TICK TALK: It’s time to get out the DEET

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May 19, 2017 - 12:00 AM

The majority of tick-borne illnesses found in Kansas are not mandatorily reported and due to the inaccessibility of testing, treatment of potentially fatal diseases may be a matter of guesswork. 
Lyme disease, characterized by its flu-like symptoms and a distinctive rash, was first recognized in Old Lyme, Conn., in 1975. It was connected to the deer tick in 1981 by scientist Willy Burgdorfer.
Since then, scientists have discovered approximately 15 tick-borne diseases.
Dana Hawkinson, an infectious disease specialist at the University of Kansas Medical Center, said in an email that the most recently discovered diseases are not likely to be new diseases, but rather have been present all along, and either have been misdiagnosed or not diagnosed at all. Senior epidemiologist Daniel Neises of the KDHE Bureau of Epidemiology and Public Health Informatics agreed.
“The assumption is that our ability to differentiate different tick-borne diseases has gotten much better and the laboratory methods that we have to detect bacterial viruses are far better than they used to be,” Neises said in a telephone interview.
However the Bourbon virus, named for the Kansas county in which it was first discovered in 2015, is of a genotype that is commonly found in Europe, Asia and Africa and never before found in the Western Hemisphere, Hawkinson said in a video on the hospital’s website.
Early into the 2017 tick season, which typically starts in March and extends into the start of winter, eight cases of tick-borne diseases statewide had been reported as of April. Two of those confirmed cases, both Rocky Mountain spotted fever, have been reported in Allen County.
“We expect to continue receiving case reports until winter again,” Neises said.
Just one tick can infect a person with a combination of the diseases, and which diseases are transmitted depends on the type of tick. Why some tick-borne diseases are more prevalent in different areas of the country depends on the circulation of the bacteria that causes them, Neises said. The longer an infected tick is attached to the human body the better chance it has of transmitting disease.
The most common ticks found in Kansas are the American dog tick, the lone star tick, the brown dog tick and the black-legged tick. The Lyme Disease Association lists diseases on its website contracted by the four types of ticks that call Kansas home.
But not all of the diseases are being tracked by the state and screening does not routinely take place, according to both Neises and Hawkinson. 
Of the tick-borne illnesses found in Kansas only ehrlichiosis- anaplasmosis, spotted fever rickettsiosis, Q fever, tularemia and lyme disease are mandatorily reported. In 2014, 212 cases of tick-borne diseases were reported in Kansas; 75 of those patients were hospitalized.
 It is unclear how accurate the reported numbers are, Hawkinson said.
 “In a rural area I would think a lot of physicians would be keyed into considering typical tick-borne illness high in the differential diagnosis and just treating based on that fact without need for testing,” he said. “ It is unclear how many of the cases may be diagnosed by interviewing and examining the patient and looking at the clinical picture, then making a presumptive diagnosis and treating with empiric treatment.”
Neises agreed and said how patients are diagnosed and the treatment they receive depends heavily upon whether a physician is aware of tick-borne diseases present in their region or where the patients have traveled. 

BUT A lack of actual testing to confirm cases means a lack of reporting in the long run. Why so many of the tick-borne illnesses found in Kansas are not mandatorily reported may have to do with factors such as overall threat, endemicity, lack of information and available testing, according to Hawkinson.
“Many of the diseases either have no specific treatment other than supportive care or the same type of treatment, (the antibiotic) doxycycline. So empirically, the patient may be treated adequately anyway,” he said.
There is a lack of testing readily available to physicians. Both Neises and Hawkinson agreed that doctors have a limited menu of tests to choose from, and although tests for the more commonly known diseases are readily accessible, tests for the lesser-known unreported diseases are more difficult to obtain.
“It is just not as easy to test for powassan disease or the borrelia disease as it is for lyme disease or Rocky Mountain spotted fever or the diseases that we are more familiar with,” Neises said. 
Due to the gap in testing and reporting, the possibility exists that tick-borne illnesses are underreported and misdiagnosed statewide, Hawkinson said.
“But that is not unique to tick-borne illness,” he said. “We try our best to diagnose and treat our patients, but medicine is not an exact science.”
Hawkinson said so long as Kansans are implementing protective procedures to avoid contact with ticks they have little to fear. Those who are bitten by a tick should preserve it by putting it in a plastic baggie and placing it in the freezer so if symptoms arise, the bacteria the tick carries can be later  identified, Neises said.

BOURBON virus to date  has been known to affect two patients. An Oklahoma patient made a full recovery, while the first and only other case in Bourbon County, Kansas, was fatal. Symptoms included fever, fatigue, rash and muscle and joint pain, according to the Lyme Disease Association website. Although the patients had symptoms similar to other tick-borne illnesses, test results proved negative for  the other diseases. Failure to effectively treat the Bourbon County patient resulted in the discovery of the disease, according to Neises. Special testing was requested and approved by the Center for Disease Control and Prevention, and researchers were able to isolate the virus that had not been discovered previously, he said. One symptom that makes it different from most other tick-borne illnesses is anorexia.
“It is likely that many ticks carry bourbon virus in the area we suspect to be its endemic area,” Hawkinson said of Bourbon County. 
Research on the virus is being conducted by the CDC in collaboration with KU Health System and KDHE to determine more cases, develop an accurate diagnostic test and characterize the spectrum of the disease in patients, he said. But the progress that has been made since 2015 has been minimal.
“Zika virus issue caused a lot of refocus of resources at the national and state level last year,” Hawkinson said.
“I still do not believe anyone is just testing residents of Bourbon County to look for evidence of exposure.”
No commercial testing is available and at this time general supportive care is the treatment.
“No one knows the extent of the spread of the virus in the tick population or the prevalence of evidence of exposure to humans,” he said.   
It is suspected that minor cases of the virus exist, according to Hawkinson. But until a test is readily available it will be difficult to begin the process of looking at actual prevalence and incidence rates throughout the community.

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