18 dead from unknown bloodstream infection
The US Centers for Disease Control and Prevention has sent additional investigators to Wisconsin to find the source of a blood infection that officials described as the largest outbreak of the bacteria now linked to at least 18 deaths.
Wisconsin health officials said on their website yesterday that the total number of reported cases now stands at 48. Infections were centered in the heavily populated southeastern quarter of the state, including the Milwaukee area and surrounding suburban counties.
Infectious disease specialists expect more infections to be found because health care providers and laboratories have been alerted to look for the bacterium called Elizabethkingia. It is named after Elizabeth O. King, a CDC bacteriologist who studied meningitis in infants.
A team of eight disease investigators, including three recently dispatched from the CDC, worked with the state's Department of Health Services to interview those infected in 11 southern counties to see if a common source of Elizabethkingia could be found.
"We want to get through all of the basic information when memories are still fresh and they remember what they've eaten and where they've been," said Michael Bell, the CDC's deputy director of healthcare quality promotion.
The organism is common in the environment, including water and soil, but it rarely causes infections, Bell said yesterday. And because the cases tested so far come from the same genetic fingerprint, investigators looked for a common source, he added.
Bell said the Wisconsin cases are the largest outbreak of Elizabethkingia recorded in published literature.
"This is essentially tenfold in what we expect to see" generally, Bell said.
A variety of potential sources have been tested, including health care products, water sources and food, but none of these have been found to be a source of the bacteria, said Bell, whose division is working with Wisconsin health officials.
The majority of patients infected are 65 or older with a history of at least one underlying serious illness, according to the state health department. Those who died all tested positive for the infection, but it's not known if Elizabethkingia caused or contributed to their deaths.