Vaccination is the be-all and end-all

Giant tropical tick has come to stay

The tick species Hyalomma marginatum is mainly found in the Mediterranean region, Asia and North Africa.

(Bild: Wikipedia/Adam Cuerden)

Due to the milder winters, the tick season now starts as early as February. In addition, the exceptionally high temperatures also provide a pleasant environment for the tropical giant tick. The bloodsuckers come to the Alpine republic with migratory birds and prefer to "land" on horses. Due to climate change, they could become a permanent resident here.

The "tick year" has long since begun in Austria, as five degrees Celsius is enough for the blood-sucking parasites to become active. The first case of tick-borne tick-borne encephalitis (TBE) was detected back in February, reported Jörg Weber, neuro-intensive care physician at Klagenfurt Regional Hospital, in Vienna on Wednesday. "TBE doesn't have to be" was the motto of the media event, which warned of the consequences of vaccination negligence.

With 104 hospitalized people diagnosed with TBE, the number of people affected in the previous year was comparatively low, but almost two thirds (63.5% or 66 people) were confronted with severe neurological symptoms, according to figures from MedUni Vienna's Center for Virology. "The proportion of infected people over the age of 50 was roughly the same," said Bernhard Haas from the Institute of Hospital Hygiene and Microbiology at KAGes Styria.

And this in turn is an indication that "vaccination intervals were not well observed", the expert explained about the "medium-heavy year" in terms of case numbers. There were around 179 cases in 2022 and 216 in 2020. Older patients generally have a higher risk of suffering a severe course with possible long-term consequences, as they are often already burdened by other diseases.

Same approach to vaccination
The vaccination schedule against TBE remains unchanged: The basic immunization consists of three vaccinations, and there is a separate vaccine for children. The first booster should be given three years after the basic vaccination, the subsequent booster vaccinations every five years up to the age of 60 and then every three years. Normally, a titer test is neither necessary nor recommended.

This is what it looks like, the giant Hyalomma tick.

(Bild: Frank Günther)

According to Georg Duscher from the Animal Health Department at the Austrian Agency for Food Safety (AGES), it is not possible to predict whether an intensive occurrence of the eight-legged ticks can be expected in 2024. And not many are carriers of the TBE virus, the proportion is in the per mille range, their occurrence in Austria is like a patchwork quilt - on the other hand, Borrelia occurs in 20 to 30 percent of ticks, but timely removal is an effective remedy here, as the transmission of the bacteria takes up to twelve hours. If, on the other hand, contact is made with a TBE tick, there is little that can be done apart from being vaccinated.

The whole of Austria is a TBE endemic area
According to Haas, the species known as the wood tick is the main vector for TBE in Central Europe - hedgehogs, martens and voles are sucked on by ticks, as are humans - and don't feel it straight away, as the insects' saliva contains painkilling substances, "the duration of the bite doesn't matter, the virus gets into the body". However, it is a myth that ticks fall from trees; instead, they live in the grass or on bushes, and the "active stripping turns the lower legs or lower extremities into bite sites." In any case, ticks can be encountered anywhere, because "the whole of Austria is a TBE endemic area."

An early emergence has been observed for years and mild winters definitely favor the ticks, said Duscher. The prolonged mild temperatures of the current year have led to an unusually early appearance of supposed giant ticks - this is the native species of the "brown tick", whose population appears to be on the increase and which usually only appears on the scene in March. According to AGES, there are 18 tick species in Austria and the most common is the common wood tick.

Every year is a tickyear
 The term "tick year" is not one that intensive care physician Weber likes to hear, as he often has to deal with TBE patients who are surprised that they have contracted the disease. These people would then argue that they had heard on the radio that this year was not such a year. A mistake, because: Every year is a tick year.

AGES asks for pictures of giant ticks
However, the tropical giant tick (Hyalomma sp.) is considered to be an up-and-comer among ticks, as it could become a permanent resident in our country due to mild winters and climate change. The animals enter the country with migratory birds and prefer to "land" on horses; 70 percent of these reported ticks were found on these hosts. "Giant ticks actively seek out the host, in contrast to the waiting native ticks.

This species is problematic because, as carriers of the Crimean-Congo haemorrhagic fever virus, they bring new problems with them," emphasized the expert. However, this virus has not yet been detected in Austria. However, domestic species also require close monitoring and are being monitored. However, AGES is asking for images of the giant tick in particular to be sent by email to [e-mail]. AGES is also currently working on an option to send in ticks.