Wilderness: Tick Bite

Tick Bites Overview

Ticks are blood-sucking members of the class Arachnida, a group of arthropods that also includes spiders, scorpions, and mites. Ticks are divided into 3 families: Ixodidae (hard ticks), Argasidae (soft ticks), and Nuttalliellidae. The Nuttalliellidae family has only one species and is only in southern Africa.

• Globally, ticks are second only to mosquitoes as vectors (carriers) of human disease. In North America, ticks outrank even mosquitoes as the leading perpetrator of vector-borne infections. Ticks cause disease in humans or animals either by transmitting germs or by secreting toxins or venoms.
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• A number of tick-borne diseases are recognized in the United States. They include Lyme disease, Rocky Mountain spotted fever, relapsing fever, Colorado tick fever, ehrlichiosis, babesiosis, tularemia, Q fever, and tick paralysis. Hard ticks transmit all the major tick-borne diseases in North America, with the exception of relapsing fever.
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• Peak infection times are in the spring and summer during the nymph portion of the tick’s 2-year life cycle (larvae, nymph, adult). The nymphs are responsible for about 90% of all infections.
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• The most effective way to combat tick-borne diseases is to focus on measures to prevent them from attaching to the body. If a tick attaches to the body, find and properly remove it. (See Tick Bite Prevention and Treatment.)

Tick Bite Causes

Ticks cause disease in humans or animals either by transmitting microorganisms or by secreting toxins or venoms after they have attached to a host.

Both sexes of ticks are bloodsuckers. Ticks are unable to fly or jump. Hard ticks encounter hosts, including humans, by climbing on vegetation and waiting passively for hours or days for someone or something to come along, so-called questing.

Vibration or a carbon dioxide plume stimulates the tick to wave its legs or move about to facilitate attachment to a passing host. When the tick encounters fur or skin, it climbs onto the host and then crawls around in search of an appropriate location on which to attach and feed. The attachment bite is usually painless and goes unnoticed.