Mon January 7, 2013
Novel Virus Discovered Near St. Joe
This past year brought some unexpected attention to the St. Joseph, Missouri area. That’s where a team of researchers identified a new virus, believed to be transmitted by ticks.
The discovery marks the first new human virus out of North America in nearly two decades, but scientists are just beginning to piece together what this means.
A sick farmer
Larry Smithers has lived off the beaten path - literally, off of dirt roads - about 17 miles northwest of St. Joseph, Mo for the past 30 years. There aren’t a lot of people out here, but there’re plenty of other creatures: birds, raccoons, turkey and –
“You can’t go out without getting ticks all over you,” says Smithers.
Smithers has mostly kept to himself on this wooded, 40-acre plot, raising quarter horses and fixing up cars. But back in 2009 his life took an unexpected turn. A few days after spending a lot of time in a woody area putting up a wired fence, he started feeling weak. He thought it might be the flu. His regular doctor referred him to Heartland Regional Medical Center in St. Joseph for x-rays. When he got there, things went downhill fast. Smithers doesn’t remember much, except that he’d never been so sick.
“Some of the neighbors thought I was going to die,” says Smithers. “Matter of fact, I thought a couple times I was too. It wasn’t good experience, I dind’t know whether was ever going to come out of it or not.
Hospital staff weren’t sure what to do, either.
Dr. Scott Folk heads infectious diseases at Heartland and prides himself on his close attention to detail. He said at first, Smithers and another patient appeared to have a certain tick-borne disease.
“Initially I thought ok, they’ve been bitten by a tick, it’s the summertime, they have a fever, low white blood cell counts, low platelet counts, certain key lab abnormalities,” he recalls. “I thought they had Ehrlichiosis.”
Ehrlichiosis a bacteria transmitted by the lone star tick. It’s something Dr. Folk sees in a handful of patients each year. He says antibiotics usually help, but that didn’t work for Smithers or the other patient. Both remained hospitalized for more than a week.
“It made me nervous,” says Dr. Folk. “It was unsettling, and it was hard to go into the patient’s room each day and scratch my head and say that we don’t know what’s wrong with you yet
Dr. Folk hoped experts at the Centers for Disease Control and Prevention (CDC) in Atlanta might know what was wrong. Missouri’s health lab doesn’t test for Ehrlichiosis, so Folk happens to sometimes sends blood samples from patients he thinks have the disease to the CDC.
He has been in touch with William Nicholson, a CDC microbiologist with an interest in tick-borne diseases, for years. Nicholson likes getting samples from Folk and other doctors from time to time for research. Nicholson doesn’t always find erlichia in samples he gets, but something else about Smithers’ blood caught his attention.
“We were puzzled because we couldn’t see anything, but there were changes in the cell that were similar to Ehrlichiosis,” says Nicholson. “I never could see Ehrlichia, but I could see changes in the cells that suggested something was going on with those cells.”
This was out of his zone of expertise, so Nicholson turned to Laura McMullen and other colleagues in neighboring pathology departments for their take. McMullen took the samples and ran a full genetic sequence on the cells. The process, called next generation sequencing, allows her to go through and compare millions of sequence possibilities, as opposed to targeting a search for one specific virus.
“By using this technology, we’re not limiting ourselves to what we’re looking for because it’s looking for anything,” says McMullen.
The technology is relatively new to the CDC. McMullen says scientists there only started using it in the last few years. It’s a huge bioinformatics process, and it takes several weeks.
Back in St. Joseph as all of this was going on, Smithers and the other patient actually got better.
Dr. Folk thinks this was in spite of any treatment. That was unsettling to him. He hoped to learn more.
And he did.
But the answers he got raised more questions.
Something totally new
McMullen’s testing did find something: something genetically unique and totally new.
“I think everyone got excited at that point,” recalls McMullen.
McMullen says the virus probably came out of the U.S., meaning it wasn’t brought in from another country, as was the case with West Nile and Sars. She and Nicholson say part of what’s significant about the discovery is that it marks the first time a new human virus has been found in the U.S. in 19 years.
The New England Journal of Medicine published the findings by Nicholson, McMullin, Folk and others last summer.
So what exactly is this new virus?
Ticks the likely suspect
The new virus is a phlebovirus. There are more than 70 members of the phlebovirus family. Ticks, mosquitoes and sandflies often carry them.\.
“Pleboviruses have been described from ticks – soft ticks and hard ticks,” says Nicholson. “But, not causing human illness on this side of the world.”
The closest phlebovirus relative to this new virus was recently identified in China and caused some fatalities. Nicholson cautions against making too much of a connection. The virus found in Missouri is still very different, but Nicholson says beyond that, not much else is known about it.
That’s why he and others have been doing research outside the lab.
“By understanding the ecology, by knowing which ticks, by knowing what time of year, by knowing which animals, we may be able to put some preventative measures in place, and that’s what we really want to do,” says Nicholson.
Searching for clues in the field
Last spring and summer, Nicholson and a team of researchers from the CDC, the state and the region met up several times around St. Joseph. They tested and tagged animals for the virus to figure out what carries it, how it’s transmitted and how widespread it is.
Nicholson suspects the lone star tick, which is common in Missouri, is a likely source of the virus, so he and others also gathered lots of ticks.
“Last trip I’d say we probably collected 30,000 or more,” says Nicholson. “These are mostly larval ticks, [you get] in large clusters when you drag a cloth across vegetation.
One area they targeted was around Larry Smithers’ fence, where they think he got sick. They’d trap the ticks by putting out buckets of dry ice. Dry ice emits carbon dioxide, which makes hungry ticks think a humans or animal is nearby.
“They become somewhat hypnotized by the gas in that area, looking for a host, and hoping a host will brush against it,” says Nicholson.
Researchers are now in the process of sifting through and testing all those ticks and animal samples.
They’re also trying to find other patients, beyond Smithers and the other patient, who may have gotten the virus. Heartland Regional has opened a clinical study, and the Missouri health department has issued notices to doctors around the state.
Nicholson says the virus doesn’t appear to be as much of a public health burden as something like West Nile virus, but he advises taking the same precautions as one would take for avoiding other tick diseases. That includes covering exposed skin, using repellents and checking for ticks after being outside.
A source of pride
Over at Heartland hospital, Dr. Folk hopes the effort leads to better diagnosis and treatment of the virus. At the same time, he and others at the hospital are thrilled by the unexpected find. They’re especially proud of the new virus’ name: Heartland Virus.
“I would have never dreamt that I would have been able to help codiscover a new virus. And that would never have been possible without the CDC” says Folk, who dons a tie that staff gave him with the phrase “Heartland Virus,” printed on it. “For me, identifying with it, being in partnership with the CDC… I view this as the pinnacle of my career, and I’m just excited to have been a part of it.”
For McMullen, the experience affirms the potential of the new sequencing technology. She thinks its application could lead to more unexpected discoveries down the road.
Nicholson underscores the chance circumstances how the new virus came about, which for all he knows, could have been around in nature, undetected, for a long time.
“This was serendipity in that we got a virus, in that we were not looking for the virus,” says Nicholson. “We were not testing for the virus. We were doing nothing that was specific for a virus. But what we were doing was still conducive to finding a virus.”
As for Larry Smithers, “patient zero” in all of this, he’s a little less enthused about the whole thing. Afterall, he got pretty sick.
“If it had went on past me I would have still been alright,” he says, laughing. “It would have all been for the better, I think.”
Smithers hopes others don’t experience what he did, so he is glad researchers have been out to his property, trying to learn more.
And that research continues.
Nicholson and others would like to come back to the area this spring, in hopes of better understanding what heartland virus is all about.