Giant kidney worms in a patient with renal cell carcinoma

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.

Diseases and parasites

Inuit in Alaska, Canada, and Russia have a long-term tradition in hunting bowhead whales that reaches back several thousands of years. Central to Inuit culture, hunted bowhead whales have undergone rigorous health evaluation by hunters and communities through various iterative processes guided by traditional customary practices. These traditional customary practices are similar to western meat hygiene designed to provide a thorough health assessment of the catch and by default, a public health judgment on food safety. With the establishment of the bowhead whale harvest monitoring program in Utqiaġvik in 1972, led by the North Slope Borough leadership and Alaska Eskimo Whaling Commission (AEWC), collaborative research on the health of bowhead whales between the AEWC, Village Whaling Captains Association, Whaling Captain’s Wives Association, research scientists, and veterinarians have continued to build on the in-depth Inuit knowledge of the bowhead whale. This chapter synthesizes the historic and current knowledge about health and disease conditions of the bowhead whale. The information provided is a coproduction of knowledge reflecting perspectives of Inuit indigenous and local knowledge, veterinary medicine, and biology.

Ectopic dioctophymosis in a dog - Clinical, diagnostic and pathological challenges of a silent disease

A 9-month old, female, stray dog was rescued and conducted to a university veterinary hospital. Moderate anemia was observed and abdominal ultrasound revealed pancreatitis. Right kidney was not visualized due to intestinal gas. Urinalysis was normal. Castration was performed three weeks later. Before discharge, abdominal ultrasound was performed for internal sutures examination. A cyst-like structure was present in the right retroperitoneal space with what appeared to be tubular worms inside it, not observed in previous evaluation. An ectopic dioctophymosis diagnosis was made. Two female Dioctophyme renale were surgically removed from the structure. Right kidney was hyperemic but not removed. No sign of peritonitis was observed. The dog recovered well. Laboratory follow-up showed no abnormalities a year after the episode and Doppler ultrasound revealed a mild right nephropathy. This is the first canine ectopic dioctophymosis case with only an abdominal cyst-like structure containing viable nematodes, successfully treated. It represents the rarity and difficulties in diagnosing ectopic dioctophymosis even in enzootic locations, highlighting the importance of ultrasonographic screening for such silent, potentially zoonotic disease.

Giant Kidney Worm: Novel Report of Dioctophyma Renale in the Kidney of a Dog in Greece

Dioctophyma renale is the largest nematode that infects domestic mammals and is the aetiologic agent of a serious renal disease, dioctophymatosis. It has an indirect life cycle with carnivores serving as final hosts and earthworms as intermediate hosts. The parasite can infect humans with signifi cant zoonotic potential. The pathogenesis of dioctophymatosis is mainly associated with the extent of renal atrophy caused by the parasites, the risk of bilateral renal infestation and the location of the parasite (extrarenal cases). Clinical diagnosis is challenging, and the only treatment option is nephrectomy or nephrotomy to remove the adult nematode. A 6-year-old female crossbreed dog presented with tachypnea, tachycardia and severe hematuria, but died shortly after presentation. Postmortem examination found the right kidney was enlarged and two adult nematodes were found in the renal pelvis. The left kidney was normal. The nematodes were collected and submitted for identifi cation. The two specimens were identifi ed as D. renale using specific identifi cation keys. Herein we present the first case of renal parasitosis by the nematode D. renale in a dog from Greece. This case highlights the need for investigation of the actual prevalence of the parasite and the use of measures for the control of its expansion aiming the protection of dogs and public health.

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.

Identification and characterization of the major pseudocoelomic proteins of the giant kidney worm, Dioctophyme renale

BACKGROUND

The giant kidney worm, Dioctophyme renale, is a debilitating and potentially lethal parasite that inhabits and destroys, typically host's right kidney, and may also be found in ectopic sites. It is circumglobally distributed, mainly in dogs, and is increasingly regarded as a threat to other domestic animals and humans. There is little information on the parasite's true incidence, or immune responses to it, and none on its biochemistry and molecular biology.

RESULTS

We characterised the soluble proteins of body wall, intestine, gonads and pseudocelomic fluid (PCF) of adult parasites. Two proteins, P17 and P44, dominate the PCF of both male and females. P17 is of 16,622 Da by mass spectrometry, and accounts for the intense red colour of the adult parasites. It may function to carry or scavenge oxygen and be related to the 'nemoglobins' found in other nematode clades. P44 is of 44,460 Da and was found to associate with fatty acids by thin layer chromatography. Using environment-sensitive fluorescent lipid probes, P44 proved to be a hydrophobic ligand-binding protein with a binding site that is highly apolar, and competitive displacement experiments showed that P44 binds fatty acids. It may therefore have a role in distributing lipids within the parasites and, if also secreted, might influence local inflammatory and tissue responses. N-terminal and internal peptide amino-acid sequences of P44 indicate a relationship with a cysteine- and histidine-rich protein of unknown function from Trichinella spiralis.

CONCLUSIONS

The dominant proteins of D. renale PCF are, like those of large ascaridids, likely to be involved in lipid and oxygen handling, although there is evidence of strong divergence between the two groups.