Tick-borne disease

Tick-borne diseases
An eschar suggestive of tick bite

Tick-borne disease Microchapters
Overview
Classification Bacterial 1-Lyme disease 2-Relapsing Fever] Typhus (Rickettsia) 1-Rocky Mountain Spotted Fever 2-Helvetica Spotted Fever 3-Ehrlichiosis 4-Tularemia 5-Rickettsiosis 6-Q fever 7-Lymphangitis more.. Viral 1-Tick-borne Meningoencephalitis 2-Colorado Tick Fever 3-Crimean-Congo Hemorrhagic Fever 4-Severe Febrile Illness 5-Bourbon virus infection more.. Protozoal 1-Babesiosis
Pathophsiology
Epidemiology and Demographics
Differentiating Tick-Borne Diseases from other Diseases
Risk Factors
Diagnosis
Treatment
Tick Removal

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Ilan Dock, B.S.; Kiran Singh, M.D. [2]

Overview

Tick-borne diseases are diseases or illnesses transmitted by ticks. As the incidence of tick-borne illnesses increases and the geographic areas in which they are found expand, it becomes increasingly important that health professionals be able to distinguish the diverse, and often overlapping, clinical presentations of these diseases.

Tick-borne disease Classification

Disease	Organism	Vector	Endemic Regions
Bacterial Infection
Borreliosis (Lyme Disease)	Borrelia burgdorferi sensu lato (bacterium) and B. mayonii	I. scapularis, I. pacificus, I. ricinus, and I. persulcatus	United States: Eastern Region Southwest Region
Relapsing Fever	Borrelia Species; Borrelia hermsii, Borellia Parkeri, Borellia duttoni, Borrelia miyamotoi	Ornithodoros species	Widespread: Spain Saudi Arabia Asia Africa Canada Western United States
Typhus (Rickettsia)
Rocky Mountain Spotted Fever	Rickettsia Rickettsii	Wood Tick (Dermacentor Variabilis), D. andersoni	United States: Eastern Region Southwest Region
Helvetica Spotted Fever	Rickettsia Helvetica	Ixodes Ricinus (European)	Europe: Sweden Switzerland France Laos
Ehrlichiosis (Anaplasmosis)	Ehrlichia Chaffeensis, E. Equi	Lone Star Tick (Amblyomma Americanum), Ixodes Scapularis	United States: South Atlantic Regions South-central Regions
Tularemia	Francisella Tularensis	D. Andersoni, D. Variabilis	United States: Widespread throughout the region, including higher populations in the Southeast, South-central, and the West.
Human neoehrlichiosis	Neoehrlichia mikurensis	Lone Star Tick (Amblyomma Americanum)'	Widespread: Europe Asia
Rickettsiosis	Rickettsia	No specific species identified	Widespread: South Africa Morocco Mediterranean
African tick-bite fever	Rickettsia africae	Amblyomma, Dermacentor, and Rhipicephalus species	Africa: Sub-Saharan West Indies
Queensland tick typhus	Rickettsia austalis	Ixodes species	Widespread: Australia Tasmania
Q fever (Typhus-like infection)	Coxiella burnetii (mimics the mechanisms of Rickettsia)	Ixodes holocyclus and Amblyomma triguttatum	Australia Widespread throughout Australia
Mediterranean spotted fever (Boutonneuse fever)	Rickettsia conorii	Brown Dog Tick (Rhipicephalus sanguineus)	Widespread: Southern Europe Southern and Western Asia Africa India
Far Eastern spotted fever	Rickettsia heilong-jiangensis	Tick	Widespread: Far portions of Eastern Russia Northern portions of China Eastern Asia
Aneruptive fever	Rickettsia helvetica	Ixodes species	Widespread: Northern and Central portions of Europe Non-specific portions of Asia
Flinders Island spotted fever (Thai tick typhus)	Rickettsia honei	Tick	Widespread in Independent Regions Australia Thailand
Japanese spotted fever	Rickettsia japonica	Tick	Japan Widespread yet isolated to portions of Japan
Mediterranean spotted fever-like disease	Rickettsia massiliae and R. monacensis	Tick	Widespread: R.massiliae induced: France Greece Spain Portugal Switzerland Sicily Central Africa Mali R.monacensis induced: Europe North Africa
Maculatum infection	Rickettsia parkeri	Tick	Americas: United States Portions of Canada South America
Tick-borne necrosis and lymphadenopathy	Rickettsia raoultii	Dermacentor marginatus	Widespread: Europe Asia
North Asian Tick Typhus	Rickettsia sibirica	Tick	Widespread: Russia China Mongolia
Lymphangitis	Rickettsia sibirica mogolotimonae	'No specific species identified	Widespread: Southern France Portugal China Africa
TIBOLA	Rickettsia slovaca	Dermacentor species	Widespread: Southern and Eastern Europe Asia
Viral Infection
Tick-borne Meningoencephalitis	TBEV virus	Ixodes Scapularis, I. Ricinus, I.persulcatus	Widespread: Europe Northern Asia
Colorado Tick Fever	CTF virus	Dermacentor andersoni	United States: Western Region
Severe Fever with Thrombocytopenia Syndrome	SFTS virus	Haemaphysalis longicornis Ixodes nipponensis Amblyomma testudinarium Rhipicephalus microplus A recent case is being assiciated with SFTS virus transmitted by a cat	Wetern Japan China
Crimean-Congo Hemorrhagic Fever	CCHF virus	Hyalomma marginatum, Rhipicephalus bursa	Widespread: South Asia North Africa Southern Europe
Severe Febrile Illness	Heartland Virus	Lone Star Tick (amblyomma americanum)	United States: Missouri Tennessee
Bourbon virus infection	Bourbon virus infection	Lone Star Tick	United States: Midwest and southern States
Protozoan Infection
Babesiosis	Babesia microti, B divergens, B.equi	Ixodes Scapularis, I. pacificus	Widespread: Northeastern United States Europe Asia

