Avian malaria is not uncommon in Central Europe, as many endemic wild birds are infected with species of Plasmodium, which cause avian malaria. In most cases these blood parasites, transmitted by mosquitoes, do not produce any symptoms in endemic birds, as they have adapted to the parasites. A team of pathologists at the Vetmeduni Vienna recently showed for the first time that native birds, too, are susceptible to avian malaria. The data collected was published in the journal Parasitology Research.
In the summers of 2001 and 2004, blackbirds died on a massive scale in Austria. At that time, researchers at the Vetmeduni Vienna analysed more than 600 deceased birds and identified the Usutu virus as the cause of death. The birds had been collected in a regional effort by Austrians and were handed over to the scientists at the Vetmeduni Vienna.
Developmental stages of Plasmodium in a blood vessel of the brain, which have led to an almost complete vessel occlusion.
Photo: Herbert Weissenböck / Vetmeduni Vienna
More than ten years later, the researchers tapped once more into the extensive sample material to test the birds that died back then for avian malaria. Until then, only birds kept at Austrian zoos and originating from countries without mosquitoes had been known to be affected by avian malaria. These types of birds at the zoo typically live in Antarctica and the far north, so they have not had the evolutionary opportunity to adapt to avian malaria.
“An infection is life-threatening for penguins at a zoo, for example,” says lead author Herbert Weissenböck. “Native birds have adapted to the blood parasites over evolutionary time. Most of them carry the pathogen, but do not contract the disease. At least that’s what we thought.”
Avian malaria found in 15 percent of the examined birds
The researchers studied organs such as the liver, spleen, lungs and brain of 233 dead birds collected during the regional action programme. They found that some 15 percent of these specimens were infested with Plasmodium to such an extent that their organs were already damaged. Consequently, the researchers assume that the cause of these deaths was avian malaria.
Endemic populations of wild birds, however, are not at risk, believes Weissenböck. “Probably, only a small part of the population consistently dies of avian malaria. This has no dramatic effect on the overall population. But it is a completely new fact that native birds are susceptible at all.”
Three different Plasmodium species identified
Around 100 different Plasmodium species are known to exist. Weissenböck and primary author Nora Dinhopl identified three species in the examined birds: P. elongatum, P. vaughani and a type related to the South American P. lutzi. This new species still needs to be analysed and classified. Surprisingly a fourth subspecies quite frequent in Central Europe, P. relictum, was not present in the dead animals. “It is possible that the P. relictum found thus far does not cause as severe symptoms. We attribute the deaths to the first three subgroups”, Weissenböck reports.
Diagnostic method developed
Weissenböck and his team used a special RNA staining method that enabled them to examine the organs of dead birds. A special stain only binds to parasite RNA in tissue sections and therefore visualizes Plasmodium.
The pathologists want to further refine this method to be able to differentiate individual parasite subspecies. “Malaria is generally diagnosed in blood. Experts can see Plasmodium in red blood cells under the microscope. This was no option for the samples from our archives though. We would like to optimise our RNA staining process for blood samples as well. This would give us a sure-fire method for identifying different parasites in blood too”, Weissenböck emphasises.
Plasmodium decimates mosquitos too
The parasite is also apparently problematic for mosquitos. In a recently published study, Lithuanian partners to the University of Veterinary Medicine Vienna demonstrated that a high load of Plasmodia is also lethal to the insects. (http://link.springer.com/article/10.1007%2Fs00436-013-3733-4). “This is probably one way the mosquito population is naturally reduced every year”, says Weissenböck.
The article ” In situ hybridization and sequence analysis reveal an association of Plasmodium spp. with mortalities in wild passerine birds in Austria”, by Nora Dinhopl, Nora Nedorost, Meike M. Mostegl, Christiane Weissenbacher-Lang and Herbert Weissenböck was published in the journal Parasitology Research. http://link.springer.com/article/10.1007/s00436-015-4328-z
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 1,300 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
Institute of Pathology and Forensic Veterinary Medicine
University of Veterinary Medicine Vienna (Vetmeduni Vienna)
T +43 1 25077-2418
Science Communication / Public Relations
University of Veterinary Medicine Vienna (Vetmeduni Vienna)
T +43 1 25077-1153
Dr. Susanna Kautschitsch | idw - Informationsdienst Wissenschaft
Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH
Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences