TICKS

INTRODUCTION

• Ticks are small arachnids in the order Parasitiformes.
• Along with mites, they constitute the subclass Acarina. 
• Ticks are ectoparasites (external parasites), living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians. 
• Ticks are vectors of a number of diseases, including Lyme disease, Q fever (rare; more commonly transmitted by infected excreta),Colorado tick fever, Rocky Mountain spotted fever, African tick bite fever, Crimean Congo hemorrhagic fever, tularemia, tick-borne relapsing fever, babesiosis, ehrlichiosis, and tick-borne meningoencephalitis, as well as bovine anaplasmosis and probably the Heartland virus.
• Some species, notably the Australian paralysis tick, are also intrinsically venomous and can cause paralysis.

Scientific classification

Kingdom:  Animalia

Phylum:  Arthropoda

Class: Arachnida

Subclass: Acari

Order: Parasitiformes

Leach, 1815

Suborder:   Ixodida

Superfamily: Ixodoidea

Leach, 1815

Families

Ixodidae – hard ticks

Argasidae – soft ticks

Nuttalliellidae

LIFE CYCLE

TYPE OF TICKS

SYMPTOMS OF TICKBORNES ILLNESS

Many tickborne diseases can have similar signs and symptoms. 

If you have been bitten by a tick and develop the symptoms below within a few weeks, a health care provider should evaluate the following before deciding on a course of treatment:

The most common symptoms of tick-related illnesses are:

-Fever/chills: With all tickborne diseases, patients can experience fever at varying degrees and time of onset.

-Aches and pains: Tickborne disease symptoms include headache, fatigue, and muscle aches. With Lyme disease you may also experience joint pain. The severity and time of onset of these symptoms can depend on the disease and the patient's personal tolerance level.

-Rash: Lyme disease, southern tick-associated rash illness (STARI), Rocky Mountain spotted fever (RMSF), ehrlichiosis, and tularemia can result in distinctive rashes:

• In Lyme disease, the rash may appear within 3-30 days, typically before the onset of fever. The Lyme disease rash is the first sign of infection and is usually a circular rash called erythema migrans or EM. 
• This rash occurs in approximately 70-80% of infected persons and begins at the site of a tick bite. It may be warm, but is not usually painful. 
• Some patients develop additional EM lesions in other areas of the body several days later.
• The rash of (STARI) is nearly identical to that of Lyme disease, with a red, expanding "bulls eye" lesion that develops around the site of a lone star tick bite. 
• Unlike Lyme disease, STARI has not been linked to any arthritic or neurologic symptoms.
• The rash seen with Rocky Mountain spotted fever (RMSF) varies greatly from person to person in appearance, location, and time of onset. About 10% of people with RMSF never develop a rash. 
• Most often, the rash begins 2-5 days after the onset of fever as small, flat, pink, non-itchy spots (macules) on the wrists, forearms, and ankles and spreads to the trunk.
•  It sometimes involves the palms and soles. 
• The red to purple, spotted (petechial) rash of RMSF is usually not seen until the sixth day or later after onset of symptoms and occurs in 35-60% of patients with the infection.
• In the most common form of tularemia, a skin ulcer appears at the site where the organism entered the body. 
• The ulcer is accompanied by swelling of regional lymph glands, usually in the armpit or groin.
• In about 30% of patients (and up to 60% of children), ehrlichiosis can cause a rash. 
• The appearance of the rash ranges from macular to maculopapular to petechial, and may appear after the onset of fever.
• Tickborne diseases can result in mild symptoms treatable at home to severe infections requiring hospitalization. 
• Although easily treated with antibiotics, these diseases can be difficult for physicians to diagnose. 
• However, early recognition and treatment of the infection decreases the risk of serious complications. 
• So see your doctor immediately if you have been bitten by a tick and experience any of the symptoms described here.

HOW IS A TICK REMOVED FROM THE SKIN?

The following is a step-by-step method that is suggested for safe and effective removal of all types of ticks. 

Web citations 2 and 3 show a diagram of how to place tweezers to remove a tick.

1. Wear hand protection such as gloves so you don't spread pathogens from the tick to your hands; use forceps or tweezers to grab the tick at skin level.
2. Grasp the tick firmly with the tweezers as close to the skin as possible without crushing the tick. Apply gentle pulling motion upward until the tick comes free. Twisting or turning the tick does not make removal easier because the mouthparts are barbed; in fact, such actions may break off the head and mouthparts, thereby increasing the chances for infection. The second web citation illustrates the proper removal of a tick.
3. Once the tick is removed, don't crush the tick because it may release pathogens. Consider keeping it in a tightly closed jar or taped to a piece of paper. Show the tick to the doctor if the person bitten becomes ill after the tick bite. Flush any removed ticks not kept for identification down the toilet or sink.
4. The area of the bite should leave a small crater or indentation where the head and mouthparts were embedded. If portions of the head or mouthparts remain, they may be removed by a doctor.
5. Thoroughly cleanse the bite area with soap and water or a mild disinfectant. Observe the area for several days for development of a reaction to the bite (rash or signs of infection). Apply antibiotic cream to the area as a precaution. Application of an antibiotic to the area may help prevent a local infection but usually does not affect the chance of developing diseases transmitted by the tick.
6. Wash hands thoroughly after handling any tick or instruments that touched a tick. Clean and disinfect any instruments that were 

HOW ARE BITES FROM TICKS PREVENTED?

The third web citation below has the CDC recommended methods (tips) for outdoor workers (and others) to avoid getting tick bites and is summarized here:

1. Avoid grassy areas and shrubs where ticks populations may be high and where they reside, waiting to grab a ride on a potential host.
2. Wear light-colored clothing so ticks can be easily seen, and brush them off.
3. Tuck pants into boots or socks to avoid ticks crawling up loose pant legs.
4. Apply insect repellant and use the brands designed to repel ticks. Follow label instructions. Avoid use of DEET-containing repellents on children. Carefully follow instructions and apply some repellents directly to skin and others to clothing. DEET-containing repellents with concentrations of 15% or less may be suitable for children. These should be carefully applied strictly following label directions. Repellents containing permethrins may be applied to clothing but not to skin. In areas that have a high tick population, DEET-containing repellents may need to be reapplied more frequently than for repelling mosquitoes. Follow the package label instructions carefully.
5. Promptly check yourself, others, and pets if exposed to areas where ticks are likely to be located.

REFERENCES : TICKS