Invasive enteritis by Strongyloides stercoralis presenting as acute abdominal distress under corticosteroid therapy

Strongyloides Hyperinfection Causing Gastrointestinal Bleeding and Bacteremia in an Immunocompromised Patient

Strongyloidiasis is a parasitic infestation caused by Strongyloides stercoralis (S. stercoralis). Most cases are asymptomatic or mildly symptomatic with respiratory, gastrointestinal, or non-specific cutaneous symptoms. However, in immunocompromised patients, such as patients on chronic corticosteroids, malignancy, or human immunodeficiency virus (HIV) infection, hyperinfection syndrome can occur. The following is a case of Strongyloides hyperinfection in an individual taking prednisone for uveitis who developed upper gastrointestinal (GI) bleed and gram-negative bacteremia.

Strongyloides stercoralis Infection at Different Altitudes of the Cusco Region in Peru

Strongyloides stercoralis affects 30-100 million people worldwide. The burden is underestimated because of the paucity of studies, limited geographical areas surveyed, and poor quality of diagnostic tests. This study aimed at determining the epidemiology of strongyloidiasis using sensitive microscopy testing in rural populations living at different altitudes in Cusco, Peru. Data were collected from subjects aged > 3 years living in Quellouno (elevation 2,600 ft) and Limatambo (elevation 8,379 ft) districts. Subjects provided one fresh stool sample and answer a standardized questionnaire. Fresh stool was tested on site using the Baermann's test and agar plate culture. Formalin-preserved stool was tested by rapid sedimentation. Eighty percent (585/715) of eligible subjects consented to participate; after excluding subjects with missing data, 65% (462/715) were included. Fifty-five percentage were female; the median age was 33 years (interquartile range 13-52), and 72% had government health insurance. Half had intestinal parasites, and Strongyloides was the most common (24.5%) followed by Giardia (15.5%), Blastocystis (14.9%), and hookworm (11.5%). The agar plate culture detected more cases of Strongyloides than Baermann's or sedimentation tests. Strongyloides infection was more common at low altitude (26.4%) than at high altitude (18.6%), but the difference was not statistically significant (P = 0.08). Older age, walking barefoot, bathing in rivers/streams, and using municipal sewage were associated with strongyloidiasis. Strongyloides was the most prevalent parasite in the areas studied and was associated with demographic, socioeconomic, and sanitary factors.

Strongyloides stercoralis hyperinfection associated with impaired intestinal motility disorder

Infection by Strongyloides stercoralis is a highly prevalent helminthiasis, which is mostly distributed in the tropical and subtropical regions of the world. Although a substantial number of cases are asymptomatic or paucisymtomatic, severe and life-threatening forms of this infection still occur and not infrequently is lately diagnosed. Gram-negative bacteria septicemia, which frequently accompanies the severe helminthiasis, contributes to the high mortality rate. Severe infection is invariably triggered by any imbalance in the host's immunity, favoring the auto-infective cycle, which increases the intraluminal parasite burden enormously. Clinical presentation of severe cases is varied, and diagnosis requires a high suspicion index. Acute abdomen has been reported in association with S. stercoralis infection, but intestinal necrosis is rarely found during the surgical approach. The authors report the case of a man who sought the emergency unit with recent onset abdominal pain. Clinical and imaging features were consistent with obstructive acute abdomen. Scattered adhesions and a necrotic ileal segment with a tiny perforation represented the surgical findings. The patient outcome was unfavorable and respiratory distress required an open lung biopsy. Both surgical specimens showed S. stercoralis infection. Unfortunately the patient underwent multiple organ failure and septicemia, and subsequently died. The authors call attention to the finding of intestinal necrosis and impaired intestinal motility disorder as possibilities for the diagnosis and risk factor, respectively, for a severe infection of S. stercoralis.

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.

High prevalence of Strongyloides stercoralis infection among the elderly in Brazil

Little is known about the frequency of intestinal parasites in the elderly due to a lack of attention given to the occurrence of these infections among older adults. This study compares the frequency of Strongyloides stercoralis and other enteroparasites between elderly living in nursing homes (n = 100) and those noninstitutionalized (n = 100) from Uberlândia, state of Minas Gerais, southeastern Brazil, associated with data of epidemiological and socio-demographic conditions. Through coproparasitological examination of both groups, enteroparasites were detected in 15 of 200 individuals examined (7.5%; CI: 5.1- 9.9). S. stercoralis was the most frequent parasite 10/200 (5%; CI: 4.2-5.8), being significantly higher in males and in individuals with autonomy for daily living activities. There were no statistical differences in the prevalence of parasites between the two groups compared. In conclusion, S. stercoralis infection was highly prevalent in elderly patients and it does not depend on whether the individual was institutionalized or not.

