Ticks carrying a mysterious and rare virus that can sicken or even kill older adults or people with underlying conditions have been found in at least six states, a new study reported Wednesday.

Test samples revealed that lone star ticks in Georgia had picked up the Heartland virus, Emory University researchers reported in Emerging Infectious Diseases, a Centers for Disease Control and Prevention publication.

“We want to bring awareness rather than panic,” said Gonzalo M. Vazquez-Prokopec, a co-author of the study and an associate professor of environmental sciences at Emory. “People tend to go out more in the spring and they might get exposed to ticks, which are increasing rapidly, particularly in the South, this time of year.”

Not much is yet known about the Heartland virus, which when transmitted to a person by a tick bite can cause fever, fatigue, decreased appetite, headache, nausea, diarrhea, and muscle or joint pain. It’s unclear if other ticks can also spread the virus or if people can be infected in other ways, the CDC said.

As of January 2021, just 50 cases of the disease caused by the virus have been reported, according to the CDC. In severe cases, patients have ended up in the hospital and while most have fully recovered with supportive care, a few older individuals with medical conditions have died, the CDC reported.

Some people infected with the virus have been diagnosed with lower than normal white blood cell counts and lower than normal counts of platelets, which aid in blood clotting. Liver function tests can show increased levels of liver enzymes, which can indicate illness.

The Heartland virus was discovered in 2009 in northwest Missouri after two men were hospitalized with symptoms including high fevers, diarrhea, and muscle pains. The virus has been reported in lone star ticks from Missouri, Alabama, Illinois, Kansas, and New York, although it’s unknown if the virus has spread to other areas of the U.S., according to the CDC.