An unexpected case of a dog from Poland co-infected with Dirofilaria repens and Dirofilaria Immitis.

BACKGROUND: Dirofilariasis is a vector-borne disease caused by parasitic nematodes of the genus Dirofilaria spp., considered an emerging concern in both veterinary and human medicine. Climate changes and human activities, such as pet travel, contribute to the spread of diseases to new non-endemic regions. Poland is dominated by subcutaneous dirofilariasis caused by D. repens infections. Cardiopulmonary dirofilariasis, also known as a heartworm disease is much more rare with only single autochthonous cases reported so far. Also, imported infections are observed sporadically in dogs traveling to endemic countries. In this study, we report the first case of a dog in Poland, never having traveled abroad, co-infected with Dirofilaria repens and Dirofilaria immitis. CASE PRESENTATION: A 14-year-old mixed breed, an intact male dog with fever, lightly pale mucosal membranes, moderate abdominal pain, and a mild cough was presented in a veterinary clinic in Warsaw, Poland. The examination of the blood sample collected for complete morphology and biochemistry revealed the presence of live microfilariae. Presence of the DNA of both microfilariae species was detected using Real-Time PCR with species-specific primers. CONCLUSIONS: Since the remaining diagnostic methods like Knott's test, antigen test or echocardiography did not reveal the presence of D. immitis, we discussed the impact of microfilariae periodicity and low worm burden infections on the limited efficiency of these techniques. We strongly recommend using a mixed diagnostic approach for the most sensitive and specific diagnosis since the ideal diagnostic method does not exist, and several factors may contribute to misdiagnosis. Furthermore, we considered factors that contribute to the uncontrolled spread of dirofilariasis such as climate changes, introduction of new species of mosquitoes competent for the transmission of the disease, and wildlife animals as an important reservoir of this parasitosis. Given that Poland shares borders with countries classified as endemic and pre-endemic for D. immitis, such as Slovakia and Ukraine, it is reasonable to anticipate a rise in autochthonous heartworm infections and shifts in the epidemiological pattern of dirofilariasis in the coming years.

Mitochondrial genetic diversity and phylogenetic relationships of Echinococcus multilocularis in Europe.

The cestode Echinococcus multilocularis is the causative agent of alveolar echinococcosis, a fatal zoonotic parasitic disease of the northern hemisphere. Red foxes are the main reservoir hosts and, likely, the main drivers of the geographic spread of the disease in Europe. Knowledge of genetic relationships among E. multilocularis isolates at a European scale is key to understanding the dispersal characteristics of E. multilocularis. Hence, the present study aimed to describe the genetic diversity of E. multilocularis isolates obtained from different host species in 19 European countries. Based on the analysis of complete nucleotide sequences of the cob, atp6, nad2, nad1 and cox1 mitochondrial genes (4,968 bp), 43 haplotypes were inferred. Four haplotypes represented 62.56 % of the examined isolates (142/227), and one of these four haplotypes was found in each country investigated, except Svalbard, Norway. While the haplotypes from Svalbard were markedly different from all the others, mainland Europe appeared to be dominated by two main clusters, represented by most western, central and eastern European countries, and the Baltic countries and northeastern Poland, respectively. Moreover, one Asian-like haplotype was identified in Latvia and northeastern Poland. To better elucidate the presence of Asian genetic variants of E. multilocularis in Europe, and to obtain a more comprehensive Europe-wide coverage, further studies, including samples from endemic regions not investigated in the present study, especially some eastern European countries, are needed. Further, the present work proposes historical causes that may have contributed to shaping the current genetic variability of E. multilocularis in Europe.

Human alveolar echinococcosis in Slovakia: Epidemiology and genetic diversity of Echinococcus multilocularis, 2000-2023.

