Lyme disease is an infection caused by a spirochete bacteria called Borrelia burgdorferi, that is often found in the deer ticks, ( Ixodes scapularis ), and in the Western black-legged tick, ( Ixodes pacificus ). The life cycle of the tick plays a pivotal role in the transmission of this disease. The tick goes through three life stages: larva, nymph, and adult. The larvae tick will feed in the late summer months. They will feed once, generally on small animals, ( the most common being the white-footed mouse ), then after feeding, will drop off the host and enter a resting phase. The tick will rest through our most severe Minnesota winters, and in the Spring the larvae will molt into nymphs, that will also feed once. The nymph also likes small animals, but can also feed on birds, people, or other critters, during late Spring or Summer. During the Fall of the second year of it’s life, the nymph will molt into an adult. It is the adult tick that likes to feed on our White-Tailed deer, but like the nymph, may also select birds, etc. After the adult feeds, it will mate, and the female tick will drop her eggs on the ground of the forest. These eggs will hatch in the following Summer, and the cycle repeats itself. The adult ticks that are infected with Lyme organisms do not pass on their infection to their offspring eggs. Each tick will have to become infected at a later stage when they feed on an animal host that is infected with the Lyme organism. After the tick becomes infected, it will remain a carrier of the Lyme disease for the rest of it’s life.
This is the most commonly diagnosed disease spread by an insect. The Center for Disease Control and Prevention ( CDC ) began watching this disease seventeen years ago, and since then the incidence of the disease has increased over thirty two fold!
Lyme disease is spread to people only by an infected tick bite. Contrary to what you hear “up the lake”, it is not contagious, cannot be spread by a bite from your pet or any contact with an animal infected with this disease, ie: Old Bucky you may be cleaning.
These ticks tend to live in the woods and high grasses. After the tick lands on your body, they will embed their mouthparts into your blood stream to begin the free eats program, as it were. Usually it will take 24 to 48 hours of this attachment before the disease can be spread, as the B. burgdorferi organism will move from the ticks midgut to their salivary glands to ultimately be injected into your body. Once inside you these organisms will rapidly multiply and spread to various organ systems, and you now have this pesky disease!
Lyme disease is divided into three stages, early, disseminated, and late.
In the early stage, the “bull’s-eye” rash in seen in about 60 to 80% of cases, so called erythema migrans, a red swollen rash. This along with, muscle & joint aches, fatigue, fever and chills. It is not fun, I assure you.
In the disseminated disease stage, more skin lesions may occur, and the first neurologic manifestations such as nerve inflammation, with associated Bell’s facial palsy, or it may involve the nerves in the heart. This can cause cardiac rhythm abnormalities. Migratory pain in joints and surrounding soft tissues is frequently seen.
Late Lyme disease may not manifest symptoms until months or even years after the initial infection. Hence the desire to treat the disease early, and throughly. The late symptoms also include more severe neurologic problems, spastic paralysis of the lower limbs, cognitive problems, encephalomyelitis, ( inflammation of the brain or spinal cord), or other nerve involvement. Patients may have chronic joint inflammatory arthritis.
Some persons infected with Lyme disease will not have symptoms until they progress into the late stage of the disease. This obviously makes diagnosing this disease difficult. The lab tests are not reliable, often we see false positive and negative results. Those persons who do have symptoms should be treated with high dose antibiotic, and nonsteroidal anti-inflammatory drugs like Motrin, etc.
There is a vaccine LYMErix, that has recently become available. The drug company says it is safe and effective, but the last unbiased report I read, called the vaccine “worrisome”, hence I don’t use it.
Our pilot with the Lyme disease was placed on treatment, and had all of symptoms ablate. While symptomatic, you should refrain from flying, but after returning to normal, flying can be resumed. Should you progress to the second or third stages of disease, you would need to apply for a Special Issuance Medical Certificate to continue flying.
William A Schmidt, M.D.
