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General Information

Elizabethkingia are bacteria that are rarely reported to cause illness in humans, and are uncommon colonizers of the respiratory tract.

The signs and symptoms of illness that can result from exposure to the bacteria can include fever, shortness of breath, chills or cellulitis. Confirmation of the illness requires a laboratory test.

Wisconsin 2016 Elizabethkingia anophelis outbreak

The Wisconsin Department of Health Services (DHS), Division of Public Health (DPH) is currently investigating an outbreak of bacterial infections caused by Elizabethkingia anophelis.

The majority of patients acquiring these infections are over 65 years old, and all patients have a history of at least one underlying serious illness.

The Department quickly identified effective antibiotic treatment for Elizabethkingia, and has alerted health care providers, infection preventionists and laboratories statewide. Since the initial guidance was sent on January 15, there has been a rapid identification of cases and healthcare providers have been able to treat and improve outcomes for patients. DHS continues to provide updates of outbreak-related information that includes laboratory testing, infection control and treatment guidance.

At this time, the source of these infections is still unknown, and the Department continues to work diligently to control this outbreak. Disease detectives from the Department and the Centers for Disease Control and Prevention (CDC) are conducting a comprehensive investigation which includes:

  • Interviewing patients with Elizabethkingia anophelis infection and/or their families to gather information about activities and exposures related to healthcare products, food, water, restaurants, and other community settings.
  • Obtaining environmental and product samples from facilities that have treated patients with Elizabethkingia anophelis infections. To date, these samples have tested negative and there is no indication the bacteria was spread by a single healthcare facility.
  • Conducting a review of medical records.
  • Obtaining nose and throat swabs from individuals receiving care on the same units in health care facilities as a patient with a confirmed Elizabethkingia anophelis to determine if they are carrying the bacteria. To date, all of these specimens tested negative, which suggests the bacteria is not spreading from person to person in healthcare settings.
  • Obtaining nose and throat swabs from household contacts of patients with confirmed cases to identify if there may have been exposure in their household environment.
  • Performing a “social network” analysis to examine any commonalities shared between patients including healthcare facilities or shared locations or activities in the community.
Type of Cases Number of Cases

Wisconsin 2016 Elizabethkingia anophelis Outbreak:
Elizabethkingia infections believed to be associated with this outbreak reported to DPH*
Case counts between November 1, 2015 and May 30, 2016

Confirmed 63
Under investigation 0
Possible cases** 4
Total cases reported to Wisconsin DPH 67

Counties with confirmed cases include Columbia, Dane, Dodge, Fond du Lac, Jefferson, Milwaukee, Ozaukee, Racine, Sheboygan, Washington, Waukesha and Winnebago.

There have been 18 deaths among individuals with confirmed Elizabethkingia anophelis infections and an additional 1 death among possible cases for a total of 19 deaths. It has not been determined if these deaths were caused by the infection or other serious pre-existing health problems. Counties where these deaths occurred are: Columbia, Dodge, Fond du lac, Milwaukee, Ozaukee, Racine, Sheboygan, Washington and Waukesha.

*This investigation is ongoing. Case counts may change as additional illnesses are identified and more cases are laboratory confirmed.
**These are cases that tested positive for Elizabethkingia, but will never be confirmed as the same strain of Elizabethkingia anophelis because the outbreak specimens are no longer available to test.

Information for Providers

The Wisconsin Division of Public Health (DPH) continues to receive reports of bloodstream infections caused by a bacterium of the genus Elizabethkingia. Elizabethkingia are opportunistic pathogens preferentially causing illness among immune compromised individuals or patients with underlying medical conditions, and are associated with high mortality. Therefore, early detection and treatment with an effective antibiotic regimen is important to increase the probability of good outcomes.

The index of suspicion for Elizabethkingia infections should be high among patients with multiple co-morbid conditions, particularly malignancy, diabetes mellitus, chronic renal disease or end-stage renal disease on dialysis, alcohol dependence, alcoholic cirrhosis, immune-compromising conditions or immunosuppressive treatment.

The Wisconsin State Laboratory of Hygiene (WSLH) receives all isolates of Elizabethkingia species submitted by Wisconsin clinical microbiology laboratories. WSLH staff identify the species of the Elizabethkingia isolates, because clinical laboratories are not able to distinguish E. anophelis from E. meningoseptica. WSLH staff further characterize the E. anophelis isolates using pulsed field gel electrophoresis (PFGE). Results of PFGE testing of these isolates have demonstrated that the vast majority of bloodstream and other body site isolates of E. anophelis have PFGE patterns that are indistinguishable. This pattern is referred to as PFGE pattern one and is the outbreak pattern. Following characterization at the WSLH, all isolates of E. anophelis are shipped to the Centers for Disease Control and Prevention (CDC) for more extensive testing and confirmation that includes using optical gene mapping.