Human alveolar echinococcosis (AE) is a serious parasitic disease caused by larval stages of Echinococcus multilocularis. Between January 2000 and October 2023, 137 AE cases were confirmed in Slovakia. The average annual incidence increased from 0.031 per 100,000 inhabitants between 2000 and 2011, to an average of 0.187 since 2012, i.e. about six times. Among patients, 45.3% were men and 54.7% were women; the mean age at the time of diagnosis was 52.8 years. Most cases were diagnosed in the age groups 51-60 years and 61-70 years (33 cases each), and eight patients fell into the age category ≤ 20 years. To better recognize the gene diversity in clinical samples, metacestodes from 21 patients collected between 2013 and 2021 were subjected to DNA sequencing of four mitochondrial genes. Using concatenated sequences of cob (603 bp), nad2 (882 bp) and cox1 (789 bp) gene fragments, 14 isolates (66.7%) were assigned to the European E5 profile of E. multilocularis, two isolates (9.5%) to the E5a subtype, four isolates (19%) to the E4 profile, and one isolate (4.8%) to haplogroup E1/E2. The E5-type profiles and E4 profiles were distributed throughout the country, whereas the E1/E2 profile was found in the patient from western Slovakia. According to the data obtained and GenBank sequences, the E5-type dispersal is so far limited to central-eastern Europe and the variant seems to be indigenous to that region. The admixture with the haplotypes E4 and E1/E2 could have taken place from a historical endemic focus during the fox expansion in the last decades. By employing the nad1 fragment, a typical European haplotype was observed in all 21 resolved Slovak samples. The acceleration in the AE incidence in the last decade suggests the emergence of the disease and the need for further research on human and animal isolates.

Dirofilaria immitis conquering the regions in Slovakia previously endemic for D. repens.

The present study was focused on the current state of Dirofilaria species distribution in the territory of the Slovak Danubian Lowland, a region previously identified endemic for Dirofilaria repens. For the research, blood samples of 330 dogs tested positive for dirofilariosis using concentration tests or "rapid heartworm tests" were sent by private veterinary practitioners for further DNA analyses and species determination. The results revealed an unquestionable change in the pattern of Dirofilaria species distribution with Dirofilaria immitis, diagnosed as the agent of mono- and co-infections with D. repens, responsible for 60.00% of all cases. The results showed that in the course of the last 5 years, D. immitis has spread significantly in Slovakia and has become the dominant causal agent of dirofilariosis in the former endemic areas of D. repens distribution, which increases infection risk for both dogs and humans.

Diversity and geographic distribution of haplotypes of Dirofilaria immitis across European endemic countries.

BACKGROUND: Dirofilaria immitis, also known as heartworm, is one of the most important parasitic nematodes of domestic dogs, causing a potentially serious disease, cardiopulmonary dirofilariosis, which can be lethal. This species seems to be less 'expansive' than its sister species Dirofilaria repens, and it is believed that climate change facilitates the spread of this parasite to new non-endemic regions. METHODS: In total, 122 heartworm isolates were analysed from nine endemic countries in Europe (Portugal, Spain, Italy, Greece, Hungary, Romania, Slovakia, and Ukraine) and a single isolate from Bangladesh by amplification and sequencing of two mitochondrial (mt) DNA markers: cytochrome c oxidase subunit 1 (COI) and dehydrogenase subunit 1 (NADH). The main aim of the current study was to determine the genetic diversity of D. immitis and compare it with D. repens haplotype diversity and distribution. DNA was extracted from adult heartworms or microfilariae in blood. Most isolates originated from dogs (Canis lupus familiaris) while 10 isolates originated from wildlife species from Romania, including eight isolates from golden jackals (Canis aureus), one isolate from a Eurasian otter (Lutra lutra) and one isolate from a red fox (Vulpes vulpes). RESULTS: Median spanning network analysis was based on the combined sequence (1721 bp) obtained from two mt markers and successfully delineated nine haplotypes (Di1-Di9). Haplotype Di1 was the dominant haplotype encompassing 91 out of the 122 sequences (75%) from all nine countries and four host species. Haplotype Di2 was the second most common haplotype, formed solely by 13 isolates from Italy. The remaining sequences were assigned to Di3-Di9 haplotypes, differing by 1-4 SNPs from the dominant Di1 haplotype. There was evidence for geographical segregation of haplotypes, with three unique haplotypes associated with Italy and four others associated with certain countries (Di4 and Di7 with Slovakia; Di8 with Greece; Di6 with Hungary). CONCLUSION: Diversity in D. immitis mt haplotypes was lower by half than in D. repens (9 vs. 18 haplotypes in D. immitis and D. repens, respectively), which may be associated with the slower expansion of heartworm in Central and NE Europe. NADH gene appears to be conserved in Dirofilaria sp. by showing lower genetic diversity than the analysed COI gene.

Pilot research on gastrointestinal parasites of the Tatra chamois (Rupicapra rupicapra tatrica).

