As the Worm Turns-A Rare Cause of Intestinal Obstruction

BACKGROUND

Anisakiasis, a zoonotic disease caused by the nematode Anisakis, poses a significant concern for public health, particularly in regions with high consumption of raw or undercooked fish.

CASE PRESENTATION

We present a case report of a 41-year-old woman who developed severe abdominal symptoms, ultimately diagnosed with intestinal obstruction due to Anisakis infestation, requiring surgery. Despite the absence of prominent eosinophilia or specific radiological findings, the diagnosis was confirmed through histological examination, highlighting the importance of considering anisakiasis in patients with a history of raw seafood consumption.

CONCLUSION

The case underscores the diagnostic challenges associated with anisakiasis, emphasizing the need for increased awareness among healthcare professionals and the public regarding the risks of consuming raw or undercooked seafood. Effective management requires a multidisciplinary approach, including clinical assessment, imaging studies, and histological evaluation, to ensure timely diagnosis and appropriate treatment.

Adhesive Bowel Obstruction (ABO) in a Stranded Narrow-Ridged Finless Porpoise (Neophocaena asiaeorientalis sunameri)

In this case report, we present a rare occurrence of a narrow-ridged finless porpoise (Neophocaena asiaeorientalis sunameri), discovered on the coast of Jeju Island, Republic of Korea, that was afflicted with adhesive bowel obstruction (ABO), a life-threatening condition that has scarcely been reported in cetaceans. Diagnosis of ABO was confirmed via radiological and clinical assessments. Post-mortem computed tomography and necropsy revealed ABO between two loops of the jejunum at the L8 level. The mesenteric tissue covering the intestinal lesion was severely thickened with increased tension. Both bowel loops were fixed to the mesentery and acutely angulated, leading to asymmetrical thickening of the cross-sectional bowel walls. The intestinal lumen was stenosed because of pressure from the firm mesenteric band, and no fecal matter was observed in the lumen of the posterior bowel or rectum. Calcified nodules were detected, and histological analysis suggested parasitic or suspected post-parasitic infections. The primary cause of the intestinal lesions is presumed to be a reaction related to parasitic infection. However, further investigations would establish a definitive link between parasitic infections and ABO in this species. This case highlights the importance of studying rare medical conditions in wildlife, providing valuable insights into marine mammal health.

Clinical and Endoscopic Features of Colonic Anisakiasis in Korea

To analyze the clinical and endoscopic features of colonic anisakiasis. A retrospective chart review of 20 patients with colonic anisakiasis, who were diagnosed by colonoscopy at 8 hospitals between January 2002 and December 2011, was performed. Patients’ mean age was 53.6±10.74 years. Seventy percent patients were men. Acute abdominal pain was a common symptom that mostly developed within 48 hr after the ingestion of raw fish, and which lasted for 1–28 days. Sixty percent patients had ingested raw fish before the diagnosis of colonic anisakiasis and 40% patients were incidentally found to have colonic anisakiasis during the screening colonoscopies. Leukocytosis and eosinophilia were each found in 20% of the patients. In all patients who underwent colonoscopy, the worms were removed with biopsy forceps, except in 1 case, and a definite diagnosis of anisakiasis was made. In some cases of colonic anisakiasis, colonoscopy may be helpful in the diagnosis and treatment to avoid surgical intervention.

Hepatic anisakiasis mimicking metastatic liver tumour

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Anisakiasis is a parasitic disease caused by anisakid nematode larvae in raw fish.

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Anisakiasis may increase with growing consumption of raw fish around the world.

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Hepatic anisakiasis presents as small, low density tumours in the liver margin.

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The lesions resemble recurrent carcinoma, and can lead to unnecessary surgery.

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Dietary investigation is warranted when liver tumour malignancy is not certain.

Introduction

Anisakiasis is a parasitic disease caused by anisakid nematode larvae, which are found in raw or undercooked fish. It occurs more frequently in the digestive tract, but has also been reported outside the gastrointestinal tract. This report details a case of rare hepatic anisakiasis that was initially diagnosed as metastatic rectal cancer.

