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.

Zoonotic dirofilariases: one, no one, or more than one parasite.

Dirofilaria spp. are vector-borne filarial nematodes that affect a variety of animal species, including humans. Dirofilaria immitis and Dirofilaria repens are the two main zoonotic species, but also other wildlife-associated Dirofilaria species are occasionally reported as causative agents of human dirofilariasis, including Dirofilaria striata, Dirofilaria tenuis, Dirofilaria ursi, Dirofilaria spectans, and Dirofilaria magnilarvata. Since the etiological identity of most of the species mentioned here is arguable, we summarized and critically discussed data concerning infections in humans, focusing on the reliability of Dirofilaria species identification. We advocate the importance of combined morphological and genomic approaches to provide unequivocal evidence for their zoonotic potential and pathogenicity.

Genetic variability of Dirofilaria repens isolates from humans and dogs in Italy.

Dirofilaria repens is a paradigmatic example of an emerging vector-borne pathogen (VBP) in both human and veterinary fields. The spatial expansion and the increasing zoonotic impact of this VBP can be related to several drivers including the genetic structure of parasite populations. Italy is one of the European countries traditionally endemic with the highest incidence of canine and human cases of subcutaneous dirofilariosis. The present study aimed to assess the genetic identity and variability of D. repens isolates of human and canine origin from areas of Central Italy, compared with those isolated from different areas of Europe by sequence analysis of mtDNA genes (i.e., 12 S rDNA and cox1). A total of twenty isolates of D. repens were obtained from biopsies of subcutaneous and ocular cases of dirofilariosis occurring in 10 dogs and 10 humans. The sequence analysis of 12 S rDNA showed that all the sequences obtained clustered as a monophyletic group with a strong nodal support, indicating that all sequence types represented D. repens. The cox1 and the 12 S sequence analysis did not show host-related polymorphisms between human and dog-derived specimens. The sequence analysis of cox1 was performed including 8 additional sequences previously obtained from human and canine isolates in the same areas. Out of the 28 sequences analyzed, 20 were grouped in a haplogroup comprising 15 haplotypes (i.e., DR1, DR2, DR4, DR5, DR7, DR8, DR10-DR18), 2 sequences matched to DR9, reported for the first time in Italy, and 6 showed peculiar polymorphisms that were not previously described. The results obtained have implications for a better understanding of the epidemiology and phylogeography of this emerging vector-borne zoonotic parasite.

[A case of pleuropulmonary dirofilariasis caused by Dirofilaria repens. Case report].

The differential diagnosis of neoplasms of various localizations is the primary task in clinical practice of all physicians. We present a description of the case of invasion with Dirofilaria repens in the lung of a 68-year-old patient. In 2016 the patient was diagnosed with cancer of the left kidney and underwent a left-sided nephrectomy. During the dynamic observation in 2019, a lump was found in the left lung, which was regarded as a metastasis. An atypical SIX resection of the left lung was performed. Microscopy of the removed lump revealed the presence of a nematode of the genus Dirofilaria, presumably D. repens. The species identity of D. repens was confirmed by polymerase chain reaction using species-specific primers. It is known that the morphological identification of parasites up to the species in the surgical material presents certain difficulties and requires high professional training of the researcher. Therefore, the diagnosis of dirofilariasis in atypical localizations of nematodes in the human body is of great importance in the differentiation of malignant and benign formations, and the use of the polymerase chain reaction method can significantly increase the accuracy in establishing the final diagnosis.

First molecular characterization of Dirofilaria Immitis in Cuba.

BACKGROUND: Dirofilarioses are widespread diseases caused by mosquito-borne nematodes of the family Onchocercidae, genus Dirofilaria. The major etiologic agent of canine dirofilariosis in the American continent is the zoonotic parasite Dirofilaria immitis. Existing reports of filarioid nematodes in Cuba are based solely on morphological and immunological analysis which do not allow unambiguous identification and/or direct detection of causal agents. RESULTS: Here we present the molecular characterization of filarioid nematodes found in a dog in Cuba. Based on the molecular and phylogenetic analysis of the 5.8S-ITS2-28S region and cox1 gene fragments, the worms were unambiguously classified as D. immitis. Sequence analysis showed high identity of the gene fragments in this study with others previously obtained from D. immitis found in dogs, wolfs and jackals but also from mosquito vectors of D. immitis. CONCLUSIONS: Further studies are guarantee to better understand the epidemiological impact of canine dirofilariosis in Cuba as well as the competence of different species of culicid mosquitoes as vectors of Dirofilaria in the country.

