Lyme disease andearly summer meningoencephalitis (TBE) are the most common tick-borne diseases in Austria. Rarely,anaplasmosis,tick-borne relapsing fever-Borreliosis throughBorrelia miyamotoi,neoehrlichiosis,rickettsiosis,babesiosis, andalpha-gal syndrome.Tularemiais usually a contact infection but is very rarely also transmitted by ticks in certain areas.Crimean-Congo hemorrhagic fever has not yet been observed in Austria.

Lyme borreliosis is an infectious disease caused by spirochetes, which are bacteria of the genus Borrelia. More than 30 percent of Ixodes ricinus ticks (common wood tick; most common tick species in central and northern Europe) are infected with Borrelia. These bacteria reside in the tick's gut and can be transmitted to the host animal/human after an approximately 12-hour (6-48-hour) blood meal from an attached tick.

Lyme disease is the most common infectious disease transmitted by Ixodes ricinus ticks in the Northern Hemisphere. It is particularly common in Central Europe and Scandinavian countries. Due to climate warming, the distribution area of infected ticks is continuously expanding northward. From about seven degrees Celsius ground temperature, Ixodes ricinus becomes active. A study from Austria showed that the risk of getting a Borrelia infection after a tick bite is 5%. 3% of the individuals developed erythema migrans (see below). The number of Lyme disease infections in Austria is estimated at 25,000 to 70,000 per year.

Symptoms of Lyme borreliosis are seen in the skin, nervous system, joints, heart and eyes.

Early summer meningoencephalitis (TBE), also called tick-borne encephalitis, is caused by the TBE virus found in the saliva of some ticks. The tick transmits the viruses immediately after being bitten. The TBE virus multiplies in human nerve cells. The disease is notifiable and typically progresses in two phases.

Symptoms

In the first phase, flu-like symptoms such as headache, fever, fatigue or joint complaints occur about seven days to two weeks after the tick bite. These symptoms (signs of illness) disappear after a few days, and a connection with a tick bite is rarely thought of. For most patients, this means the disease is over and they are probably immune to TBE viruses for life.

In about five to 15 percent of patients, after a symptom-free interval, there is a second phase of illness involving the central nervous system. The symptoms of this meningitis or brain inflammation are severe headaches, photophobia, dizziness, concentration disorders, speech disorders, and walking disorders. These signs of illness can last for weeks to months. In severe courses, paralysis of the arms, legs or facial nerves can occur and lead to permanent disabilities. About one percent of patients with neurological symptoms die from TBE. In children, the disease is mild in most cases, that is, without severe or permanent damage.

Prevention

A vaccination protects against infection with TBE. There is no specific therapy against the disease, the treatment aims at alleviating the symptoms.

Occurrence in Austria

Austria is one of the areas most affected by TBE in Europe. Ticks contaminated with TBE viruses occur in all federal provinces. Cases of the disease are reported annually from all federal provinces.

Source: BMSGPK Annual statistics of notifiable infectious diseases

Anaplasmas(Anaplasma phagocytophilum) are small, gram-negative (possess a protective capsule that protects them from infection-fighting white blood cells) pleomorphic (can take on a variety of appearances) rod-shaped bacteria that multiply primarily in host cells, i.e. are obligately intracellular. In the infected cells in the blood, the white blood cells (granulocytes), anaplasmas are present as small mulberry-like inclusions called morulae. In humans, they can occasionally cause a very febrile disease called human granulocytic anaplasmosis.

The pathogen has been known in veterinary medicine since 1932, and the first human infection was reported in the 1990s. Transmission to humans occurs through tick bites. The most common vector in Europe is the common wood tick(Ixodes ricinus).

Symptoms

Up to 75 percent of anaplasma infections proceed without recognizable signs of illness (symptoms). After an incubation period of about 5 to 30 days, flu-like symptoms (high fever, headache, aching limbs, muscles and joints) may occur. Rarely, abdominal pain, nausea, vomiting and diarrhea (diarrhea) occur. Severe complications such as multiple organ failure, meningitis, and acute respiratory distress syndrome may occur in people with compromised immune systems. The mortality of untreated anaplasmosis is reported to be 2 to 3 percent.

Prevention

A vaccine is not currently available.

Occurrence in Austria

Anaplasma phagocytophilum DNA was first detected in the common wood tick(Ixodes ricinus) and red deer in 2002. The occurrence of Anaplasma in ticks and red deer has been repeatedly confirmed since then. Human diseases with source of infection in Austria are very rare but severe courses have been documented.

