Welcome To The World Of Ticks

Introduction

Ticks are small arachnids, part of the order Parasitiformes. Along with mites, they constitute the subclass Acari. Ticks are ectoparasites (external parasites), living by feeding on the blood of mammals, birds, and sometimes reptiles and amphibians.

Almost all ticks belong to one of two major families, the Ixodidae or hard ticks, which are difficult to crush, and the Argasidae or soft ticks. Adults have ovoid or pear-shaped bodies which become engorged with blood when they feed, and eight legs. As well as having a hard shield on their dorsal surfaces, hard ticks have a beak-like structure at the front containing the mouthparts whereas soft ticks have their mouthparts on the underside of the body. Both families locate a potential host by odour or from changes in the environment. Because of their habits of ingesting blood, ticks are vectors of at least twelve diseases that affect humans and other animals.

Ticks cannot jump or fly, but often climb grasses and shrubs in order to come in contact with people or animals walking by so they can attach themselves and feed on blood.

Recognition

Ticks are arthropods that are sometimes mistakenly called insects. Insects have three body regions, six legs, and typically possess wings. Ticks lack wings, have two body regions, and depending upon their developmental stage, may have either six or eight legs. Ticks possess tremendous potential for transmitting disease-causing organisms to humans and other animals. These organisms include protozoa, viruses, and bacteria. Bites from certain ticks can cause a rare limp paralysis starting in the lower limbs and moving upwards with death resulting if the tick is not promptly removed. Additionally, tick bites can cause skin irritations or even allergic reactions in sensitive people who are repeatedly bitten.

LYME DISEASE

The symptoms are usually divided into 3 stages, and they mimic several different commonly occurring diseases.

Symptoms: Spreading rash, fever, flu-like symptoms, aches.


  1. Stage 1: Expanding rash (Erythema migrans or EM rashes). 3-30 days after bite.

    • Ringlike/builseyelike appearance to rash.

    • One or more rash sites.

    • May or may not have flu symptoms.

    • May come and go or persist.


  2. Stage 2: Complications or disorders of the heart or nervous system.

    • Heart. Varying degrees of blockage of the heart muscle.

    • Nervous system. Meningitis, encephalitis, facial paralysis.

    • "Bell's palsy," other conditions involving peripheral nerves.

    • Migratory pain in joints, tendons, muscles, and bones, often without joint swelling orredness.


  3. Stage 3: Months to years after disease onset.

    • Arthritis that appears and disappears intermittently for several years.

    • Enlarged knee joints.

    • Erosion of cartilage and bone.


Treatment notes:

  1. Once bitten by a blacklegged/deer tick possessing the spirochete, it may not produce antibodies in the victim for up to 6 weeks. Therefore, it takes time to verify that one has Lyme disease.

  2. Oral medications for Lyme disease can destroy the spirochetes in the blood and give an antibody reading that the person is "cured." However, the spirochete may persist in the brain and reappear in the person 5-10 years later. Therefore, intravenous treatment is advised over oral medications by some physicians considered experts in this area, especially for persons showing Stage 2 and Stage 3 symptoms.


Tick Removal:

  1. The best way to remove a tick found attached to a person or pet is to firmly grasp it with a pair of tweezers as close to the skin as possible.

  2. Pull it firmly but gently backwards until the tick pulls free.

  3. Do not touch the tick, but save it in rubbing alcohol for later identification.


Epidemiological Notes:

  1. Epidemiologists have isolated an unidentified type of spirochete from ticks collected in southeastern Missouri which appears to be different from Borrelia burgdorferi.

  2. Initial studies show that infection by this "new/different" spirochete can result in the expanding rash (EM) but that it is less often followed by multiple skin lesions than with Lyme disease.

  3. Therefore, more than one species of tick may be the vector. It is best to characterize the Missouri victims as suffering from a "Lyme-like" illness rather than Lyme disease.


Diseases Transmitted by Ticks