An elderly Michigan resident is the latest to die from a rare and unexplained bacterial outbreak that has sickened 54 people in Wisconsin, killing 17, heath officials confirmed Thursday.
The bacteria, Elizabethkingia anopheles, is commonly found in the environment but rarely infects humans. Historically, outbreaks of the bacteria haven’t reached more than around 10 people, making the outbreak in Wisconsin—and now Michigan—the largest ever recorded.
Investigators from the Centers for Disease Control and Prevention have teamed up with state and local authorities to try to track down the source of the bacteria, which is so far unknown. Since the beginning of last November, the outbreak has spread to at least 12 counties in two states.
“Our disease detectives are working diligently to find the source,” Jennifer Miller, spokesperson for the Wisconsin Department of Health Services, told the Milwaukee Journal Sentinel.
Elizabethkingia was originally identified in 1959 by CDC bacteriologist Elizabeth King but has made little news since then, rarely ever causing infections—let alone outbreaks. The germs are likely opportunistic pathogens, infecting people who have weakened immune systems. Of the 55 cases reported so far, most were in people over the age of 65 who suffered from chronic conditions, such as cancer and diabetes.
Bloodstream infections, such as the ones reported in the current outbreak, produce symptoms including fever, chills, shortness of breath, and cellulitis (skin infection), and have a high mortality rate.
Although isolates of Elizabethkingia have been known to be resistant to multiple antibiotics, the strains causing the current outbreak appear to still be susceptible to a number of drugs, making treatments easier.
Previous outbreaks of Elizabethkingia in hospitals have been linked to contaminated sinks, but so far, water samples in Wisconsin have turned up negative.
Currently, only labs at the CDC can accurately distinguish Elizabethkingia bacteria.