A new case of the still-mysterious Bourbon virus was confirmed in Missouri, likely originating within the state, local authorities said in a June 30 press release.
The virus, which researchers think is spread by ticks, was unknown until 2014, and both knowledge and treatment of it are still scarce. According to the CDC, "As of June 27, 2017, a limited number of Bourbon virus disease cases have been identified in the Midwest and southern United States. Some people who have been infected later died."
Bourbon virus (named for Bourbon County in Kansas where it was first found, not for the liquor) was identified in 2015 as a Thogotovirus. Others in the genus are tick-borne, which gives credence to the idea that Bourbon virus is as well.
The infected patient had not traveled out of Missouri recently, indicating the patient likely caught the virus in the state. They were bitten by a tick while visiting Maramec State Park in Missouri soon before becoming ill, and ticks at the park have tested positive for Bourbon virus. CDC and Missouri Department of Health and Senior Services officials are investigating to determine health risks and to enable improved testing for the illness. They are currently looking for any other cases and collecting ticks in Missouri to test for Bourbon virus.
Symptoms of the infection include fever, nausea and vomiting, fatigue, headaches and body aches, and rash. Blood tests of previous cases also showed low levels white blood cells and platelets, which fight infection and enable blood clotting, respectively.
"All of these tick-born illnesses start out similarly, with headache, fever, chills, sometimes nausea and vomiting and body aches," John Brown, a travel medicine physician with Mercy Hospital in Missouri, told KY3. "So all of those symptoms, especially in the summertime and especially if you've been outdoors around ticks, are very suspicious for a tick-born illness."
Rocky Mountain spotted fever and ehrlichiosis are the most common tick-borne diseases in Missouri; Bourbon virus is still rare.
The first known case of Bourbon virus was in 2014, when a man in Bourbon County, Kansas, passed away after 11 days of the then-unknown illness. The virus likely initiated the multi-organ failure and cardiac arrest that ultimately killed him. The original case had suffered multiple tick bites while working outside several days before symptoms began.
Bourbon virus was found when testing the patients' blood sample for Heartland virus, another tick-borne disease. When another virus was found instead of Heartland virus, genetic testing showed it was a Thogotovirus. Two other Thogotoviruses are known to cause illness in humans, though cases are not common.
The CDC developed blood tests for the virus that year, but a vaccine treatment specifically targeted to the virus is unavailable. Prevention and supportive medical care to mitigate its effects are still helpful though. Those who are over age 50 or have other chronic health conditions are more at risk for possibly severe complications; most people with tick-borne illnesses have a full recovery.
Precautions against Bourbon virus are the same as for any tick-borne illness, on the likely probability that it is one as well. When outdoors in areas where ticks can live, people are advised to cover bare skin, wear tick repellent with at least 2o% DEET, and do tick checks on a regular basis.