[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.

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.

A rare clinical presentation of human Dirofilaria repens infection as a pseudo-tumour of the epididymis - Case Report.

Introduction. Epididymal dirofilariasis is one of the unusual manifestations of this zoonosis. In Slovakia, this is the third case out of 20 Dirofilaria repens infected patients in whom the worm (the parasite) was identified in the epididymis. The patient felt a painless tumour about 2 cm in size on the left testicle. During ultrasound examination, the radiologist observed a cyst containing a live worm within the epididymis. After mechanical stimulation, the movement characteristic for filarial worms (´filarial dance sign´) appeared. An orchiectomy was performed at the Department of Urology in the University Hospital in Kosice. Histopathology confirmed a parasitic cyst with a worm, and based on characteristic morphological features, the parasite was identified as Dirofilaria repens. Objective. The aim of case report is to alert physicians to the possibility dirofilarial infection of the epididymis, where tumors and cystic structures often occur and to present clinical signs of the disease.

A case of inguinal hernia associated with atypical Dirofilaria repens infection in a dog.

BACKGROUND: Dirofilaria repens is a filarioid nematode transmitted by mosquitoes. Adult D. repens are typically localized in the subcutaneous tissue of the host, but other, atypical localizations have also been reported. There have been several reports of clinical cases involving an association of parasites and hernias in both animals and humans. However, it is unclear if parasitic infection can act as a triggering factor in the development of hernias. METHODS: A 12-year-old dog was referred to a private veterinarian clinic in Satu Mare, northwestern Romania due to the presence of a swelling in the lateral side of the penis (inguinal area). The dog underwent hernia repair surgery during which four long nematodes were detected in the peritoneal serosa of the inguinal hernial sac. One female specimen was subjected to genomic DNA extraction to confirm species identification, based on amplification and sequencing of a 670-bp fragment of the cytochrome c oxidase subunit 1 (cox1) gene. Treatment with a single dose of imidacloprid 10% + moxidectin 2.5% (Advocate, Bayer AG) was administered. RESULTS: The nematodes were morphologically identified as adult D. repens, and the BLAST analyses revealed a 100% nucleotide similarity to a D. repens sequence isolated from a human case in Czech Republic. CONCLUSIONS: We report a case of an atypical localization of D. repens in the peritoneal cavity of a naturally infected pet dog with inguinal hernia and discuss the associations between hernia and parasitic infections.

First report of Dirofilaria repens infection in a microfilaraemic cat from Romania.

The present study describes the first report of Dirofilaria repens infection with the presence of both microfilariae and adult nematodes in a cat from Northeastern Romania. Briefly, a 5-year-old male mixed breed cat was presented to a veterinary clinic in Iasi (Romania), for neutering, in early February 2020. During the surgery, two whitish worms were removed from the internal part of the scrotum. Two adult nematodes, one female and one male, were identified, on the basis of morphological features, as D. repens with whitish, cylindrical bodies, measuring 12.5 cm and 6.5 cm in length, respectively. At histology, the female nematode showed two cavitated structures containing myriads of variably arranged microfilariae. The male had a transversal diameter of 350 µm, a 10 µm thick cuticle and a ridge-period of 10 Μm. multiplex PCR confirmed the diagnosis of D. repens from both nematodes. The Knott's test revealed the presence of microfilariae of D. repens. Routine biochemistry panel was within range with one exception, urea serum level slightly increased. The haematology results revealed an increased number of neutrophils, lymphocytes and eosinophils. The cat had an infection with Otodectes cynotis as well. The cat was discharged with the following therapy recommended: oral doxycycline (10 mg/kg) for 30 days and topical moxidectin, monthly doses. After six months, the Knott's test gave negative results. Further studies should include new insights of D. repens infection in cats concerning its epidemiology, diagnosis and control.

Oral migration of Dirofilaria repens after creeping dermatitis.