Pathophysiology

Tick-borne illnesses are caused by infection with a variety of pathogens, including rickettsia and other types of bacteria, viruses, and protozoa. Because ticks can harbor more than one disease-causing agent, patients can be infected with more than one pathogen at the same time, compounding the difficulty in diagnosis and treatment.

Life Cycle and Spread of Disease

General Tick Life Cycle

This image displays an example of the tick lifecycle, based on stages and the months that they are most likely to occur during.

• A tick's life cycle is composed of four stages: hatching (egg), nymph (six legged), nymph (eight legged), and an adult.
• Ticks require blood meal to survive through their life cycle.
• Hosts for tick blood meals include mammals, birds, reptiles, and amphibians. Ticks will most likely transfer between different hosts during the different stages of their life cycle.
• Humans are most often targeted during the nymph and adult stages of the life cycle.
• Life cycle is also dependent on seasonal variation.
• Ticks will go from eggs to larva during the summer months, infecting bird or rodent host during the larval stage.
• Larva will infect the host from the summer until the following spring, at which point they will progress into the nymph stage.
• During the nymph stage, a tick will most likely seek a mammal host (including humans).
• A nymph will remain with the selected host until the following fall at which point it will progress into an adult.
• As an adult, a tick will feed on a mammalian host. However unlike previous stages, ticks will prefer larger mammals over rodents.
• The average tick life cycle requires three years for completion.
  • Different species will undergo certain variations within their individual life cycles.

Spread of Tick-borne Disease

• Ticks require blood meals in order to progress through their life cycles.
• The average tick requires 10 minutes to 2 hours when preparing a blood meal.
• Once feeding, releases anesthetic properties into its host, via its saliva.
• A feeding tube enters the host followed by an adhesive-like substance, attaching the tick to the host during the blood meal.
• A tick will feed for several days, feeding on the host blood and ingesting the host's pathogens.
• Once feeding is completed, the tick will seek a new host and transfer any pathogens during the next feeding process.

Epidemiology and Demographics

Incidence

• Tick based infections are generally non-specific in regards to age, race, or gender. (However babesiosis is more frequently observed in older, male populations. An explanation for this has not yet been formulated.)
• Certain tick-borne illnesses will vary within patient populations when an auto-immune deficiency is present.
• Tick bites are more frequently reported during the spring and summer months which are noted to be in correlation with high tick activity.
• Higher risks are associated with individuals traveling within endemic areas.
• Inoculation within endemic areas is usually the result of a tick bite however transmission has been identified as a result of transfusions or transplantation.

