The first genetically confirmed case of Dioctophyme renale (Nematoda: Dioctophymatida) in a patient with a subcutaneous nodule

First record of Dioctophyme renale (Goeze, 1782) in the pampas fox (Lycalopex gymnocercus, Fischer, 1814) (Carnivora: Canidae)

Dioctophyme renale (Goeze 1782) has not previously been reported in the pampas fox (Lycalopex gymnocercus) (Fisher 1814), the most abundant canid of southern South America. A wild adult pampas fox female was found dead due to unknown causes in Santa Fe province, Argentina. Post-mortem examination revealed three red worms measuring 10, 11 and 15 cm long, each with an approximate width of 5 mm. All of them were found free in the abdominal cavity. The worms were all male and were identified through morphological examination and molecular analysis as D. renale. No worm was found in the kidneys. This study reports the first case of dioctophymatosis in the pampas fox in Argentina, increasing the range of wild aberrant host species infected by the giant kidney worm in the Neotropical region.

REVIEW OF DIOCTOPHYME RENALE: ETIOLOGY, MORPHOLOGY, BIOLOGY, ECOEPIDEMIOLOGY, PATHOGENESIS, SYMPTOMATOLOGY, DIAGNOSIS, TREATMENT, AND PREVENTION

Dioctophyme renale has a worldwide distribution and has been diagnosed in several wild and domestic animals as well as in humans. As numerous reports in the literature exist concerning the presence of D. renale in different animal species, as well as its diagnosis, treatment, and confirmation in new geographic areas, we reviewed existing information to contribute to the knowledge of the etiology, biology, epidemiology, pathogenesis, symptoms, diagnosis, treatment, and prevention of D. renale. Results of dioctophymosis may range from asymptomatic infection to even death of the host. Diagnosis is based on data from morphology, imaging, and antibody testing, with surgical treatment being the most effective. A high potential for infection of pets exists when there is overlap with wild parasitized animals; given common risk factors for infections in humans, D. renale should be considered as having zoonotic potential.

Abdominal dioctophymosis in a domestic cat from the Peruvian rainforest confirmed morphologically and molecularly

A case of abdominal dioctophymosis in a domestic cat was found in San Juan Bautista district, the Peruvian rainforest, in the Loreto department of Peru. The pet went to a veterinary clinic for a routine ovariohysterectomy during which a large nematode was found in the abdominal cavity. The nematode was morphologically identified as an adult female of Dioctophyme sp. A few morphological parameters, such as the vagina distance from the anterior part and the egg size, were different than D. renale. Partial sequences of the cytochrome c oxidase subunit I (cox1) and the small subunit 18S ribosomal RNA genes were compared with the references from public sequence database and showed a genetic identifies of 89.25% and 99.65% with D. renale, respectively. This is the first mitochondrial molecular analysis of a Dioctophyme specimen from South America and the results showed up to 12.5% nucleotide sequence variation in cox 1 gene of D. renale.

Occurrence of Dioctophyme renale (Goeze, 1782) in road-killed canids of Iran and its public health implication

Dioctophyme renale, is the largest of parasitic nematodes, which infects different species of fish-eating carnivores worldwide. The northern provinces of Iran (Guilan and Mazandaran) located in south of the Caspian Sea are suitable for parasitic infections due to the mild and humid climatic conditions. From separate surveys of road-killed canids in various parts of the Caspian Sea littoral area in Iran, 70 carcasses were collected along the roads of Guilan and Mazandaran from 2015 to 2017. Dioctophyme renale detected by direct observation and molecular methods based on Cytochrome c oxidase subunit 1 (COX1 gene) sequencing analysis. Molecular investigation was also performed to validate prevalence and reduce false negative concerns. Dioctophyme renale was found in eight of 70 carnivores, mostly in the right kidneys, as well as two cases in the abdominal cavity of a dog and a golden jackal. More carcasses on the roads were seen with lacerated internal organs. Given the frequent number of giant kidney worms in canids in the region, the transmission of this zoonotic helminth to humans seems possible, since the area is a tourism hub in the country. The infection burden of this helminth should be investigated using DNA analysis of kidney tissue of road-killed carnivores in Iran.

