Illinois E. anophelis cluster unrelated to Wisconsin outbreak

A cluster of rare infections caused by Elizabethkingia anophelis that has sickened 10 patients in Illinois is not related to a similar outbreak in Wisconsin, according to the CDC and local health officials.

Six of the 10 patients diagnosed with E. anophelis infections in Illinois since 2014 have died, according to the Illinois Department of Public Health (IDPH). The majority of infections in the state have involved patients who are aged older than 65 years, and many of the deaths occurred in patients with underlying health conditions, according to the IDPH.

Figure 1. Gram-negative Elizabethkingia anophelis bacteria isolated from specimens obtained during a recent outbreak in Wisconsin

Source: CDC

The CDC said health care providers in Illinois should be aware of the cluster and should consider E. anophelis as a potential cause of bloodstream infections. Patients with compromised immune systems or serious underlying health conditions are at greater risk for illness associated with Elizabethkingia infections, which often are difficult to treat with antibiotics. Signs and symptoms of infection include fever, shortness of breath, chills and cellulitis.

Previously, the CDC said it was testing water, soil and various medical products to determine the cause of the outbreak in Wisconsin, which included at least 59 people as of April 20, according to the Wisconsin Department of Health and Human Services (WDHS).

CDC spokesman Tom Skinner told Infectious Disease News that the agency is “no closer” to finding the cause of the Wisconsin outbreak than it was last month when it linked a case of E. anophelis in a Michigan patient who died to the original cluster. Skinner said the Illinois cluster is not related to the cases in Wisconsin or Michigan.

“Although this strain of Elizabethkingia is different than the one seen in the Wisconsin outbreak, our investigatory methods remain the same, and we continue to work with the CDC and our local health departments to investigate this cluster of cases and develop ways to prevent additional infections,” IDPH Director Nirav D. Shah, MD, said in a statement.

There have been 11 cases of E. anophelis infection identified recently in Illinois. Earlier this month, the IDPH announced that tests from an infected patient in Illinois matched the strain of E. anophelis in Wisconsin.

Elizabethkingia bacteria — named for Elizabeth O. King, a CDC bacteriologist who discovered it — are commonly found in the environment in soil, river water and reservoirs, but do not typically cause illness in humans.

Eighteen of the patients with confirmed cases of E. anophelis infection in Wisconsin have died, the WDHS said. Health officials in all three states say they have been unable to determine if E. anophelis is the cause of death in any of the patients because so many of them have underlying health conditions.

The discovery of the Illinois cases came after the IDPH sent alerts to hospitals and laboratories in the state in February and March asking them to report all cases of Elizabethkingia as far back as Jan. 1, 2014. CDC testing of samples from Illinois confirmed the 10 cases of E. anophelis, but also showed they were unrelated to the Wisconsin strain.

The CDC says advancements in laboratory testing have made it possible to differentiate E. anophelis from other types of Elizabethkingia and to identify patient clusters within the species. – by Gerard Gallagher

Disclosures: Skinner is a spokesman for the CDC. Shah is the director of the Illinois Department of Public Health.