Rickettsiae are obligate intracellular bacteria (multiply primarily in host cells) that are distributed worldwide and can multiply exclusively in living cells. They are found in ticks as well as in mites, fleas and lice. Only a few species of rickettsiae are pathogens of humans.

The tick-borne rickettsiae are grouped together as the tick-borne fever group.

It includes Rocky Mountain spotted fever, native to America, caused by Rickettsia rickettsii, and rickettsiosis caused by R. parkeri. Dermacentor variabilis, D. andersonii, and Amblyomma maculatum act as vectors there.

The Rickettsia conorii complex includes Mediterranean tick-bite fever, transmitted by the brown dog tick (Rhipicephalus sanguineus). In addition, in 2002, the University of Marseille reported the case of a 36-year-old patient who developed a febrile infection with a generalized rash caused by Rickettsia aeschlimannii following a tick bite by Hyalomma marginatum in Morocco. Other rickettsial species in Europe include R. helvetica, R. monacensis, R. raoultii, and R. slovaca. The latter two cause a disease called TIBOLA (tick-borne lymphadenopathy) or SENLAT (schalp eschar and neck lymphadenopathy after tick bite), which occurs mainly after bites from Dermacentor ticks.

Louse spotted fever is a notifiable infectious disease caused by Rickettsia prowazekii. It is a typical disease of the uncultivated, occurring in times of war and hardship, and is transmitted primarily by the clothes louse.

Symptoms

In Rocky Mountain spotted fever, the incubation period is a few days to two weeks. Symptoms include a sudden onset of fever, headache, nausea with vomiting, muscle aches, and rash on the wrists, ankles, and forearms. The rash is seen in only about one in two patients.

Mediterranean tick-bite fever is a severe illness with high fever, severe muscle and joint pain, fatigue, and exhaustion. Patients with underlying diseases are at much higher risk.

In TIBOLA / SENLAT, a skin lesion develops at the tick bite site that resembles a cigarette butt burn and is called an eschar. It often occurs on the scalp. Enlargement of lymph nodes in the neck and throat area is also found. Accompanying symptoms include fever, fatigue, and skin rashes. However, SENLAT can also be triggered by other pathogens. In Austria, for example, SENLAT was detected for the first time after a Borrelia infection.

In louse spotted fever, after an incubation period of 10 to 14 days, chills, increasingly high fever, headache, pain in the limbs and clouding of consciousness (if the brain is also affected) occur. A blue- to red-spotted skin rash is typical.

Prevention

A vaccine is currently not available.

Occurrence in Austria

About 17 percent of Ixodes ricinus ticks are infected with rickettsiae (R. helvetica, R. raoultii, R. monacensis, R.slovaca). In the Vienna area, about every second tick was infected with rickettsiae, followed by Carinthia (23.8 percent positive) and Lower Austria (18.8 percent positive). Human diseases with an infectious source in Austria have not been documented in recent decades.

Louse spotted fever was still of great importance in Austria until the post-war years.

Tularaemia (rabbit plague) is a notifiable infectious disease caused byFrancisella tularensis, a gram-negative (possess a protective capsule that protects them from infection-fighting white blood cells) bacterium that is endemic (localized) throughout Austria, especially in the Austrian-Slovak borderlands along the Morava River. Various small mammals such as rodents and hares act as reservoirs. In mice from these areas, mixed infections with different Borrelia species and withFrancisella tularensis can be detected. Francisella tularensis is found in bothdermacentor andIxodes ricinus ticks. Routes of infection usually include skin or mucosal contact with infectious animal material, consumption of inadequately heated contaminated meat or other food, and ingestion of contaminated water or inhalation of contaminated dust.

Symptoms

In tick-bite transmission, a punched-out ulcer (Eschar-like) develops around the bite site, followed by regional lymphadenitis (lymphadenitis) and occasionally fever (ulceroglandular form). Aerogenous transmission may result in high-fever pneumonia. Microbiological diagnosis is necessary, especially because of the differentiation from rickettsial infections and the implementation of appropriate therapy.

Prevention

A vaccine is currently not available.

Occurrence in Austria

Of the 418 cases of tularemia observed in western Slovakia between 1985 and 1998, 45 were transmitted by tick bite. In Austria, a total of 42 human cases of tularemia were reported between 01/01/2009 and 31/03/2018; the exact route of transmission is unknown in most cases. Tick-borne transmission was recently documented in a child from Salzburg.

This disease is caused by the obligate intracellular bacterium Neoehrlichia mikurensis and it was first described in 2010. Infections have subsequently also been detected in individuals from Sweden, Germany, the Czech Republic, Austria, and China.

