Tick-borne disease
Encyclopedia
Tick-borne diseases are disease
s or illnesses transmitted by tick
s. 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 illnesses are caused by infection with a variety of pathogen
s, including rickettsia
and other types of bacteria, virus
es, 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.
treatment is often justified based on clinical presentation alone.
, fatigue, joint pain, or rash
es. People can limit their exposure to tick bites by wearing light-colored clothing (including pants and long sleeves), using insect repellent
with 20%–30% DEET
, tucking their pant legs into their socks, checking for ticks frequently, and washing and drying their clothing (in a hot dryer).
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
s or illnesses transmitted by tick
Tick
Ticks are small arachnids in the order Ixodida, along with mites, constitute the subclass Acarina. Ticks are ectoparasites , living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians...
s. 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 illnesses are caused by infection with a variety of pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
s, including rickettsia
Rickettsia
Rickettsia is a genus of non-motile, Gram-negative, non-sporeforming, highly pleomorphic bacteria that can present as cocci , rods or thread-like . Being obligate intracellular parasites, the Rickettsia survival depends on entry, growth, and replication within the cytoplasm of eukaryotic host cells...
and other types of bacteria, virus
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
es, and protozoa
Protozoa
Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...
. 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.
Diagnosis and treatment
In general, specific laboratory tests are not available to rapidly diagnose tick-borne diseases. Due to their seriousness, antibioticAntibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
treatment is often justified based on clinical presentation alone.
Exposure
Ticks tend to be more active during warmer months, though this varies by geographic region and climate. Areas with woods, bushes, high grass, or leaf litter are likely to have more ticks. Those bitten commonly experience symptoms such as body aches, feverFever
Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...
, fatigue, joint pain, or rash
Rash
A rash is a change of the skin which affects its color, appearance or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cracked or blistered, swell and may be painful. The causes, and...
es. People can limit their exposure to tick bites by wearing light-colored clothing (including pants and long sleeves), using insect repellent
Insect repellent
An insect repellent is a substance applied to skin, clothing, or other surfaces which discourages insects from landing or climbing on that surface. There are also insect repellent products available based on sound production, particularly ultrasound...
with 20%–30% DEET
DEET
N,N-Diethyl-meta-toluamide, abbreviated DEET, is a slightly yellow oil. It is the most common active ingredient in insect repellents...
, tucking their pant legs into their socks, checking for ticks frequently, and washing and drying their clothing (in a hot dryer).
Bacteria
- Lyme diseaseLyme diseaseLyme disease, or Lyme borreliosis, is an emerging infectious disease caused by at least three species of bacteria belonging to the genus Borrelia. Borrelia burgdorferi sensu stricto is the main cause of Lyme disease in the United States, whereas Borrelia afzelii and Borrelia garinii cause most...
- Organism: Borrelia burgdorferi sensu latoBorrelia burgdorferiBorrelia burgdorferi is a species of Gram negative bacteria of the spirochete class of the genus Borrelia. B. burgdorferi is predominant in North America, but also exists in Europe, and is the agent of Lyme disease....
(bacterium) - Vector: deer tick (Ixodes scapularis (=I. dammini), I. pacificus, I. ricinus (Europe), I. persulcatus (Asia))
- Endemic to: North America and Eurasia
- Symptoms: FeverFeverFever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...
, arthritisArthritisArthritis is a form of joint disorder that involves inflammation of one or more joints....
, neuroborreliosis, erythema migransErythema migransErythema chronicum migrans refers to the rash often seen in the early stage of Lyme disease. It can appear anywhere from one day to one month after a tick bite. This rash does not represent an allergic reaction to the bite, but rather an actual skin infection with the Lyme bacteria, Borrelia...
, cranial nerve palsy, carditisCarditisCarditis is the inflammation of the heart or its surroundings.It is usually studied and treated by specifying it as:*Pericarditis is the inflammation of the pericardium*Myocarditis is the inflammation of the heart muscle...
, fatigue, and influenza like illness. - Treatment: Antibiotics
- Organism: Borrelia burgdorferi sensu lato
- Rocky Mountain Spotted FeverRocky Mountain spotted feverRocky Mountain spotted fever is the most lethal and most frequently reported rickettsial illness in the United States. It has been diagnosed throughout the Americas. Some synonyms for Rocky Mountain spotted fever in other countries include “tick typhus,” “Tobia fever” , “São Paulo fever” or “febre...
