Lyme disease and deer ticks

Clark Throssell

Clark Throssell, Ph.D., discusses Lyme disease and deer ticks with Timothy Gibb, Ph.D. Gibb is an entomologist at Purdue University. Tim has worked on numerous insect problems throughout his career, including turfgrass pests and insects that impact human health. You may reach Gibb at gibbs@purdue.edu for more information.

Q: Describe the distribution and life cycle of the deer tick.

The deer tick, properly called a black-legged tick, is widespread on the East Coast, throughout the Midwest and along the West Coast. It continues to spread and is now found in isolated pockets throughout the country.

The black-legged tick has four major life stages; egg, larva, nymph and adult. The adults lay eggs that overwinter in soil and hatch in spring. The eggs develop into larvae, nymphs and then into adults. Except for the egg stage, each life stage of the black-legged tick requires a blood meal to survive. Rodents, deer, birds, horses, dogs, humans and other animals can serve as a source for the blood meal.

Q: What has to happen for the black-legged tick to transmit Lyme disease to a person?

First, not all black-legged ticks carry Lyme disease. Nymphs are the most likely life stage to transmit Lyme disease to humans, and most disease transmission occurs from May through July. Nymphs are about the size of the head of a pin. When a nymph comes in contact with a human, it seeks an area of bare skin and bites. People are unable to feel the bite, and the nymph needs to attach for a minimum of 24 hours to transmit the bacteria to a person.

Q: How do nymphs come in contact with people?

Nymphs of black-legged ticks crawl to the top of knee or waist-high vegetation and wait for an animal or person to brush against the vegetation. As the animal or person brushes the vegetation, the nymph grabs onto the person or their clothing with its legs and crawls until it finds a suitable area of bare skin to bite.

Q: What can be done on a golf course to minimize contact with black-legged ticks?

Black-legged ticks are not found in mowed areas. Therefore, regular mowing of rough, fairways, tees and greens is a good way to exclude black-legged ticks. Golfers and maintenance staff should avoid areas of tall vegetation when possible. They also should conduct a tick check after being on the golf course, particularly if they have been in knee- or waist-high vegetation, and take a shower.

Spraying an over-the-counter insect repellant that contains DEET on legs, ankles, feet and shoes is a good idea before venturing out on the golf course. It’s not practical or necessary to spray an insecticide on large areas of a golf course to control black-legged ticks.

Q: What are the symptoms and long-term health consequences of Lyme disease?

Each person reacts differently to Lyme disease, but common symptoms that occur seven to 14 days after being bitten by a black-legged tick are fever, headache, fatigue, neck pain and stiffness in joints and muscles. If diagnosed early, Lyme disease can be effectively treated with antibiotics because the causal disease agent is a bacterium.

If you suspect that you have Lyme disease, a medical care provider can perform a test to determine the presence of the disease-causing bacteria. Only about 60 percent of people infected with Lyme disease show the “bull’s-eye” rash commonly associated with the disease.Lyme disease can have serious health consequences for those bitten by a disease-transmitting black-legged tick. Left untreated, or not treated in a timely fashion, Lyme disease can cause significant long-term health problems, including arthritis in large joints and damage to the nervous system that may lead to incapacitation and even death.

The incidence of Lyme disease is increasing, and people — including golfers and golf course maintenance staff who enjoy outdoor activities — need to be vigilant about Lyme disease.