Presentation of case

A 60-year-old male underwent radical resection for stage III rectal cancer followed by adjuvant chemotherapy for six months. Seven months after surgery, a new, 10 mm diameter area of low density was seen in segment 4/8 margin of the liver on enhanced computed tomography (CT) scan. Metastatic liver tumour from rectal cancer was suspected. Laparoscopic partial hepatectomy was performed. The diagnosis was revised to hepatic anisakiasis when pathological examination revealed anisakis simplex larvae in the necrotic tissue.

Discussion

Anisakiasis outside of the gastrointestinal tract is a rare finding, but may be seen more frequently with the recent increase in the consumption of raw fish around the world. Hepatic anisakiasis may mimic tumours in the liver. Clinicians should consider dietary inquiry and further evaluation in patients with liver margin tumours less than 20 mm in size that are not positively malignant, as hepatic anisakiasis may be a possible diagnosis.

Conclusion

We report a rare case of hepatic anisakiasis which initially presented as suspected metastatic cancer. Hepatic anisakiasis should be considered in the differential diagnosis of low density liver tumours less than 20 mm, where the patient’s diet includes raw fish.

Anisakiasis in the Small Intestine with Excessive Bleeding That Was Difficult to Diagnose Endoscopically

Anisakiasis involves the stomach in most cases and occurs rarely in the small intestine. Anisakiasis in the small intestine is associated with abdominal pain and obstruction and is rarely associated with intestinal bleeding. Unlike in the stomach, anisakiasis in the small intestine is difficult to diagnose anatomically. The patient in this case study developed hypovolemic shock due to excessive bleeding and underwent emergency surgery. With the recent increase in the consumption of raw fish around the world, this report provides an important finding of bleeding in the small intestine due to an unknown cause.

Molecular Epidemiology of Anisakis and Anisakiasis: An Ecological and Evolutionary Road Map

This review addresses the biodiversity, biology, distribution, ecology, epidemiology, and consumer health significance of the so far known species of Anisakis, both in their natural hosts and in human accidental host populations, worldwide. These key aspects of the Anisakis species' biology are highlighted, since we consider them as main driving forces behind which most of the research in this field has been carried out over the past decade. From a public health perspective, the human disease caused by Anisakis species (anisakiasis) appears to be considerably underreported and underestimated in many countries or regions around the globe. Indeed, when considering the importance of marine fish species as part of the everyday diet in many coastal communities around the globe, there still exist significant knowledge gaps as to local epidemiological and ecological drivers of the transmission of Anisakis spp. to humans. We further identify some key knowledge gaps related to Anisakis species epidemiology in both natural and accidental hosts, to be filled in light of new 'omic' technologies yet to be fully developed. Moreover, we suggest that future Anisakis research takes a 'holistic' approach by integrating genetic, ecological, immunobiological, and environmental factors, thus allowing proper assessment of the epidemiology of Anisakis spp. in their natural hosts, in human populations, and in the marine ecosystem, in both space and time.

Anisakis - immunology of a foodborne parasitosis

Anisakis species are marine nematodes which can cause zoonotic infection in humans if consumed in raw, pickled or undercooked fish and seafood. Infection with Anisakis is associated with abdominal pain, nausea and diarrhoea and can lead to massive infiltration of eosinophils and formation of granulomas in the gastrointestinal tract if the larvae are not removed. Re-infection leads to systemic allergic reactions such as urticarial or anaphylaxis in some individuals, making Anisakis an important source of hidden allergens in seafood. This review summarizes the immunopathology associated with Anisakis infection. Anisakiasis and gastroallergic reactions can be prevented by consuming only fish that has been frozen to -20°C to the core for at least 24 hours before preparation. Sensitization to Anisakis proteins can also occur, primarily due to occupational exposure to infested fish, and can lead to dermatitis, rhinoconjunctivitis or asthma. In this case, exposure to fish should be avoided.