We report an autochthonous case of oral dirofilariasis in a 46-year-old female patient exposed in South-Eastern France. The patient first presented eyelid creeping dermatitis of one-week duration, then a sub-mucosal nodule appeared in the cheek. The entire nodule was removed surgically. Histologically, the nodule appeared as inflammatory tissue in which a worm was seen. The molecular analysis, based on cox1 and 12S sequences, identified Dirofilaria repens. Ivermectin treatment was given prior to diagnosis, while taking into consideration the most common causes of creeping dermatitis, but treatment was ineffective. The oral form of dirofilariasis is uncommon and could lead to diagnostic wandering.

TITLE: Migration orale de Dirofilaria repens après une dermatite rampante. ABSTRACT: Nous rapportons un cas autochtone de dirofilariose buccale chez une patiente de 46 ans exposée dans le sud-est de la France. La patiente a d'abord présenté une dermatite rampante des paupières d'une durée d'une semaine, puis un nodule sous-muqueux est apparu dans la joue. Le nodule entier a été retiré chirurgicalement. Histologiquement, le nodule est apparu comme un tissu inflammatoire dans lequel un ver a été observé. L'analyse moléculaire, basée sur des séquences de cox1 et 12S, a identifié Dirofilaria repens. Le traitement à l'ivermectine a été administré avant le diagnostic tout en tenant compte des causes les plus courantes de la dermatite rampante, mais il était inefficace. La forme orale de la dirofilariose est rare et pourrait conduire à une errance diagnostique.

[Inguinal lymphadenitis due to invasion of Dirofilaria repens].

The paper presents the case of the right-sided inguinal inflammation of a lymph node as a result of invasion of Dirofilaria repens, the parasitic pathogen of subcutaneous dirofilariasis in animals of the canine family. The diagnosis was verified on the basis of the parallel application of morphological studies of cross sections of the nematode in histological samples and the molecular biological method polymerase chain reaction of scrapings of histological material. The localization of this helminth inside the cavities of the human body is extremely rare. Only isolated cases of atypical localization of D. repens are described: in the organs of the chest, cervical lymphatic node in the spermatic cord and epididymis, which led to pseudotumor formations that needed to be differentiated with neoplastic processes. This case is of great interest to experts of various fields (surgeons, oncologists, infectious disease specialists and pathologists), primarily in the differential diagnosis of malignant neoplasms of the lymphatic system.

There is a worm in my eye! Ocular dirofilariasis.

INTRODUCTION: To report a case of ocular dirofilariasis in Central Italy (Pisa, Tuscany) and review the previous cases of ocular dirofilariasis reported in Italy. CASE DESCRIPTION: A 67-year-old man complained about recurrent ocular redness and discomfort previously treated as conjunctivitis. The slit-lamp examination showed a round, translucent cystic swelling under the bulbar conjunctiva of the right eye, near the lateral canthus. Inside this lesion was observed the presence of a motile worm. A surgical procedure was immediately performed, excising a thin, segmented, greyish worm identified as Dirofilaria repens. After the excision, no recurrence of the symptomatology was recorded. CONCLUSION: Ocular dirofilariasis can lead to misdiagnosis due to its rare ocular manifestations and it is considered an emergent zoonosis in European countries. In Italy from 2001 to January 2018, seven new cases were reported in the literature. In our opinion, it is critical to record all the new cases to assess the epidemiological situation and increase the awareness of this rare infection.

Subconjunctival Dirofilaria repens infection in a dog resident in the UK.

Dirofilaria repens infection was diagnosed in a 5-year-old female German shepherd crossbreed, originally from Romania but brought into the UK in February 2014. The dog presented with conjunctivitis in March 2014 and then again 2 months later with additional ocular and nasal mucopurulent discharge. Bacterial cultures from the nasolacrimal duct were negative for bacterial growth. The case was referred in August 2014 for ophthalmic examination, which revealed abnormalities in both eyes, especially the left. They included mild palpebral conjunctival hyperaemia and marked follicular conjunctivitis, as well as a dorsonasal bulbar conjunctival mass. Serum biochemistry was unremarkable and a conjunctival biopsy taken from the dorsonasal bulbar conjunctival mass revealed eosinophilic/lymphoplasmacytic conjunctivitis. At re-examination, nematodes were found in the area of the previous biopsy site and in the ventral palpebral conjunctival fornix. Polymerase chain reaction and sequencing confirmed these to be D. repens. Treatment with 10% imidacloprid and 2·5% moxidectin (Advocate Spot-On) was successful, and clinical signs resolved over a 6-week period. This case report indicates that D. repens infection should be considered as a possible aetiological cause of ocular lesions in dogs in the UK, especially those with a history of foreign travel. Implications for establishment and spread of D. repens in the UK are discussed.