- Organism: Rickettsia rickettsii
- Vector: wood tickDermacentor variabilisDermacentor variabilis, also known as the American dog tick, is a species of tick that is known to carry bacteria responsible for several diseases in humans, including Rocky Mountain spotted fever and tularemia . It is one of the most well-known hard ticks.Though D...
(Dermacentor variabilis), D. andersoni - Region (US): East, South West
- Vector: Amblyomma cajennenseAmblyomma cajennenseAmblyomma cajennense or Cayenne tick is species of tick found in a range from the southern part of the United States to northern Argentina, through Central America and some of the Caribbean.-Clinical significance:...
- Region (Brazil): São PauloSão Paulo (state)São Paulo is a state in Brazil. It is the major industrial and economic powerhouse of the Brazilian economy. Named after Saint Paul, São Paulo has the largest population, industrial complex, and economic production in the country. It is the richest state in Brazil...
, Rio de JaneiroRio de Janeiro (state)Rio de Janeiro is one of the 27 states of Brazil.Rio de Janeiro has the second largest economy of Brazil behind only São Paulo state.The state of Rio de Janeiro is located within the Brazilian geopolitical region classified as the Southeast...
, Minas GeraisMinas GeraisMinas Gerais is one of the 26 states of Brazil, of which it is the second most populous, the third richest, and the fourth largest in area. Minas Gerais is the Brazilian state with the largest number of Presidents of Brazil, the current one, Dilma Rousseff, being one of them. The capital is the...
. - Symptoms:Fever, headache, altered mental status, myalgiaMyalgiaMyalgia means "muscle pain" and is a symptom of many diseases and disorders. The most common causes are the overuse or over-stretching of a muscle or group of muscles. Myalgia without a traumatic history is often due to viral infections...
, and rashRashA rash is a change of the skin which affects its color, appearance or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cracked or blistered, swell and may be painful. The causes, and... - Treatment: AntibioticAntibioticAn antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
therapy, typically consisting of doxycycline or tetracycline.
- EhrlichiosisEhrlichiosisEhrlichiosis is a tick-borne disease of dogs usually caused by the organism Ehrlichia canis. Ehrlichia canis is the pathogen of animals. Humans can become infected by E. canis and other species after tick exposure. German Shepherd dogs are thought to be particularly affected by the disease, other...
anaplasmosisAnaplasmosisAnaplasmosis is a disease caused by a rickettsial parasite of ruminants, Anaplasma spp. The organism occurs in the white blood cells and is transmitted by natural means through a number of haematophagous species of ticks...
(formerly human granulocytic ehrlichiosis or HGE)- Organism: Ehrlichia chaffeensis, E. equi (renamed to Anaplasma phagocytophilumAnaplasma phagocytophilumAnaplasma phagocytophilum is a gram-negative bacterium that is unusual in its tropism to neutrophils...
) - Vector: lone star tickAmblyomma americanumAmblyomma americanum, or lone star tick, is a species of tick in the genus Amblyomma. It's average length is 1/4 inch.-Distribution:...
(Amblyomma americanum), I. scapularis - Region (US): South-Atlantic South-Central
- Organism: Ehrlichia chaffeensis, E. equi (renamed to Anaplasma phagocytophilum
- Relapsing feverRelapsing feverRelapsing fever is an infection caused by certain bacteria in the genus Borrelia. It is a vector-borne disease that is transmitted through the bites of lice or soft-bodied ticks.-Louse-borne relapsing fever:...
- Organism: BorreliaBorreliaBorrelia is a genus of bacteria of the spirochete phylum. It causes borreliosis, a zoonotic, vector-borne disease transmitted primarily by ticks and some by lice, depending on the species...
species - Vector: Ornithodoros species
- Region (US): West
- Symptoms: Relapsing fever typically presents as recurring high fevers, headaches, and muscular pain, with less common symptoms including rigors, joint pain, altered mentation, cough, painful urination, and rash.
- Treatment: antibiotics are the treatment for relapsing fever, with doxycycline, tetracycline, or erythromycin being the treatment of choice.
- Organism: Borrelia
- TularemiaTularemiaTularemia is a serious infectious disease caused by the bacterium Francisella tularensis. A Gram-negative, nonmotile coccobacillus, the bacterium has several subspecies with varying degrees of virulence. The most important of those is F...