Severe strongyloidiasis: a systematic review of case reports

BACKGROUND

Strongyloidiasis is commonly a clinically unapparent, chronic infection, but immuno suppressed subjects can develop fatal disease. We carried out a review of literature on hyperinfection syndrome (HS) and disseminated strongyloidiasis (DS), in order to describe the most challenging aspects of severe strongyloidiasis.

METHODS

We conducted a structured search using PubMed to collect case reports and short case series on HS/DS published from 1991 to 2011. We restricted search to papers in English, Spanish, Italian and French. Case reports were classified as HS/DS according to given definitions.

RESULTS

Records screened were 821, and 311 were excluded through titles and abstract evaluation. Of 510 full-text articles assessed for eligibility, 213 were included in qualitative analysis. As some of them were short case series, eventually the number of cases analyzed was 244.Steroids represented the main trigger predisposing to HS and DS (67% cases): they were mostly administered to treat underlying conditions (e.g. lymphomas, rheumatic diseases). However, sometimes steroids were empirically prescribed to treat signs and symptoms caused by unsuspected/unrecognized strongyloidiasis. Diagnosis was obtained by microscopy examination in 100% cases, while serology was done in a few cases (6.5%). Only in 3/29 cases of solid organ/bone marrow transplantation there is mention of pre-transplant serological screening. Therapeutic regimens were different in terms of drugs selection and combination, administration route and duration. Similar fatality rate was observed between patients with DS (68.5%) and HS (60%).

CONCLUSIONS

Proper screening (which must include serology) is mandatory in high - risk patients, for instance candidates to immunosuppressive medications, currently or previously living in endemic countries. In some cases, presumptive treatment might be justified. Ivermectin is the gold standard for treatment, although the optimal dosage is not clearly defined in case of HS/DS.

Dexamethasone effects in the Strongyloides venezuelensis infection in a murine model

The aim of this study was to investigate the immunomodulatory effects of glucocorticoids on the immune response to Strongyloides venezuelensis in mice. Balb/c mice were infected with S. venezuelensis and treated with Dexamethasone (Dexa) or vehicle. Dexa treatment increased circulating blood neutrophil numbers and inhibited eosinophil and mononuclear cell accumulation in the blood, bronchoalveolar, and peritoneal fluid compared with control animals. Moreover, Dexa decreased tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-3 (IL-3), IL-4, IL-5, IL-10, and IL-12 production in the lungs and circulating immunoglobulin G1 (IgG1), IgG2a, and IgE antibody levels while increasing the overall parasite burden in the feces and intestine. Dexa treatment enhanced the fertility of female nematodes relative to untreated and infected mice. In summary, the alterations in the immune response induced by Dexa resulted in a blunted, aberrant immune response associated with increased parasite burden. This phenomenon is similar to that observed in S. stercoralis-infected humans who are taking immunosuppressive or antiinflammatory drugs, including corticosteroids.

Epidemiological aspects of strongyloidiasis in Brazil

The objective of this review was to outline an epidemiological profile of Strongyloides stercoralis by parasitological and serological diagnosis in inhabitants, and to associate this profile with different immunosupression situations, in Brazil, over 20 years (1990-2009). The occurrence of S. stercoralis using parasitological methods was 5·5%, being 4·8% in rural and 5·0% in urban areas, characterizing the country as hyperendemic. There was a diversity of techniques used as a diagnostic tool and only 39·1% of the studies presented results based on at least 1 specific method. The occurrence increased with age, being 12·1%, for those over 60 that suggests an epidemiological condition of concern for the elderly population. Of the seroepidemiological studies in the general population the mean positivity in serum samples was 21·7% and 29·2%, using an immunofluorescence antibody test and enzyme-linked immunosorbent assay (ELISA), respectively. The occurrence of strongyloidiasis in immunosuppressed individuals was 11·8% by parasitological methods and 19·5% using immunological methods. Considering that Brazil is a tropical country and that the character of chronicity and autoinfection of the parasite that can result in severe forms of hyperinfection or dissemination makes strongyloidiasis an important medically and socially neglected problem.

