The Centers for Disease Control (CDC) found no signs of Bourbon virus in any of the samples after testing more than 7,000 ticks collected at Meramec State Park.
A statement released Wednesday by the Missouri Department of Health and Senior Services (DHSS) stated just because no virus was found in the samples does not mean the virus is not present in some ticks in the park.
Instead, it means no ticks that might have been infected at the time of this investigation were trapped and tested.
Heartland virus was detected in one group of ticks.
In September DHSS and the CDC worked with local public health agencies to test for evidence of Bourbon virus in the blood of some Missouri state park workers.
The results of those tests will not be released due to patient privacy laws.
The death last summer of Meramec State Park Assistant Superintendent Tamela Wilson from complications related to the Bourbon virus were tied to a tick bite she sustained while in the park around Memorial Day weekend.
Wilson’s daughter, Amie Wilson May, says she hasn’t had any news from the CDC or the state since shortly after her mother’s death.
“I’m glad they didn’t find any ticks with the virus,” she said. “I just think that is strange.”
At the time, Wilson was only the fifth confirmed case of Bourbon virus since it was first discovered in 2014.
Public Health Supervisor Tony Buel said this year the Franklin County Health Department has seen an increase in overall tick borne disease cases being reported.
“The Bourbon virus is new to the scene but there are three we see quite a bit of, Rocky Mountain spotted fever (RMSF), anaplasmosis and ehrlichiosis,” Buel explained. “This year there have been 44 reported cases of RMSF, eight cases of anaplasmosis and 19 cases of ehrlichiosis in the county.”
Buel added the Rocky Mountain spotted fever reports follow state- and nation-wide reports as being the most frequently reported rickettsial illness.
“Some of these reports were due to past infections but all of them were newly reported to the health department this calendar year,” Buel said. “Ticks have also been known to infect humans with other diseases such as tularemia and a Lyme-like disease called Southern tick-associated rash illness or STARI.”
Patients diagnosed with Bourbon virus have shown signs similar to infection with Heartland virus and ehrlichiosis (the latter is a type of bacteria transmitted by ticks), including fever, muscle aches, fatigue, headache, anorexia, diarrhea and rash.
Like Heartland virus and ehrlichiosis, Bourbon virus can affect blood cells that help the body fight infection and prevent bleeding.
There is no vaccine or specific treatment for the Bourbon virus.
The ticks collected were “pooled” in groups for testing.
The size of the pool is dependent on the type of tick (seed tick, deer tick, etc.).
The ticks were collected using a flagging technique.
White flags made of a felt material are waved in the weeds and tall grass areas where ticks are known to live.
As the fabric brushes by the ticks they attach themselves to it and are then picked off and sorted by species, gender and age.