Dirofilaria immitis and D. repens show circadian co-periodicity in naturally co-infected dogs.

BACKGROUND: Dirofilaria immitis and Dirofilaria repens are mosquito-borne zoonotic filarioids typically infecting dogs, causing a potentially fatal cardiopulmonary disease and dermatological conditions, respectively. The females are larviparous, releasing the larvae (microfilariae) into the bloodstream, which further develop in mosquito vectors. However, microfilaremia greatly fluctuates during a 24-h period. As the sampling time can greatly influence the accuracy of diagnosis, the aim of the present study was to assess the circadian periodicity of D. immitis and D. repens in naturally co-infected dogs in an endemic area of Romania and to investigate possible differences of periodicity between these two species. METHODS: Overall, four dogs harbouring natural co-infection with D. immitis and D. repens were selected and sampled every two hours for two consecutive days: two dogs in July 2014 and two in July 2015. At each sampling time, a 0.7 ml blood sample was taken. Modified Knott's test was performed on 0.5 ml, and the remaining 0.2 ml were used for DNA extraction and molecular amplification, both in single and duplex PCR reactions. Microfilariae of both species were morphologically identified and counted in each collected sample, microfilaremia was calculated, and fluctuation was charted. RESULTS: The dynamics of microfilaremia showed similar patterns for both Dirofilaria species. In all four dogs, D. immitis was present at all sampling times, with several peak values of microfilaremia, of which one was common for all dogs (1 am), while minimum counts occurred between 5 and 9 am. Similarly, for D. repens, one of the peak values was recorded in all dogs at 1 am, while minimum counts (including zero) occurred at 9 and 11 am. Single species-specific PCR reactions were positive for both D. immitis and D. repens in all collected samples, while duplex PCR failed to amplify D. repens DNA in many cases. CONCLUSIONS: Both Dirofilaria immitis and D. repens microfilariae are subperiodic, following a similar variation pattern, with peak values of microfilaremia registered during the night in Romania. Duplex PCR fails to identify the infection with D. repens in co-infected dogs when the ratio of microfilaremia is in favour of D. immitis.

Clinical and pathological effects of Dirofilaria repens and Dirofilaria immitis in a dog with a natural co-infection.

Canine dirofilarioses are mosquito-borne zoonotic diseases with a continuous expansion of their geographical distribution, as a consequence of different climatic and ecological factors. Dirofilaria immitis, the aetiological agent of heartworm disease, has gained a major veterinary interest, mainly due to its severe clinical implication. In the last decades, D. repens, despite of being regarded as a less pathogenic species, regained attention due to its recognized zoonotic potential. Romania has been traditionally regarded as a non-endemic country, but recent epidemiological surveys are highlighting the presence of both D. repens and D. immitis. The present case report describes the clinical and pathological features of a natural co-infection with D. repens and D. immitis in 5year old male Boxer from north-western Romania. Based on clinical and laboratory investigations, a diagnosis of kidney failure and chronical cystitis was established. The parasites were identified by morphology and confirmed by PCR and sequencing. To the best of our knowledge this is the first worldwide report of the ectopic presence of D. repens adults in the pelvic cavity and mesentery by natural infection and first report of the ocular localization of this parasite for Romania. The clinical and paraclinical findings suggest the implication of D. repens microfilariae in the aetiology of histopathological lesions. Further investigations are needed in order to establish the actual pathogenic potential of D. repens, a frequently neglected parasite.

