Anisakiasis--a neglected diagnosis in the West

A diagnostic protocol designed for determining allergic causes in patients with blood eosinophilia

BACKGROUND

Blood eosinophilia is a common laboratory abnormality, and its characterization frequently represents a quandary for primary care physicians. Consequently, in France, specialists and particularly hematologists, often must investigate patients who present with blood eosinophilia that often, but not always, occurs because of allergic causes. Both the Departments of Hematology and Parasitology at Toulouse University Hospitals established a collaboration to rule out allergic causes of eosinophilia, particularly helminthiases, prior to initiating more sophisticated investigations.

METHODS

Since 2004, the authors employed the same protocol to investigate eosinophilic outpatients who attended the clinic of Parasitology at Toulouse University Hospitals, and they reported the performance of this diagnostic procedure that was designed to be rapid (no hospitalization required) and only moderately expensive.

RESULTS

A total of 406 patients who presented with blood eosinophilia greater than 0.5 (×10⁹, giga cells per litter, G/L) had an allergic etiology in 350 (86.2%) cases. Among the remaining 56 subjects, 17 did not undergo a follow-up and 39 were referred to another specialized department, mostly Hematology. However, only 21 patients attended then were subsequently investigated. Non-allergic causes of eosinophilia, including 3 cases of the lymphoid variant of hypereosinophilic syndrome and 2 cases of myeloproliferative disorder, were identified in 14 patients, whereas 7 remained diagnosed as having idiopathic eosinophilia.

CONCLUSION

This study underlines the need to investigate patients presenting with even moderate blood eosinophilia. The work-up that was employed appears to be efficient and versatile and may be used by any medical specialist, such as in hematology, infectious disease, or internal medicine departments, who needs to investigate eosinophilic patients and should initially rule out any etiology of allergic eosinophilia.

Anisakidosis: a fortuitous mimicker of gastrointestinal malignancy

A 51-year-old woman presented with epigastric pain, vomiting and diarrhoea. Her sister was recently diagnosed with duodenal adenocarcinoma, manifesting similar symptoms. Imaging revealed thickened gastric antrum with enlarged local lymph nodes. Endoscopy illustrated 3 worms embedded in the antral wall, identified as Anisakis simplex larvae. Larvae removal and a 2-week albendazole regimen treated the symptoms. With globalisation of cultural culinary practices, physicians must be vigilant of anisakidosis. Its ability to mimic peptic ulcer disease, chronic gastritis and malignancy necessitates broader differential diagnoses and lower thresholds for endoscopy.

Intestinal Anisakiasis Treated Successfully with Prednisolone and Olopatadine Hydrochloride

The clinical characteristic of gastrointestinal anisakiasis is severe abdominal pain after eating raw fish. Intestinal anisakiasis is more uncommon than gastric anisakiasis. Most patients with intestinal anisakiasis need hospitalization because anisakiasis can cause intestinal obstruction, ileus, peritonitis or intestinal perforation. We report a case of intestinal anisakiasis. A 43-year-old woman presented with symptoms of intermittent abdominal pain 2 days after eating raw fish. Her brother had eaten the same food and had been suffering from gastric anisakiasis. Abdominal ultrasonography in this patient showed localized jejunal wall thickening with dilated lumen of proximal jejunum and ascites. According to the clinical course and examinations, she was diagnosed with intestinal anisakiasis. Administration of prednisolone 5 mg/day and olopatadine hydrochloride 10 mg/day improved her symptoms quickly without hospitalization. Prednisolone was administered for 10 days, and olopatadine hydrochloride was administered for a total of 6 weeks according to ultrasonographic findings. Six months after the treatment, the abdominal ultrasonography demonstrated normal findings. This case demonstrates that ultrasonography was quite useful for the diagnosis and surveillance of intestinal anisakiasis. Furthermore, treatment with corticosteroid and an antiallergic agent could be an option for patients with intestinal anisakiasis.

