Deep in the throes of summer already – where did this year go? – I thought I would report on a topic relevant for our international travelers as well as all of us at home. Here in the United States, the majority of vector-borne diseases are zoonoses (i.e. animal diseases) transmitted by tick vectors. Ticks can transmit bacteria, such Rickettsia rickettsia that causes Rocky Mountain spotted fever (RMSF); viruses, such as the Flavivirus Powassan virus that can lead to Powassan encephalitis; as well as protozoa, e.g. Babesia microti, that leads to Babesiosis. One tick, the Lone Star, has even been associated with the Alpha-Gal allergy, which is a delayed allergic reaction to mammal meat. Unfortunately, the number of cases of tickborne diseases have been increasing over time and expanding into new geographic areas. There’s also been a growing number of tick varieties recognized to cause disease.
In the US, RMSF is associated with the most severe and fatal outcomes. North Carolina, Arkansas, Oklahoma, Tennessee, and Missouri account for over 60% of cases but in recent years the number of cases has significantly increased in areas of Arizona too.
Travelers can contract many of the same diseases abroad. In addition, they are at risk for others such as Tick-borne Encephalitis, Crimean-Congo Hemorrhagic Fever, Kyasanur Forest Disease, Omsk Hemorrhagic Fever, and South African Tick Bite Fever.
Thankfully, many tickborne illnesses still respond to Doxycycline and treatment should not be delayed if symptoms are clinically consistent with disease. According to the Infectious Disease Society of America, antimicrobial treatment is generally not recommended as prophylaxis after a known tick bite. In some circumstances, a onetime dose of Doxycycline 200 mg may be given after a bite but only in known high risk Lyme areas and only if circumstances meet all of the criteria.
You can find more about the information above from the CDC’s multiple tick related resources. Here are my top three:
- Tickborne Diseases of the United States, A Reference Manual for Health Care Providers, Fourth Edition, 2017. This is simply a wonderful, concise, beautifully designed document. There’re excellent photographs of the various ticks, maps that show the locations of all the diseases, and terrific summaries regarding symptoms, diagnostic tests, and appropriate treatment regimens. There are also sections on prevention and tickborne diseases abroad. Here’s what they have to say regarding prevention and tick removal:
- Use repellent that contains 20 percent or more DEET, picaridin, or IR3535 on exposed skin for protection that lasts several hours. Use products that contain permethrin on clothing. Treat clothing and gear, such as boots, pants, socks and tents with products containing 0.5% permethrin. Additional repellent options are available. For more information, see http://cfpub.epa.gov/oppref/insect/.
- Treat dogs and cats for ticks as recommended by a veterinarian.
- Check for ticks daily, especially under the arms, in and around the ears, inside the belly button, behind the knees, between the legs, around the waist, and on the hairline and scalp.
- Shower soon after being outdoors.
- For tips on “tick-safe” landscaping, see cdc.gov/lyme/prev/in_the_yard.html.
- Use fine-tipped tweezers to grasp the tick as close to the skin’s surface as possible. You may use specialized tick removal tools, if you already have them. The key is to remove the tick as soon as possible. Avoid folklore remedies such as using nail polish, petroleum jelly, or heat to make the tick detach from the skin.
- Pull upward with steady, even pressure. Don’t twist or jerk the tick; this can cause the mouth-parts to break off and remain in the skin. If this happens, remove the mouth-parts with clean tweezers. If you are unable to remove the mouth parts easily, leave them alone and let the skin heal.
- After removing the tick, thoroughly clean the bite area and your hands with rubbing alcohol, an iodine scrub or soap and water.
- Diagnosis and Management of Tickborne Rickettsial Diseases: Rocky Mountain Spotted Fever and Other Spotted Fever Group Rickettsioses, Ehrlichioses, and Anaplasmosis — United States, A Practical Guide for Health Care and Public Health Professionals, MMWR, Recommendations and Reports / May 13, 2016 / 65(2); 1–44. This also has very useful photos, maps, and summary diagrams. CE is available here.
- For the latest trends, see CDC Public Health Grand Rounds Emerging Tickborne Diseases. It features four very informative speakers and content on what is being done to prevent the spread of these illnesses. CE is available.
If you and your travelers take appropriate precautions, the risk of a tick borne illness is very low. So by all means, slather on some DEET and enjoy what nature has to offer.
I went to the woods because I wished to live deliberately, to front only the essential facts of life, and see if I could not learn what it had to teach, and not, when I came to die, discover that I had not lived.
Henry David Thoreau
Have a lovely summer everyone,
Julie Richards, Immediate Past President
American Travel Health Nurses Association