What are some tick-related encephalitides?

From the Guidelines

Tick-related encephalitides include several serious neurological infections transmitted by ticks, primarily Tick-borne Encephalitis (TBE), Powassan virus encephalitis, Colorado tick fever, Rocky Mountain spotted fever, Ehrlichiosis, and Anaplasmosis. These infections can cause significant morbidity and mortality, with mortality rates ranging from 1-20% depending on the specific pathogen 1. The most common tick-related encephalitides are:

• Tick-borne Encephalitis (TBE), which is most common in Europe and Asia, caused by a flavivirus 1
• Powassan virus encephalitis, which affects North America, with a 10% case-fatality rate 1
• Other tick-borne illnesses, such as Rocky Mountain spotted fever, Ehrlichiosis, and Anaplasmosis, which can also cause significant neurological damage and have mortality rates ranging from 1-20% 1 Diagnosis relies on serological testing and PCR of blood or cerebrospinal fluid, and treatment is primarily supportive, as no specific antiviral therapy exists for most tick-borne encephalitides, though doxycycline (100mg twice daily for 7-14 days) is effective for bacterial causes like Ehrlichiosis 1. Prevention is crucial through tick avoidance measures including protective clothing, DEET-containing repellents, prompt tick removal, and vaccination for TBE in endemic areas 1. It is essential to prioritize prevention and early treatment to reduce the risk of morbidity and mortality associated with these diseases.

From the Research

Tick-Related Encephalitides

Some tick-related encephalitides include:

• Tick-borne encephalitis (TBE) 2, 3, 4, 5, 6
• Powassan encephalitis 2
• Lyme borreliosis 2
• Rocky Mountain spotted fever (RMSF) 2
• Colorado tick fever (CTF) 2

Characteristics of Tick-Borne Encephalitis

Tick-borne encephalitis is characterized by:

• A biphasic disease course with a viraemic phase and a neurological phase 5
• Non-specific influenza-like symptoms during the viraemic phase 5
• Central and peripheral nervous system symptoms during the neurological phase 5
• A mortality rate of around 1% of confirmed cases, depending on the viral subtype 5
• Long-term neurological deficits in a minority of patients after acute tick-borne encephalitis (TBE) 5
• A post-encephalitic syndrome in 40%-50% of patients, which significantly impairs daily activities and quality of life 3, 4, 5

Prevention and Treatment

There is no specific treatment for tick-borne encephalitis, but:

• Vaccination can effectively prevent the disease and is indicated for persons living in or visiting tick-borne encephalitis endemic areas 2, 3, 4, 6
• Immunization and protection against tick bites are critical in preventing tick-borne encephalitis 6