In vivo and in vitro studies on the sonographical detection of Ascaris lumbricoides

Ultrasonography of Parasitic Diseases in Domestic Animals: A Systematic Review

Simple Summary

The aim of this literature review was to summarize the current knowledge on the application of ultrasonography in diagnosis, staging and monitoring of helminthic diseases in domestic animals. We selected and analyzed 122 papers about the application of ultrasonography in parasitic disease in ruminants, equids, swine, and companion animals. Helminths can be recognized in ultrasound images by their morphology, size, and location. In some cases, the parasites are not directly seen by ultrasound, but the lesions caused by them can be easily visualized. Ultrasound imaging is taking on an increasingly important role in veterinary parasitology.

Abstract

The aim of this review was to summarize the current knowledge on the application of ultrasonography in diagnosis, staging and monitoring of helminthic diseases in domestic animals. Only peer reviewed papers written in English language were included in this systematic review. All papers concerning unicellular parasites, wild animals, non-domestic experimental animals, or ex vivo or in vitro applications of ultrasonography were excluded from the review. A total of 122 papers met the inclusion criteria. Among them 47% concerned nematodes, 37% cestodes, and 16% trematodes with the genus Dirofilaria, Echinococcus, and Fasciola the most represented, respectively. Helminths can be recognized in ultrasound images by their morphology, size, and location. In some cases, the parasite stages are not directly seen by ultrasound, but the lesions caused by them can be easily visualized. Ultrasound imaging is taking on an increasingly important role in the diagnosis, staging, monitoring, and control of parasitic diseases in veterinary medicine. However, it cannot replace the clinical approach and the diagnostic tests commonly used in veterinary parasitology.

Ultrasonography for early diagnosis of Toxocara canis infection in puppies

Toxocara canis is one of the most common intestinal parasites in dogs and represents a highly infectious zoonotic parasite worldwide. Adult worms live in the bowel of dogs, and infections in puppies are commonly acquired transplacentally. The biology of the parasite and the commonly used diagnostic method, based on faecal examination, often prevent an early diagnosis of toxocariasis in puppies. Ultrasonographic diagnosis of intestinal ascariasis could be a feasible alternative method to diagnose T. canis infection in puppies during the prepatent period. The present study evaluated the diagnostic accuracy of ultrasonography for the diagnosis of intestinal toxocariasis in new-born puppies during the prepatent period. Fifty-four new-born puppies were prospectively recruited in the study. Each dog underwent intestinal ultrasonography and copro-microscopic examination every 5 days, starting from the 10th day post-birth. Intestinal ultrasonography visualized adult T. canis nematodes in the puppies' small intestine from the 10th day post-birth. On the 15th day after birth, ultrasonography showed 100% specificity and 85.4% sensitivity in diagnosing T. canis infection, despite negative results deriving from the copro-microscopic examination performed at the same time point. Our results showed that ultrasonography can be used as test for early diagnosis of T. canis infection in new-born puppies during the prepatent period. Early ultrasonographic diagnosis of T. canis infection in puppies could help control the disease in dogs and reduce the zoonotic risk for the human population.

Sonographic images of hepato-pancreatico-biliary and intestinal ascariasis: A pictorial review

Abstract

Despite advancement in the diagnosis and treatment of intestinal helminthiasis, ascariasis remains the most common cause of helminthic infections in the developing countries. Ultrasound offers a rapid, safe, and noninvasive approach to the diagnosis of intestinal ascariasis. Ultrasound is also the modality of choice for diagnosis of hepatobiliary ascariasis, which is relatively rare and is due to migration of intestinal worms through the papilla of Vater. We present an imaging spectrum of hepato-pancreatico-biliary and intestinal ascariasis.

Main messages

• Ascariasis refer to infestation by the round worm ascaris lumbricoides.

• Ascaris eggs are excreted in faeces and are infective to humans.

• Eggs hatch to larva, travel to the lungs and mature to adult worms.

• Intestinal obstruction can be caused by multiple ascariasis forming bag of worms.

Sonographic features of intestinal and biliary ascariasis in childhood: case report and review of the literature

Despite the fact that Ascaris lumbricoides is one of the commonest intestinal infections in developing countries, there are very few reports in the literature about the sonographic findings of intestinal and biliary ascariasis in childhood. The clinical manifestations, diagnostic procedures and imaging appearance of intestinal and biliary ascariasis in two patients are discussed with a brief review of the literature.

Imaging of ascariasis

Ascaris lumbricoides is one of the most common parasitic infestations of the gastrointestinal tract worldwide. During the intestinal phase of the disease, the adult worms usually remain clinically silent, sometimes causing a variety of non-specific abdominal symptoms. When present in large numbers, the worms may get intertwined into a bolus, causing intestinal obstruction, volvulus or even perforation. Occasionally, the adult Ascaris worm may migrate into the Vater's ampulla and enter the bile duct, gall bladder or pancreatic duct, leading to a variety of complications such as biliary colic, gallstone formation, cholecystitis, pyogenic cholangitis, liver abscess and pancreatitis. Imaging plays a significant role in showing the presence of worms and possible complications in intestinal as well as hepatobiliary ascariasis. This pictorial essay aims to illustrate various imaging features of ascariasis and its associated complications.

Ultrasonographic features of pseudotumorous form of ascariasis

We report the ultrasonographic findings of a 60 year old woman with pseudotumorous form of ascariasis. Real-time ultrasonographic examination using a curved array transducer revealed grossly thickened small bowel loops, multiple small circular deposits throughout the peritoneal cavity, and a moderate amount of ascites. The English literature on the different forms of abdominal ascariasis is reviewed. Specific signs, which include the 'strip' sign, the 'four-lines', 'inner tube', or 'double tube' sign, the 'bull's eye' or 'target' sign, a 'worm mass' or 'spaghetti-like' appearance, and the 'zig-zag' sign can be present in any form of abdominal ascariasis, as they represent the image of the Ascaris worms visualized under ultrasonographic examination. However, the non-specific signs are not peculiar to A. lumbricoides infections, but are results of secondary changes due to A. lumbricoides infections in the corresponding organs.