INTRODUCTION AND OBJECTIVE: The Tatra chamois (Rupicapra rupicapra tatrica) is a significant representative of the High Tatra Mountains endemic fauna species. In terms of health hazards for these animals, an important role is played by parasitic infections that can lead to a significant depletion of the entire population. OBJECTIVE: The aim of the study was to describe the occurrence of gastrointestinal parasites of Tatra chamois in the current environmental and climatic conditions of the High Tatra Mountains. MATERIAL AND METHODS: During the pilot project in 2014 - 2017, a total of 494 chamois faecal samples were collected from the Slovak High Tatra and 114 samples in the Polish part of the mountain and examined using standard coprological methods. RESULTS: The results revealed that the overall positivity for gastrointestinal parasites in chamois of the Slovak High Tatra reached 74.7%. Most frequent were protozoa - Eimeria spp. (42.7%), helminths were represented by Moniezia spp. tapeworms (23.5%), eggs of GIS-strongylids (7.1%), and sporadically Capillaria spp. (1.4%). The chamois from the Polish Tatra Mts. were infected with Eimeria spp. (43.9%), GIT-strongylids (9.6%), and Moniezia spp. (6.1%). Parasitic infection was determined in 59.6 % of faecal samples from the Polish part of the mountains. Statistical analyses revealed a significant difference in Moniezia spp. occurrence in different Slovak Tatra Mts. Regions, as well as between Slovak and Polish Tatra Mts. CONCLUSIONS: Initial research on the gastrointestinal parasites of the Tatra chamois revealed one indisputable finding - a relatively high prevalence of the genus Moniezia, which is closely linked to the climate and microclimate conditions of the mountains. Further intensive research on parasite composition and distribution in Tatra chamois is needed in broader temporal, ecological, and zoological contexts.

Clinical and Hematologic Findings in Babesia canis Infection in Eastern Slovakia.

PURPOSE: Babesia canis infection occurs in many locations throughout Europe. However, various studies report different clinicopathological findings in affected dogs. This study was focused on changes in clinical and hematologic parameters in dogs with B. canis infection from eastern Slovakia. METHODS: The study was prospective and included 45 dogs with suspected babesiosis. Babesia canis infection was confirmed by PCR in 34 cases and by blood smear microscopy in 24 (70.6%) of them. Hematology results, clinical examination from these dogs, and possible co-infection with other tick-borne pathogens by PCR were subsequently evaluated. RESULTS: The major clinical signs found included lethargy (91%), fever (59%), anorexia (59%), pigmenturia (47%) and icterus (18%). Mortality rate was 6%. Thrombocytopenia was the most common hematologic change, observed in 100% of the dogs with B. canis infection. Other frequent findings were lymphopenia (82%) and anemia (68%). No co-infections were detected. Anaplasma phagocytophilum infection was diagnosed by PCR only in one dog, which was not infected with B. canis. CONCLUSIONS: This study showed that B. canis infection in eastern Slovakia should be diagnosed by PCR when there is clinical suspicion of the disease, as almost 30% of the infected sick dogs did not have demonstrable parasites in their blood smear by microscopy. Lymphopenia is a frequent hematologic finding in B. canis infection and observed even more often than anemia. However, in agreement with previous studies, thrombocytopenia remains the most common hematologic finding associated with B. canis infection.

Dirofilaria immitis Pulmonary Dirofilariasis, Slovakia.

Dirofilaria immitis is a parasite related to pulmonary dirofilariasis in humans, its accidental hosts. We detected an autochthonous case of D. immitis infection in a woman from Slovakia. The emergence and spread of this parasite in Europe indicates a critical need for proper diagnosis of infection.

Thelazia callipaeda in Slovakia - From sporadic cases to endemic areas.

Spirurid nematode Thelazia callipaeda, transmitted by the fruit fly Phortica variegata, is a causative agent of an ocular parasitic disease called also canine thelaziosis. Dogs, cats, and wild canids are considered the primary definitive hosts for the parasite, but humans may also serve as aberrant definitive hosts. For long decades the geographic range of T. callipaeda was strictly limited to the territory of Asia, but after the year 2000, the parasite began to spread rapidly through Europe. The first autochthonous infections of dogs and foxes in Slovakia were recorded in 2016. In the present study, the results of a whole-area surveillance for canine thelaziosis are reported. Altogether, 142 cases of infection caused by T. callipaeda were diagnosed by veterinarians in dogs between 2016 and the first quarter of 2021, and two cases of feline thelaziosis were recorded. The majority of the dogs showed mild ocular signs manifested by conjunctivitis; 8.5% of them suffered from more serious mucopurulent discharge, and in two dogs corneal ulceration was recorded. The screening revealed increasing trends in the occurrence of canine thelaziosis from both a temporal and spatial point of view and unambiguously confirms the endemic status of T. callipaeda in Slovakia with the prospect of its further expansion.