Strongyloides stercoralis hyper-infection syndrome in HIV+/AIDS patients in Iran

Strongyloides stercoralis is an intestinal nematode in humans, distributed through tropical and subtropical regions of the world. In most individuals, the infection has a chronic nature due to auto-infection at the low level. Accelerated auto-infection, mainly after an alteration in immune status, can cause a syndrome of severe hyper-infection or potentially fatal disseminated strongyloidiasis. Due to the increasing numbers of immunocompromised patients in Iran, strongyloidiasis is an emerging public health concern in the country. In the current study, which was carried out between 2003 and 2005, for the investigation on strongyloidiasis in HIV(+)/AIDS patients, a total of 781 patients were examined by agar plate culture, formalin ether concentration, and direct smear preparation of stool samples. According to the results, 2 out of 781 HIV( + )/AIDS patients were found infected with S. stercoralis, but both patients were at the progressive stage of AIDS and showing severe hyper-infection syndrome. In both cases, numerous rhabditiform and filariform larvae were found in fresh stool direct smears, and rapid and intensive development of parasite in agar plate cultures. In conclusion, in the progressive stages of AIDS, as a result of immunosuppression conditions or in the context of chemotherapy, S. stercoralis is capable of inducing overwhelming infection.

Strongyloides Stercoralis Hyperinfection in Systemic Lupus Erythematosus and the Antiphospholipid Syndrome

OBJECTIVE

The Strongyloides stercoralis hyperinfection syndrome (SHS) may develop in individuals with asymptomatic infection receiving immunosuppressive treatment. This report summarizes current knowledge regarding SHS in patients with systemic lupus erythematosus (SLE) and associated antiphospholipid syndrome (APS).

METHODS

Two patients with active SLE and associated APS presenting with SHS are reported. Additional cases of strongyloidiasis in SLE were identified and reviewed.

RESULTS

Patient 1: A 34-year-old woman with SLE and APS characterized by active glomerulonephritis, stroke, and several hospital-acquired infections presented with vomiting and diffuse abdominal pain. Intestinal vasculitis was suspected, and treatment with methylprednisolone and cyclophosphamide was given. Response was partial. A gastric biopsy revealed S. stercoralis larvae. She received ivermectin and eventually recovered. Patient 2: A 37-year-old man with active glomerulonephritis and APS with recurrent thrombosis presented with digital necrosis. Necrotizing vasculitis was suspected and treated with immunosupressants. He suddenly developed respiratory failure secondary to alveolar hemorrhage and bronchoalveolar lavage was performed. The patient developed Gram-negative septic shock and died. The postmortem result of bronchoalveolar lavage yielded Strongyloides larvae. Nine cases of strongyloidiasis and the SHS in SLE patients reported in the literature were identified and reviewed. Five of these patients died; none had associated APS.

CONCLUSIONS

These cases suggest that the SHS can exacerbate SLE and APS, predisposing to Gram-negative sepsis and death. Immunocompromised patients need an early diagnosis and specific treatment of parasitic diseases and their complications. The SHS should be considered in the differential diagnosis of lupus complications in patients from endemic areas.

Intestinal strongyloidiasis and hyperinfection syndrome

In spite of recent advances with experiments on animal models, strongyloidiasis, an infection caused by the nematode parasite Strongyloides stercoralis, has still been an elusive disease. Though endemic in some developing countries, strongyloidiasis still poses a threat to the developed world. Due to the peculiar but characteristic features of autoinfection, hyperinfection syndrome involving only pulmonary and gastrointestinal systems, and disseminated infection with involvement of other organs, strongyloidiasis needs special attention by the physician, especially one serving patients in areas endemic for strongyloidiasis. Strongyloidiasis can occur without any symptoms, or as a potentially fatal hyperinfection or disseminated infection. Th2 cell-mediated immunity, humoral immunity and mucosal immunity have been shown to have protective effects against this parasitic infection especially in animal models. Any factors that suppress these mechanisms (such as intercurrent immune suppression or glucocorticoid therapy) could potentially trigger hyperinfection or disseminated infection which could be fatal. Even with the recent advances in laboratory tests, strongyloidiasis is still difficult to diagnose. But once diagnosed, the disease can be treated effectively with antihelminthic drugs like Ivermectin. This review article summarizes a case of strongyloidiasis and various aspects of strongyloidiasis, with emphasis on epidemiology, life cycle of Strongyloides stercoralis, clinical manifestations of the disease, corticosteroids and strongyloidiasis, diagnostic aspects of the disease, various host defense pathways against strongyloidiasis, and available treatment options.

Severe strongyloidiasis in corticosteroid-treated patients: case series and literature review

OBJECTIVE

To describe the main features of severe strongyloidiasis in corticosteroid-treated patients

METHODS

We report on 3 cases of corticosteroid-treated patients with severe strongyloidiasis and review cases of severe strongyloidiasis in corticosteroid-treated patients reported in the literature.

