Summary

Strongyloidiasis is a common parasitic infection. Gastric location of the parasite is quite rare. Patients at risk are those undergoing immunosuppressive therapy, individuals with malignant hematologic disorders, transplantations, diabetes mellitus, malnutrition, chronic renal failure, chronic alcohol consumption, patients with acquired immune deficiency syndrome and elderly people. We report an atypical presentation of strongyloidiasis with gastric involvement in a diabetic patient.

Introduction

Strongyloides stercoralis is an intestinal helminth of class Nematoda, which infects the small intestine of humans. Strongyloidiasis is characterized by parasitic-endogenous and free-living-exogenous life cycles. These nematodes can be observed throughout the world, but they are endemic in some regions especially in Africa, West Indies, Southeast Asia, South America, Bangladesh and Pakistan[1]. Strongyloidiasis can present with a wide variety of symptoms, sometimes with mild to moderate gastrointestinal complaints, sometimes with allergic skin rush. Moreover, delayed diagnosis and treatment may lead to opportunistic infections called hyperinfection and may be fatal in some patients especially those with underlying serious diseases[2]. Hyperinfection syndrome occurs when the normal life cycle of the parasite in humans is augmented, resulting in massive infection of the gastrointestinal tract, circulatory system, and lungs[3]. This type of opportunistic infection can be seen in patients with malnutrition, malignancy, organ transplantation, diabetes, AIDS, or during immunosuppressive treatment[2,4]. The diagnosis of strongyloidiasis in humans is based on finding rhabditoid larvae of the parasite in fresh fecal material or after stool concentration techniques. The histological diagnosis of strongyloidiasis from endoscopic biopsies and surgical specimens is usually incidental. The identification of Strongyloides stercoralis in tissues is often difficult possibly because of scarcity of parasites, their small size, and because pathologists are usually not familiar with this parasite[4].

Case Presentation

A 78-year-old male patient had admitted to local state hospital with complaints of epigastric pain, nausea and vomiting. He had suffered from these complaints for two months. An upper gastrointestinal endoscopy had revealed hyperemia and erosions at gastric antrum. The patient had been discharged after a twenty days of treatment with relief from the symptoms. The same symptoms recurred after a short period and he was referred to our hospital. Meanwhile he had lost 25 kg. At his admittance, physical examination was almost normal other than peripheral edema. Laboratory examination revealed a hyperglycemia of 161 mg/dl and hypokalemia with hypochloremia. An upper gastrointestinal endoscopic examination was repeated and esophagitis was observed at the lower segment of the esophagus. The cardia and fundus were normal, while edema was observed at corpus and antrum (Figure 1). Histopathological examination of the gastric biopsy revealed adult forms of Strongyloides stercoralis in gland lumens and lamina propria accompanied by mixed inflammatory cell infiltration consisting of numerous plasma cells, lymphocytes, eosinophils, and a few neutrophils (Figure 2-3). In addition, gastric epithelium showed regenerative changes. The patient did not receive a specific treatment for strongyloidiasis as he refused treatment.

Figure 1: Edema and hyperemia observed at the antrum.

Figure 2: Gastric biopsy revealed inflammatory infiltrates consisting of numerous eosinophils and few parasites (H&E, x200).

Figure 3: Adult form of Strongyloides stercoralis larvae shown in the crypts of gastric epithelium (H&E, x400).

Discussion

Strongyloidiasis is a common parasitic infection that affects 30 to 100 million people worldwide[5]. Strongyloidiasis is traditionally considered a tropical and subtropical disease. However, factors like globalism and migration have changed this geographical distribution[6]. The frequency of strongyloidiasis among intestinal parasitic infestations was found 0.2 % in Turkey in a recent study[7]. Males older than 60 years are the most frequently affected subjects[8].

The clinical presentation of S. stercoralis may be quite variable. The first attack can be very acute or even silent. Fever and chills may be present. Other constitutional symptoms such as fatigue, weakness, and pain all over the body may accompany the clinical course. Blood counts performed during hyperinfection may show eosinophilia but may also show a suppressed eosinophil count. Patients with eosinophilia often have a better prognosis[9]. Gastrointestinal symptoms are the most frequent complaints but they are nonspecific. Abdominal pain, diarrhea, constipation, anorexia, weight loss, throat pain, nausea, vomiting, and gastrointestinal bleeding are the known symptoms of the disease. Hypokalemia and other electrolyte abnormalities may reflect these gastrointestinal disturbances[10].