First Record of Anisakis simplex Third-Stage Larvae (Nematoda, Anisakidae) in European Hake Merluccius merluccius lessepsianus in Egyptian Water

The prevalence of infection and the identification of anisakid larvae in European hake Merluccius merluccius lessepsianus from Hurghada City, Red Sea Governorate, Egypt, were investigated. Fish samples were collected during the period of February and November 2014. Twenty-two (36.66%) out of sixty examined fish specimens were found to be naturally infected with Anisakis type I larvae mostly found as encapsulated larvae in visceral organs. There was a positive relationship between host length/weight and prevalence of infection. Based on morphological, morphometric, and molecular analyses, these nematodes were identified as third-stage larvae of Anisakis simplex. The present study was considered as the first report of anisakid larvae from European hake in the Egyptian water.

An anisakis larva attached to early gastric cancer: report of a case

Gastrointestinal anisakidosis is a nematode infection caused by the ingestion of larvae-infected raw or undercooked fish. The Japanese like to eat raw or undercooked fish, so gastric anisakiasis is a common disease in Japan. However, reports of anisakiasis with gastrointestinal cancer are rare. A 63-year-old Japanese male was diagnosed with a small early gastric cancerous lesion associated with gastric anisakiasis. From our experience and based on a review of the literature, the attachment of an anisakis larva to early gastric cancer is not considered accidental.

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.

Anisakidosis of the sigmoid colon disguising as metastatic carcinoma: a case report and review of the literature

Intestinal anisakidosis is a rare nematode infestation caused by the ingestion of larvae-infected raw or undercooked fish. Most cases are incidentally diagnosed during surgery for other reasons. We present such a case of anisakid larvae seen in a patient's sigmoid colon resected for adenocarcinoma, where a subserosal nodule caused by the inflammatory reaction to the worm was presumed to be a lymph node involved by metastatic tumor. With the increasing popularity of raw fish consumption, the incidence of this parasitic infection is bound to increase, requiring surgical pathologists to be cognizant of its existence and aware of its histologic appearance.

Genetic characterization of Anisakis typica and Anisakis physeteris from marine mammals and fish from the Atlantic Ocean off Brazil

Until now, Anisakis typica has been the sole anisakid identified by means of genetic markers from the Atlantic Ocean off Brazil. In this study we developed, and applied to larvae and adults, an A. typica-specific molecular identification protocol based on the complete intergenic transcribed spacer (ITS) region. Anisakids from the dolphin Sotalia guianensis and from the frigate tuna, Auxis thazard, caught off the coast of Brazil, were processed using two DNA extraction methods. Molecular diagnosis identified A. typica in 13 of 15 samples. Complete ITS analysis showed that the remaining two isolates were in fact A. physeteris. Maximum parsimony analysis of complete ITS region (915 bp) confirmed these results. Our study verified the dominance of A. typica infecting hosts from the Brazilian coast and showed, for the first time, the presence of A. physeteris in the intermediate/paratenic host A. thazard in this region.

Sensitization to the fish parasite Anisakis simplex: clinical and laboratory aspects

Hypersensitivity to Anisakis simplex is a worldwide medical problem. The parasite larvae die after freezing or cooking, but the tolerance of sensitized subjects to eating frozen fish remains a matter of controversy with contradictory findings. The aim of this study was to test if intolerance to properly cooked/frozen fish was due to the recognition of a particular allergen. Sixty-four patients with Anisakis simplex sensitization were studied by an IgE multiblot using simultaneously five different antigenic extracts. The antigens tested were a crude extract, excretory/secretory allergens, a heated extract, and two gradient ethanol precipitates of the crude extract. Intolerance was reported by 20% of the patients and was not related to the detection of any special allergen, nor to total or specific IgE levels. Intolerant patients only reported a higher frequency of digestive symptoms than the patients who tolerated fish ingestion. The most sensitive immunoblot antigen source was the 50-66% ethanol fraction of a crude extract (10x concentrated) that was found to be positive in 100% of the samples. Interestingly, 95% sensitivity in the IgE-immunoblot assay could be achieved using only two allergens, Ani s 1 and Ani s 4. Allergens from the dead larvae remain a problem for 20% of the sensitized subjects. The use of a fractionated and concentrated crude extract improved the sensitivity of the immunoblot assay.