Two emerging tick-borne viruses are spreading across the United States with potentially fatal consequences. Heartland virus and Bourbon virus, both transmitted by lone star ticks, have killed at least seven people in the country.
Heartland virus first emerged in 2009 in Missouri and has since spread to multiple states across the Midwest and South. The virus causes fever, fatigue, headaches, and in severe cases, thrombocytopenia, a dangerous drop in blood platelet counts. Bourbon virus was identified more recently in 2015 in Kansas, also transmitted by the aggressive lone star tick species.
Lone star ticks have expanded their geographic range dramatically over the past two decades, moving northward as climate change warms previously cooler regions. These ticks are known for their aggressive feeding behavior and tendency to bite humans. A single tick can transmit both viruses, increasing the risk of dual infections.
The fatality rate for Heartland virus infections reaches approximately 10 percent of confirmed cases, while Bourbon virus shows similarly concerning mortality rates. No vaccines or specific antiviral treatments currently exist for either virus. Medical management remains supportive, focusing on managing symptoms and complications like bleeding disorders.
Cases appear predominantly in spring and early summer months when tick activity peaks. Healthcare providers across affected regions have heightened surveillance for these infections, as symptoms often mimic other tick-borne illnesses like Lyme disease or Rocky Mountain spotted fever, potentially causing diagnostic delays.
Public health officials recommend tick prevention strategies including use of acaricides on clothing, checking skin thoroughly after outdoor exposure, and removing ticks promptly. The geographic expansion of lone star tick populations suggests these viruses will likely continue spreading to new regions, making awareness among both healthcare providers and the public essential.