What are ticks?
Ticks are Arachnids, a class of animals that also includes spiders, mites, chiggers and scorpions. All ticks are wingless and have four pairs of legs, each containing a small suction cup. Ticks are external parasites, meaning that they require a host for food and/or shelter. For ticks, an animal (human or otherwise) serves as the host.
Ticks are divided into 2 major groups: soft ticks (Family: Argasidae) and hard ticks (Family: Ixodidae).
- Soft ticks are tough and leathery looking; they have more than one young (nymph) stage; and their sexes cannot be differentiated. Though soft ticks are not vectors of many arboviruses (viruses transmitted by Arthropods), they do act as vectors of African swine fever virus among pigs.
- Hard ticks posses a hard dorsal shield that is small in females and covers the whole male. They have only one larval and one young (nymph) stage. Hard ticks are carriers of many diseases including:
► See How to Prevent Tick Bites (PDF)
What ticks are present in New York City and what diseases do they transmit?
Three types of hard ticks are resonsible for transmitting the tick-borne diseases reported among New Yorkers.
American dog ticks (Dermacentor variablis) are about 1/8" long and are common in New York City. They are dark brown with scattered patterns of white on the body below the head. Females are larger then males. They are the vector for Rocky Mountain spotted fever and tick paralysis.
Blacklegged ticks, also referred to as deer ticks (Ixodes scapularis), are about 1/3" long and commonly occur in the northeastern and mid-western United States. Females are larger then males and have a red body. Males are dark brown/black. They are the vector for an array of diseases including Lyme disease, anaplasmosis, babesiosis, and tick paralysis. The blacklegged tick occurs, but is not prevalent in NYC. Most recently it was collectd from Pelham Bay Park in the Bronx; Clay Pit Pond, High Rock and Wolfe's Pond Parks in Staten Island; and Alley Pond Park, Highland Park and Floyd Bennett Field in Queens and Brooklyn. Some of the ticks from Pelham Bay and Clay Pit Pond Parks tested positive for Borrelia burgdorferi, the bacterium that causes Lyme disease. It is abundant throughout Westchester, Nassau, and Suffolk Counties and many counties in upstate New York.
Lone star ticks (Amblyomma americanum) are about 1/3" long, and are rarely seen in New York City, but are common in the southeastern and south-central states. Females are mostly brown/beige with a white spot in the middle of the body. Males have scattered spots or streaks along the body. It is the vector for human monocytic ehrlichiosis, tick paralysis, and Southern Tick Associated Rash Illness (STARI). This tick is not typically found in New York City. It is predominantly found in the southeastern/south-central areas of the United States, although surveillance shows it is advancing into the northeastern US.
What is the tick life cycle?
The life cycle of a hard tick consists of four stages: egg, larva, nymph, and adult. The lifespan of the average tick is about two years. In order for ticks to survive, grow, and reproduce, they take frequent blood meals from a host. To obtain blood, the tick will attach to the host by inserting its mouthparts into the skin. A hard tick may remain embedded in the skin for up to a week or until it is engorged (swollen) with blood.
How do ticks transmit diseases?
Ticks transmit diseases while feeding on a host's blood. An infected tick can transmit the disease pathogen (disease-causing agent), through the saliva and the gut contents. The infection process begins when a hard tick nymph takes a blood meal from an animal host (e.g., field mouse), which may also be a reservoir for any number of pathogens. After becoming fully engorged with blood, it falls off the host. Eventually the tick molts (transforms) into an adult tick. If the tick is a female, it must find another host and take a blood meal in order to mature its eggs. Male ticks only feed intermittently. After feeding from a host that was a reservoir for pathogens, a tick is capable of injecting that pathogen into the blood stream of its next host.
What is tick paralysis and what are its symptoms?
Tick paralysis occurs when an engorged and egg-bearing female tick produces a neurotoxin in her salivary glands while attached to the host. It is mostly found among young children. The symptoms of tick paralysis include fatigue and numbness in the arms and legs. As time progresses, paralysis of the extremities occurs, followed by paralysis of the tongue and face. More severe symptoms include convulsions and respiratory failure. Once the tick is removed, the symptoms will vanish almost immediately.
What is the treatment for tick paralysis?
The only treatment for tick paralysis is to remove the tick. If symptoms persist, contact a physician immediately. If possible, keep the tick and bring it to the physician for proper identification.
What is the best way to remove a tick?
If a tick is crawling on you, remove the tick and discard immediately. If the tick is embedded in the skin, follow these steps:
- Using a pair of tweezers, grab a hold of the tick at the point where it is closest to the skin (this is the head of the tick). Do not grab the body of the tick, as separating it from embedded mouthparts of the head may cause secondary infection.
- Gently and carefully, pull up on the tick with slow, even pressure to gradually ease out the mouthparts.
- If tweezers are not available, use fingers shielded with tissue paper or rubber gloves. Do not handle ticks with bare hands.
- After removing the tick, wash the areas and your hands with alcohol or soap and water.
- Do not use petroleum jelly, nail polish remover, or heat to remove the tick since these methods may increase the risk of infection with a tick-borne disease.
- Do not squash or squeeze the tick during removal.
- If possible, place the tick in alcohol or in a plastic zip lock bag and store in the freezer for identification. If your physician suspects a tick-borne disease he/she may ask to see the tick.
- Contact your medical provider immediately if you go on to develop any signs or symptoms of a tick-borne disease.
How can I prevent tick bites and lessen be less likely to get a tick-borne disease?
When traveling or staying in tick habitat (i.e. tall grass, overgrown brush, etc.), particularly during warmer months when ticks are more active, use the following guidelines:
- Wear light colored clothing while entering tick habitats, as it will be easier to notice ticks on your clothing;
- Tuck pants into socks and shirts into pants to prevent any ticks from attaching to your skin.
- Tie hair up or wear a hat while entering a tick habitat.
- Ticks on clothing may be killed by tumbling clothes in a dryer on the highest heat for at least one hour.
- Wear gloves while gradening because ticks generally live under the soil and in leaf litter.
- Use insect repellant containing DEET. Repellents containing picaridin and oil of lemon eucalyptus are also known to be effective. For more information visit the EPA website on repellants.
- Permethrin products can be applied to clothing/boots (not to skin), actually kill ticks that come in contact with the treated clothing, and usually stay effective through several washings.
- Use flea and tick repellents on your pet. Speak to your veterinarian for guidance on appropriate products.
- When outdoors, check for ticks on yourself, children, and pets every 2 to 3 hours and upon returning from outdoors.
- Look for ticks in all joint areas, the navel, behind ears, in the hairline, and in other skin folds.
- Wash all skin treated with insect repellent thoroughly.
- Showering within two hours of coming indoors can also reduce the risk of being bitten by a tick.
Around the Home
- Keep your lawn mowed, cut overgrown brush, and remove leaf litter to reduce tick populations.
- When mowing the lawn, wear a hat, long pants, and shoes. Adult ticks crawl up branches and grass to grab onto a passing host.
Photographs: Courtesy of the Lyme Disease Foundation
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Last Updated July 24, 2013