Tick-borne disease

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.

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, fever, fatigue, joint pain, or rashes. 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).^[1]

Examples

Wikispecies has information related to: Ixodida

Major tick-borne diseases include:

Bacteria

• 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

• 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.

• 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

• Tularemia
  • Organism: Francisella tularensis, A. americanum
  • Organism: D. andersoni, D. variabilis
  • Region (US): Southeast, South-Central, West, Widespread

Virus

• Tick-borne meningoencephalitis
  • Organism: TBEV aka FSME virus, a flavivirus from family Flaviviridae
  • Vector: deer tick (Ixodes scapularis), I. ricinus (Europe), I. persulcatus (Russia + Asia))
  • Endemic to: Europe and Northern Asia

• Colorado tick fever
  • Organism: CTF virus, a coltivirus from Reoviridae
  • Vector: D. andersoni
  • Region: US (West)

• Crimean-Congo hemorrhagic fever
  • Organism: CCHF virus, a nairovirus, from Bunyaviridae
  • Organism: Hyalomma marginatum, Rhipicephalus bursa
  • Region: Southern part of Asia, Northern Africa, Southern Europe

Protozoa

• Babesiosis
  • Organism: Babesia microti, B. equi
  • Vector: I. scapularis, I. pacificus
  • Region (US): Northeast West Coast

• Cytauxzoonosis
  • Organism: C. felis
  • Vector: D. variabilis (American Dog Tick)
  • Region (US): South, Southeast

Toxin

• Tick paralysis
  • Cause: Toxin
  • Vector: D. andersoni, D. variabilis West
  • Region (US): East

References

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