Species and Regions

United States

American Dog Tick (Dermacentor Variabilis)

• Pacific Coast and east of the Rocky Mountains.
• Transmits tularemia and rocky mountain spotted fever.
• Primarily infects humans during the spring and summer months.

Blacklegged tick (Ixodes Scapularis)

• Northeastern and upper Midwest.
• Transmits Lyme disease, babesiosis, anaplasmosis, and Powassan disease.
• Primarily infects humans during the spring, summer, and fall months.

Brown dog tick (Rhipicephalus Sanguineus)

• Widespread throughout the United States.
• Transmits Rocky mountain spotted fever.

Gulf Coast Tick (Amblyomma Maculatum)

• Atlantic Coast and Gulf of Mexico (Along the coast of Northeastern Virginia until the Southern most portions of Florida. From Southeast Florida through the Gulf of Mexico into Texas).
• Transmits Rickettsia parkeri rickettsiosis (spotted fever).

Lone Star Tick (Amblyomma Americanum)

• Southeastern and Eastern United States.
• Transmits Ehrlichiosis, tularemia, STARI and Bourban virus.

Rocky Mountain Wood Tick (Dermacentor Andersoni)

• Colorado, Nevada, eastern California, eastern Oregon, eastern Washington, Idaho, Montana, Wyoming, and Utah.
• Transmits Rocky mountain spotted fever, Colorado tick fever, and tularemia.

Western Blacklegged tick (Ixodes Pacificus)

• Pacific Coast
• Transmits Anaplasmosis and Lyme Disease.

International

Hyalomma Marginatum

• Widespread: North Africa, Europe, and Asia.
• Transmits Crimean-Congo hemorrhagic fever.

Ixodes Ricinus

• Widespread throughout Europe and parts of North Africa.
• Transmits encephalitis and Lyme Disease.

Ixodes Persulcatus

Dermacentor Reticulatus

Differentiating Tick-Borne Diseases from other Diseases

Disease	Symptoms
Bacterial Infection
Borreliosis (Lyme Disease)	Flu-like illness, fatigue, fever, arthritis, neuroborreliosis, cranial nerve palsy, carditis and erythema migrans.
Relapsing Fever	Consistently documented high fevers, flu-like illness, headaches, muscular soreness or joint pain, altered mental state, painful urination, rash, and rigors.
Typhus (Rickettsia)
Rocky Mountain Spotted Fever	Fever, alterations in mental state, myalgia, rash, and headaches.
Helvetica Spotted Fever	Rash: spotted, red dots. Respiratory symptoms (dyspnea, cough), muscle pain, and headaches.
Ehrlichiosis Anaplasmosis	Fever, headache, chills, malaise, muscle pain, nausea, confusion, conjunctivitis, or rash (60% in children and 30% in adults).
Tularemia	Ulceroglandular, Glandular, Oculoglandular, Oroglandular, Pneumonic, Typhoidal.
Viral Infection
Tick-borne meningoencephalitis	Early Phase: Non-specific symptoms including fever, malaise, anorexia, muscle pains, headaches, nausea, and vomiting. Second Phase: Meningitis symptoms, headache, stiff neck, encephalitis, drowsiness, sensory disturbances, and potential paralysis.
Colorado Tick Fever	Common symptoms include fever, chills, headache, body aches, and lethargy. Other symptoms associated with the disease include sore throat, abdominal pain, vomiting, and a skin rash. A biphasic fever is a hallmark of Colorado Tick Fever and presents itself in nearly 50% of infected patients.
Crimean-Congo Hemorrhagic Fever	Initially infected patients will likely feel a few of the following symptoms; headache, high fever, back and joint pain, stomach pain, vomiting, flushed face, red throat petechiae of the palate, and potentially changes in mood as well as sensory perception.
Protozoan Infection
Babesiosis	Non-specific flu like symptoms.

Risk Factors

• The greatest risk factor associated with tick-borne diseases is actually being bitten by a tick.
• Traveling or residing within endemic regions will increase chances of infection.
• Tick activity is generally heightened during certain the spring and summer months.
• Within endemic regions, tick may choose an animal host, including a domesticated animal such as a dog or cat.
• Although rare, cases of blood transfusion and organ transplantation have been recorded as methods of transmission.
• All together, individuals who spend time outdoors and/or have pets that go outdoors in endemic regions are at risk for tick-borne disease.