Symptoms

The symptoms (signs of illness) of neoehrlichiosis are nonspecific: after an incubation period of approximately 7 to 14 days, malaise, muscle and joint pain, high fever up to 40 °C, and weight loss occur. Other symptoms described in the literature include headache, cough, nausea, and vomiting. The duration of the fever is reported to be up to eight months. Laboratory diagnostics reveal anemia (anemia of the blood).

Prevention

A vaccine is currently not available.

Occurrence in Austria

About four percent of ticks are infected with the bacterium Neoehrlichia mikurensis. In Vienna and Tyrol, ticks are most frequently affected with just over eight percent. Human diseases with a source of infection in Austria have been documented repeatedly, but almost exclusively in patients with an impaired immune system, such as those with leukemia, rheumatism or after organ transplantation. A study from Austria, conducted at the Medical University of Vienna, showed that the pathogen was detectable in 2.5% of healthy individuals after a tick bite without causing disease.

Tick-borne relapsing fever occurs primarily in Africa, Asia, the Americas (North, Central, and South), the Middle East, southern Russia, and sporadically in the Mediterranean region (Spain, Portugal). Leather ticks of the genus Ornithodorus are reservoirs and vectors of relapsing fever borrelia - with the exception of B. duttonii, for which humans themselves are the reservoir.

Louse relapsing fever is a notifiable infectious disease caused by Borrelia recurrentis. It is a typical disease of the uncultured, occurring in times of war and hardship, and is transmitted primarily by the clothes louse, only rarely by ticks.

Symptoms

After an incubation period of 1-14 days (often about five days), the disease begins with sudden high fever, joint, head, chest, and limb pain, nausea, and sometimes shortness of breath. Cough and a small-spotted exanthema (skin rash) may occur. Increased bleeding tendency with nosebleeds and bleeding into the skin are also not uncommon, as well as clouding of consciousness and yellowing of the skin (icterus). The first episode of fever lasts about 5-7 days, followed by a fever- and symptom-free interval of 1-21 days (often 5-7 days). Subsequent febrile episodes usually decrease in duration and intensity. In addition, the central nervous system may also be affected in the form of meningitis. Relapsing fever Lyme disease can be treated with antibiotics; untreated, mortality is about 20 percent.

Prevention

A vaccine is not currently available.

Occurrence in Austria

In Austria acquired (autochthonous) cases are not known. Tick-borne and louse-borne relapsing fever cases detected in our country in recent years were without exception imported diseases.

Babesia are unicellular parasites that infect the red blood cells of vertebrates. Transmission to humans occurs through tick bites. The most common vector in Europe is the common wood tick(Ixodes ricinus). The wood tick(Dermacentor reticulatus) is a vector of Babesia canis canis, the causative agent of canine babesiosis ("canine malaria").

Symptoms

The disease is rarely diagnosed in humans. Infection is often clinically inconspicuous, i.e., without symptoms. If symptoms do occur, they resemble malaria in some respects. The incubation period is approximately one to three weeks. Fever, anemia and jaundice may occur. In acute cases, coffee-brown to red-colored urine is common.

Prevention

A vaccine is currently not available.

Occurrence in Austria

In Austria, Babesia divergens, Babesia venatorum and Babesia microti have been detected in ticks so far. Human diseases with source of infection in Austria have been described.

This disease is caused by the Crimean-Congo fever virus (CCHFV). The virus is transmitted byHyalomma ticks, which are found in warmer regions of southeastern Europe (Bulgaria, Kosovo) and Asia (Turkey), among others. Over 30Hyalomma species have been identified as vectors. Domestic and wild animals, e.g. cows, sheep, camels or goats act as hosts to spread the pathogen. The virus was first isolated in Africa (Congo) in 1956 from the blood sample of a diseased person. The disease pattern "Crimean hemorrhagic fever" had already been known since 1944.

Transmission of the pathogen can also occur through direct contact with blood or meat from infected animals. Nosocomial infections (infections in hospitals) have also been repeatedly documented. In August 2016, a person died in Spain for the first time from Crimean-Congo fever, having been infected in Spain through a tick bite.

Symptoms

Signs of illness usually appear three to seven days after infection. The disease begins suddenly with high fever, headache, pain in the limbs, vomiting, and diarrhea. As the disease progresses, skin rashes and general bleeding may occur. The mortality rate ranges from 2 to 50 percent.

Prevention

A vaccine is not currently available. As a preventive measure, protection against tick bites is recommended in affected areas (insect repellent, closed light-colored clothing, regular self-examination for ticks).

