Tick-Borne Encephalitis - Symptoms, Diagnosis, and Treatment

Introduction:

Tick-borne encephalitis virus is distributed through the bite of an infected tick. The tick-borne encephalitis virus can occasionally spread to individuals through eating or drinking virus-contaminated foods like raw milk or cheese from sheep, infected goats, or cows. Tick-borne encephalitis virus can be encountered in parts of the region extending from western and northern Europe and northern and eastern Asia. Therefore, people who travel to these areas will be at risk for infection. Tick-borne encephalitis virus is rare in the United States. The ticks that distributed the tick-borne encephalitis virus are most active from April through November. Therefore, people who participate in outdoor activities or are near forests are at the highest risk of tick-borne encephalitis virus.

What Is Tick-Borne Encephalitis?

Tick-borne encephalitis (tick-borne encephalitis) is one of the causes of central nervous system viral infections. Approximately 12,000 clinical cases of tick-borne encephalitis are reported annually, but this figure is considered significantly lower than the total number of clinical cases.

Most viral infections result from infected ticks, which often stay firmly attached to the skin for days. Occasionally, the infection can result from drinking unpasteurized milk from infected goats, sheep, or cows. In addition, people come in contact with ticks during outdoor activities at an altitude of about 2000 meters. However, there is no direct person-to-person transmission.

• Prevalence - Eastern, central, northern, and increasingly western European countries and northern China, Mongolia, and the Russian Federation.

• Family - Flaviviridae.

What Are the Symptoms of Tick-Borne Encephalitis?

Most infections remain asymptomatic. In the case of clinical disease, the incubation period for tick-borne encephalitis lasts one month (most commonly two days) and is followed by one to eight days. General cold symptoms are present. Some of the symptoms of tick-borne encephalitis are mentioned below:

• Fatigue.

• Headache.

• General malaise.

• Fever greater than 38 °C (Celsius)/ 100.4 degrees Fahrenheit.

After an asymptomatic interval of twenty days, some patients experience a second phase of symptoms of the disease called "biphasic illness." The symptoms of the second phase are mentioned below:

• Fever frequently more than 40 °C/104 degrees Fahrenheit.

• Central nervous system involvement.

• Meningitis, which includes fever, headache, and a stiff neck.

• Encephalitis, which shows drowsiness, confusion, and sensory disturbances.

• Myelitis.

• Radiculitis.

• Paralysis.

• Permanent sequelae.

• Death, in rare cases.

The Russian Federation has reported higher mortality rates, possibly related to a different virus subtype. The severity of infection increases with the patient's age, but the risks of death have been reported from all age groups. Tick-borne encephalitis has no specific treatment.

The complications include

• Memory loss.

• Personality changes.

• Fatigue.

• Vision problems.

• Epilepsy.

• Difficulty hearing.

• Difficulty speaking.

• Coma.

• Breathing becomes difficult.

• Death.

What Are the Clinical Features of Tick-Borne Encephalitis?

Tick-borne encephalitis can present as a biphasic illness as follows: the first phase is a nonspecific febrile illness that might be accompanied by symptoms such as headache, malaise, nausea, anorexia, myalgia, and/or vomiting. This phase usually lasts for seven days, followed by an afebrile and asymptomatic period, which is typically present for about one week. The second phase involves the central nervous system, and findings can include meningeal signs, cognitive dysfunction, ataxia, and limb paresis.

How Is Tick-Borne Encephalitis Transmitted?

Tick-borne encephalitis (tick-borne encephalitis) virus is transmitted by ticks, specifically hard ticks belonging to the family Ixodidae. Ticks become infected when they receive infected vertebrate host blood. Small rodents can transmit the virus during the next blood meal. Ticks can also get the virus in various stages.

• Transstadially - From larva to nymph to adult ticks.

• Transovarially - From adult female tick to eggs.

• Co-feeding on infected animals.

• Increased risk of tick activity and spread risk occurs from April through November and in warmer areas.

Other modes of viral transmission are mentioned below:

• Consumption of unpasteurized milk.

• Cheese from infected goats, sheep, or cows.

• Slaughtering of infected animals.

• Blood transfusion.

• Organ transplantation.

• Breastfeeding.

• Laboratory exposure.

How Is Tick-Borne Encephalitis Diagnosed?

The proper diagnosis is made by the doctor or healthcare professionals. Healthcare providers diagnose the infection based on the following criteria.

• Evaluation of signs and symptoms.

• History of travel.

• History of possible exposure to ticks while traveling.

• Blood or spinal fluid examination.

• Additional tests to examine other infections that can cause similar symptoms.

How Is Tick-Borne Encephalitis Treated?

There is no specific medication to treat tick-borne encephalitis virus infection. However, there is a vaccine available to prevent tick-borne encephalitis virus infection. Other treatment modes are mentioned below,

• Adequate rest.

• Fluids.

• Over-the-counter pain medications to relieve some symptoms.

• Hospitalization in severe cases.

• Additional breathing support.

• Staying hydrated.

Tick-borne encephalitis virus can spread to individuals through the infected tick bite. Some preventive measures can be followed to prevent the spread of tick-borne encephalitis. The soundest way to prevent tick-borne encephalitis is to protect from tick bites.

How to Protect Oneself From Tick-Borne Encephalitis?

The preventive measures for tick-borne encephalitis are mentioned below,

• Use insect repellent.

• Treat clothing and gear with 0.5 % Permethrin.

• Inspect the body and clothing for ticks after outdoor activities.

• Avoid eating or drinking infection-risk products.

The risk of tick-borne encephalitis is very common for most travelers. However, travelers are at high risk if they plan to:

• Visit areas with tick-borne encephalitis active ticks from April through November.

• Take part in outdoor activities such as hiking, trekking, hunting, fishing, or camping.

All travelers visiting countries with tick-borne encephalitis must follow the steps to avoid tick bites. If someone plans to travel during the warmer months and partake in outdoor activities, they should be concerned about the need for vaccination with their doctor or healthcare provider. The following considerations are evaluated before vaccination.

• Visiting location

• Activities while traveling.

• Chance of future travel.

• Potential severe outcomes of tick-borne encephalitis infection.

• Vaccine doses.

• Cost and possible side effects.

The tick-borne encephalitis vaccine is obtainable for children and adults. Three doses are needed to complete the series; discuss with the healthcare provider as early as possible before traveling.

What Is the Schedule for Tick-Borne Encephalitis Vaccination?

Conclusion:

Tick-borne encephalitis is a human viral contagious disease affecting the central nervous system and happening in many parts of Europe and Asia. An infected tick bite causes the virus. Tick-borne encephalitis is most often personified as a two-phased illness. Symptoms like fever, headache, fatigue, muscular ache, and nausea. The second phase involves meningitis or encephalitis. Insect repellents and protective clothing are used to prevent tick bites. In addition, a vaccine is also available to prevent the condition.