EFFICACY OF HIGH‐LEVEL DISINFECTANTS FOR GASTROINTESTINAL ENDOSCOPE DISINFECTION AGAINST STRONGYLOIDES STERCORALIS

Background: Guidelines for high‐level disinfection of gastrointestinal endoscopes have been published in many countries; however, none of them have a statement for disinfection against the parasite Strongyloides stercoralis. To establish a method for gastrointestinal endoscope disinfection against Strongyloides stercoralis, we examined the disinfection efficacy of high‐level disinfectants (3% glutaraldehyde, 0.55% ortho‐phthalaldehyde, and 0.3% peracetic acid) and 70% ethanol by in vitro tests. Methods: Strongyloides stercoralis larval suspension (0.05 mL) was added to 0.95 mL of each disinfectant and disinfection time measured under low magnification microscopy. Results: Among the high‐level disinfectants, peracetic acid was more efficacious for disinfection against Strongyloides stercoralis than glutaraldehyde and ortho‐phthalaldehyde. Ethanol was also efficacious for parasite killing. Conclusion: These results suggested that peracetic acid be recommended for gastrointestinal endoscope disinfection in regions with endemic Strongyloides stercoralis.     

Disseminated strongyloidiasis in a patient with acquired immunodeficiency syndrome

We report a case of Strongyloides stercoralis hyperinfection in a Spanish patient who had never traveled to an endemic area and in whom HIV infection and long-term immunosuppressive treatment most likely contributed to the dissemination of strongyloidiasis.     

Strongyloides stercoralis larvae or egg: Which came first?

Strongyloides stercoralis (SS) hyperinfection is a well‐documented condition. However, SS eggs in stool samples are not commonly observed during routine analysis. Here, we report a case on SS hyperinfection where both larvae and eggs were observed in the stool sample of an immunossupressed liver allograft transplanted patient.     

Strongyloides hyperinfection following hematopoietic stem cell transplant in a patient with HTLV‐1‐associated T‐cell leukemia

Strongyloides stercoralis has the potential to cause accelerated autoinfection in immunocompromised hosts. Screening tests for strongyloidiasis may be falsely negative in the setting of immunosuppression. We report a case of Strongyloides hyperinfection syndrome in a patient with human T‐lymphotropic virus type 1‐associated T‐cell leukemia early after hematopoietic stem cell transplant. The diagnosis was made by stool ova and parasite examination, despite a negative screening enzyme‐linked immunosorbent assay. Because of anticipated prolonged neutropenia, an extended course of treatment was utilized.     

Strongyloides stercoralis infection in an intestinal transplant recipient

Strongyloides stercoralis is a helminth in tropical and subtropical areas. It may cause latent infection and progress to Strongyloides hyperinfection syndrome, which is associated with a high mortality rate. Transplant recipients under the treatment of immunosuppressant agents are at risk of severe S. stercoralis infection. According to related literature, most cases of S. stercoralis infection after solid organ transplantation are caused by reactivation of latent infections in the recipients, whereas only a few are acquired from the donors. We report on an intestinal transplant recipient who had S. stercoralis infection diagnosed by a larva of this parasite found in the stool from the ileostomy stoma 1 month after transplantation. The donor was considered the source of the infection because the donor was from an endemic area and had marked eosinophilia, and the recipient had no contact history or clinical manifestations related to the S. stercoralis infection before transplantation. The patient was treated with ivermectin and exhibited no evidence of infection after 7 months.     

Usefulness of Strongyloides stercoralis Serology in the Management of Patients with Eosinophilia

Strongyloides stercoralis infection is being increasingly diagnosed out of endemic areas. The aim of this study is to evaluate the usefulness of S. stercoralis serology for the management of probable strongyloidiasis in patients presenting with eosinophilia. Overall, 147 patients were included, 89 (60.5%) patients had a positive S. stercoralis serology. Strongyloides stercoralis larvae were detected only in 15 (10.2%) patients. Twenty-eight patients had human immunodeficiency virus infection. Eighty patients received ivermectin 200 mcg/Kg/day for 2 days, and follow-up 6 months after treatment could be performed in 32 patients: 26 (81.3%) patients reached the response to treatment criteria (negative serology 6 months after treatment or when by enzyme-linked immunosorbent assay the optical density ratio of post-treatment to pre-treatment decreased to 0.6), and 11 (34.4%) patients fulfilled the cure criteria (negative serology 6 months after treatment). Strongyloides stercoralis serology is a useful diagnostic tool both in the diagnosis of probable strongyloidiasis and follow-up after treatment.     

