Ivo Rudolf

The common vole ( Microtus arvalis ) is one of the most abundant rodent species in Europe and is known for its cyclic population outbreaks, which result in significant crop damage and an increased risk of transmission of zoonotic pathogens to humans. In this study, we confirmed that common voles are an important reservoir of multiple zoonotic pathogens in South Moravia, Czech Republic, with a high prevalence of infection and frequent co‐infections. Overall, we found 70 (50%), 72 (51.4%), 50 (35.7%) and 35 (25%) positive voles for Leptospira spp., Bartonella spp., Brucella spp. and TULV, respectively. Our results highlight the significant epidemiological role of this species in agricultural ecosystems. Therefore, further studies are needed to monitor vole populations and other small mammal species in this area to better understand pathogen dynamics and assess potential risks to human and animal health.

Introduction: Black flies (Simuliidae) are globally distributed blood‐feeding arthropods and vectors of viral, bacterial, and parasitic pathogens to many animal species, including humans. We investigated the occurrence of selected vector‐borne pathogens in black flies in South Moravia, Czech Republic, and evaluated their possible role in the circulation of vector‐borne pathogens. Methods: A total of 11,600 black flies comprising four species of the genus Simulium , namely Simulium ( Boophthora ) erythrocephalum (De Geer, 1776), Simulium ( Wilhelmia ) lineatum (Meigen, 1804), Simulium ( Wilhelmia ) balcanicum (Enderlein, 1924), and Simulium ( Wilhelmia ) turgaicum (Rubtsov, 1940) were pooled and screened for the following arthropod‐borne pathogens and parasites endemic in Central Europe: viruses (alphaviruses, bunyaviruses and flaviviruses), bacteria ( Borrelia burgdorferi sensu lato, Borrelia miyamotoi , Anaplasma phagocytophilum , Neoehrlichia mikurensis , Bartonella spp., Rickettsia spp., Francisella tularensis , Coxiella burnetii , and Brucella spp.), protista ( Babesia spp., Encephalitozoon spp. and Enterocytozoon spp.) and filaria ( Dirofilaria spp., Setaria spp., and Onchocerca spp.). Results: Almost all pools were negative for known arthropod‐borne pathogens and parasites. However, four new Bartonella spp. variants were found that share similarity with other bartonellae reported from diverse arthropods and humans. The phylogenetic analysis of Bartonella sequences from Czech black flies provides further evidence about an expanding diversity of Bartonella lineages in arthropods globally, including hematophagous species (e.g., ticks, mosquitoes, and biting flies) and non‐hematophagous species (e.g., bees and ants). These bartonellae have the potential to cause pathogenic infections in humans who are exposed to arthropods carrying these bacteria. Conclusions: Summing up, this study provides for the very first time valuable data for characterising the risk to public and veterinary health from black flies and the infections they may carry in Europe. Further testing, however, should include a wider geographic, seasonal, and taxonomic range of black flies.

The European subtype of tick-borne encephalitis virus (TBEV-Eur; species Orthoflavivirus encephalitidis, family Flaviviridae) was the only tick-borne flavivirus present in central Europe known to cause neurologic disease in humans and several animal species. Here, we report a tick-borne flavivirus isolated from Alpine chamois (Rupicapra rupicapra rupicapra) with encephalitis and attached ticks, present over a wide area in the Alps. Cases were detected in 2017 in Salzburg, Austria, and 2023 in Lombardy and Piedmont, Italy. The virus strains exhibit 94.8–97.3% nucleotide identities to each other and are more closely related to Louping ill viruses (LIV; Orthoflavivirus loupingi; 90–92% identities) than to TBEV-Eur (less than 88%). The chamois-derived virus strains, tentatively termed “Alpine chamois encephalitis virus”, form a well-supported independent genetic clade with Spanish goat encephalitis virus, clearly separated from other LIV. This supports its designation as a new virus subtype with the proposed shared taxonomic name “Spanish goat and Alpine chamois encephalitis virus subtype” within the species Orthoflavivirus loupingi. The zoonotic potential of this newly identified virus subtype as well as its host range in other animal species including farm animals needs to be further investigated.

Brucellosis is one of the most important zoonoses worldwide, primarily affecting livestock but also posing a serious threat to public health. The major Brucella species are known to cause a feverish disease in humans with various clinical signs. These classical Brucella species are (re‐)emerging, but also novel strains and species, some of them transmitted from rodents, can be associated with human infections. As a result of our review on rodent‐borne brucellosis, we emphasise the need for more comprehensive surveillance of Brucella and especially Brucella microti in rodent populations and call for further research targeting the ecological persistence of rodent‐associated Brucella species in the environment, their epizootic role in wild rodents and their virulence and pathogenicity for wildlife.

