of an outbreak of a bacteria that has sickened 44 people in southern Wisconsin and may have contributed to 18 deaths. Lab tests suggest a common source of the bacteria, called Elizabethkingia. But the investigation, which started in January, has not revealed the source, health officials said.

Most of the patients are elderly, with serious underlying health conditions. No cases have been reported among children, and there is no evidence of transmission from one person to another, said Karen McKeown, state health officer. “We have not been able to identify the common theme between all of these that would point us to the source,” McKeown said. “We are pursuing every clue.” READ MORE