Donor‐derived strongyloidiasis after organ transplantation in Norway

Strongyloides stercoralis is an intestinal helminth which in humans can cause asymptomatic chronic infection maintained for decades through its auto‐infective cycle. During solid organ transplantation, recipients may unintentionally receive an organ infected with strongyloides. This is a very rare complication but may have deadly outcome if not detected. We hereby report two transplant recipients whom developed Strongyloides hyperinfection syndrome after organ transplantation from the same deceased donor. Recipient 1 was kidney transplanted and presented at day 65 post engraftment with diarrhea and subsequent septicemia and gastric retention. Larvae were detected in gastric aspirate. Recipient 2 was simultaneously kidney and pancreas transplanted and presented at day 90 post engraftment also with gastric retention and septicemia. Larvae were demonstrated on duodenal biopsy and stool sample. The clinical course was complicated with severe duodenal bleedings, gastric retention, meningitis, and prolonged hospitalization. Retrospective testing of pre‐transplant donor serum was positive for Strongyloides stercoralis antibodies. As a result of disease severity and gastric retention albenazole was administered via a jejunal tube and ivermectin subcutaneously in both recipients. S stercoralis was successfully eradicated and the transplants ended up with unaffected graft function. Following these two cases, we started systematic screening of all deceased donors for serum Strongyloides IgG in October 2016. After having screened 150 utilized donors one tested positive for Strongyloides, which initiated prophylactic ivermectin treatment to organ recipients. No symptoms or disease developed. Our center will continue to screen all donors as prophylactic treatment may avert this potentially lethal complication in cases of donor‐derived Strongyloides infection.     

Strongyloides stercoralis infection in allogeneic stem cell transplant: a case report and review of the literature

Strongyloides stercoralis infections may be documented in low‐endemicity areas, particularly in immigrants from endemic areas. The case of a patient from Bangladesh, an immigrant to Italy who developed a S. stercoralis infection after allogeneic stem cell transplant, is described, and 7 further cases are reviewed. Because of the atypical clinical presentation, the low predictive role of the eosinophil count, and the low sensitivity of the microbiological tests, diagnosis of strongyloidiasis is a challenging problem. When a case of S. stercoralis infection is suspected, previous exposure may be the only clue to guide the diagnostic approach.     

Molecular diagnosis of Strongyloides stercoralis among transplant candidates

Strongyloidiasis can occur without any symptoms or as a potentially fatal hyperinfection or disseminated infection, principally in immunosuppressed patients. Our study aimed to evaluate the application of conventional polymerase chain reaction (cPCR) and real‐time PCR (qPCR). Polymerase chain reaction (PCR) and real‐time PCR (qPCR) targeting the 18S rRNA gene for detection of Strongyloides stercoralis infection among transplant candidates were applied in stool samples obtained from 150 transplant candidates, preliminarily analyzed by parasitological methods. S. stercoralis larvae were visualized in 15/150 (10.0%) transplant candidates by parasitological methods. DNA from S. stercoralis was amplified in 26/150 (17.3%) and 49/150 (32.7%) stool samples of transplant candidates, using cPCR and qPCR, respectively. The results suggest that molecular methods, especially qPCR, should be used as an additional tool for diagnostic of S. stercoralis infection among transplant candidates.     

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.     

Expanded infectious diseases screening program for Hispanic transplant candidates

M.A. Fitzpatrick, J.C. Caicedo, V. Stosor, M.G. Ison. Expanded infectious diseases screening program for Hispanic transplant candidates. Transpl Infect Dis 2010: 12: 336–341. All rights reserved Abstract: Most guidelines for pre‐transplant screening recommend enhanced screening among patients with potential exposure to such pathogens as Strongyloides stercoralis and Trypanosoma cruzi, the cause of Chagas disease. The incidence of these diseases in the Hispanic immigrant population has not been extensively studied. Transplant candidates who were evaluated by our program's Hispanic Transplant Program were referred for expanded infectious disease screening including Mycobacterium tuberculosis, S. stercoralis, Leishmania, and T. cruzi. Between December 2006 and December 2008, 83 patients were screened. Most were from Mexico but we also screened patients from Ecuador, Puerto Rico, and Peru. Most patients lived in urban locations before moving to the United States. Latent tuberculosis infection (LTBI) was found in 20%, and 6.7% had serologic evidence of S. stercoralis infection. These patients underwent treatment of latent infection without difficulty. To date, 14 patients have undergone living‐donor kidney transplantation. Two of these patients had positive Leishmania titers and are being followed clinically, 1 was treated for S. stercoralis, and 2 were treated for LTBI pre‐transplant. All have done well without evidence of screened pathogens an average of 348 days (range 65–766 days) post transplant. Expanded screening identifies endemic infections in the Hispanic immigrant population that can be treated before transplant, thereby minimizing post‐transplant infectious complications.     

