Concerns over mysterious bacterial outbreak in US

There is increasing concern over a rare and unexplained bacterial outbreak in the US that has resulted in 54 people falling sick and 17 deaths in two states. The bacteria, Elizabethkingia anophelis does not normally infect humans and historically, outbreaks of the bacteria have not reached beyond ten people, making the outbreak in Wisconsin, and now Michigan, the largest ever recorded. Investigators are struggling to identify the source of the bacteria; since November, the outbreak has spread to at least 12 counties in the two states. This type of bloodstream infection has a high mortality rate and currently only labs at the Centres for Disease Control can accurately distinguish the Elizabethkingia bacteria.

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.