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 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.

Diagnosis and treatment

In general, specific laboratory tests are not available to rapidly diagnose tick-borne diseases. Due to their seriousness, antibiotic treatment is often justified based on clinical presentation alone.

Examples

Major tick-borne diseases include:

• Lyme disease
• Organism: Borrelia burgdorferi sensu lato (bacterium)
• Vector: deer tick (Ixodes scapularis (=I. dammini), I. pacificus, I. ricinus (Europe), I. persulcatus (Asia))
• Endemic to: North America and Eurasia
• Tick-borne meningoencephalitis
• Organism: TBEV aka FSME virus, a flavivirus
• Vector: deer tick (Ixodes scapularis), I. ricinus (Europe), I. persulcatus (Russia + Asia))
• Endemic to: Europe and Northern Asia
• Rocky Mountain Spotted Fever
• Organism: Rickettsia rickettsii
• Vector: wood tick (Dermacentor variabilis), D. andersoni
• Region (US): East, South West
• Vector: Amblyomma cajennense
• Region (Brazil): São Paulo, Rio de Janeiro, Minas Gerais.
• Babesiosis
• Organism: Babesia microti, B. equi
• Vector: I. scapularis, I. pacificus
• Region (US): Northeast West Coast
• Ehrlichiosis anaplasmosis (formerly human granulocytic ehrlichiosis or HGE)
• Organism: Ehrlichia chaffeensis, E. equi (renamed to Anaplasma phagocytophilum)
• Vector: lone star tick (Amblyomma americanum), I. scapularis
• Region (US): South-Atlantic South-Central
• Relapsing fever
• Organism: Borrelia species
• Vector: Ornithodoros species
• Region (US): West
• Colorado tick fever
• Organism: Coltivirus
• Vector: D. andersoni
• Region (US): West
• Tularemia
• Organism: Francisella tularensis, A. americanum
• Organism: D. andersoni, D. variabilis
• Region (US): Southeast, South-Central, West, Widespread
• Tick paralysis
• Cause: Toxin
• Vector: D. andersoni, D. variabilis West
• Region (US): East
• Cytauxzoonosis
• Organism: C. felis
• Vector: D. variabilis (American Dog Tick)
• Region (US): South, Southeast
• Crimean-Congo hemorrhagic fever
• Organism: Rhipicephalus bursa
• Organism: Hyalomma marginatum marginatum
• Region (Turkey)

External links

• 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