Severe strongyloidiasis associated with hypogammaglobulinaemia

The association of severe strongyloidiasis and hypogammaglobulinaemia in one patient is described. Severe strongyloidiasis was observed twice (March 1971 and June 1974), and the Strongyloides stercoralis infestation probably lasted for at least 58 months (from March 1971 to December 1975), in spite of successive thiabendazole courses of treatment. Immunological studies performed disclosed severe, steady hypogammaglobulinaemia but no abnormality in cell-mediated immunity. The respiratory infections also seen during the follow-up were ascribable more to humoral immunity impairment than to cell-mediated immunity impairment. This is the first report of the association of hypogammaglobulinaemia and severe strongyloidiasis, and it suggests that humoral immunity plays a relevant role in the human defences against S. stercoralis infestation.     

Coinfection of Strongyloides stercoralis and Aspergillus found in bronchoalveolar lavage fluid from a patient with stubborn pulmonary symptoms

We report a case involving coinfection with Strongyloides stercoralis (S. stercoralis) and Aspergillus found in the bronchoalveolar lavage fluid (BALF) of an elderly male patient who had a medical history of autoimmune pancreatitis (AIP) and who was treated with prednisone therapy 6 months previously. The patient presented with stubborn pulmonary symptoms and signs because of Aspergillus invasion and mechanical destruction caused by larval migration. We found S. stercoralis and Aspergillus in his BALF that provided diagnostic proof.     

Case Report: Real-Time Polymerase Chain Reaction in Stool Detects Transmission of Strongyloides stercoralis from an Infected Donor to Solid Organ Transplant Recipients

Solid organ transplant recipients can acquire Strongyloides stercoralis from an infected donor. The diagnosis of S. stercoralis in immunocompromised individuals may be challenging due to a lower sensitivity of available parasitological and serological methods, compared with immunocompetent individuals. Recently, a real-time polymerase chain reaction (RT-PCR) in stool has been developed for S. stercoralis diagnosis. We report two cases of S. stercoralis infection transmitted by a donor to two solid organ transplant recipients, who were diagnosed with RT-PCR in stool. This test could play an important role in S. stercoralis diagnosis in immunosuppressed patients, facilitating rapid treatment initiation and reducing the risk of severe strongyloidiasis. Adherence to current recommendations of screening among donors and recipients from endemic areas is also urgently needed.     

Efficacy of parasitological methods for the diagnosis of Strongyloides stercoralis and hookworm in faecal specimens

To compare the efficacy of stool examination for the detection of Strongyloides stercoralis and hookworm, a total of 634 stool samples from the routine laboratory service of the Pharmacia Faculty, Federal University of Bahia, Brazil, were examined by agar plate culture (APC), Baermann-Moraes and spontaneous sedimentation. The sensitivity of agar plate culture, calculated by combining results of all 3 methods, was 95% for S. stercoralis and 77.6% for hookwoorm. Moreover, APC had superior accuracy than Baermann-Moraes and spontaneous sedimentation for S. stercoralis and hookworm diagnosis, respectively. The S. stercoralis and hookworm positive samples from the laboratory routine, obtained after the previous analysis, along with those initially selected, were used to evaluate the concordance between microscopic examination and both the type of furrows left by larvae and the time for culture positivity using the APC method. Of 115 stool samples positive for S. stercoralis and 92 positive for hookworm, 110 (95.7%) and 89 (96.7%), respectively, had concordant results for furrows and morphological characteristics. The cumulative percentage of positivity increased to 94% by the third day of observation; at this time, only 19.6% of hookworm-positive samples had positive culture plates. Analyses of 74 S. stercoralis-positive stool samples stored at 4 °C for 24, 48 and 72 h showed the presence of larvae in 48.6%, 28.4% and 23% of samples, respectively when re-examined by the APC. As a definitive diagnosis of strongyloidiasis depends on the microscopic demonstration of parasites, increasing the sensitivity of the detection requires the use of different parasitological methods, including APC.     