Rhabditiform and filariform larvae may be seen in the microscopic evaluation of fresh fecal material while adult worms or eggs of the parasite are less common[11]. Occult or frank bleeding may be present. Esophagitis, gastritis, duodenitis, ileitis, pseudomembranous colitis, and proctitis have been reported with this parasite. Mucosal ulceration is most frequently seen in the small intestine, but may be present through the entire gastrointestinal tract[9].

This infection is usually located at the duodenum or jejunum, while gastric location of the parasite is quite rare. The parasites in gastric and duodenal locations are found in the gastric crypts or in the duodenal glands. The most common finding in histological evaluation of the biopsies is a non-pathognomonic acute or chronic gastritis or duodenitis[12]. The infection is usually asymptomatic. However, strongyloidiasis infection should be considered if symptoms such as abdominal discomfort, chronic diarrhea, nausea, vomiting, anorexia and weight loss are present[4]. Massive infection may occur in the immunocompromised host, causing the hyperinfection syndrome or disseminated strongyloidiasis. Patients at risk are those undergoing immunosuppressive therapy, individuals with malignant hematologic disorders, transplantations, diabetes mellitus, malnutrition, chronic renal failure, chronic alcohol consumption, patients with acquired immune deficiency syndrome and elderly people[2,4,13]. We have reported an atypical presentation of strongyloidiasis with gastric involvement in a diabetic patient.

Reference

1) Adedayo O, Grell G, Bellot P: Hyperinfective strongyloidiasis in the medical ward: review of 27 cases in 5 years. South Med J 2002, 95:711-716 [ Özet ]

2) Gutierrez Y, Bhatia P, Garbadawala ST, Dobson JR, Wallace TM, Carrey TE: Strongyloides stercoralis eosinophilic granulomatous enterocolitis. Am J Surg Pathol 1996, 20:603-612 [ Özet ]

3) Ramdial PK, Hlatshwayo NH, Singh B: Strongyloides stercoralis mesenteric lymphadenopathy: clue to the etiopathogenesis of intestinal pseudo-obstruction in HIV-infected patients. Ann Diagn Pathol 2006, 10:209-214 [ Özet ]

4) Rivasi F, Pampiglione S, Boldorini R, Cardinale L: Histopathology of gastric and duodenal Strongyloides stercoralis locations in fifteen immunocompromised subjects. Arch Pathol Lab Med 2006, 130:1792-1798 [ Özet ]

5) Lim S, Katz K, Krajden S, Fuksa M, Keystone JS, Kain KC: Complicated and fatal strongyloides infection in Canadians: risk factors, diagnosis and management. CMAJ 2004, 171:479-484 [ Özet ]

6) Siddiqui A, Berk S: Diagnosis of Strongyloides stercoralis infection. Clin Infect Dis 2001, 33:1040-1047 [ Özet ]

7) Gülnaz Ç: Mustafa Kemal Üniversitesi Tıp Fakültesi Parazitoloji Laboratuarına başvuran hastalarda bağırsak parazitlerinin dağılımı. Türkiye Parazitoloji Dergisi 2006, 30:302-304

8) Genta RM: Global prevalence of strongyloidiasis: critical review with epidemiologic insights into prevention of disseminated disease. Rev Infect Dis 1989, 2:755-767 [ Özet ]

9) Keiser PB, Nutman TB: Strongyloides stercoralis in the immunocompromised Population. Clin Microbiol Rev 2004,17:208-217 [ Özet ]

10) Liepman M: Disseminated Strongyloides stercoralis. A complication of immunosuppression. JAMA 1975, 231:387-388 [ Özet ]

11) Ho PL, Luk WK, Chan AC, Yuen KY: Two cases of fatal strongyloidiasis in Hong Kong Pathology. 1997, 29:324-326 [ Özet ]

12) Lemos LB, Qu Z, Laucirica R, Fred HL: Hyperinfection syndrome in strongyloidiasis: report of two cases. Ann Diagn Pathol 2003, 7: 87-94 [ Özet ]

13) Meine GC, Dietz J, Rocha M, Mattos T, de Souza AR, Conteletti FR: Atypical gastric presentation of strongyloidiasis in HIVinfected patient-case report. Digestive and Liver Disease 2004, 36: 760-762 [ Özet ]