Although Elizabethkingia are multidrug-resistant bacteria, antimicrobial susceptibility testing (AST) conducted at Wisconsin clinical microbiology laboratories of recent isolates of Elizabethkingia demonstrated most of the isolates tested are susceptible to fluoroquinolones, rifampin and trimethoprim/sulfamethoxazole. AST (MIC testing) and characterization of strains has been conducted at the CDC on 9 isolates of Elizabethkingia from blood specimens collected from Wisconsin residents (see table below). These isolates include 5 Elizabethkingia anophelis with PFGE outbreak pattern 1, 3 isolates of E. anophelis with non-outbreak PFGE patterns and 1 isolate of Elizabethkingia species. These MIC results demonstrate susceptibility to fluoroquinolones, minocycline, rifampin and trimethoprim/sulfamethoxazole. The medical literature suggests combination treatment with these agents may be more effective than monotherapy. Whenever possible, treatment should be guided by AST.

Results of Elizabethkingia antimicrobial susceptibility testing and characterization, 9 isolates from blood indicated by month and year of specimen collection, Wisconsin, 3/2014 - 1/2016.

Elizabethkingia testing and characterization

MIC micrograms/mL
Isolates E. anophelis: 3 strains E. anophelis: 5 strains E. species: 1 strain
PFGE pattern Non-outbreak Outbreak (pattern 1) Non-outbreak
Collection dates 3/14, 10/15, 12/15 12/1/15 - 1/5/16 1/16
Antimicrobic MIC Range MIC: Range MIC: Mode MIC
Ciprofloxacin 2 - 8 1 - 4 2 8
Doxycycline 4 - 16 2 - 4 2 16
Levofloxacin 1 - >16 1 - 2 2 8
Minocycline 0.5 - 1 0.25 (all) 0.25 1
Moxifloxacin 0.5 - >4 ≤0.25 - 0.5 0.5 1
Pip-Tazo^ >128/4 (all) >128/4 (all) >128/4 >128/4
Rifampin ≤0.5 - 1 ≤0.5 (all) ≤0.5 ≤0.5
TMP-SMX° 0.5/9.5 - 2/38 ≤0.5/9.5 - 2/38 1/19 - 2/38 1/19
Vancomycin 32 - >32 32 - >32 32 >3

Broth MIC medium: Cation adjusted Mueller-Hinton broth (CAMHB).
Testing conducted at the Antimicrobial Resistance and Characterization Laboratory, Centers for Disease Control and Prevention (CDC).
The characterized as Elizabethkingia species. Isolates 3/2014 and 10/2015 were from cultures of blood specimens collected prior to the outbreak interval.
If no interpretation is indicated, there are no approved breakpoints or they are under investigation.
Not all antimicrobics are appropriate for treatment of infections at all anatomic sites.

Because this outbreak is ongoing, and out of an abundance of caution, DPH recommends the use of contact precautions in addition to standard precautions for managing patients with Elizabethkingia infections. In acute care facilities, contact precautions should be maintained for the duration of admission, and receiving facilities should be notified of the patient’s history of Elizabethkingia infection upon transfer. In long-term care and assisted living facilities, residents can be managed according to the DPH Guidelines for the Prevention and Control of Antibiotic-Resistant Organisms in Healthcare Settings, P-42513.

  • Immediately report the identification of any isolation of Elizabethkingia species from any body-site specimen to the DPH by calling 608-267-9003.
  • Fax requested medical records (including face sheet) to 608-266-0049.
  • Some clinical laboratories use bacterial detection systems with software that is not updated to report Flavobacterium meningosepticum or Chryseobacterium meningosepticum as Elizabethkingia meningosepticum. Therefore, please report the detection of any isolate that is identified as F. meningosepticum, C. meningosepticum or E. meningosepticum.
  • Submit all Elizabethkingia isolates (or F. meningosepticum or C. meningosepticum) expeditiously to the WSLH for confirmatory testing via the facility clinical microbiology laboratory.


Questions about Elizabethkingia? Contact us!
Phone: 608-267-9003 | Fax: 608-261-4976

Wisconsin Local Health DepartmentsRegional officesTribal agencies

Last revised September 28, 2021