Medical experts publish new guidelines in hopes of reducing tick-borne illness
While once confined to secluded areas, disease-carrying ticks are becoming increasingly common. Over the past twenty years, the number of cases of tick-borne illnesses (TBIs) reported annually to the Centers for Disease Control and Prevention (CDC) has more than doubled, totalling 50,865 formal reports in 2019 - but the actual figure could be higher, experts say.
While Lyme disease is the most common TBI - accounting for roughly 70 per cent of annual cases, ticks can cause a range of ailments.
In response to the growing number of TBIs, the Wilderness Medical Society convened a panel to develop guidelines for their prevention and management.
"In the United States, 95 per cent of human vector-borne diseases reported to the CDC per year are attributable to tick-borne pathogens," reads an excerpt from the report.
"Given the increased incidence of TBI, it is critical for providers to be comfortable with the prevention and management of tick bites."
The guidelines won't come as a surprise to individuals already versed in tick bite prevention techniques. The authors say they align with existing CDC literature but emphasize concepts that will be relevant to health care providers.
THE GUIDELINES
The full list of guidelines, along with recommendations for health care providers has been published online on the Wilderness Medical Society's website, with the following key points:
Wear long-sleeved clothing when traveling in tick habitat.
Light-coloured clothing may not reduce the risk of tick bites but makes it easier to identify ticks on clothes during tick checks.
N-diethyl-meta-toluamide (DEET) is an effective tick repellent. It can be used in children over the age of two months.
The efficacy of picaridin compares favorably to DEET. It may have a superior safety profile when compared to DEET.
Permethrin-treated clothing may further reduce the risk of TBI when used in combination with a skin-based tick repellent such as DEET or picaridin.
Avoid essential oils, citriodiol, nootkatone, and IR3535 as a first-line repellent as they have either a lower repellent efficacy or significantly shorter duration of action.
Evidence supporting tick checks is contradictory but may help prevent TBI when combined with showering or bathing within two hours of returning from tick habitat.
Washing clothes at temperatures over 54°C/130°F and drying clothing in high heat for ten minutes kills ticks and may reduce the risk of TBIs.
When feasible, avoid areas with high grass or leaf litter. When in tick habitat, walk in the middle of trails to reduce the chance of contact with ticks.
Mechanical removal by pulling upward, or perpendicular to skin with forceps, directly on an embedded tick, is the best currently available method. Commercial devices may also work, but there is no evidence suggesting they are superior. Pulling embedded ticks with straight, steady pressure is preferred over a twisting movement.
Chemical strategies that involve exposing attached ticks to petroleum jelly, fingernail polish, isopropyl alcohol, gasoline, or methylated spirits are ineffective and not recommended.
There is no evidence that using local or systemic medications such as locally infiltrated anesthetics or systemic ivermectin is effective in removing or exterminating attached ticks.
Remove ticks as soon as possible. To meaningfully reduce the risk of Lyme disease, ticks should be removed within 36 hours.
A single dose of 200 mg doxycycline orally is recommended after a high-risk tick bite to reduce the risk of Lyme disease if given within 72 hours.
Outside of high-risk Lyme disease exposures, prophylactic antibiotics are not indicated.
Individuals who develop systemic or high-risk symptoms (fever, generalized rash, arthralgias, cranial nerve palsy, dyspnea, or syncope) related to a suspected TBI should be evacuated to a higher level of medical care.
Individuals who develop symptoms suggestive of Lyme carditis such as dyspnea, dizziness, or syncope should receive a screening ECG as soon as possible and would benefit from a thorough cardiovascular evaluation in an appropriate clinical setting.
Although no vaccine for tick-borne encephalitis is currently available in the United States, vaccines such as Encepur appear to be efficacious for inducing seroconversion against tick-borne encephalitis.
Educational programs should be encouraged as these can change behavior and lower rates of TBI.
SOURCE: Wilderness Medical Society
TICKS AND LYME DISEASE IN CANADA
Not all ticks carry the bacteria that causes Lyme disease - or any disease, for that matter.
There are several types of ticks found in Canada, but only black-legged ticks can transmit bacteria that cause the condition and only if they are infected with it, according to the Government of Canada's website.
Early detection is one of the best ways to treat Lyme disease.
Experts say the condition is on the rise in Canada and the U.S. due to a combination of ticks expanding northward and warmer weather, which is allowing the arachnids to survive in climates that were previously too cold.
It can take three days to one month for symptoms of Lyme disease to occur and it can be successfully treated with antibiotics.
Thumbnail image created by Cheryl Santa Maria. Tick sign: Garbort71/Getty Images Pro.
