Key points about tick-borne encephalitis
- Tick-borne encephalitis is a viral infection transmitted by ticks, without human-to-human transmission.
- Evolution can be biphasic, with a risk of severe neurological damage.
- There is no specific curative treatment.
- The disease can lead to lasting neurological after-effects.
- La vaccination and prevention of insect bites are the most effective means of protection.
What is tick-borne encephalitis?
Tick-borne encephalitis is a viral infectious disease caused by tick-borne encephalitis virus (TBE virus), a flavivirus. It is transmitted mainly by bite from infected ticks (mostly Ixodes ricinus in Europe). More rarely, transmission can occur through the consumption of raw milk or unpasteurized dairy products originating from infected animals. After the bite, the virus multiplies locally and can then spread throughout the body. The infection may remain asymptomatic or progress to central nervous system involvement.
Tick-borne encephalitis worldwide
Tick-borne encephalitis is a endemic zoonosis large areas of Central and Eastern Europe, Scandinavia, Russia, and North Asia. Several thousand human cases are reported each year, with varying incidence depending on the region and season. The disease is closely linked to environmental factors, climatic and behavioral factors (outdoor activities, exposed professions). In several European countries, a increase in incidence has been observed, in connection with the expansion of tick habitat areas and climate change.
Symptoms of tick-borne encephalitis
Evolution is often biphasicThe first phase corresponds to a flu-like syndrome (fever, headaches, muscle aches, fatigue) for a few days, followed by a transient remission. In some patients, a second phase occurs with a neurological impairment Meningitis, encephalitis, or meningoencephalitis, sometimes associated with altered consciousness, focal neurological deficits, or paralysis. Severity increases with age.
Diagnosis of tick-borne encephalitis
The diagnosis is based on the exposure context (stay in an endemic area, tick bite) and the neurological clinical picture. Confirmation is serological, by detecting specific antibodies (IgM and IgG) in the blood and/or cerebrospinal fluid. CSF analysis usually shows a lymphocytic meningitisBrain imaging can be useful to assess severity or rule out other diagnoses.
Treatment of tick-borne encephalitis
There is no specific antiviral treatment against the tick-borne encephalitis virus. Treatment is symptomaticTreatment involves hospitalization, management of fever and pain, and neurological monitoring. Severe cases may require intensive care. Persistent neurological sequelae are possible.
Prevention
Prevention relies primarily on the vaccinationwhich is effective and recommended for people living in or staying in endemic areas, as well as for people exposed professionally or through their leisure activities. individual protective measures Prevention measures against tick bites are essential: wearing protective clothing, using repellents, checking skin after exposure, and promptly removing ticks. The consumption of raw, unpasteurized milk should be avoided in high-risk areas.
FAQ
The virus is transmitted through the bite of infected ticks or, more rarely, by consuming contaminated raw milk.
The disease combines a flu-like syndrome followed by neurological symptoms.
The majority of patients recover spontaneously and without any lasting effects. Unfortunately, in severe cases, neurological sequelae may persist.
There is no specific treatment for this disease. Treatment consists solely of relieving the symptoms.
It is essential to protect oneself against tick bites (long clothing, repellents, body inspection) and avoid consuming raw milk in at-risk areas.
Yes, under certain conditions for travellers, people exposed professionally or those living in endemic areas.