Molecular Study of Echinococcus granulosus Cestodes in Ukraine and the First Genetic Identification of Echinococcus granulosus Sensu Stricto (G1 Genotype) in the Country.

INTRODUCTION: Cystic echinococcosis is a globally distributed zoonotic disease of great medical and veterinary importance, which is caused by the cestode Echinococcus granulosus sensu lato. In Ukraine, two areas of the prominent circulation of the parasite are established, the southern steppe zone with sheep as the main transmitter, and the northern forest-steppe zone and Polissia, where pigs are mainly responsible for maintaining the E. granulosus transmission. METHODS: Given that only a few studies have so far addressed the genetic diversity of the parasite in Ukraine, we have sequenced partial mitochondrial genes of cytochrome c oxidase 1 (789 bp), NADH dehydrogenase 1 (602 bp) and 12S rRNA (333-334 bp) in pig metacestodes from the Sumy region (farms close to Sumy, northeastern Ukraine) and the Kyiv region (a farm in Bila Tserkva, central Ukraine). RESULTS: Four isolates from four pigs in the Sumy region were identified as E. canadensis (G7 genotype), the major E. granulosus s.l. species circulating in Eastern Europe, including the three microvariants (G7A, G7B, G7C). Three isolates from the two pigs in the Kyiv region were classified as E. granulosus s.s. (G1 genotype), including one microvariant (G1A). CONCLUSION: To our knowledge, this is the first genetic record of E. granulosus s.s. with the presumed highest infectivity and virulence among the E. granulosus s.l. species in Ukraine. The finding has implications for public health as local control programmes should take into consideration different development rate of this parasite in dogs and the greater risk of the species for human infection.

Dirofilaria spp. and Angiostrongylus vasorum: Current Risk of Spreading in Central and Northern Europe.

In the past few decades, the relevance of Dirofilaria immitis and Dirofilaria repens, causing cardiopulmonary and subcutaneous dirofilariosis in dogs and cats, and of Angiostrongylus vasorum, causing canine angiostrongylosis, has steadily increased in Central and Northern Europe. In this review, a summary of published articles and additional reports dealing with imported or autochthonous cases of these parasites is provided for Central (Austria, Czechia, Germany, Hungary, Luxemburg, Poland, Slovakia, Slovenia, and Switzerland) and Northern (Denmark, Finland, Iceland, Norway, and Sweden) Europe. Research efforts focusing on Dirofilaria spp. and A. vasorum have varied by country, and cross-border studies are few. The housing conditions of dogs, pet movements, the spread of competent vectors, and climate change are important factors in the spread of these nematodes. Dogs kept outside overnight are a major factor for the establishment of Dirofilaria spp. However, the establishment of invasive, diurnal, synanthropic, competent mosquito vectors such as Aedes albopictus may also influence the establishment of Dirofilaria spp. The drivers of the spread of A. vasorum remain not fully understood, but it seems to be influenced by habitats shared with wild canids, dog relocation, and possibly climatic changes; its pattern of spreading appears to be similar in different countries. Both Dirofilaria spp. and A. vasorum merit further monitoring and research focus in Europe.

Mosquito surveillance of West Nile and Usutu viruses in four territorial units of Slovakia and description of a confirmed autochthonous human case of West Nile fever, 2018 to 2019.

BackgroundDespite the known circulation of West Nile virus (WNV) and Usutu virus (USUV) in Slovakia, no formal entomological surveillance programme has been established there thus far.AimTo conduct contemporaneous surveillance of WNV and USUV in different areas of Slovakia and to assess the geographical spread of these viruses through mosquito vectors. The first autochthonous human WNV infection in the country is also described.MethodsMosquitoes were trapped in four Slovak territorial units in 2018 and 2019. Species were characterised morphologically and mosquito pools screened for WNV and USUV by real-time reverse-transcription PCRs. In pools with any of the two viruses detected, presence of pipiens complex group mosquitoes was verified using molecular approaches.ResultsAltogether, 421 pools containing in total 4,508 mosquitoes were screened. Three pools tested positive for WNV and 16 for USUV. USUV was more prevalent than WNV, with a broader spectrum of vectors and was detected over a longer period (June-October vs August for WNV). The main vectors of both viruses were Culex pipiens sensu lato. Importantly, WNV and USUV were identified in a highly urbanised area of Bratislava city, Slovakias' capital city. Moreover, in early September 2019, a patient, who had been bitten by mosquitoes in south-western Slovakia and who had not travelled abroad, was laboratory-confirmed with WNV infection.ConclusionThe entomological survey results and case report increase current understanding of the WNV and USUV situation in Slovakia. They underline the importance of vector surveillance to assess public health risks posed by these viruses.