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.

The first report of Dirofilaria repens infection in dogs from Colombia.

Dirofilariasis is a mosquito-borne disease caused by Dirofilaria parasites, affecting both wild and domestic animals, including humans considered as accidental hosts. Dirofilaria repens is the principal causative agent of dirofilariasis in the Old World, with increasing reports of the parasite in countries where it has not been previously identified, due to several factors such as the expansion of mosquito vectors' geographical distribution. By utilizing newly designed primers for molecular detection and confirming through next-generation sequencing, here, we report the first plausible cases of D. repens in dogs from Colombia. Our results support the classification of this species as an emergent pathogen in the Americas. Finally, we encourage an increase in diagnostic and surveillance efforts to prevent and control the current and future dirofilariasis cases in this region.

Occurrence of Dirofilaria repens in wild carnivores in Poland.

Dirofilaria repens is an expanding vector-borne zoonotic parasite of canines and other carnivores. Sub-clinically infected dogs constitute the most important reservoir of the parasite and the source of infection for its mosquito vectors. However, occurrence of D. repens infection in wild animals may contribute to the transmission of the parasite to humans and may explain the endemicity of filariae in newly invaded regions. The aim of the current study was to determine the occurrence of D. repens in 511 blood and spleen samples from seven species of wild carnivores (wolves, red foxes, Eurasian badgers, raccoons, raccoon dogs, stone martens, and pine martens) from different regions of Poland by means of a PCR protocol targeting the 12S rDNA gene. Dirofilaria repens-positive hosts were identified in seven of fourteen voivodeships in four of the seven regions of Poland: Masovia, Lesser Poland, Pomerania and Warmia-Masuria. The highest prevalence was found in Masovia region (8%), coinciding with the highest previously recorded prevalence in dogs in Central Poland. The DNA of Dirofilaria was detected in 16 samples of three species (total prevalence 3.13%). A low and similar percentage of positive samples (1.9%, 4.2% and 4.8%) was recorded among badgers, red foxes, and wolves, respectively. Dirofilaria repens-positive hosts were identified in seven of fourteen voivodships. Based on detection in different voivodeships, D. repens-positive animals were recorded in four out of the seven regions of Poland: in Masovia, Lesser Poland, Pomerania, and Warmia-Masuria. The highest prevalence of filariae was found in Masovia region (8%), reflecting the highest previously recorded prevalence in dogs (12-50%) in Central Poland. In summary, we conducted the first comprehensive study on the epidemiology of D. repens in seven species of wild hosts in all seven regions of Poland and identified the first case of D. repens infection in Eurasian badgers in Poland and the second in Europe.

Haplotypes of Dirofilaria repens from Poland and selected countries of Central, North-Eastern Europe and the Middle East: An evaluation on the relation between the genetic diversity and the geographic distribution of the fast-spreading parasite.