Rare case of Dioctophyme renale (Nematoda: Enoplida) and Dirofilaria sp. (Nematoda: Spirurida) in the subcutaneous tissue of a cat in Espírito Santo, Brazil

Dioctophyme renale is the largest parasitic nematode of animals. It is most often found in the right kidney, but can also occur in the urinary system, ears, free abdominal cavity, mammary gland, thoracic cavity, and more rarely in subcutaneous tissue. The genus Dirofilaria has specific parasitic characteristics according to its location, and may parasitize the respiratory tract or even the skin, varying according to species. This report describes a case of Dioctophyme renale and Dirofilaria sp. in the subcutaneous tissue of a cat in the state of Espírito Santo, Brazil. An adult male mongrel cat showed physical enlargement in the left inguinal region, diagnosed as a subcutaneous nodule. Surgical excision and histopathological evaluation of the nodule were performed, and Dioctophyme renale and Dirofilaria sp. were found inside. Dioctophymosis and heartworm disease are present in Brazil and most other countries, but this is the unprecedented case of the association of Dioctophyme renale and Dirofilaria sp. in the subcutaneous tissue of a cat.

Dioctophimosis: A Parasitic Zoonosis of Public Health Importance

Dioctophyme renale, the giant kidney worm, is a renal nematode from domestic and wild mammals that has zoonotic potential. In humans, dioctophimosis has been reported in several countries, mainly on the Asian continent, totaling more than 40 cases, which describe the parasite mainly infecting the kidneys, bladder, urethra and skin. Infection in animals and humans is related to the ingestion of the infective larva (L3) present in the aquatic oligochaete annelid (mandatory intermediate host) or fish and anurans (facultative paratenic hosts). Thus, the infection is related to the habit of drinking water contaminated with the mandatory intermediate host, as well as raw or undercooked meat from the facultative paratenic hosts. Dioctophimosis destroys the renal parenchyma and, in some cases, can cause the death of its hosts. In this chapter, we discuss the main topics regarding dioctophimosis in humans, domestic and wild animals, highlighting its importance in public health.

Dioctophyme renale (Goeze, 1782) (Nematoda, Dioctophymidae) parasitic in mammals other than humans: A comprehensive review

A comprehensive review of the infection of mammals with the nematode Dioctophyme renale (Goeze, 1782) (Nematoda, Dioctophymidae) is presented. Mammals, including man, are the definitive hosts for this parasite. Several aspects of the infection with the parasite in mammals other than humans are critically evaluated: geographical distribution, host species recorded so far and the relative importance of the different hosts, location of parasites within the host, prevalence and intensity of the infection, diagnostic methods, pathology induced by the parasites, epidemiology and the methods of control and treatment. The authors provide an updated review about the infection, based on a extensive bibliographic search worldwide, and point out the most relevant aspects of the biology of the parasite as well as several research topics which need to be explored for a better understanding of the biology of this interesting and important parasitic nematode.

Dioctophyme renale in a domestic cat (Felis catus): Renal location and nephrectomy

Dioctophymosis is caused by Dioctophyme renale, nematode with indirect life cycle. Its intermediate host is a freshwater oligochaete and its definitive host is a wild or household carnivore. The adult nematode develops in the definite host, generally locating itself in the kidney. This article was meant to describe the first nephrectomy performed in a domestic cat due to renal dioctophymosis in Argentina. The subject showed a non-specific appearance of generally feeling ill, hematuria and mild diarrhea. It was diagnosed through abdominal ultrasound, followed by exploratory celiotomy and nephrectomy. After verifying absence of free specimens, the right kidney was removed. This organ was found to be enlarged in a spheroidal manner in contrast to the left kidney, with significant thickening of the renal capsule, excessive congestion of vessels and adhesions involving the caudal vena cava. An adult nematode was removed from the right kidney and identified as Dioctophyme renale. Reports of feline dioctophymosis are scarce being most of them necropsy findings. In this we are presenting a confirmed case of D. renale removed by surgery from a live cat. The results presented here reinforces the fact that cats are also appropriate definitive hosts for this parasite.

