Bourbon Virus – Credit CDC
A couple of months ago I wrote about the Kansas DOH Statement On A New, Possibly Tickborne Virus detected in a Bourbon County man (hence the name) who died from what appeared (based on blood work and symptoms) to be a tickborne disease last summer.
They eventually isolated a novel strain of the Thogotovirus –variants of which have been found in ticks in Africa and southern Europe. This week the CDC’s EID Journal published a research paper on that virus (see below), and the CDC has put up a new Bourbon Virus FAQ.
Volume 21, Number 5—May 2015
A previously healthy man from eastern Kansas, USA, sought medical care in late spring because of a history of tick bite, fever, and fatigue. The patient had thrombocytopenia and leukopenia and was given doxycycline for a presumed tickborne illness. His condition did not improve. Multiorgan failure developed, and he died 11 days after illness onset from cardiopulmonary arrest. Molecular and serologic testing results for known tickborne pathogens were negative. However, testing of a specimen for antibodies against Heartland virus by using plaque reduction neutralization indicated the presence of another virus. Next-generation sequencing and phylogenetic analysis identified the virus as a novel member of the genus Thogotovirus.
The discovery of Bourbon virus, in addition to recent discoveries of tick-associated Heartland and severe fever with thrombocytopenia syndrome viruses (19,20), suggests that the public health burden of these pathogens has been underestimated. As nonselective molecular methods of pathogen identification (i.e., NGS sequencing) become more widely used, ideally in combination with classical microbiologic techniques, it is anticipated that similar discoveries will be made in the future.
It is currently not known how many human infections and disease cases might be attributable to this novel pathogen. On the basis of limited information for our case-patient, health care providers might consider Bourbon virus as a potential infectious etiology in patients in whom fever, leukopenia, and thrombocytopenia develop without a more likely explanation and who have shown negative results for other tickborne diseases (e.g., ehrlichiosis, anaplasmosis, or Heartland virus disease) or have not responded to doxycycline therapy. Work is planned to identify additional human infections with this novel virus, as well as to explore its potential geographic distribution. Also, more comprehensive virologic characterizations and field work are ongoing to better understand the biology of, and to identify potential vectors and reservoirs for, Bourbon virus. These data will be critical to further characterize the epidemiology and illness caused by Bourbon virus and to implement potential prevention and control measures.
This from the CDC’s Division of Vector-Borne Diseases (DVBD)
Frequently Asked Questions
Bourbon virus belongs to a group of viruses called thogotoviruses. Viruses in this group are found all over the world. A few of these viruses can cause people to get sick.
We do not yet fully know how people become infected with Bourbon virus. However, based on what we know about similar viruses, it is likely that Bourbon virus is spread through tick or other insect bites.
As of February 12, 2015, only one case of Bourbon virus disease had been identified in eastern Kansas in late spring 2014. The man who was infected later died. At this time, we do not know if the virus might be found in other areas of the United States.
Because there has been only one case identified thus far, scientists are still learning about possible symptoms caused by this new virus. In the one person who was diagnosed with Bourbon virus disease, symptoms included fever, tiredness, rash, headache, other body aches, nausea, and vomiting. The person also had low blood counts for cells that fight infection and help prevent bleeding.
People likely become infected with Bourbon virus when they are bitten by a tick or other insect. Therefore, people who do not take steps to protect themselves from tick or insect bites when they work or spend time outside may be more likely to be infected.
There is no vaccine or drug to prevent or treat Bourbon virus disease. Therefore, preventing bites from ticks and other insects may be the best way to prevent infection. Here are ways to protect yourself from tick and other bug bites when you are outdoors:
- Use insect repellents
- Wear long sleeves and pants
- Avoid bushy and wooded areas
- Perform thorough tick checks after spending time outdoors
Additional information on reducing exposure to ticks is available on the CDC Ticks website.
Currently, no laboratory tests are routinely available to tell if a person is infected with Bourbon virus. Tests that will help a doctor diagnose Bourbon virus infection are being developed. See your healthcare provider if you have any symptoms that concern you.
Because there is no medicine to treat Bourbon virus disease, doctors can only treat the symptoms. For example, some patients may need to be hospitalized and given intravenous fluids and treatment for pain and fever. Antibiotics are not effective against viruses, including Bourbon virus.
Scientists do not yet know what animals can get infected or become sick from Bourbon virus. Studies are ongoing to look at this. See your veterinarian if your pet or livestock have any symptoms that concern you.
There is a growing realization that the public health burden of tick and other vector borne diseases is likely much greater than previously appreciated.
- In 2013, the CDC revised their Estimate Of Yearly Lyme Disease Diagnoses In The United States, indicating that the number of Lyme Disease diagnoses in the country is probably closer to 300,000 than the 30,000 that are officially reported each year to the CDC.
- A little over two years ago (see New Phlebovirus Discovered In Missouri) we learned about the new `Heartland Virus’ which made headlines when it was detected in two Missouri farmers with no epidemiological links and living 60 miles apart. Since then the number of cases – while small – has continued to grow (see MMWR: Heartland Virus Disease — United States, 2012–2013).
- SFTS or Severe Fever with Thrombocytopenia Syndrome - which was first discovered in China in 2009, but has also been found in Japan and Korea - is genetically similar to the recently discovered Heartland Virus (see EID Journal: Two Dispatches On SFTS).
The CDC lists a growing number of other diseases carried by ticks in the United States, including: Anaplasmosis, Babesiosis , Ehrlichiosis, , Rickettsia parkeri Rickettsiosis, Rocky Mountain Spotted Fever (RMSF), STARI (Southern Tick-Associated Rash Illness), Tickborne relapsing fever (TBRF), Tularemia, and 364D Rickettsiosis.
Whether a new and emerging threat, or simply the result of our ability to finally recognize a long-time foe, we are becoming more cognizant of the dangers posed by ticks. With no vaccines to protect us, it makes sense to take additional precautions against ticks and other vector-borne diseases.
The following CDC website offers advice on: Preventing Tick Bites
And for some more Tick-borne disease related blogs, you may wish to revisit: