by Tammera J. Karr, PhD
There is no way around it – Ticks are just plain nasty. The very mention of these little bugs makes the skin crawl for many. According to the Centers for Disease Control, ticks in the United States can carry and transmit over 16 pathogens to humans. Lyme disease is the one most frequently talked about today, but others like Rocky Mountain Spotted Fever have been on the rise in Oregon, especially Eastern and Central areas.
One that took me by surprise is Tickborne Relapsing Fever (TBRF), this is transmitted by the bite of soft ticks. TBRF has been reported in 15 states: Arizona, California, Colorado, Idaho, Kansas, Montana, Nevada, New Mexico, Ohio, Oklahoma, Oregon, Texas, Utah, Washington, and Wyoming and is associated with sleeping in rustic cabins and vacation homes.
Relapsing fever is a bacterial infection characterized by recurring episodes of fever, headache, muscle and joint aches, and nausea. It is caused by certain species of Borrelia spirochetes. There are two types of relapsing fever: Tick-borne relapsing fever (TBRF) and Louse-borne relapsing fever (LBRF)
Tick-borne relapsing fever occurs in the Western United States and is usually linked to sleeping in rustic, rodent-infested cabins in mountainous areas. So much for that special vacation in a rustic Forest Service Lookout…. I’m sticking to my Hideout RV, thank you very much.
The new kid on the bug pathogen block is 364D rickettsiosis. This new nasty is transmitted by the Pacific Coast tick. Mostly this has been found in California. However, it makes sense that it is only a matter of time before it is reported in Southern Oregon.
Spotted fever group rickettsioses (spotted fevers) are a group of diseases caused by closely related bacteria. These bacteria are spread to people through the bite of infected mites and ticks. The most serious and commonly reported spotted fever group rickettsiosis in the United States is Rocky Mountain spotted fever (RMSF).
Other causes of spotted fever group rickettsioses (spotted fevers) in the United States include: Rickettsia parkeri rickettsiosis, caused by R. parkeri, Pacific Coast tick fever, caused by Rickettsia philipii, and Rickettsialpox, caused by Rickettsia akari
Spotted fever can range from mild to life-threatening. Most people who get sick with a spotted fever other than RMSF will have an eschar (dark scab at the site of tick or mite bite), fever, headache, and rash. Doxycycline is the treatment of choice for all spotted fever infections.
Now that we are all paranoid over ticks, here is some information I came across this week on ticks favoring select blood types. A group of researchers in the Czech Republic conducted a pilot study using in vitro method (this is considered the least accurate of study methods, and this study has not been replicated for obvious reasons.). Blood from volunteers was placed on the perimeter of the filter paper placed on a Petri dish. One hundred nymphal Ixodes ricinus ticks were collected near the Brno Reservoir. Ixodes ricinus ticks are the most common species of ticks in Europe as well as in the Czech Republic. They are also the primary vector of Borrelia burgdorferi, the bacteria which causes Lyme disease.
Tick behavior was monitored at 1 and 2-minute intervals to determine which drop of blood they preferred. “It can be stated that the most statistically preferred was blood group A, followed by the second groups – O and AB,” writes Žákovská. Type B blood was the least preferred blood group. Of course, the findings need to be replicated in an in vivo study, since other factors could influence the ticks’ feeding preferences in a living organism.
The study’s authors conclude that “blood group might be one of the factors determining the feeding preferences of Ixodes ricinus ticks.” And they warn, “people with the risk blood type A should take appropriate measures to protect themselves more effectively, and decrease the risk of contracting dangerous zoonotic diseases transmitted by ticks.”
Are ticks the only bugs that carry pathogens?
No – mosquitoes have also been found to carry and transmit a wide range of pathogens including Lyme in some areas of the country. Most recently the news has reported on West Nile and Zirka.
Studies on mosquitoes have shown preferences for certain blood types, according to a literature review by the authors. These studies used human volunteers. “In one case, they allowed the mosquitoes to feed on the exposed hands of volunteers,” explains Žákovská. “In the second study, the experimenters were studying only ‘landing’ preferences of mosquitoes with an amputated proboscis.”
A 2009 study published in the journal BMC Biology showed that DEET can interfere with vital nervous system enzymes. The researchers discovered that the chemical blocked the enzyme cholinesterase, which is necessary for transmitting messages from the brain to the muscles in insects. The researchers noted that it may affect the nervous systems of mammals as well.
If you are sensitive to or worried about chemical exposure, consider trying an essential oil spray made of Witch Hazel, lemongrass, peppermint, eucalyptus, tea tree and lavender oil. Choose 100% pure essential oils with no additives or adulterants
To a bug-free fun in the sun season.