CHRONIC STRONGYLOIDIASIS IN TASMANIAN VETERANS—CLINICAL DIAGNOSIS BY THE USE OF A SCREENING INDEX

Abstract Chronic infection with Strongyloides stercoralis presents a diagnostic problem because of the low recovery of the organism from stools and the insensitivity of current serological tests. Of 150 former Far East POWs, 26 (17%) had S. stercoralis in stools. The clinical features in 18 stool-positive patients were compared to those in 24 stool-negative patients and showed that strongyloidiasis was associated with a higher frequency of alteration in bowel habit, upper abdominal discomfort, rash and eosinophilia. On the basis of these features, a screening index was devised which largely separated stool-positive and stool-negative patients and led to helpful therapy in three of four patients with compatible symptoms who lacked a definitive diagnosis. Treatment with thiabendazole appeared to be superior to treatment with mebendazole.     

Coinfection of <Emphasis Type="Italic">Schistosoma mansoni</Emphasis> and <Emphasis Type="Italic">Strongyloides stercoralis</Emphasis> in a Patient with Variceal Bleeding

Abstract We report a case of hepatosplenic schistosomiasis with portal hypertension and variceal bleeding in an immigrant patient from Egypt, coinfected with Strongyloides stercoralis. The diagnosis was based on the following: (a) identification of Schistosoma mansoni ova in the stools and colonic biopsy specimens, (b) portal hypertension and esophageal varices with normal liver function and the absence of hepatic cirrhosis stigmata, (c) history of migration from an endemic area and (d) ultrasonographic findings of spleen and liver enlargement, fibrosed portal tracts, and normal lobular architecture of liver parenchyma. Hepatosplenic schistosomiasis should be suspected in any patient from an endemic area who has splenomegaly, portal hypertension, and esophageal varices bleeding in the absence of stigmata of liver cirrhosis and hepatic insufficiency. Coinfection with S. stercoralis could be attributed to common epidemiological features of the parasites and the patient’s habits.     

Fatal Strongyloides hyper-infection in a patient with myasthenia gravis

Purpose

We report a fatal case of Strongyloides hyper-infection as the result of corticosteroid therapy of a patient with myasthenia gravis.

Case presentation

Our patient was a farmer with a past history of living in an endemic area for Strongyloides stercoralis in Iran. Hyper-infection was diagnosed during the advanced-stage disease by demonstration of enormous number of larvae in the direct smears prepared from both the stool and tracheal secretions. Unfortunately, despite appropriate anti-parasite therapy, the patient died due to respiratory failure.

Conclusion

We recommend the provision of more awareness in high-risk people prior to immunosuppressive therapy, through screening for S. stercoralis, even in non-endemic regions.     

Screening of living organ donors for endemic infections: Understanding the challenges and benefits of enhanced screening

Living organ donor candidates are screened for medical and psychosocial contraindications to donation. One important goal of this process is to prevent donor‐derived infectious diseases transmissions. These transmissions are exceptionally rare, but have the potential to cause significant morbidity and mortality. The Organ Procurement and Transplantation Network now requires each recovery hospital to develop a protocol for evaluating living donors for tuberculosis and other geographically defined endemic pathogens, including Trypanosoma cruzi (the causative pathogen of Chagas’ disease), Strongyloides stercoralis, and West Nile Virus (WNV), in addition to universal screening for blood‐borne pathogens. Enhanced screening requirements were developed in response to the changing epidemiology and endemicity of these diseases, as well as recent case reports of donor‐derived disease transmission. Living organ donor disease screening presents a number of unique challenges to clinicians and policy‐makers, including deciding which donors to test, which testing modality to use, when to test, and appropriate interpretation of results. This review will analyze the epidemiology of T. cruzi, S. stercoralis, and WNV, the assays available for screening for these diseases, and the subsequent impact on the living organ donor process.     

Intestinal Damage in Strongyloidiasis: The Imbalance Between Cell Death and Proliferation

Strongyloidiasis is an endemic tropical parasitosis caused by Strongyloides stercoralis that also affects immigrants in nontropical countries. The nematode colonizes the duodenum and upper jejunum, inducing mucosal alterations. Because integrity is essential for a functional barrier, we aimed to study apoptosis and proliferation in the small bowel epithelium infected with S. stercoralis. We evaluated 23 patients and 17 controls. Apoptotic cells were detected by TUNEL and M30 immunolabelling, whereas proliferation was scored by Ki67 immunostaining and mitotic counting. Infection increased apoptotic indices in duodenum and jejunum (P < 0.001). Conversely, it decreased cell proliferation in both segments (P < 0.001). Our results showed that intestinal strongyloidiasis promotes an imbalance between cell death and proliferation. This is the first evidence of disruption of the epithelial kinetics with S. stercoralis infection, though the mechanisms remain unclear. Furthermore, our results support the idea that strongyloidiasis disturbs the mucosal integrity and can compromise the intestinal barrier.