A human case of Dioctophyma renale (giant kidney worm) accompanied by renal cancer and a retrospective study of dioctophymiasis

Due to the rarity of human cases and the nonspecific clinical symptoms of dioctophymiasis, Dioctophyma renale infection is not well recognized and is easily neglected or misdiagnosed. Recently, we diagnosed a human case of dioctophymiasis accompanied by renal cancer. To enhance the understanding of human dioctophymiasis, this case is presented here, and a retrospective study of this disease was conducted based on relevant papers screened from PubMed and three Chinese databases. In the end, 32 papers describing 37 human cases of dioctophymiasis were assessed. These cases were distributed in ten countries of Asia, Europe, North America and Oceania, with the highest number in China (n = 22). The majority of the cases occurred in adults (91.9%, 34/37) and involved the kidneys (83.8%, 31/37). Ectopic parasitism mainly occurred in subcutaneous tissue (83.3%, 5/6). A proportion of 45.9% (17/37) of individuals had a history of eating raw or undercooked fish or frogs. The main clinical manifestations of human dioctophymiasis were loin pain (59.5%) and hematuria (59.5%). All the cases were diagnosed based on the morphological characteristics of eggs or adults in urine or tissue sections. Currently, there is no strictly defined therapeutic approach. This is the first retrospective analysis of human cases of dioctophymiasis. These review data will deepen our understanding of dioctophymiasis and help avoid misdiagnosis in clinical practice.

The role of freshwater fish in the life cycle of Dioctophyme renale in Southern Brazil

Brazil stands out by the diverse records of Dioctopphyme renale in different hosts; however, there is little information about the life cycle of the nematode in the region. This study aims to report on third-stage larvae infections in fish in southern Brazil. In this context, 324 fish of different species belonging to Characiformes, Cyprinodontiformes and Siluriformes were collected in an urban area of Rio Grande do Sul State, where domestic and wild hosts were reported with the nematode. Of the total fish examined, 25(7.7%) were found to be parasitized by third-stage larvae of D. renale which were found encysted in the stomach serous membrane and in the celoma cavity of Hoplosternum littorale (Siluriformes) with a prevalence of 53.2% (25/47) and mean intensity of infection of 4.4 larvae/host (1 to 13 larvae). The occurrence of larvae in H. littorale indicates the presence of parasitosis in the region; however, the contribution of this fish species as a source of infection for dogs in urban areas must be considered with caution given the difficulties these dogs may face in the capture and predation of the fish to the point of effectively maintaining the urban cycle of D. renale. In addition, the low level of larvae registered in the total sample of fish examined indicates that these hosts are unlikely to play an important role in the transmission of D. renale to domestic animals in the region of the study.

Occurrence of Dioctophyme renale larvae (Goeze, 1782) (Nematoda: Enoplida) in a new host from southern Brazil

Abstract Dioctophymatosis is caused by the giant kidney worm Dioctophyme renale which occurs in dogs, cats, and wild mammals. In Brazil, the disease has been diagnosed in dogs from several states around the country. In the present study, the occurrence of D. renale larvae in snakes from southern of Brazil is reported. Three specimens of Philodryas patagoniensis (Serpentes: Dipsadidae) (common names in Brazil: “parelheira”, “papa-pinto”) roadkill in the county of Capão do Leão, State of Rio Grande do Sul, southern Brazil, were necropsied. Two third-stage larvae of D. renale were found in the coelomic cavity of P. patagoniensis. This study reveals a new host for D. renale larvae in the southern region of the State of Rio Grande do Sul, Brazil. This particular geographic area of the country has stood out as several cases of D. renale infection have been reported in a number of vertebrates from this region including domestic dogs and cats and wild animals such as carnivores, fish, and freshwater turtles.