Diagnosis

Physical Examination

A round red rash with a 2-5 mm central black area (eschar, an area of dead tissue) as shown in the photo is suggestive of a tick bite.

Laboratory Findings

In general, specific laboratory tests are not available to rapidly diagnose tick-borne diseases. Serological tests are frequently performed, but may be unreliable in differentiating acute from chronic conditions.

Treatment

Medical Therapy

• Antibiotic treatment is often justified based on clinical presentation alone. However all clinical treatments must be tailored according to a patients personal profile; considering age, immunocompetance, pregnancy, allergen profile, splenic function, and current medical status.
• If there is a collection of pus, the area will need to be incised and drained.

Disease	Treatment
Bacterial Infection
Borreliosis (Lyme Disease)	Antibiotics Doxycycline Amoxicillin (first-line in pregnancy)
Relapsing Fever	Antibiotics Erythromycin (first-line) Doxycycline Tetracycline
Typhus (Rickettsia)
Rocky Mountain Spotted Fever	Antibiotics Doxycycline Tetracycline
Helvetica Spotted Fever	Antibiotics Broad-spectrum antibiotic therapy Penicillin
Ehrlichiosis Anaplasmosis	Antibiotics Doxycycline, dosages should begin prior to lab results if ehrlichiosis is suspected. Adults: 100 mg PO q12h for 7-14 days Children (under 100lbs/45kg): 2.2 mg/kg PO q12h for 7-14 days
Tularemia	Antibiotics Streptomycin Gentamicin Doxycycline Ciprofloxacin
Other Spotted Fevers (Rickettsia bacterial infections)	Antibiotics Doxycycline Adults: 100 mg PO q12h for 7-14 days Children (under 100lbs/45kg): 2.2 mg/kg PO q12h for 7-14 days
Viral Infection
Tick-borne meningoencephalitis	No specific drug therapy. May require hospitalization and supportive care, including anti-inflammatory drugs, corticosteroids, or, if necessary, incubation and ventilator support.
Colorado Tick Fever	There are no current therapies associated with Colorado Tick Fever. The majority of patients exhibiting symptoms recover completely, however severe cases require hospitalization.
Crimean-Congo Hemorrhagic Fever	Treatment for Crimean-Congo Hemorrhagic Fever is primarily supportive including balancing electrolytes, oxygen abnormalities, and if necessary, hemodynamic support. In vitro, Crimean-Congo Hemorrhagic Fever is responsive to an antiviral treatment with Ribavirin.
Protozoan Infection
Babesiosis	Antibiotics Atovaquone AND Azithromycin Clindamycin AND Quinine

The best way to remove a tick

1. Use fine-tipped tweezers or notched tick extractor, and protect your fingers with a tissue, paper towel, or latex gloves. Persons should avoid removing ticks with bare hands.
2. Grasp the tick as close to the skin surface as possible and pull upward with steady, even pressure. Do not twist or jerk the tick; this may cause the mouthparts to break off and remain in the skin. (If this happens, remove mouthparts with tweezers. Consult your health care provider if illness occurs.)
3. After removing the tick, thoroughly disinfect the bite site and wash your hands with soap and water.

Tick removal process

• Do not squeeze, crush, or puncture the body of the tick because its fluids may contain infectious organisms. Skin accidentally exposed to tick fluids can be disinfected with iodine scrub, rubbing alcohol, or water containing detergents.

Removal of an embedded tick using fine-tipped tweezers

• Save the tick for identification in case you become ill. This may help your doctor to make an accurate diagnosis. Place the tick in a sealable plastic bag and put it in your freezer. Write the date of the bite on a piece of paper with a pencil and place it in the bag.

Gallery

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  Tick bite. Adapted from Dermatology Atlas.

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  Tick bite. Adapted from Dermatology Atlas.

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  Tick bite. Adapted from Dermatology Atlas.

Related Chapters

• Lyme disease
• Tick-borne meningoencephalitis
• Rocky Mountain Spotted Fever
• Babesiosis
• Ehrlichiosis
• Relapsing fever
• Colorado tick fever
• Tularemia
• Tick paralysis
• Cytauxzoonosis