Subcutaneous dirofilariosis is a fast-spreading infection of dogs, and occasionally of other carnivores and humans. Several factors contribute to its spread, including climate change, which facilitates development and survival of Dirofilaria repens in the mosquito vector. Movement/relocation of infected definitive hosts (dogs) from endemic regions to non-endemic regions is another possible cause of local emergence and the presence of a wide variety of wild reservoirs of the parasite may also contribute to its spread. The main aim of this study was to evaluate the genetic diversity of D. repens from different regions of Europe and to evaluate the spread of identified haplotypes and their geographic origin. A total of 95 D. repens isolates were obtained from Central and Eastern Europe (Poland, Belarus, Ukraine, Austria, Romania), NE Europe (Lithuania, Latvia, Estonia), Italy and Israel. All but two positive samples were obtained from the blood of dogs while one positive sample was obtained from an adult worm from a human case from the Lublin area in SE Poland and one sample was obtained from Anopheles plumbeus mosquito from Austria. Genetic diversity in D. repens isolates was evaluated by PCR amplification and sequencing of three genetic markers, including two mitochondrial genes (mtDNA): the cytochrome c oxidase subunit I (COI) and dehydrogenase subunit I (NADH). Additionally, the genomic marker, internal transcribed spacer 1 (ITS-1) was amplified and sequenced. Haplotypes were differentiated based on sequence alignments by identifying Single Nucleotide Polymorphism (SNPs) using DnaSP and Mega X. PopArt was used to construct a haplotype network including all identified haplotypes. Both mtDNA sequences (COI and NADH) were combined together for phylogenetic and network analyses. Altogether 18 haplotypes (DR1-DR18) were identified in combined mtDNA markers among 95 analysed samples. Haplotype DR1 was the most common encompassing 66 isolates: 42 isolates from Poland (41 from dogs and one from a human), 13 from Lithuania, 4 from Latvia, 2 from Ukraine and 5 from Romania. All other haplotypes grouped around haplotype DR1 separated by 1-5 SNPs, forming a star-like shape. Haplotype DR2 was the second most common haplotype, formed by six isolates from Romania. Interestingly, haplotype DR3 was represented only by four isolates from Israel. The remaining 15 haplotypes were represented by 1-4 isolates of different origins. Our study showed that only minor genetic diversity was found in D. repens since all isolates appear to have clustered in or branched out from haplotype DR1 with 1-5 SNP differences. The genetic diversity appears to be governed by geographic origin since isolates from neighbouring populations (countries) appear to share unique haplotypes while other populations that are geographically distant from individual haplotypes.

Filariasis in dogs brought to the Veterinary Teaching Hospital, University of Peradeniya, Sri Lanka.

Dirofilariasis is the predominant emerging zoonotic filariasis in the world. The two most frequent filarial worms that infect dogs are Dirofilaria repens and Dirofilaria immitis. This study reports filariasis among dogs brought to the Veterinary Teaching Hospital (VTH) at the University of Peradeniya and signifies the first molecular characterization of D. repens, responsible for an emerging zoonotic filarial disease in Sri Lanka. Blood samples were collected and were morphologically analyzed using Modified Knott's Technique, followed by molecular analyses. The difference in filariasis prevalence among gender, breed, and age categories was analyzed using a chi-square test. Infection intensities were analyzed using the Mann-Whitney U test and the Kruskal Wallis test. The dogs were brought to the clinic for either vaccination and/or for a regular checkup, and most were sick having non-specific clinical signs. Among the 87 dogs tested, 27.6% were positive for Dirofilaria. Conventional PCR and bi-directional sequencing of genomic DNA of microscopically tested positive samples revealed that the species in Sri Lanka was D. repens. The infection was significantly higher in males (39.1%) than in females (14.6%; χ2 = 0.447, p = 0.011), though it is not significant between puppies (age < 1 year) and adult dogs. More crossbred dogs were infected compared to older and purebred dogs. There was no difference in intensity of infection based on their gender, age, or breed. Sequences obtained from the current study were unique and were only 63% identical to those of D. repens reported from South India. The high number of Dirofilaria infections in domestic dogs indicates a potential reservoir for emerging human dirofilariasis cases in Sri Lanka. Thus, morphological and molecular diagnosis, along with epidemiological assessment of these zoonoses, is critical for the formulation of effective public health programs and control mechanisms.

Two cases of ectopic dirofilariasis by Dirofilaria immitis in subconjunctival and subcutaneous tissues in dogs.

We report two cases of ectopic dirofilariasis caused by Dirofilaria immitis in the subconjunctival and subcutaneous tissues of dogs. In Case 1, a 10-year-old female poodle suffered from a subconjunctival mass in the left eye that was refractory to antibiotic and steroid treatments. The mass was removed surgically, and a whitish nematode was identified within the mass. In Case 2, a stray 3-year-old male greyhound was rescued and transferred to a local veterinary hospital. During care, two nematodes were observed on the left hind paw and leg. The observed worms were not typical of D. immitis; therefore, the species was confirmed using molecular methods. Phylogenetic analysis revealed high genetic identity with other previously reported D. immitis strain. Subcutaneous and subconjunctival dirofilariasis have been mainly caused by D. repens. To the best of our knowledge, this is the first report of subconjunctival ectopic dirofilariasis by D. immitis in a dog, and the first report of subcutaneous localization in Korea. Therefore, in endemic regions, ectopic dirofilariasis caused by D. immitis should be considered as a differential diagnosis in subconjunctival and subcutaneous masses.

