Rare outbreak of Elizabethkingia bacteria leading to deaths in the Midwestern United States

Abstract:

An outbreak of the recently discovered bacteria Elizabethkingia anophelis is occurring in the Midwestern United States. While Elizabethkingia bacterium is prevalent in the environment and normally does not cause illness, the current outbreak in Wisconsin has resulted in at least 56 confirmed cases and 17 deaths. Most of the cases were over the age of 65 and all of them had at least one serious underlying health condition. These bacteria are multi-drug resistant and resistant to some cleaning products, but there are classes of antibiotics that are effective treatment. The source of the outbreak is unknown, but officials from the Wisconsin Department of Health Services and the CDC are investigating potential environmental and healthcare-associated sources, as Elizabethkingia is known to be healthcare associated. While the source of this outbreak is only potentially healthcare associated at this point, all healthcare associated outbreaks are tragic reminders of the importance of infection control and prevention.

Main Article:

Wisconsin is currently experiencing a deadly outbreak of Elizabethkingia anophelis¹. E. anophelis is a bacterium isolated from mosquito guts in 2011 which are commonly found in soil, water, reservoirs and insects². Elizabethkingia does not usually cause illness. However, the current Wisconsin outbreak has 56 confirmed cases as of March 30, 2016 and has caused around 17 deaths across 13 Wisconsin counties¹. The outbreak has spread to Michigan where an additional case, which resulted in the death of the patient, was identified³.

Symptoms of Elizabethkingia infection include fever, chills, shortness of breath and cellulitis (a bacterial skin infection). Elizabethkingia infections affect the bloodstream and generally only people with compromised immune systems or serious underlying health issues³. This is the case in the current outbreak where the majority of patients are over age 65 and all patients have at least one serious underlying illness¹. Elizabethkingia bacteria are multi-drug resistant but there are classes of antibiotics that are effective,¹ including fluoroquinolones, rifampin and trimethoprim/sulfamethoxazole. The bacteria can also resist disinfectants like bleach². Prompt recognition and treatment can improve patient outcomes¹.

Outbreaks of Elizabethkingia are known to be healthcare associated⁴, but the source of the current outbreak has not been determined¹. Because the discovery of E. anophelis is relatively new and because it rarely causes human infection, researchers aren’t entirely sure how it is transmitted². Wisconsin and Centers for Disease Control and Prevention researchers are testing potential sources, environmental and health care associated, but no source of the bacteria has been found yet². The CDC has the only lab equipped to distinguish between E. anophelis and a similar bacteria, E. meningoseptica.

infection prevention solely through treatment and cleaning may be challenging

Since E. anophelis causes illness in immunocompromised individuals and might be healthcare associated, infection prevention is an important aspect of controlling the outbreak. Wisconsin Division of Public Health recommends that patients with Elizabethkingia be managed with contact precautions in addition to standard precautions¹. However, because the bacteria are multi-drug resistant and resistant to some disinfectants, infection prevention solely through treatment and cleaning may be challenging. Determining the source of the outbreak may be the best way to prevent future cases.

Outbreaks that have no clear source but may be healthcare associated are a reminder that everyone, from health care product manufacturers to healthcare staff, has an important responsibility when it comes to infection control and prevention. Control of the current outbreak will depend on early detection and reporting of suspected cases, testing to confirm a diagnosis and proper administration of appropriate treatment.

References:

1. Wisconsin Department of Health Services. Diseases and Conditions (2016, March). Elizabethkingia. Accessed March 30, 2016:. https://www.dhs.wisconsin.gov/disease/elizabethkingia.htm
2. Vox Science and Health (2016, March). Elizabethkingia the rare and deadly bacteria that’s sickening people in the Midwest, explained. Accessed March 30, 2016: http://www.vox.com/2016/3/22/11278908/elizabethkingia-virus-symptoms
3. Michigan Department of Health and Human Services (2016, March). Michigan case of bacterial bloodstream infection matches cluster in Wisconsin [Press Release]. Accessed March 30, 2016: http://www.michigan.gov/mdhhs/0,5885,7-339-73970_71692_71696-379248–,00.html
4. Lau, S.K.P. et. al. (2015). Evidence for Elizabethkingia anophelis Transmission from Mother to Infant, Hong Kong. Emerging Infectious Diseases. 21(2): 232-241. Doi: http://dx.doi.org/10.3201/eid2102.140623