In the frame of the entomological VectorNet network and its capacity building activities, we collected original mosquito distribution data in southern Poland and bordering areas of the Czech Republic, Germany and Slovakia, in June and September–November 2023. Because of the suspected occurrence of Aedes japonicus or Ae. koreicus in Poland, provided by a photo posted early 2022 on iNaturalist, we targeted the exotic Aedes species in our sampling strategy, but also collected data on other mosquito species. Besides some adult catches, we mainly collected mosquito immature stages from artificial and natural water containers but occasionally from other aquatic habitats. In addition, we collated citizen data and modelled the distribution of Ae. japonicus in Europe incorporating the newly collected data. During this snapshot field study, a total of 162 samples, including 139 yielding mosquitoes, were taken from 111 locations across 47 administrative units, resulting on the detection of 22 mosquito taxa. Our study provides the first substantiated records of Ae. japonicus and Anopheles petragnani in Poland (the second confirmed by molecular identification). While Ae. japonicus is clearly established over a large part of the country, no other exotic mosquito species was detected. The presence of Ae. japonicus was also confirmed at one location by four citizen records submitted to MosquitoAlert in 2023. Regarding native mosquitoes, we identified their presence in 127 species/NUTS3 combinations (113 for Poland, including a single record for An. petragnani). An updated modelling of the distribution of Ae. japonicus suggests higher environment suitability in Central and Eastern Europe than has been previously estimated. Aedes japonicus is probably widespread in the Czech Republic and Slovakia, and might soon colonise the bordering region of Ukraine. Its establishment extends the putative mosquito vector list for West Nile and Rift Valley fever viruses in Central Europe.

The family Cimicidae comprises ectoparasites feeding exclusively on the blood of endothermic animals. Cimicid swallow bugs specifically target swallow birds (Hirundinidae) and their nestlings in infested nests. Bugs of the genus Oeciacus are commonly found in mud nests of swallows and martins, while they rarely visit the homes of humans. Although—unlike other cimicid species—the house martin bug Oeciacus hirundinis has never been reported as a vector of zoonotic pathogens, its possible role in arbovirus circulation in continental Europe is unclear. Samples of O. hirundinis were therefore collected from abandoned house martin (Delichon urbicum) nests in southern Moravia (Czech Republic) during the 2021/2022 winter season and checked for alpha-, flavi- and bunyaviruses by RT-PCR. Of a total of 96 pools consisting of three adult bugs each, one pool tested positive for Usutu virus (USUV)-RNA. Phylogenetic analysis showed that the virus strain was closely related to Italian and some Central European strains and corresponded to USUV lineage 5. The detection of USUV in O. hirundinis during wintertime in the absence of swallows raises the question for a possible role of this avian ectoparasite in virus overwintering in Europe.

We detected 24 Encephalitozoon cuniculi positive Ixodes ricinus ticks of 284 collected in the Czech Republic. Since the route of transmission of microsporidia is not fully understood, the presence of microsporidia in ticks raises the question of whether they may be involved in the transmission of these pathogens.

Background:Brucella microti is a pathogen of rodents and wild mammals. Here, we report the first probable infection with B. microti in a mammalogist. Methods: In the study, we provided complete clinical description as well as laboratory analysis of probable human infection caused by B. microti. Results: Considering the clinical course of the infection, the obvious epidemiological link (a bite by an infected rodent), the isolation of a pathogen from a sick vole that was affected by clinical infection with B. microti, and the specific serological response (slow agglutination test) in human patient, we can conclude that the human disease described here was probably caused by B. microti, an emerging bacterial pathogen transmitted by rodents. Conclusion: Rodents and other wildlife need to be monitored not only for established zoonotic agents such as hantaviruses, lymphocytic choriomeningitis virus, Leptospira spp., Francisella tularensis, but also for Brucella microti and other atypical rodent-borne brucellae.

Ťahyňa virus (TAHV) is an orthobunyavirus and was the first arbovirus isolated from mosquitoes in Europe and is associated with floodplain areas as a characteristic biotope, hares as reservoir hosts and the mammal‐feeding mosquitoes Aedes vexans as the main vector. The disease caused by TAHV (“Valtice fever”) was detected in people with acute flu‐like illness in the 1960s, and later the medical significance of TAHV became the subject of many studies. Although TAHV infections are widespread, the prevalence and number of actual cases, clinical manifestations in humans and animals and the ecology of transmission by mosquitoes and their vertebrate hosts are rarely reported. Despite its association with meningitis in humans, TAHV is a neglected human pathogen with unknown public health importance in Central Europe, and a potential emerging disease threat elsewhere in Europe due to extreme summer flooding events.

Aedes koreicus is an invasive mosquito species originating from East Asia. It has recently been introduced into several countries in Southern, Central and Eastern Europe as well as Central Asia in many of which it has successfully established populations. The biology and ecological requirements of the species are largely unknown, but it is considered as a potential vector of pathogens that requires careful monitoring. We report here the first detection of Ae. koreicus in the Czech Republic, based on a citizen report.