Tick Talk—It’s Just a Matter of Time
Lyme Disease is caused by the transmission of a bacteria called Borellia burgdorferi from a bite from an infected black legged tick, also known as a deer tick. Lyme can also be transmitted by the Western black legged tick, found predominantly in California, Oregon and Washington State. The tick must be attached for at least 24 hours before transmission can occur. While most cases of transmission occur after 36 hours of attachment, it can take up to 72 hours for a tick to transmit the bacteria responsible for Lyme Disease.
In contrast to Lyme, another tick-borne disease, Powassan virus (POWV) which causes encephalitis and meningitis, can be transmitted in as little as 15 minutes. Although rare, cases have been increasing in northeastern states, including New York, and those in the Great Lakes region. It is not within the scope of this article to discuss POWV. More information can be obtained at https://www.cdc.gov/powassan/faqs.html#what-is.
The incidence of Lyme Disease in the United States has more than doubled over the last two decades and continues to rise as ticks spread throughout New York State and migrate further west. Ninety five percent of U.S. cases are reported from fifteen states in the Northeast and the District of Columbia, New York among them. Although Lyme Disease is the most common tick-borne disease in the U.S., Rocky Mountain Spotted Fever, Babesiosis, Tularemia, Anaplasmosis and Ehrlichiosis are also carried by ticks.
The size of the tick depends upon their life stage and varies accordingly, from the size of a grain of sand (larva) to the size of an apple seed (adult). The nymph and the adult female are the usual culprits of spreading disease. Whereas transmission can occur anytime during the year, the months of June and July are the most threatening months for disease transmission by the nymph. The adult tick is more likely to infect during the cooler months and is more easily detected on the human body due to its larger size.
From left to right: larva, nymph, adult male, adult female placed on a dime for reference of relative size
Ticks do not fall from trees, they do not fly or jump. Ticks possess eight legs that they use for “questing”. Strategically positioning themselves on commonly used paths, ticks sense body heat, moisture and odors and simply climb onto the body and latch on.
Its back legs attach to the tips of grasses or shrubs and lie in wait, while the front legs extend outward waiting for an animal or human to brush up against them.
Ticks usually wander from the site of attachment up higher on the body where wild or domesticated animals find it difficult to swat them off. In humans, they settle in several common locations where the skin is thinner which facilitates puncture. In and around the hair and ears, under the arms, inside the belly button, around the waist, between the legs and in back of the knees are favorite hideouts where ticks can remain unnoticed, especially if they are in the smaller nymph stage of development—the size of a poppy seed or the tip of a new crayon. After puncturing the skin, they insert a feeding tube from their mouths. Barbs on the feeding tube and secretions of saliva which contain a cement-like substance assures a firm attachment. The saliva also contains an anesthetic which prevents the host from feeling the presence of the tick. Typically, tick bites do not itch or cause pain.
The tick requires a new host from which to acquire a blood meal during each of the four stages of its lives in order to survive. As the tick feeds and becomes engorged on the blood of the host, small amounts of the tick’s saliva enter the host and pass on a pathogen if the tick is infected. Estimates vary on the percentage of ticks that are reported to be infected. Some sources state that only 33% of ticks are infected, while other estimates range from less than 1% to up to 50%, depending on the geographic location of the tick.
Awareness and timeliness is the key. Ticks can be found in your own backyard and hang out in dead leaves, tall grass, shrubs, wooded trees and shaded vegetation. They don’t like short grass in open sun. There are many reasons for the annual increase of tick bites and Lyme Disease, including range expansion and increasing numbers of ticks. With climate change causing mild winters and early springs, we’ve given ticks the gift of time. Take it back! Do a thorough body check after you’ve been outside. Rather than wait to see a medical professional for removal, immediately remove the tick yourself and then seek medical care.
To remove a tick, use a fine tipped tweezers and grab the tick as close to the skin as possible. Pull straight upward with steady even pressure. Do not twist or jerk the tick. Wash the area with soap and water or alcohol. Then wash your hands. Safely bring the tick with you to the Emergency Department or to your medical provider’s office so that it can be identified. Your provider will ask you a number of questions including where the tick bite occurred, when it was removed, and whether the tick was flat or engorged with blood. Determination will be made as to whether the bite was from a black legged tick and whether doxycycline is appropriate and safe for you to take. There are a number of considerations to be made before a decision is made to treat prophylactically.
Prophylaxis after exposure to a tick bite and treatment for a diagnosed infection of Lyme Disease are two separate processes.
Post-Exposure Prophylaxis (PEP) with preventative antibiotics has only been shown to be effective against Lyme Disease and only if administered shortly after removal. Since most tick bites are not infectious, routine PEP is not recommended. Current clinical guidelines recommend preventing Lyme with a one time dose of doxycycline.
Treatment for Lyme Disease can be prescribed if a positive diagnosis is determined. Regardless of prophylaxis or treatment, return to your provider if fever, rash or malaise (discomfort, unease) occurs within days or a month after a bite. The most common manifestation of a tick bite is a rash (sometimes in the form of a “bull’s eye”) in the first month after a bite, but about half of those with early disseminated Lyme Disease do not have a rash or don’t recall being bitten.
Perhaps it should be noted that there is controversy regarding the prophylaxis and treatment of Lyme Disease. Some “Lyme literate” physicians contend that the 2020 Clinical Practice Guidelines adopted by the Infectious Diseases Society of America, American Academy of Neurology, and American College of Rheumatology for the Prevention, Diagnosis and Treatment of Lyme Disease may be inadequate. It should also be noted that the decision to provide unnecessary prophylaxis has much to do with antibiotic resistance, adverse drug reactions and an increase in healthcare costs.
Furthermore, despite treatment with a 2-4 week course of antibiotics for an infection which cures most cases of Lyme disease, some patients can develop Post-Treatment Lyme Disease Syndrome which can cause pain, fatigue or difficulty thinking that lasts more than 6 months. Neurological and arthritic complications can also occur. Continued antibiotic treatment is not indicated and poses serious health risks in these cases.
A vaccine for Lyme Disease is not currently available. In 2002, LYMERix®, a previous vaccine for Lyme disease, was taken off the market by the manufacturer due to a lack of consumer interest. A new vaccine, VLA15, is in Phase 3 clinical (human) trials of study. In addition, a monoclonal antibody injection is scheduled to begin human trials soon which would provide seasonal prophylaxis annually against Lyme disease.
Avoiding tick habitat, staying on a central mowed path, performing daily tick checks, bathing within two hours of being outdoors, washing clothes after coming indoors in hot water or drying them on high heat for ten minutes, using EPA recommended insect repellants and managing one’s yard will serve you well to prevent tick bites.
Identifying an insect repellant that is appropriate for your needs is easy with a tool provided by the Environmental Protection Agency (EPA), available at https://www.epa.gov/insect-repellents/find-repellent-right-you. In addition, permethrin-factory treated clothing is available on-line which is ideal for camping. Permethrin spray is also available for treating clothing and shoes but should never be used on the body. DEET in a concentration of no greater than 25%, Picardin, IR 3535 and Oil of Lemon Eucalyptus are safe alternatives for topical application. Consult the EPA tool for products available under proprietary names for purchase at stores or on-line.
There are a number of helpful images available on the CDC website regarding how to remove ticks, where to conduct tick checks on the body, an image of ticks on a poppy seed muffin for size comparison, as well as many others available at https://www.cdc.gov/ticks/gallery/.
In summary, if you have encountered a tick, don’t panic! Simply being aware of the facts buys you plenty of time to prevent an infection of Lyme Disease. Be informed. Know how to prevent and take action if you get bit. Be prepared. Have a fine tipped tweezers available in a first aid kit in your cottage. Above all, continue to safely enjoy the outdoors and the multitude gifts nature has to offer!
Karen Spinelli Davidson, PharmD
References Available Upon Request