Researchers Still Working To Understand Elizabethkingia's Effects
The vast majority of Elizabethkingia-caused infections known to medicine have struck individuals with compromised immune systems: people already battling one or more other serious diseases; patients recovering from organ transplants or other major medical procedures; the elderly; and infants. A healthy person's immune system can easily handle Elizabethkingia bacteria introduced to the body. But when that system struggles, these bacteria can get into the bloodstream and bodily fluids, and begin to multiply.
From the bloodstream, the different species of Elizabethkingia can cause serious diseases in adults, including bacteremia, or blood infection; meningitis (most reported cases have involved infants); pneumonia; skin infections; and sepsis, in which the body damages its own tissue in the course of a dramatic response to infection.
Symptoms of a bacterial bloodstream infection, including one caused by Elizabethkingia, can include fever (and chills), shortness of breath, and cellulitis, an infection of the skin.
"With bloodstream infections you will often get fever, shaking, chills," said Dr. Nasia Safdar, an infectious disease specialist with University of Wisconsin Hospitals and Clinics, in a March 9 interview on Wisconsin Public Radio's Central Time. "If the infection is in a particular body site like the skin, you might see redness or inflammation of the skin. If it's a pneumonia you might get respiratory symptoms. But it's not something I would consider to be a low-grade or subtle infection. It's usually fairly significant, fairly apparent."
But symptoms can vary widely and resemble those of many other bacterial infections. In a UW Health Q&A, Safdar also noted that, "the symptoms are very non-specific and are the same for any infection."
The variety of diseases Elizabethkingia infection can cause, the time public health officials have taken to understand the Wisconsin outbreak, and many recent medical research papers indicate that clinicians and microbiologists are still learning about the bacteria's genetics, how it infects people and how its infection spreads.
Given that Elizabethkingia anophelis was first discovered in a mosquito gut, researchers have investigated whether mosquitoes have passed the bacteria to humans. Additionally, except for cases of mother-to-infant infection, the medical community generally agrees that Elizabethkingia bacteria are not contagious and cannot be transmitted from one person to another.
"This bacteria has always affected humans, but is an opportunistic pathogen. It doesn't affect healthy humans who are otherwise doing well," said Safdar in the UW Health Q&A. "Those at risk are individuals who are very immune compromised for a number of reasons such as age, or they've had a transplant or are on dialysis. There is no danger to the community."
Elizabethkingia can resist many antibiotics, which means immunocompromised patients have even fewer defenses. That said, these bacteria are susceptible to a few specific kinds of antibiotics, including fluoroquinolones and rifampin. Many of the success stories in the medical literature involve treating Elizabethkingia infections with a combination of these antibiotics, with doctors closely monitoring a patient’s condition and discontinuing, introducing or changing the dosage of individual drugs accordingly. The Wisconsin Department of Health Services guide to the current outbreak includes treatment information for medical professionals.