Tick-borne encephalitis: Treatment, symptoms, advice and help

About tick-borne encephalitis

Tick-borne encephalitis (TBE) is a viral infectious disease involving the central nervous system.

The term refers to three distinct infections caused by three virus sub-types: European or Western tick-borne encephalitis virus, Siberian tick-borne encephalitis virus, and Far-Eastern tick-borne encephalitis virus (formerly known as Russian Spring Summer encephalitis virus).

Tick-borne encephalitis: Incidence, Age and Sex

Tick-borne encephalitis is chiefly an occupational disease of forestry workers frequenting forests and brushy areas that are the vector ticks’ habitat. Many cases occur in children who play in these locations. Infections occur in the spring and summer (accounting for the disease name) with a speak incidence in July. Tick-borne encephalitis may also be acquired by consuming raw milk products from infected cows, sheep, or goats or by contact with slaughtered acutely infected animals.

Signs & symptoms of tick-borne encephalitis: Diagnosis

After an incubation period of 7 to 14 days, a severe febrile illness consisting of headache, myalgia and upper respiratory symptoms develops and, in 75% to 90% of patients, rapidly resolves. In the remaining cases there is aseptic meningitis, meningoencephalitis, or myelitis and the recrudescence of fever, headache, and such CNS signs as neck stiffness, tremor, somnolence, disturbed mentation, cranial nerve palsies, generalized weakness, and cerebellar signs.

Causes and prevention of tick-borne encephalitis

During outbreaks, the viruses are spread directly among horses and burros by mosquito vectors, with tangential transmission to humans but there is no human to human spread. Live attenuated and killed vaccines are available for laboratory workers. Inactivated equine vaccines are administered routinely in some areas; however inadequate inactivation resulting in residual infectious virus is suspected to have caused livestock deaths and epizootics. Travellers to enzootic areas must take precautions against mosquito bites.

Tick-borne encephalitis: Complications

In approximately 3% of patients with CNS involvement, a progressive course of paresis or paralysis affecting the proximal musculature and pharyngeal and respiratory muscles may ensue. Of patients with CNS involvement, 20% die, and higher fatality rates are found among children younger than 5 years. Spontaneous abortion, congenital foetal infection, CNS and other malformations, and foetal death have been documented after infection during pregnancy. Thrombocytopenia and elevated liver enzymes have been reported in some cases.

Tick-borne encephalitis: Treatment

Treatment of convulsions and ventilatory support in the event of bulbar paralysis may be necessary. No specific therapy is available.