An Overview of Fish-borne Nematodiases among Returned Travelers for Recent 25 Years- Unexpected Diseases Sometimes Far Away from the Origin

Along with globalization of traveling and trading, fish-borne nematodiases seems to be increasing in number. However, apart from occasional and sporadic case reports or mini-reviews of particular diseases in particular countries, an overview of fish-borne nematodiasis among travelers have never been performed. In this review, we gathered fishborne nematodiasis among travelers for recent 25 years by an extensive global literature survey using appropriate keywords, e.g. travelers diseases, human infection, anisakiasis, gnathostomiasis, capillariasis, sushi, sashimi, ceviche, Gnathostoma, Pseudoterranova, Anisakis, Capillaria, etc., as well as various combinations of these key words. The Internet search engines PubMed, Medline, Google and Googler Scholar were used as much as possible, and the references of every paper were checked in order to identify useful and reliable publications. The results showed unexpectedly high incidence of gnathostomiasis and low incidence of anisakidosis. The different incidence values of the infection with several fish-borne zoonotic nematode species are discussed, as well as some epidemiological aspects of the infections. The difficulties of differential diagnosis in non-endemic countries are emphasized. It is concluded that travelers must avoid risky behaviors which can lead to infection and that physicians and health authorities must advice travelers on the risks of eating behaviors during travel.

Dioctophyme renale: prevalence and risk factors of parasitism in dogs of São Cristóvão district, Três Barras county, Santa Catarina State, Brazil

Dioctophyme renale is a nematode that can be found parasitizing the kidney, peritoneal cavity and, rarely, other organs of canids and mustelids. This disease has high occurrence in the municipality of Três Barras, state of Santa Catarina, thus making this an interesting area to study the epidemiological aspects of infection by D. renale in dogs. Among 197 dogs, 14.2% showed the parasite eggs in urine and 16.4% showed IgG antibodies anti-D. renale in serum samples according to the indirect ELISA method; among seropositive dogs, 15 (37.5%) animals did not show any parasite eggs in their urine. Parasitism was more frequent in females, and there was no finding of interference from age on parasitism. Factors such as water potential and presence of paratenic hosts in the studied region were reported by the owners of dogs and may have contributed to the occurrence of parasitism.

Giant kidney worms in a patient with renal cell carcinoma

Dioctophyma renale (D. renale), or giant kidney worms, are the largest nematodes that infect mammals. Approximately 20 cases of human infection have been reported. We present a case of a 71-year-old man with a recent history of unintentional weight loss and painless haematuria, passing elongated erythematous tissue via his urethra. CT revealed a left renal mass with pulmonary nodules and hepatic lesions. On microscopy, the erythematous tissue passed was identified as D. renale. On subsequent renal biopsy, pathology was consistent with renal cell carcinoma. This is the first reported case of concomitant D. renale infection and renal cell carcinoma, and the second reported case of D. renale infection of the left kidney alone.

Improvement of an enzyme immunosorbent assay for detecting antibodies against Dioctophyma renale

An available enzyme-linked immunosorbent assay (ELISA) was studied for the detection of anti-Dioctophyma renale antibodies in the sera of dogs using, detection of parasite eggs in urine sediment as a reference test. ELISA uses a soluble antigenic preparation of esophagus of D. renale and the optimal dilutions of the antigen, serum and conjugate were determined by means of checker board titration, using positive (n=13) and negative (n=27) reference serum. The specificity and sensitivity of the ELISA were 93.8% and 92.3% respectively and the kappa index was good (0.76). These results suggest that ELISA described may prove to be an effective serological test for detecting dogs infected and exposed to this parasite mainly dogs that are not eliminating parasite eggs through their urine.