Unravelling the genetic diversity and relatedness of Echinococcus multilocularis isolates in Eurasia using the EmsB microsatellite nuclear marker.

The cestode Echinococcus multilocularis is the causative agent of alveolar echinococcosis, a severe helminthic zoonotic disease distributed in the Northern Hemisphere. The lifecycle of the parasite is mainly sylvatic, involving canid and rodent hosts. The absence of genetic data from most eastern European countries is a major knowledge gap, affecting the study of associations with parasite populations in Western Europe. In this study, EmsB microsatellite genotyping of E. multilocularis was performed to describe the genetic diversity and relatedness of 785 E. multilocularis isolates from four western and nine eastern European countries, as well as from Armenia and the Asian parts of Russia and Turkey. The presence of the same E. multilocularis populations in the Benelux resulting from expansion from the historical Alpine focus can be deduced from the main profiles shared between these countries. All 33 EmsB profiles obtained from 528 samples from the nine eastern European countries belonged to the European clade, except one Asian profile form Ryazan Oblast, Russia. The expansion of E. multilocularis seems to have progressed from the historical Alpine focus through Hungary, Slovakia, the Czech Republic and southern Poland towards Latvia and Estonia. Most of the samples from Asia belong to the Asian clade, with one EmsB profile shared between Armenia and Turkey, and two between Turkey and Russia. However, two European profiles were described from two foxes in Turkey, including one harboring worms from both European and Asian clades. Three EmsB profiles from three Russian samples were associated with the Arctic clade. Two E. multilocularis profiles from rodents from Lake Baikal belonged to the Mongolian clade, described for the first time here using EmsB. Further worldwide studies on the genetic diversity of E. multilocularis using both mitochondrial sequencing and EmsB genotyping are needed to understand the distribution and expansion of the various clades.

Fifteen years since the first record of Trichinella pseudospiralis in Slovakia: What's new?

The presence of Trichinella pseudospiralis has been increasingly reported in Europe in the last decade. The parasite was recorded for the first time in Central Europe in 2003-2004, in eastern Slovakia, in pigs, rats and a cat from a pig breeding farm. In the following years, it was also repeatedly diagnosed in co-infection with T. britovi in sylvatic animals from this area. Molecular analyses revealed a distinctive genetic relationship of the Slovak isolate with those from Finland and Sweden, suggesting the potential role of migratory birds of prey in the transmission of the parasite. Thus, potential host species, including mammals and birds, were investigated for the presence of T. pseudospiralis. During 2006-2018, a total of 360 carcasses of raptorial, carrion-feeding and scavenging birds were collected and examined using artificial digestion of pectoral muscle samples. Muscle larvae were detected in muscle of one golden eagle (Aquila chrysaetos), two common kestrels (Falco tinnunculus) and one peregrine falcon (F. peregrinus). Molecular analyses confirmed the presence of T. pseudospiralis. These findings in diurnal raptorial species represent new host records for Trichinella spp. In 2017, a mandatory examination of pigs (Sus scrofa domesticus), red foxes (Vulpes vulpes) and wild boars (Sus scrofa) revealed one wild boar from the central part of territory to be infected with T. pseudospiralis. Our data confirm that the parasite has already established itself in Slovakia, and thus adequate veterinary measures and public education are needed to prevent its transmission to the food chain and the risk of human infection.

Ocular Dirofilariasis after Clinically Manifested Subcutaneous Migration of the Parasite: A Case Report.

Dirofilaria repens is the causative agent of human subcutaneous or, less often, ocular dirofilariasis. The work presents a rare case of ocular dirofilariasis manifested by previous subcutaneous migration accompanied by severe headache symptoms. In February 2017, a 58-yr-old man from Trnava region, western Slovakia, noticed red and itchy stripes on his left leg. Inflamed but painless stripes disappeared and showed up again every 5-7 days, migrating gradually towards the head. Approximately one month after the first skin's alterations, strong pain in the left temple, with the swelling of the left face and the enlargement of mandibular lymph nodes appeared. Several days later, the patient felt excruciating pain of the right eyeball accompanied by strong nausea and subsequent vomiting. Ocular examination revealed the presence of a live worm in the subconjunctival space and morphological and molecular analyses of extracted helminth confirmed D. repens as etiological agent of the infection. According to clinical manifestation of the infection, it could be supposed that ocular form of the disease was the result of the migration of a parasite through the subcutaneous tissues. Moreover, a rare phenomenon of lymphadenitis of underlying lymph nodes and the swelling of left face accompanied the migration.

