Asymptomatic colonic anisakiasis

Anisakis simplex (s.s.) larvae (Nematoda: Anisakidae) hidden in the mantle of European flying squid Todarodes sagittatus (Cephalopoda: Ommastrephidae) in NE Atlantic Ocean: Food safety implications

Few reports exist upon the occurrence and localization of zoonotic anisakid nematodes in T. sagittatus, especially in the mantle of the squid. The occurrence and site of infection of larval anisakids in 98 T. sagittatus caught West off St. Kilda, NE Atlantic Ocean, were investigated. Squids were examined for anisakids using the UV-Press method. In total, 689 nematodes were detected in the viscera and mantle. According to morphology, all the larvae (L₃) were assigned to genus Anisakis. Diagnostic allozymes and mtDNA cox2 sequence analysis permitted to genetically identify all larvae as Anisakis simplex (s.s.) (N = 100). Overall prevalence (P = 81%) and mean intensity (mI = 8.6) of infection with A. simplex are provided. Most of the larvae present in the mantle cavity were embedded in the stomach wall or attached in the outer layer of the stomach and caecum (49%). Over a third of squids (37%) hosted A. simplex (s.s.) larvae in the mantle. A novel schematized representation of larvae distribution in the mantle is provided, showing where they were mostly located. According to the results obtained, the risk of anisakiasis associated with consumption of raw or undercooked T. sagittatus should be considered.

Endoscopic submucosal dissection of colonic anisakiasis

A 61-year-old male with no relevant past medical history underwent a colonoscopy for routine screening of colorectal cancer. Colonoscopy revealed a pearly and hard submucosal lesion of less than 10 mm in diameter in the ascending colon, with normal mucosa. An abdominopelvic computed tomography (CT) scan was performed, which was normal. Endoscopic submucosal dissection (ESD) was performed and the lesion appeared to originate from the muscularis propia. Thus, the muscularis propia and part of the serosa of the colonic wall were cut and the perforation was finally closed with hemoclips.

Adult intussusception caused by colonic anisakis: A case report

BACKGROUND

Colo-colonic intussusception is an uncommon phenomenon in an adult. Adult intussusception accounts for < 5% of total cases, and the colo-colonic type is < 30% of cases. Although surgical management has been the treatment of choice for intestinal intussusception in adults, because most frequent causes for adult intussusception are malignant in origin, the importance of the roles of preoperative colonoscopic evaluation has recently been emerging.

CASE SUMMARY

We report an extremely rare case of adult colo-colonic intussusception caused by colonic anisakiasis and successfully treated by endoscopic removal of the Anisakis body. A 59-year-old man visited the emergency department due to 1 day of lower abdominal colicky pain. Abdominopelvic computed tomography (APCT) revealed the presence of mid-transverse colon intussusception without definite necrosis, which was possibly related with colorectal cancer. Because there was no evidence of necrosis at the intussusception site, a colonoscopy was performed to target the colonic lesion and obtain tissue for a histopathological diagnosis. An Anisakis body was found when inspecting the suspicious colonic lesion recorded by APCT. The Anisakis body was removed with forceps assisted by colonoscopy. The patient’s symptoms improved dramatically after removing the Anisakis. A reduced colon without any pathological findings was seen on the follow-up APCT. Without any further treatment, the patient was discharged 5 d after the endoscopy.

CONCLUSION

When colonic intussusception without necrosis occurs in an adult, physician should consider a colonoscopy to exclude causes cured by endoscopy.

Asymptomatic anisakiasis of the colon incidentally diagnosed and treated during colonoscopy by retroflexion in the ascending colon

A 74-year-old man with diabetes underwent colonoscopy as routine screening for colon cancer. An Anisakis larva was found incidentally during colonoscopy using the retroflexion technique in the ascending colon, and was removed using a forceps. Asymptomatic colonic anisakiasis is very rare, and few reports have described diagnosis and treatment of anisakiasis during colonoscopy by the retroflexion technique in the ascending colon. We have reported this rare case along with a literature review.

Common Symptoms from an Uncommon Infection: Gastrointestinal Anisakiasis

Clinicians can be forgiven for thinking of anisakiasis as a rare condition low in the differential diagnosis of abdominal pain. Gastrointestinal anisakiasis is a zoonotic parasitic disease caused by consumption of raw or undercooked seafood infected with nematodes of the genus Anisakis. Even though the reported cases indicate that this is a rare disease, the true incidence of the disease could be potentially higher than what is reported in the literature as cases can go undiagnosed. Diagnosis and treatment of gastric anisakiasis are made by a compatible dietary history, direct visualization, and removal of the larvae via gastroscopy. Serologic testing and imaging studies are useful in the diagnosis of intestinal anisakiasis and conservative management should be considered. This disease may mimic other diseases and lead to unnecessary surgery. This emphasizes the importance of suspecting gastrointestinal anisakiasis by history taking and by other diagnostic modalities.