Deer Tick Nymph

Despite dating back over a century, Lyme disease was named as recently as 1975 after a cluster of cases were identified in the town of Lyme, Connecticut and in 1982, the bacterium responsible for the disease was identified.

In the United States, black-legged ticks (hard bodied ticks more commonly known as deer ticks) are the only known transmitters of the disease.

Recent years have seen a large increase in reported cases and this trend appears to be accelerating to the point that congress is considering increasing the Lyme disease budget of the CDC (the Centers for Disease Control and Prevention) threefold.

The Cause

The life cycle of the deer tick comprises three growth stages: the larva, nymph and adult. Larval activity peaks in August, nymphs are active during the summer months, and adults are active during the spring and fall.   Host-seeking larvae are not infected and infected adult ticks are large enough to be noticed and are usually removed within 24 hours before the bacterium is transmitted.

An Adult Deer Tick

Humans, and their pets, tend to be infected when they are bitten by infected nymphs between late May and August.   This is when the nymphs are most active and outdoor activity is at its highest during summer.   As nymphs are about the size of a poppy seed, they often go unnoticed until fully engorged and are responsible for nearly all human Lyme disease cases.   In New England, up to 25% of nymphs have been found to harbor the Lyme disease bacteria.

Prevention

Check the skin and scalp for deer ticks, both at the beginning and the end of any outdoor activity, tuck pant legs in socks and use insect repellent.   Insecticides can be used to treat property.   A local veterinarian can advise on the best way to protect pets. If a nymph or adult deer tick is found, the entire tick should be immediately removed.

As the bacteria is carried in the tick’s salivary glands, it is important not to cause trauma to the tick (such as applying heat or covering it in Vaseline) as this will likely cause the tick to release saliva into the host and increasing the risk of the bacteria being transferred.

Symptoms and Treatment

Bullseye Lyme Disease Rash

Typical symptoms, according to the CDC include “fever, headache, fatigue, and a characteristic skin rash… which often takes a bull’s-eye appearance and is observed in about 80% of Lyme disease patients… If left untreated, infection can spread to joints, the heart, and the nervous system.”

If bitten by a tick in an area, such as New England, that is known to have Lyme disease, medical attention should be sought right away so that a proper diagnosis can be made and antibiotic treatment started.

Later in this series, we will later discover how the spread of Lyme Disease is tied into overall changes in the Ecosystem.

In the next installment, one talks to Patrick Comins of The National Audubon Society to establish the vital role played by birds.