— -- A deadly bacterial outbreak is being investigated in Wisconsin with at least 44 reported cases, killing 18 people, according to the Wisconsin Department of Health Services.
The rare infection results from a naturally occurring bacteria called Elizabethkingia anophelis, which are found in soil, fresh water and reservoirs, health officials said. Symptoms include fever, shortness of breath, chills or redness on the skin.
The outbreak has primarily affected people over the age of 65 and everyone infected had a history of at least one serious underlying health condition, according to the Department of Health Services. State and federal health officials said they're looking to find the source of the outbreak.
“Determining the source of the bacteria affecting patients in Wisconsin is a complex process,” State Health Officer Karen McKeown said in a statement this week. “While we recognize there will be many questions we cannot yet answer, we feel it is important to share the limited information we have about the presence of the bacteria, as we continue our work to determine the source.”
The 44 cases were reported from Nov. 1, 2015, to March 2, 2016, according to state health officials. A search for past outbreaks in medical literature suggests this is likely the largest-ever recorded outbreak of the bacteria.
Investigators used advanced molecular detection to pinpoint the bacteria as Elizabethkingia anophelis, which was discovered only in 2011, according to a spokesman for the U.S. Centers for Disease Control and Prevention, who also noted that investigators are currently testing environmental samples, including water, to find the source of the outbreak.
Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center, said infections from this bacteria are rare but that they are more likely to occur in health care settings when the bacteria contaminates medical equipment.
"Outbreaks of Elizabethkingia have been associated with contaminated ventilators or contaminated [injectable] medication or tube feeding or something like that and then it gets into the blood stream," Schaffner explained.
He said the bacteria can be particularly deadly in premature infants, who do not have fully developed immune systems. The bacteria does not spread from person to person.
There are usually between five to ten cases of Elizbethkingia in each state per year, according to a CDC spokesman, who said that the CDC has five disease detectives in the state currently and will likely send more staff to help stop the outbreak.