Tick-borne encephalitis
Overview
A viral infection (flavivirdae) of the central nervous system which is transmitted by ticks. Ticks usually feed on small rodents who are the main carriers of the virus. Transmission may also occur through the consumption of untreated milk. The incubation period is usually 1 to 2 weeks. The symptoms occur in two phases: the first involves symptoms of a general viral illness (fever, headache, nausea, aching muscles) followed by a period of remission and then central nervous system inflammation such as meningitis. However, many patients only suffer the first phase of the disease.
Symptoms
* Fever * Malaise * Aching muscles * Anorexia * Nausea
Prevention
While a vaccination is available for those at high risk, travellers should try to avoid areas where the disease is prevalent. If it is essential to go walking in long grass or undergrowth, suitable clothing should cover arms and legs, with trousers tucked into socks for protection. DEET can also be used as a repellent. Those trekking can impregnate cloth with permethrin to use as a ground sheet to sit on in infected areas. If a tick gets onto the skin, it should be removed using the correct technique of pulling it straight from the skin using tweezers or a similar instrument, not twisting
Diagnosis
The TBE virus may be present in a seronegative strain or subtype. In such cases a marker for TBE infection is elevated IFN-g in CSF.
Treatment
There are four main catgeories of treatment for TBE: * interferon treatment (similar to interferon used for the treatment of Hepatitis C) * antibiotic treatment for possible tickborne coinfections