Until a short while ago, infections with the parasite Dirofilaria repens was regarded as a classical traveler's disease in Austria. Mosquitoes from abroad passed the parasite on to dogs, in some cases even to humans.
The most recent research data from the Vetmeduni Vienna have shown, for the first time that the parasite has been imported to Austria and established here. In mosquitoes from the state of Burgenland, the scientists found larvae of the parasite. The infected mosquitoes possibly migrated to Austria through Eastern and Southern Europe. The results of this research were published in the journal Parasites & Vectors.
The scientists use special mosquito traps to collect the insects.
Photo: Carina Zittra / Vetmeduni Vienna
The parasite Dirofilaria repens is a roundworm that primarily attacks the subcutaneous tissue of dogs and causes lumps in the skin, swelling, and itching. Dogs, cats, foxes, wolves and martens can be infected in addition to dogs.
"In humans, 16 cases of human dirofilariosis have been recorded since the year 2000, but the dark figure is definitely higher", says the lead author Katja Silbermayr. Humans, however, are so-called dead end hosts; the parasite does not reproduce in humans and therefore poses no major risk.
Silbermayr is a veterinarian and performs research on parasitic skin diseases. She emphasizes, "So-called cutaneous dirofilariosis is quite unknown among veterinarians in our latitudes. Therefore, through our work we wish to create greater awareness among medical experts. Lumps in the skin need not necessarily be tumors; they may be a sign of dirofilariosis. Only appropriate treatment or prevention can restrain the spread of this parasite."
Austrian-wide screening discloses dirofilaria in the state of Burgenland
Experts at the Institute of Parasitology investigated about 8,000 mosquitoes from the whole of Austria in 2012. They found Dirofilaria repens in two towns: Mörbisch and Rust at the lake Neusiedl. There were two different types of mosquitoes that carried Dirofilaria repens: Anopheles maculipennis and Anopheles algeriensis.
"Basically these parasites are not choosy in selecting their vector or carrier, i.e. the mosquito. Throughout the world Dirofilaria repens is found in the most diverse types of mosquitoes. We may well be able to demonstrate these parasites in other types of mosquitoes", says Silbermayr.
The reason for immigration: traveling and adoption
The cause of immigration, according to Silbermayr, is that dog owners travel with their pets, especially to southern countries. The adoption of pets from abroad also spreads parasites into Austria. Global warming is, according to Silbermayr, no crucial factor in the spread of Dirofilaria repens.
The scientists believe that Dirofilaria repens will spread further in Austria. The parasite is already quite rampant in Spain, Portugal, Italy, Croatia, Hungary and Slovenia. "It's merely a question of time until it spreads further in Austria."
A related parasite not yet discovered in Austria
Dirofilaria immitis, also known as the heartworm, is a related but much more dangerous parasite. It is transmitted exactly like Dirofilaria repens by mosquitoes to dogs, and settles in the lungs and the heart. At these sites the heartworm, which is about 20-30 cm long, leads to heart failure, dyspnea, and general deterioration. This parasite has not yet been found in mosquitoes in Austria.
"To prevent insect bites we have preparations with a prophylactic effect, which are either applied as a spot-on to the animals' skin, or provided in tablet form. Once the parasite is in the animal, the treatment is usually laborious and long-drawn. Depending on the severity of the affliction, it may be associated with complications", explains Silbermayr.
The life cycle of Dirofilaria repens
The infectious larvae of the parasite are transferred to dogs by a mosquito bite. In the skin the larvae mate and form so-called new microfilaria, which then reach the dog's bloodstream. Mosquitoes in Austria absorb the parasite when feeding on the dog's blood and are then able to infect further animals.
The article „Autochthonous Dirofilaria repens in Austria“, by Katja Silbermayr, Barbara Eigner, Anja Joachim, Georg G Duscher, Bernhard Seidel, Franz Allerberger, Alexander Indra, Peter Hufnagl and Hans-Peter Fuehrer w Parasites & Vectors veröffentlicht. http://www.parasitesandvectors.com/content/7/1/226
About the University of Veterinary Medicine, Vienna
The University of Veterinary Medicine, Vienna in Austria is one of the leading academic and research institutions in the field of Veterinary Sciences in Europe. About 1,200 employees and 2,300 students work on the campus in the north of Vienna which also houses five university clinics and various research sites. Outside of Vienna the university operates Teaching and Research Farms. http://www.vetmeduni.ac.at
Dr. Katja Silbermayr
Institute of Parasitology
University of Veterinary Medicine Vienna (Vetmeduni Vienna)
T +43 1 25077-2211
Science Communication / Public Relations
University of Veterinary Medicine Vienna (Vetmeduni Vienna)
T +43 1 25077-1153
Dr. Susanna Kautschitsch | idw - Informationsdienst Wissenschaft
27.03.2015 | Oak Ridge National Laboratory
How did the chicken cross the sea?
27.03.2015 | Michigan State University
In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...
The IPH presents a solution at HANNOVER MESSE 2015 to make ship traffic more reliable while decreasing the maintenance costs at the same time. In cooperation with project partners, the research institute from Hannover, Germany, has developed a sensor system which continuously monitors the condition of the marine gearbox, thus preventing breakdowns. Special feature: the monitoring system works wirelessly and energy-autonomously. The required electrical power is generated where it is needed – directly at the sensor.
As well as cars need to be certified regularly (in Germany by the TÜV – Technical Inspection Association), ships need to be inspected – if the powertrain stops...
When an earthquake hits, the faster first responders can get to an impacted area, the more likely infrastructure--and lives--can be saved.
The Atlantic overturning is one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards. Also known as the Gulf Stream system, it is responsible for the mild climate in northwestern Europe.
Scientists now found evidence for a slowdown of the overturning – multiple lines of observation suggest that in recent decades, the current system has been...
Because they are regularly subjected to heavy vehicle traffic, emissions, moisture and salt, above- and underground parking garages, as well as bridges, frequently experience large areas of corrosion. Most inspection systems to date have only been capable of inspecting smaller surface areas.
From April 13 to April 17 at the Hannover Messe (hall 2, exhibit booth C16), engineers from the Fraunhofer Institute for Nondestructive Testing IZFP will be...
25.03.2015 | Event News
19.03.2015 | Event News
17.03.2015 | Event News
27.03.2015 | Agricultural and Forestry Science
27.03.2015 | Materials Sciences
27.03.2015 | Ecology, The Environment and Conservation