Dirofilaria repens Testicular Infection in Child, Italy.

Testicular Dirofilaria repens infection was identified and confirmed by sequence analysis in a child in northeastern Italy. Because human dirofilariasis is emerging in southern and eastern Europe, this parasitic infection should be considered in the differential diagnosis of scrotal swelling in disease-endemic countries to avoid unnecessary interventions, such as orchiectomy.

Nationwide molecular survey of Dirofilaria immitis and Dirofilaria repens in companion dogs and cats, United States of America.

BACKGROUND: Heartworms, Dirofilaria immitis, are known to be widespread in dogs and cats in the USA, but there have been no country-wide prevalence studies performed to date. There have also been no large-scale studies to determine whether the closely related species, Dirofilaria repens, occurs in the USA. METHODS: To provide this large-scale data, we examined whole blood samples (n = 2334) submitted from around the USA to the Molecular Diagnostic Laboratory at Auburn University between 2016 and 2022. Quantitative PCRs for D. immitis (targeting 16S rRNA) and D. repens (targeting cytochrome c oxidase subunit 1 gene) were performed to determine the presence of Dirofilaria DNA. DNA sequencing was performed to confirm the results. RESULTS: Dirofilaria immitis DNA was found in 6.3% (68/1080) of the dogs from 17/39 states, and 0.3% (4/1254) of the cats from 4/42 states. None of the dogs or cats were positive for D. repens. The average 16S rRNA copy number of D. immitis in the dogs was 1,809,604 in 200 µl whole blood, while only a single copy was found in each of the four D. immitis-positive cats. The prevalence of D. immitis in dogs of different ages, sexes, and breeds did not differ significantly, but the prevalence in Southern states (7.5%, 60/803) was significantly higher than in the Western (1.7%, 1/58), Midwest (3.3%, 4/120), and Northeastern states (3.1%, 3/98) (P < 0.05). Dogs positive for D. immitis were identified in each study year (2016: 4.2%, 2/48; 2017: 9.8%, 4/41; 2018: 5.1%, 8/156; 2019: 4.9%, 15/306; 2020: 9.8%, 26/265; 2021: 4.9%, 13/264). Interestingly, dogs infected with Hepatozoon spp. (11.8%, 37/313) were significantly more likely to also be positive for D. immitis than dogs without evidence of Hepatozoon infection (3.9%, 30/760) (P < 0.0001). CONCLUSIONS: To our knowledge, this is the first nationwide molecular survey of Dirofilaria spp. in dogs and cats in the USA, and the largest molecular survey of canine and feline dirofilariosis worldwide. Further studies are warranted to combine PCR with standard heartworm diagnostics to better understand the prevalence of Dirofilaria spp. and aid in determining the risks posed to dogs and cats in the USA.

Dirofilaria immitis antigenemia and microfilaremia in Iberian wolves and red foxes from Portugal.

BACKGROUND: Dirofilaria immitis is a parasitic nematode endemic in the Mediterranean countries, which causes cardiopulmonary dirofilariosis in wild and domestic animals. Despite being recognized hosts of D. immitis, wild carnivores such as wolves and foxes are frequently disregarded when considering a potential role in the transmission of these zoonotic nematodes. In Portugal, studies available regarding D. immitis circulation are scarce, likely underestimating its relevance. To add knowledge on this, we sought to assess Iberian wolves (Canis lupus signatus) and red foxes (Vulpes vulpes) from northern Portugal for D. immitis antigenemia and microfilaremia. METHODS: Blood samples from 42 Iberian wolves and 19 red foxes were collected, during 2010-2012, in Peneda-Gerês National Park. Antigenemia was searched for by rapid antigen detection test kits (Uranotest Dirofilaria ®). Microfilaremia was assessed by polymerase chain reaction (PCR). Nucleic acids were extracted from blood using QIAamp® DNA Mini Kit (Qiagen), and DNA was screened for the presence of microfilaria using a conventional PCR targeting the 5.8S-internal transcribed spacer 2-28S regions, followed by bidirectional sequencing, Basic Local Alignment Search Tool analysis and phylogenetic analysis. RESULTS: Three red foxes had antigenemia, with an occurrence of 15.8% (95% confidence interval [CI] 3.4-39.6), while showing no evidence for the presence of microfilaremia. No wolf samples presented evidence for D. immitis antigenemia. Nevertheless, two wolves were positive for D. immitis microfilaremia (4.8%; 95% CI 0.6-16.2%) as revealed by PCR and confirmed by bidirectional sequencing. CONCLUSIONS: Although Dirofilaria microfilaremia in wolves does not necessarily correlate to an endangerment of the infected animal's health, positive individuals can act as a reservoir for further infection if the intermediate mosquito hosts are present. To the best of our knowledge, one single study had reported that wolves were suitable Dirofilaria hosts, but microfilaremia have never been reported.

