For several months, researchers have been combing two farms and surrounding conservation areas in northwest Missouri, collecting thousands of ticks.
They’re also contacting hospitals in the area and testing patients — all in an effort to learn more about a new virus whose discovery was announced last month.
Named the Heartland virus, it’s the first new virus native to the United States found since the hantavirus emerged in 1993.
Not that scientists are comparing it to hantavirus, or anything else at this point.
“Immediately there’s going to be a lot of questions about where is it, how I get it, how can I prevent it,” said William Nicholson, who served as director of a Centers for Disease Control and Prevention reference diagnostic lab before he began doing research full time. “That’s what we’re working on now.”
Researchers are hoping to figure out which animals or insects might carry the virus and how exactly it was transmitted to humans.
The virus was put in the spotlight by a paper published Aug. 30 in the New England Journal of Medicine. Scientists on the case found that this strain — which they suspect is tick-borne — is different from other viruses that cause similar symptoms in those infected.
Two farmers, Robert Wonderly and Larry Smithers, were hospitalized in 2009 at St. Joseph’s Heartland Regional Medical Center — the virus’ namesake — with fevers and histories of tick bites. In this part of the country, those symptoms, combined with abnormal test results, usually mean the patient has a specialized bacterial infection.
That type of infection is something Scott Folk, the physician who consulted on the cases at Heartland Regional, commonly encounters.
But Folk saw that these patients weren’t responding to doxycycline, the antibiotic used to treat the bacterial infections he usually comes across. While most patients feel better within a day or two, the two farmers were still hospitalized five or six days into their illness.
“These two gentlemen were very, very slow to get better,” Folk said.
Meanwhile, at the CDC, when scientists compared gene sequences in the farmers’ viruses and those of known strains, they found something unique — “very, very removed from everything,” Nicholson said.
“Seeing the virus particles indicated that we had a completely different thing going on,” said Laura McMullan, a CDC senior scientist who worked on the case.
The last time a new virus emerged in this country was 1993, when the hantavirus was discovered. It is transmitted by the droppings or saliva of rodents. This summer three people have died from an outbreak in California.
Now two northwest Missouri hospitals are working with the CDC to sign up volunteer patients who have similar symptoms and test them for the Heartland virus and other infections. The CDC also is contacting hospitals in western Missouri to find additional patients.
Nicholson said the CDC has had “plenty of phone calls” from people around the country with possible reports of the new virus. But right now, researchers only know for certain that the virus is in northwest Missouri.
“At this point, we are suspecting that this is a tick-borne virus,” Nicholson said. “We are still hoping to gain additional evidence through ecological studies as well as lab studies.”
Despite the work that remains, Nicholson and McMullan say that the discovery of a new virus in itself is exciting.
“You know now what you’re dealing with,” McMullan said.