RESULTS

One hundred and fifty-one cases of severe strongyloidiasis complicated a therapy with corticosteroids were evaluated. The mean age of the patients was 48+/-17 years and 71% were men. Corticosteroids were given for hematological malignancies in 34 (23%), systemic lupus erythematosus or vasculitis in 27 (18%), and nephropathy or renal transplantation in 32 (21%). At time of infection, the mean daily dosage of prednisone-equivalent was 52+/-42 mg (median: 40 mg) and 84% of patients had received a cumulative dosage of prednisone-equivalent higher than 1000 mg. The total duration of treatment ranged from 4 days to 20 years (6 months or less: 69%). Non-specific gastro-intestinal symptoms were reported in 91% of these patients associated or not with pulmonary complaints. Low-grade fever was present in 54% of patients. Fifty-nine patients (39%) experienced severe bacterial or yeast infection during the course of severe strongyloidiasis. Peripheral eosinophilia was detected at presentation in 32% of patients. Strongyloidiasis was usually confirmed by repeated stool examinations. Thiabendazole was the treatment the more widely used. Eighty-nine patients (59%) deceased during the course of the disease.

CONCLUSIONS

Severe strongyloidiasis is a risk in every corticosteroid-treated patient who has traveled to a soil-infested country, even if the contact was 30 years prior. This diagnosis should be suspected in patients who either experience unusual gastro-intestinal or pulmonary symptoms or suffer from unexplained Gram-negative bacilli sepsis.

Strongyloidiasis in patients at a comprehensive cancer center in the United States

BACKGROUND

The frequency of Strongyloides stercoralis infestation and complication in patients with cancer in the United States is unknown.

METHODS

The authors performed a retrospective analysis of S. stercoralis infection in patients who were undergoing cancer treatment at The University of Texas M. D. Anderson Cancer Center (Houston, TX).

RESULTS

The overall S. stercoralis infection frequency was approximately 1.0 per 10,000 new cancer cases between 1971 and 2003. Twenty-two of 25 patients (88%) were U.S. residents (19 from Texas; 1 each from Mississippi, Tennessee, and Puerto Rico), and the remaining 3 (13%) were from Latin America. Thirteen (52%) had solid-organ malignancies, whereas 12 (48%) had hematologic malignancies (lymphoma or multiple myeloma, n=8; leukemia, n=3; aplastic anemia, n=1). Twelve patients (48%) received systemic corticosteroids, 9 (36%) received antineoplastic therapy, and 2 underwent hematopoietic stem cell transplantation (HSCT). Diarrhea was reported in 13 patients (57%), and eosinophilia was observed in 11 patients (48%); 4 patients (16%) had probable hyperinfection syndrome (in 3 cases of polymicrobial gram-negative bacteremia, 1 patient had Klebsiella pneumoniae pneumonia, whereas 1 patient presented with K. pneumoniae lung infection alone). Evidence of definite pulmonary hyperinfection syndrome was observed in 2 HSCT recipients (8%). Fourteen (74%) of 19 patients responded to thiabendazole therapy. Two patients with definite pulmonary hyperinfection syndrome developed fatal S. stercoralis hemorrhagic alveolitis despite receiving high-dose thiabendazole plus ivermectin therapy.

CONCLUSIONS

In the current study, strongyloidiasis was uncommon in patients with cancer and remained localized in individuals with solid-organ malignancies. Definite pulmonary accelerated autoinfections were observed only in HSCT recipients. Therefore, pre-HSCT S. stercoralis screening in individuals from endemic regions of the United States warrants further study.

Strongyloidiasis associated with amebiasis and giardiaisis in an immunocompetent boy presented with acute abdomen

Strongyloides stercoralis (SS) is an intestinal nematode that is mainly endemic in tropical and subtropical regions and sporadic in temperate zones. SS infection frequently occurs in people who have hematologic malignancies, HIV infection and in individuals undergoing immunosuppressive therapy. In this study, we report a 12- year-old immunocompetent boy who was admitted to our hospital with acute abdomen. Laboratory evaluation showed strongyloidiasis, amebiasis and giardiasis. Clinical and laboratory findings immediately improved with albendazole therapy. Therefore, when diarrhea with signs of acute abdomen is observed, stool examinations should be done for enteroparasitosis. This approach will prevent misdiagnosis as acute abdomen. Complete clinical improvement is possible by medical therapy without surgical intervention.

A case of Strongyloides stercoralis and mesenteric tuberculous infection with acute abdominal pain in an HIV-positive patient

We describe an HIV-positive female patient who had acute abdominal pain as the initial presentation of Strongyloides stercoralis infection. The diagnosis was established by identifying rhabditiform larvae in stool. She also had intra-abdominal tuberculosis without intestinal perforation. To our knowledge, this is the first reported case of such a presentation.