Occurrence in Austria

Hyalomma ticks have been repeatedly detected in Germany since 2015. In October 2018, the University of Veterinary Medicine Vienna succeeded in detectingHyalomma marginatum in Austria for the first time. The tick proved to be free of Crimean-Congo fever virus (CCHFV). Human diseases with a source of infection in Austria have never been documented before.

This allergy to the sugar galactose-alpha-1,3-galactose (alpha-gal) is caused in some people by the bite of certain tick species. Alpha-gal syndrome was first described in the USA in 2009. Subsequently, this form of allergy has been detected in people on other continents, including Europe (Sweden, Norway, Germany, Switzerland, Italy, France, Austria).

Symptoms

Reactions occur 3 to 7 hours after consumption of mammalian products (red meat, gelatin, dairy products, etc.), beginning with severe itching, often over the entire body, sometimes accompanied by skin rashes (urticaria). Severe reactions may include abdominal pain, nausea, vomiting, diarrhea (diarrhea), swollen hands, and even respiratory distress, hypotension, and fainting (anaphylactic reactions).

Prevention

There is no specific therapy for this allergy. Patients are advised to avoid red meat (beef, pork, sheep, game, etc.) and gelatin. If dairy products also cause symptoms, these should also be avoided. Affected patients are usually prescribed an emergency kit with medication.

Occurrence in Austria

Cases acquired in Austria are known.

There is a vaccination against early summer meningoencephalitis (FSME), which is recommended according to the Austrian vaccination schedule.

Ticks(Ixodida) belong to the class of arachnids and subclass of mites. Adults (adults) have eight legs, and the body is lenticular in shape. Since ticks are parasites, they need another organism as a host to survive. Therefore, they suck blood from vertebrates and can be vectors (transmitters) of disease.

Evolution

The origin of the tick is about 300 million years ago in the Carboniferous (age of ferns). Even older findings of the related scorpions and mites are proven with fossil findings. At the latest from 70 million years before our time the most important groups of theIxodida, the family of the ticks, exist.

As natural enemies of the ticks have been found so far:

• Fungal species such asMetarhizium anisopliae andBeauveria bassiana, which grow on ticks and kill them.
• Nematodes, which infest and kill ticks.
• Pea wasp(Ixodiphagus hookeri), which lays eggs in the tick. Hatched wasp larvae eat ticks from the inside.
• Observations that wood ants eat scale ticks are controversial among scientists.

The tick does not fall from trees, but lives on the ground on the low vegetation. There it lies in wait for a passing animal or human. If the host passes the lurking tick, it allows itself to be stripped from the plant and clings on. The risk of shedding a tick is much lower in winter than between March and October.

Children are particularly at risk

Children are at increased risk because of their disposition and size. This is because children like to play where ticks are found: in undergrowth, along forest edges, in tall grass. Ticks like to settle in the head area of children.

"Ticks drop from trees onto their victims."

On the one hand, ticks allow themselves to be stripped from the host/human, but on the other hand, ticks live close to the ground and rarely climb more than a meter in height. Because ticks travel only short distances, they tend to stay close to the ground, lurking on grasses, shrubs and in the herb layer (first layer of vegetation above the ground) for hosts for their next blood meal. Read more here.

"Ticks pretreated with oil, butter and glue are easier to remove."

Use only tapered tick tweezers, a tick hook, or have a health care professional remove the tick. Chemical treatment is not recommended because ticks suffocate very slowly and pathogens such as Borrelia can be transmitted during this time. You can read more about this here.

"I can only get infected with a tick-borne disease in high-risk areas."

Tick hazard maps often show TBE risk areas. These are areas where ticks are particularly likely to carry the tick-borne encephalitis pathogen. But anywhere ticks are found, a tick can carry pathogens.

"I just need to protect myself from ticks in the summer."

If the temperature and humidity are right, the tick can be active year-round. Generally, ticks are most comfortable from spring through fall, and that's when the risk of a tick bite is greatest. Ticks like temperatures of 10 to 20 degrees Celsius and humid weather. Read more here.

"Vaccination is effective against all tick diseases."

Unfortunately, this is not true. Vaccination effectively protects against infection with the tick-borne encephalitis virus. However, tick vaccination does not protect against infection with the Lyme disease bacterium. Only preventive measures such as appropriate clothing, the use of repellents and tick control during and after outdoor activities can help.

This project was developed in cooperation with the University of Veterinary Medicine Vienna and the Medical University Vienna on behalf of the Federal Ministry of Social Affairs, Health, Care and Consumer Protection.