- Organism: Francisella tularensis, A. americanum
- Organism: D. andersoni, D. variabilis
- Region (US): Southeast, South-Central, West, Widespread
Viruses
- Tick-borne meningoencephalitisTick-borne meningoencephalitisTick-borne encephalitis is a viral infectious disease involving the central nervous system. The disease most often manifests as meningitis, encephalitis, or meningoencephalitis. Although TBE is most commonly recognized as a neurological disorder, mild fever can also occur...
- Organism: TBEV aka FSME virus, a flavivirusFlavivirusFlavivirus is a genus of the family Flaviviridae. This genus includes the West Nile virus, dengue virus, tick-borne encephalitis virus, yellow fever virus, and several other viruses which may cause encephalitis....
from family FlaviviridaeFlaviviridaeThe Flaviviridae are a family of viruses that are primarily spread through arthropod vectors . The family gets its name from Yellow Fever virus, a type virus of Flaviviridae; flavus means yellow in Latin... - Vector: deer tick (Ixodes scapularis), I. ricinus (Europe), I. persulcatus (Russia + Asia))
- Endemic to: Europe and Northern Asia
- Organism: TBEV aka FSME virus, a flavivirus
- Colorado tick feverColorado tick feverColorado Tick Fever is an obtuse viral infection transmitted from the bite of an infected tick...
- Organism: CTF virus, a coltivirusColtivirusColtivirus is a genus of viruses that infects vertebrates, invertebrates, and plants. It includes the causative agent of Colorado tick fever....
from ReoviridaeReoviridaeReoviridae is a family of viruses that can affect the gastrointestinal system and respiratory tract. Viruses in the family Reoviridae have genomes consisting of segmented, double-stranded RNA... - Vector: D. andersoni
- Region: US (West)
- Organism: CTF virus, a coltivirus
- Crimean-Congo hemorrhagic feverCrimean-Congo hemorrhagic feverCrimean–Congo hemorrhagic fever is a widespread tick-borne viral disease, a zoonosis of domestic animals and wild animals, that may affect humans. The pathogenic virus, especially common in East and West Africa, is a member of the Bunyaviridae family of RNA viruses. Clinical disease is rare in...
- Organism: CCHF virus, a nairovirusNairovirusNairovirus is a genus in the family Bunyaviridae that include viruses with circular, negative-sense single stranded RNA. It got its name from the Nairobi sheep disease that affects the gastrointestinal tracts of sheep and goats...
, from BunyaviridaeBunyaviridaeBunyaviridae is a family of negative-stranded RNA viruses. Though generally found in arthropods or rodents, certain viruses in this family occasionally infect humans. Some of them also infect plants.... - Vector: Hyalomma marginatum, Rhipicephalus bursa
- Region: Southern part of Asia, Northern Africa, Southern Europe
- Organism: CCHF virus, a nairovirus
Protozoa
- BabesiosisBabesiosisBabesiosis is a malaria-like parasitic disease caused by infection with Babesia, a genus of protozoal piroplasms. After trypanosomes, Babesia are thought to be the second most common blood parasites of mammals and they can have a major impact on health of domestic animals in areas without severe...
- Organism: Babesia microti, B. equi
- Vector: I. scapularis, I. pacificus
- Region (US): Northeast West Coast
- CytauxzoonosisCytauxzoonosisCytauxzoonosis is a mostly fatal tick-borne disease of domestic cats. It is identified as the blood parasite Cytauxzoon felis.In Africa, this disease is carried by ungulates, but in North America, it is carried by bobcats, particularly in the South...
- Organism: C. felis
- Vector: D. variabilis (American Dog Tick)
- Region (US): South, Southeast
Toxin
- Tick paralysisTick paralysisTick paralysis is the only tick-borne disease that is not caused by an infectious organism. The illness is caused by a neurotoxin produced in the tick's salivary gland. After prolonged attachment, the engorged tick transmits the toxin to its host...
- Cause: Toxin
- Vector: D. andersoni, D. variabilis West
- Region (US): East
External links
- Tick-Borne Diseases: Recommendations for Workers and Employers - National Institute for Occupational Safety and Health
- Tickborne Diseases - National Center for Infectious Diseases (CDC)
- Tickborne Disease Website - Massachusetts Department of Public Health
- Tick bite fever - Health 24
- Ixodes Scapularis - 3D animation of Deer or Blacklegged Tick from US Army site