Bartonella species in medically important mosquitoes, Central Europe.

Here, we provide the first mass molecular screening of medically important mosquitoes for Bartonella species using multiple genetic markers. We examined a total of 72,115 mosquito specimens, morphologically attributed to Aedes vexans (61,050 individuals), Culex pipiens (10,484 individuals) and species of the Anopheles maculipennis complex (581 individuals) for Bartonella spp. The initial screening yielded 63 Bartonella-positive A. vexans mosquitoes (mean prevalence 0.1%), 34 Bartonella-positive C. pipiens mosquitoes (mean prevalence 0.3%) and 158 Bartonella-positive A. maculipennis group mosquitoes (mean prevalence 27.2%). Several different Bartonella ITS sequences were recovered. This study highlights the need for molecular screening of mosquitoes, the most important vectors of arthropod-borne pathogens, for potential bacterial agents.

Ticks (Acari: Ixodidae) Parasitizing Red Foxes (Vulpes vulpes) in Slovakia and New Data About Subgenus Pholeoixodes Occurrence.

BACKGROUND: Distribution and biology of Pholeoixodes ticks is not very well understood. The goal of the study was to collect new data on the Pholeoixodes tick occurrence in Slovakia. METHODS: Tick infestation of red foxes in the regions of Kosice, Presov, Bratislava and Zilina was studied during the period 2017-2018. Ticks were collected from the fur of animals using tweezers and identified using appropriate keys. In total, 146 red foxes (Vulpes vulpes) were investigated. RESULTS: In total, 39 (26.7%) of animals were found to be infected with ticks from five species. Pholeoixodes ticks were found on 13 (3.4%) of the foxes: Ixodes hexagonus (Leach, 1815) on 5 specimens (3.4%), in the Kosice, Presov and Zilina regions; I. crenulatus (Koch, 1844) on 8 specimens (5.5%) in the Presov and Bratislava regions; Ixodes ricinus (Linnaeus, 1758) collected from 25 (17.2%) foxes in every locality; Dermacentor reticulatus (Fabricius, 1794) from 5 foxes (3.4%) in the Kosice, Presov and Zilina regions; Haemaphysalis concinna (Koch, 1844), from 4 foxes (2.8%) from the Kosice region. CONCLUSIONS: Ixodes hexagonus has been previously recorded in Slovakia. However, this is the first finding of I. crenulatus in the country. The morphological features of the I. crenulatus specimens found in Slovakia were identical to those of ticks described in Poland and descriptions given in identification keys.

Pseudo-Tumor of the Epididymis, a Rare Clinical Presentation of Human Dirofilaria repens Infection: a Report of Autochthonous Case of Dirofilariasis in Southwestern Slovakia.

PURPOSE: Dirofilariasis caused by the filarial nematode Dirofilaria repens is mainly a disease of dogs and other carnivores. Also, humans can be accidentally infected with this parasite. The infective third-stage filariform larvae are transmitted by various species of mosquitoes. Until this day, a total of 17 human cases caused by D. repens have been diagnosed in Slovakia, 11 subcutaneous, 4 ocular, 1 pulmonary and 1 in the epididymis. The aim of this report was to describe an unusual clinical case of dirofilariasis of the scrotum. METHODS: Extirpated worm was subjected to the molecular and histological identification. PCR for the amplification of cytochrome oxidase subunit 1 (CO1) was performed using specific D. repens primer pair. RESULTS: Here we document the 13th case of human dirofilariasis in a 46-year-old man from southwestern Slovakia. Very rare in humans, genital involvement manifests itself as pseudotumor nodule affecting the epididymis. The patient consulted a general practitioner due to a palpable subcutaneous lump in the scrotum. Routine laboratory analysis revealed blood eosinophilia (16.6%). The ultrasound examination was indicated, and subsequently, surgical excision of the right epididymal nodule was performed. On the basis of histological microscopic examination and PCR-based detection, the helminth was identified as Dirofilaria repens. This represents the ninth case of autochthonous dirofilariasis in Slovakia. CONCLUSIONS: The majority of D. repens infections were recorded in southwestern regions of Slovak Republic, which are considered to be endemic areas for canine dirofilariasis. Our described patient also comes from southwestern part of Slovakia (Topolníky, Dunajská Streda region).