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.

Acute Small-Bowel Obstruction From Intestinal Anisakiasis After the Ingestion of Raw Clams; Documenting a New Method of Marine-to-Human Parasitic Transmission

Enteric anisakiasis is a known parasitic infection. To date, human infection has been reported as resulting from the inadvertent ingestion of the anisakis larvae when eating raw/undercooked fish, squid, or eel. We present a first reported case of intestinal obstruction caused by anisakiasis, after the ingestion of raw clams.

Parametrial anisakidosis

Anisakidosis is a parasitic infection caused by anisakid nematodes in the genera Anisakis and Pseudoterranova. Infection is not uncommon in the United States due to increased raw seafood consumption. We report the first known case of parametrial anisakidosis in a 42-year-old woman and review existing literature.

Unusual cause of small intestine obstruction in a child

Introduction

Anisakiasis is caused by human infection by the anisakis larvae, a marine nematode found in undercooked or raw fish. Infection with the parasite Anisakis simplex is common in Japan and northern European countries. With the increased popularity of eating sushi and raw fish infection with anisakis is expected to rise.

Case presentation

We present the case of a 14-year-old boy who had eaten sushi 3 days before the onset of symptoms and had small bowel obstruction caused by enteric anisakiasis. To the best of our knowledge this is the first reported case of intestinal anisakiasis presenting as a bowel obstruction in a child.

Conclusion

Enteric anisakiasis is very rare, and its diagnosis is usually made after laparotomy. Nevertheless, when signs of acute abdomen develop after the ingestion of raw fish, such as sushi or sashimi, the possibility of enteric anisakiasis should be considered.

Comparison of the clinical characteristics of patients with small bowel and gastric anisakiasis in jeju island

Background/Aims

Anisakiasis is frequent in Jeju Island because of the people's habit of ingesting raw fish. This study evaluated the clinical characteristics of patients with small bowel anisakiasis and compared them with those of patients with gastric anisakiasis.

Methods

We retrospectively reviewed the medical records of 109 patients diagnosed with anisakiasis between May 2003 and November 2011.

Results

Of the 109 patients diagnosed with anisakiasis, those with suspicious anisakiasis (n=38) or possible anisakiasis (n=12) were excluded. The age and gender distributions did not differ between patients with small bowel anisakiasis (n=30; age, 45±13 years) and those with gastric anisakiasis (n=29; age, 46±10 years). The mean duration of hospitalization was 5.4±4.3 days for patients with small bowel anisakiasis and 0.5±1.7 days for patients with gastric anisakiasis. Small bowel anisakiasis was accompanied by leukocytosis (76.7% vs 25.5%, p=0.003) and elevated C-reactive protein levels (3.4±3.2 mg/dL vs 0.5±0.3 mg/dL, p=0.009). Contrast-enhanced abdominopelvic computed tomography showed small bowel wall thickening with dilatation in 93.3% (28/30) of patients and a small amount of ascites in 80.0% (24/30) of patients with small bowel anisakiasis.

Conclusions

Compared with gastric anisakiasis patients, small bowel anisakiasis patients had a longer hospitalization time, higher inflammatory marker levels, and small bowel wall thickening with ascites.

A case of duodenal anisakiasis with duodenal ulcer

Humans can be incidentally parasitized by third-stage larvae of Anisakis species following the ingestion of raw or undercooked seafood. Acute gastric anisakiasis is one of the most frequently encountered complaints in Korea. However, duodenal anisakiasis with duodenal ulcer had not been reported in Korea, despite the habit of eating raw fish. In this case, a 47-year-old man was hospitalized because of sharp epigastric pain and repeated vomiting after eating raw fish 3 days previously. On admission, esophagogastroduodenoscopic examination revealed an active duodenal bulb ulcer. At 5 mm away from the ulcer margin, a whitish linear worm was found with half of its body penetrating the duodenal mucosa. Herein, we report this case of duodenal anisakiasis accompanied by duodenal ulcer.