Further data on the distribution of Dirofilaria spp. in the Czech Republic in dogs.

Based on previously published data, the Czech Republic is regarded an endemic country of the onchocercid nematodes Dirofilaria immitis (Leidy, 1856) and Dirofilaria repens Railliet et Henry, 1911. Nevertheless, while cases of D. repens are commonly reported from dogs in South Moravia, no recent records of D. immitis are available. Therefore, the present study was performed to clarify the occurrence of both species of Dirofilaria Railliet et Henry, 1910. Blood samples of 551 dogs sampled during 2015 and 2016 were analysed microscopically for presence of microfilariae and blood sera were examined by IDEXX SNAP® 4Dx® test (IDEXX, USA). DNA from blood of microscopically positive dogs was extracted and PCR protocol amplifying fragment of cytochrome c oxidase I (COI) gene was performed; PCR products were then sequenced. All dogs from the Bohemian part of the Czech Republic were negative. The prevalence of D. repens in the Moravian region was 5.7 % (27/476). BLAST analyses of obtained sequences confirmed the presence of D. repens (99-100% identical to KX265049). All sampled animals showed a negative result for D. immitis antigen in IDEXX SNAP® 4Dx® test. Our study confirmed the previously reported occurrence of D. repens in South Moravia and revealed its spreading from the epicentre to the north and west. PCR with subsequent sequencing together with negative results for D. immitis antigen in IDEXX SNAP® 4Dx® test revealed only D. repens infection. A previously published autochthonous infection of dogs with D. immitis in South Moravia was not confirmed.

A study on canine dirofilariasis in selected areas of Sri Lanka.

OBJECTIVES: Canine dirofilariasis is a mosquito borne zoonotic filarial parasitic disease caused by Dirofilaria species. In Sri Lanka, human dirofilariasis is endemic and well documented. Even though canine dirofilariasis is an established infection among dog populations in Sri Lanka, the prevalence and risk factors were not documented in Kanthale divisional secretariat, Eastern Province of Sri Lanka. Therefore, the main objective of this study is to determine the prevalence of dirofilariasis and to identify the exposure-related risk factors in dogs using an interviewer administered questionnaire in Kanthale divisional secretariat. RESULTS: Out of 162 blood samples collected from dogs, 47.5% (n = 77/162) were positive for the presence of microfilariae by direct smear. Of 162 samples 58.6% (n = 95/162) were molecularly identified as D. repens. Species-specific primer pair DIR3/DIR4 that amplified 5S rRNA was used. The current study observed a significant association between mongrels and canine dirofilariasis (p = 0.049), where 61.3% (n = 95) out of 155 mongrels showed PCR positivity. This study showed no significant association between the occurrence of dirofilariasis and the age, sex, rearing method, presence or absence of skin rash, and stray or domestic dogs. Dirofilaria immitis was not identified in direct smear test and PCR.

Dirofilaria repens predominates in shelter dogs from South Romania.

Canine filarioids are zoonotic vector-borne parasitic nematodes distributed mostly in the tropics and subtropics. The aim of this study was to determine the prevalence, distribution, etiology and genetic variation of canine filarioid infections by three different PCR techniques in four Southern Romanian counties. Blood samples of 300 shelter dogs were screened for infections with canine filarioids by real-time PCR. To determine filarioid species and coinfections, samples positive in the initial screening were further tested by conventional PCR and sequenced. Results indicated that 17% of the tested dogs were positive for at least one filarioid species. The prevalence of D. repens infection was 11.7%, significantly higher than that of D. immitis (4.7%) and A. reconditum (1.3%) (p ≤ 0.003). The high prevalence of canine filarioid infections represents a challenge to animal and human health in the South of Romania, and they should be constantly monitored.

