The CDC is investigating what it calls ’the largest recorded outbreak’ of a rare bloodstream bacterial infection which has resulted in the death of seventeen patients in Wisconsin and one patient in Michigan since November 2015. The bacteria Elizabethkingia anopheles, is commonly present in the environment including water and soil but rarely causes infection. The majority of infected patients infected are older and have a history of at least one underlying serious illness, according to the Wisconsin Department of Health Services.
Dr. Yun F (Wayne) Wang, Associate Professor of Pathology & Laboratory Medicine, Emory University School of Medicine, Director of Microbiology, Immunology & Molecular Diagnostics, Grady Memorial Hospital (website):
Expertise: clinical microbiology, antimicrobial resistance, laboratory diagnosis of infectious diseases including HIV and tuberculosis.
“The majority of patients in Wisconsin affected with Elizabethkingia were over the age of 65 years, and had serious underlying health conditions. All the samples were initially classified as Elizabethkingia meningoseptica by the Wisconsin State Laboratory of Hygiene. The same samples were tested at the Centers for Disease Control and Prevention (CDC) by using a method called optical gene mapping and the species of the outbreak strain was identified as Elizabethkingia anophelis. Thus, a general clinical laboratory cannot distinguish E. anophelis from E. meningoseptica, which is why the CDC has recommended that all suspected samples be sent to them.
“Both Elizabethkingia species are resistant to a number of antibiotics and have very similar resistance patterns. Importantly, E. meningosepticum is thought to be more resistant to powerful broad spectrum antibiotics when compared to ones that are commonly used to treat infections. Hence it is vital that the cause of infection should be identified quickly in suspected patients so the correct antibiotics can be prescribed.
“It’s difficult to predict how long it will take for CDC to identify the source of the current outbreak. The risk of outbreak spreading shall be low, unless a different strain is responsible for this outbreak. Because Elizabethkingia is resistant to some but not all antibiotics, it can be controlled. The key is to identify the organism quickly and use the right antibiotic accordingly. There is no evidence of transmission from one person to another.
“Whether in infants or adults, E. meningosepticum and E. anopheles are mostly hospital acquired, with less than 15% acquired in the community. Patients who have compromised immune systems as a result of other illnesses or having recently undergone surgical procedures are primarily at risk for E. meningosepticum. In newborns, the main risk factor for E. meningosepticum infection is prematurity. As a biofilm-forming organism, it commonly colonizes sink drains and medical equipment as well as cleaning solutions.”
Dr. Nirav Patel, Assistant Professor of Infectious Diseases, Saint Louis University and Infection Control Officer at SSM Health Saint Louis University Hospital (website):
Expertise: Transplant infectious diseases, hospital acquired infections, infections due to multi-drug resistant organisms
“The biggest challenge with the current outbreak is that the Elizabethkingia looks like it is coming from a single source, but the patients are spread out over a fairly wide area, involving more patients than have ever been in an outbreak with this organism before. The bug typically only causes diseases in patients who are debilitated and chronically ill, with multiple other active medical problems, and frequent exposures to various health care settings. It’s also slightly unusual in terms of the treatment but they’ve figured out what antibiotics are needed, so hopefully that will help. In my mind, the general public is not at risk, but those who are chronically ill are definitely at risk. It’s unlikely to spread a great distance from Wisconsin and Michigan but we don’t know the source, so vigilance is appropriate.”
Declared interests (see GENeS register of interests policy):
No interests declared