Image of the month. Strongyloides stercoralis hyperinfection and syndrome of inappropriate secretion of antidiuretic hormone

Anemia, intractable vomiting, chronic diarrhea, and syndrome of inappropriate antidiuretic secretion: a diagnostic dilemma: Disseminated strongyloidosis in a patient with newly diagnosed HTLV infection-case report and review of literature

RATIONALE

Strongyloidiasis hyperinfection and disseminated disease have high mortality rates due to several complications and early detection of Strongyloides infection is therefore prudent.

PATIENT CONCERNS

A 37-year-old male patient came with chronic diarrhea, intractable vomiting and was found to have hyponatremia, and anemia on the initial laboratory tests.

DIAGNOSES

Further work up revealed syndrome of inappropriate antidiuretic secretion to be the cause of the hyponatremia in addition to gastrointestinal loses. His hospital course was complicated by persistent hyponatremia and later development of partial small bowel obstruction.

INTERVENTIONS

Considering his symptoms we had a suspicion of small bowel pathology for which he underwent an esophagogastroduodenoscopywith biopsies that revealed strongyloidosis as the cause of his symptoms. He was also found to have human T-cell lymphotropic virus infection, likely contributing to the disseminated disease.

OUTCOMES

He was started on ivermectin with complete resolution of symptoms and improvement of hyponatremia.

LESSONS

It is very important to suspect Strongyloides infection in a patient presenting with syndrome ofinappropriate antidiuretic secretion as hyperinfection and disseminated disease can be life threatening without antihelmintic therapy.

Strongyloidiasis with emphasis on human infections and its different clinical forms

Strongyloidiasis (caused by Strongyloides stercoralis, and to a lesser extent by Strongyloides fuelleborni) is one of the most neglected tropical diseases with endemic areas and affecting more than 100 million people worldwide. Chronic infections in endemic areas can be maintained for decades through the autoinfective cycle with the L3 filariform larvae. In these endemic areas, misdiagnosis, inadequate treatment and the facilitation of the hyperinfection syndrome by immunosuppression are frequent and contribute to a high mortality rate. Despite the serious health impact of strongyloidiasis, it is a neglected disease and very little is known about this parasite and the disease when compared to other helminth infections. Control of the disease is difficult because of the many gaps in our knowledge of strongyloidiasis. We examine the recent literature on different aspects of strongyloidiasis with emphasis in those aspects that need further research.

Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) in Strongyloides stercoralis Hyperinfection

Strongyloides stercoralis (S. stercoralis) is a soil transmitted intestinal roundworm that has a unique ability to multiply within the human host and reinfect the human carrier by a process of autoinfection. By this property, S. stercoralis can persist as an occult infection for many decades. In situations of immunosuppression or other permissive gastrointestinal conditions, there occurs a massive increase in parasite multiplication. The parasites penetrate through the intestinal mucosa and are carried in circulation and can cause multisystem involvement. We report a case of a 76-year-old Columbian male who presented with intractable vomiting and hyponatremia who was then diagnosed to have syndrome of inappropriate antidiuretic hormone (SIADH). The patient's symptoms improved after treatment with two doses of ivermectin and his serum sodium levels returned to normal. S. stercoralis infection should be suspected in patients from endemic regions who present with gastrointestinal symptoms and unexplained hyponatremia.

Diagnostic yield of double-balloon enteroscopy with intestinal juice analysis for intestinal strongyloidiasis

Strongyloidiasis is relatively common in tropical and subtropical areas. Most patients with Strongyloides stercoralis hyperinfection are immunocompromised, most commonly from corticosteroids or human T-cell lymphoma virus type 1 (HTLV-1) infection. We encountered a patient with HTLV-1 infection accompanied by paralytic ileus, in whom strongyloidiasis in the duodenum and jejunum was disclosed by esophagogastroduodenoscopy (EGD) and double-balloon enteroscopy (DBE). Until the age of 7 years, he lived on Amami-Oshima Island, Japan, where both S. stercoralis and HTLV-1 are endemic. EGD and peroral DBE disclosed white villi, edematous mucosa, and the disappearance of folds in the duodenum and jejunum. Biopsy specimens from the white villi in the duodenum and jejunum revealed S. stercoralis larvae. In both duodenal and jejunal juice, the rhabditiform larvae moved around. Because the larvae invade the lymph vessels, resulting in lymphangiectasia in edematous enteritis, the appearance of white villi may reflect villous atrophy/destruction and mucosal edema. Although our patient revealed no eosinophilia and negative stool specimens for parasites or ova, EGD and DBE with multiple biopsies and intestinal juice analysis are valuable diagnostic tools for strongyloidiasis.

Strongyloides stercoralis infection in the immunocompromised host

Strongyloides stercoralis is an intestinal nematode acquired in the tropics or subtropics. Most often, it causes chronic, asymptomatic infection, but a change in immune status can increase parasite numbers, leading to hyperinfection syndrome, dissemination, and death if unrecognized. Corticosteroid use is most commonly associated with hyperinfection syndrome. Diagnosis of Strongyloides infection is based on serology and serial stool examinations for larvae. The treatment of choice for chronic, asymptomatic infection is oral ivermectin. Alternative pharmacologic agents include albendazole and thiabendazole. For hyperinfection syndrome, ivermectin remains the drug of choice, though therapy duration must be individualized with the end point being complete parasite eradication. Recurrent strongyloidiasis should prompt an evaluation for human T-cell lymphotropic virus type 1 coinfection. No test of cure is currently available, although immunoglobulin G antibody levels have been shown to decline within 6 months of successful treatment.

Disseminated strongyloidiasis complicating glioblastoma therapy: a case report

Strongyloides stercoralis is an intestinal parasite that can cause fatal opportunistic infections in immunocompromised patients. Here we report an immunocompromised patient with glioblastoma who developed disseminated strongyloidiasis 6 weeks after completion of standard radiotherapy and concurrent temozolomide chemotherapy. She was effectively treated with albendazole and ivermectin. Strongyloidiasis should be considered in patients being treated for glioma who have lived or traveled to high risk areas and developed gram negative sepsis, along with gastrointestinal or respiratory symptoms, skin rash or SIADH.

Endoscopic and histopathological study on the duodenum of Strongyloides stercoralis hyperinfection

AIM: To investigate endoscopic and histopathological findings in the duodenum of patients with Strongyloides stercoralis (S. stercoralis) hyperinfection.

METHODS: Over a period of 23 years (1984-2006), we investigated 25 patients with S. stercoralis hyperinfection who had had an esophagogastroduodenoscopy before undergoing treatment for strongyloidiasis. The clinical and endoscopic findings were analyzed retrospectively.

RESULTS: Twenty-four (96%) of the patients investigated were under immunocompromised condition which was mainly due to a human T lymphotropic virus type 1 (HTLV-1) infection. The abnormal endoscopic findings, mainly edematous mucosa, white villi and erythematous mucosa, were observed in 23 (92%) patients. The degree of duodenitis including villous atrophy/destruction and inflammatory cell infiltration corresponded to the severity of the endoscopic findings. The histopathologic yield for identifying larvae was 71.4% by duodenal biopsy. The endoscopic findings of duodenitis were more severe in patients whose biopsies were positive for larvae than those whose biopsies were negative (Endoscopic severity score: 4.86 ± 2.47 vs 2.71 ± 1.38, P < 0.05).

CONCLUSION: Our study clearly demonstrates that, in addition to stool analysis, endoscopic observation and biopsies are very important. We also emphasize that S. stercoralis and HTLV-1 infections should be ruled out before immunosuppressive therapy is administered in endemic regions.