Canine microfilaraemia in some regions of Iran.

BACKGROUND: Dirofilaria immitis and Dirofilaria repens are vector-borne zoonotic parasites which affect mainly dogs and humans worldwide. In Iran, information about the distribution of those nematodes is scant in several regions. Therefore, we investigated the prevalence of these filarial parasites in stray dogs from five Iranian provinces where no information about these parasites is available. METHODS: Blood samples were collected from 344 stray dogs in five provinces of Iran (i.e. Mazandaran, Gilan, Esfahan, Qazvin and Loresan). The presence of microfilariae was assessed using direct smear, modified Knott's test, molecular detection of filarial DNA (cox1 gene) and Wolbachia endosymbiont of parasitic nematodes (ftsZ gene) by conventional PCR (cPCR). All of the PCR products were sequenced and phylogenetic analysis was performed. RESULTS: In total, 75 dogs (21.8%) were found to be positive for D. immitis by cPCR. Infection was detected in all provinces, with the highest prevalence in Gilan province (22/28; 78.6%). Acanthocheilonema reconditum was diagnosed in five dogs (1.4%) from three provinces (i.e. Esfahan, Mazandaran, Gilan). Two dogs were infected with both parasites and three were only infected with A. reconditum. Dirofilaria repens infection was not found in the examined population. Representative sequences of the D. immitis cox1 gene from dogs from the northern provinces (Mazandaran, Gilan, Qazvin) were grouped together and distinctly separate from the ones from western and central provinces (Lorestan and Esfahan), suggesting that different nematode populations are present in the country. CONCLUSION: The data reported herein fill existing gaps in knowledge about canine filarial infection in two Iranian provinces and record the highest prevalence of D. immitis ever reported in the country (i.e. 78.6%). A geographical review of the literature about Dirofilaria spp. and A. reconditum infections in dogs and humans has also been summarized, indicating that D. immitis and D. repens are distributed in 22 of 31 provinces in Iran, whereas A. reconditum is present in fewer regions. Effective control strategies are advocated for owned dogs, and a national program for the management of stray dogs is needed to minimize the risk of infection in animals and humans.

Selection of new diagnostic markers for Dirofilaria repens infections with the use of phage display technology.

Dirofilaria repens is a parasitic nematode causing vector-borne disease (dirofilariasis), considered an emerging problem in veterinary and human medicine. Although main hosts are carnivores, particularly dogs, D. repens shows high zoonotic potential. The disease spreads uncontrollably, affecting new areas. Since there is no vaccine against dirofilariasis, the only way to limit disease transmission is an early diagnosis. Currently, diagnosis depends on the detection of microfilariae in the host bloodstream using modified Knott's test or multiplex PCR. However, the efficacy of tests relying on microfilariae detection is limited by microfilariae periodic occurrence. Therefore, a new reliable diagnostic test is required. Our study aimed to select new diagnostic markers for dirofilariasis with potential application in diagnostics. We focused on single epitopes to ensure high specificity of diagnosis and avoid cross-reactivity with the other parasite infections common in dogs. Using phage display technology and 12-mer peptides library, we selected epitopes highly reactive with IgG from sera of infected dogs. Additionally, our study presents the possibility of detecting D. repens specific cell-free DNA in dogs with no microfilaria but high IgG and IgM antibody levels against parasite somatic antigen.

Autochthonous Human Dirofilaria repens Infection in Austria.

PURPOSE: This report describes a rare autochthonous case of human D. repens infection in Austria. Dirofilariosis is a mosquito-borne parasitic infection that predominantly affects dogs. Human D. repens infections have primarily been reported in Mediterranean countries, but are emerging throughout Central and Northern Europe. METHODS: The worm was removed surgically and identified using PCR and DNA sequencing. The consensus sequences were compared against reference sequences of Dirofilaria repens from GenBank. RESULTS: The 56-year-old woman acquired the infection, which presented as a subcutaneous nodule, in Vienna, Austria. This is the second autochthonous case of human D. repens infection in Austria. CONCLUSION: The reasons for the emergence of D. repens and other parasitic infections in Central and Northern Europe are manifold, including climate change and globalization. This case demonstrates that with the growing number of D. repens infections, health care professionals must place further emphasis on emerging infectious diseases to ensure appropriate diagnostics and treatment in the future.