The mysterious death of a Kansas man was caused by a new, never-before-seen tick-borne virus.

The unidentified man from Bourbon County died over the summer. It took the last six months for doctors at the University of Kansas Hospital and state and national epidemiologists to figure out his cause of death, ABC News reported. 

"Its genome is similar to viruses that have been found in eastern Europe, Africa and Asia, but no virus like that has ever been identified in the western hemisphere," University of Kansas Hospital infectious disease expert Dr. Dana Hawkinson said in a video prepared last week by the hospital. 

Since this man is the only known victim of this tick-borne virus, it was dubbed the "Bourbon virus."

Hawkinson called the six months where he and his colleagues were struggling to find the man's cause of death "frustrating." 

"We just couldn't answer questions for the family and ourselves as to why this was happening to this gentleman," he told ABC News. 

Symptoms of this new illness include anorexia, muscle aches, elevated liver enzymes and damaged blood platelets. 

The illness is similar to another tick-borne illness called the heartland virus, but the heartland virus doesn't cause anorexia, reported ABC News.