Dirofilaria repens microfilariae from a human node fine-needle aspirate: a case report.

BACKGROUND: Human dirofilariosis is still a little known infection even in endemic areas. Dirofilariosis is zoonotic infection usually abortive in humans; instead, we report a very rare case (the 4th in the world), the first in Italy, in which at least two infective larvae became mature adults that mated and produced active microfilariae even though they did not reach peripheral blood. CASE PRESENTATION: A 30-year-old Italian woman presented with a transient oedematous swelling on the left abdominal wall with a creeping eruption followed by the occurrence of a subcutaneous nodular painless mass in the iliac region. One month later, a similar temporary swelling appeared on the contralateral inguinal region associated with intermittent joint discomfort in both knees. The patient had recently travelled abroad, therefore many possible diagnoses were to be ruled out. Routine laboratory investigations revealed eosinophilia. An ultrasound examination of the iliac swelling evidenced a well-defined cyst with a big filamentous formation in continuous movement. A fine-needle aspiration of the lesion was performed for parasitological, cytological and histological exams. The prompt microscopic examination of the aspired material showed the presence of numerous microfilariae that were initially morphologically attributed to Mansonella ozzardi. Subsequently, the revision of the Giemsa stained film and molecular analyses of the biological material, allowed to identify Dirofilaria repens as etiological agent of infection. CONCLUSIONS: We report of a case in whom microfilariae were detected in fine-needle aspirate of subcutaneous node, without evidence of microfilaraemia, and the infection failed to become fully patent. Therefore we confirm that complete development and fertilization of D. repens worms in human hosts may occur, at variance with what is commonly believed, that Dirofilaria worms cannot fully develop in humans.

[Human dirofilariasis: clinical and diagnostic signs and diagnostic methods].

The clinical and diagnostic signs caused by the tissue location and migration of adult Dirofilaria in the human body determine the use of different methods for the diagnosis of dirofilariasis. During their investigations, the authors modified polymerase chain reaction (PCR): they chose and synthesized primers and selected amplification regimens for them and obtained agarose gel bands that corresponded to PCR fragment length nucleotide sequences that were equal to 245 bp for D. (N.) repens and 656 bp for D. immitis. There was 100% agreement in the results of PCR and microscopic examination of sera from 32 dogs and 1 female patient with low parasitemia and in the blood nucleotide sequence characteristic of D. repens.

Canine Dirofilaria infections in two uninvestigated areas of Serbia: epidemiological and genetic aspects.

In 2009 canine filarial infections were investigated in two northern areas of Serbia (Pancevo and Veliko Gradiste), applying morphometry, biochemical staining, and immunological kit to detect Dirofilaria immitis antigens, and two home-made ELISAs to detect antibodies to D. repens and D. immitis somatic/metabolic polyproteins. Moreover, molecular tools were applied to analyze the phylogenetic relationships of the isolates. The microfilariae detected in 21/122 dogs (17.2%) were identified as D. repens (n=21) and D. immitis (n=2). D. immitis antigens were found in another 13 animals with occult infection. All of the 15 heartworm-positive dogs also had antibodies to this parasite, which were detected in another 13 subjects, indicating an overall D. immitis seroprevalence rate of 22.9%. Serology for D. repens revealed evidence of antibodies in 42.6% of the dogs, but was negative for 4 microfilaremic dogs. As for the two different areas, the prevalence of microfilariae and/or D. immitis antigens, mainly due to D. repens microfilaremic animals, was not significantly higher in Veliko Gradiste (33.3%) than in Pancevo (22%). However, serology showed a different epidemiological picture. Heartworm infection occurred more often in both areas, and antibodies to dirofilarial nematodes were detected in 72.9% of dogs living in Pancevo, a rate higher than in those living in Veliko Gradiste (57.1%). No risk factors for infection were found, confirming the uselessness of prophylactic drugs against D. repens, and suggesting the presence in these areas of sunrise- or sunset-biting mosquitoes as important vectors. The results indicate the need for both appropriate entomological studies and further research on the intra-species variability shown by D. repens.