What can a tick transmit besides encephalitis? - briefly
Ticks transmit Lyme disease, Rocky Mountain spotted fever, anaplasmosis, babesiosis, ehrlichiosis, and tick‑borne relapsing fever. Additional agents include Powassan virus and Tularemia.
What can a tick transmit besides encephalitis? - in detail
Ticks serve as vectors for a wide range of pathogenic agents that cause human disease. In addition to the viruses that can cause encephalitic syndromes, they transmit bacteria, protozoa, and other viruses that affect the skin, blood, joints, and nervous system.
- Borrelia burgdorferi – agent of Lyme disease; produces erythema migrans, arthritis, and cardiac conduction disturbances.
- Anaplasma phagocytophilum – causes human granulocytic anaplasmosis; symptoms include fever, leukopenia, and elevated liver enzymes.
- Ehrlichia chaffeensis – responsible for human monocytic ehrlichiosis; presents with fever, rash, and hepatic involvement.
- Rickettsia rickettsii – produces Rocky Mountain spotted fever; characterized by high fever, headache, and a maculopapular rash that may become petechial.
- Rickettsia parkeri – leads to a milder spotted fever with eschar formation at the bite site.
- Borrelia miyamotoi – causes relapsing fever–type illness with recurrent spikes of fever and chills.
Protozoan parasites transmitted by ticks include:
- Babesia microti – causes babesiosis; manifests as hemolytic anemia, fever, and thrombocytopenia, especially in immunocompromised hosts.
- Babesia divergens – less common in humans, produces severe hemolysis in Europe.
Viral agents other than those causing encephalitis:
- Tick‑borne encephalitis virus – already excluded, but related flaviviruses such as Powassan virus can cause meningoencephalitis and, in some cases, isolated febrile illness without neurological signs.
- Heartland virus – a phlebovirus identified in the United States; produces fever, fatigue, and leukopenia.
- Severe fever with thrombocytopenia syndrome virus (SFTSV) – an emerging bunyavirus in East Asia; leads to high fever, low platelet count, and multi‑organ dysfunction.
Emerging and less‑characterized agents:
- Candidatus Neoehrlichia mikurensis – associated with vascular inflammation and thrombosis; detection requires molecular methods.
- Rickettsia helvetica – linked to mild febrile illness and, rarely, perimyocarditis.
These pathogens illustrate the diversity of diseases that ticks can introduce into human populations, underscoring the need for prompt recognition, appropriate laboratory testing, and targeted antimicrobial or supportive therapy.