A new virus has been discovered in northwest Missouri, where in June 2009 it sickened two men who live miles apart.
The Centers for Disease Control and Prevention says so far it's unclear what causes the virus, which is called the Heartland virus. The CDC says an investigation is under way to determine if the illness stems from bites from ticks or other insects.
Symptoms of Heartland virus include fever, diarrhea and fatigue. Both patients were treated at Heartland Regional Medical Center in St. Joseph and recovered after about a month.
CDC researchers have been in northwest Missouri collecting samples from ticks and other animals to determine the cause of the virus and how it's transported. CDC is also working to determine if other people have been infected.