Murine strongyloidiasis: the effects of cyclosporin A and thiabendazole administered singly and in combination

Strongyloides hyper-infection in a lung transplant recipient: Case report and review of the literature

CASE PRESENTATION

A 63-year-old man with a left single lung transplant for end-stage combined restrictive and obstructive lung disease developed persistent pulmonary infiltrates and recurrent gram-negative bacteremia post-transplant. Bronchoalveolar lavage fluid revealed a nematode on Papanicolau staining compatible with Strongyloides stercoralis larvae on day 50 post-transplant. Although Strongyloides serology performed post-transplant was negative, a retrospective review of the medical record revealed marked peripheral blood eosinophilia on several occasions before transplantation. Despite reduction in immunosuppression and treatment with albendazole and ivermectin, the patient developed another episode of Escherichia coli bacteremia. He died 3 months post-transplant from pulmonary and neurological complications.

DIAGNOSIS

Strongyloides hyper-infection.

DISCUSSION

Strongyloides hyper-infection syndrome is known to occur in immunocompromised patients, but it has only been reported once in a lung transplant recipient. This case illustrates the importance of screening for parasitic infections before transplantation in patients with marked eosinophilia, especially among immigrants from countries in which Strongyloides is endemic. Hyper-infection syndrome may appear years after infection in the context of immunosuppression or immunodeficiency. This case also highlights the association between Strongyloides hyper-infection and bacteremia with enteric organisms.

Syndrome of Inappropriate Anti-Diuretic Hormone Secretion Secondary to Strongyloides stercoralis Infection in an Allogeneic Stem Cell Transplant Patient: A Case Report and Literature Review

Syndrome of inappropriate anti-diuretic hormone (SIADH) has been reported to be associated with systemic Strongyloides stercoralis. Here, we report a case of a stem cell transplant (SCT) recipient who developed severe SIADH secondary to systemic S Stercoralis. The SIADH resolved quickly after treating the systemic S Stercoralis with ivermectin. A systematic review of the literature was performed by PubMed, Scopus, and Cochrane database search. Only eight cases of S Stercoralis in allogeneic SCT recipients have been previously reported. To our knowledge, ours is the first reported case of SIADH secondary to S Stercoralis infection in an allogeneic SCT recipient. Prior to transplantation, even if asymptomatic, patients from endemic regions should be screened with strongyloides immunoglobulin (Ig)G serology. Pretransplantation eosinophilia should be evaluated by screening multiple stool samples for ova and parasites. Transplant candidates with positive serology or stool tests can be treated pretransplantation to eradicate infection. Patients at risk for S Stercoralis who develop nonspecific gastrointestinal complaints, rash, pulmonary infiltrates, or gram-negative bacteremia or meningitis may have S Stercoralis hyperinfection syndrome. Our case indicates that the development of SIADH may be an additional clue to this diagnosis. Appropriate diagnostic studies, including repeat stool and other body fluid sampling, should be expedited and ivermectin therapy initiated rapidly to prevent significant morbidity and mortality.

Strongyloides Stercoralis Infection Among Human Immunodeficiency Virus (HIV)-Infected Patients in the United States of America: A Case Report and Review of Literature

Patient: Male, 61

Final Diagnosis: Strongyloides stercolaris-associated diarrhea

Symptoms: Diarrhea • epigastric pain • nausea • weight loss

Medication: Ivermectin

Clinical Procedure: Colonic biopsies

Specialty: Infectious Diseases

Helminths in organ transplantation

With transplantation becoming an increasingly routine form of treatment for diverse populations, and with international travel becoming ever more accessible and affordable, the danger of transplantation-mediated helminth infections, exacerbated by coincident immunosuppression, must be considered. In this Review, we attempt to catalogue all clinically-relevant helminthiases that have been reported to coincide with transplantation, whether by transplantation-mediated transmission, reactivation of latent infections in an immunosuppressed context, or possible de-novo infection during the immunosuppressed peritransplant period. Helminthiasis has been reported in cases of kidney, liver, bowel, pancreas, heart, lung, and stem-cell transplant, and blood transfusion. For each helminthiasis, known risk factors, symptoms, and suggested options for screening and treatment are given. We conclude that helminths are a small but important and potentially severe source of disease after transplantation, and, with options for diagnosis and treatment, these pathogens warrant greater consideration during organ implantation. The achievement of immunological tolerance using helminth-derived products is also an exciting future prospect.

Repurposing drugs for the treatment and control of helminth infections

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Drug repurposing continues to be the central drug discovery strategy for helminths.

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Most repurposed drugs come from veterinary medicine and known drug classes.

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Only a handful of drugs have advanced clinically.

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More collaborations and funding are needed to advance discoveries to the market.

Helminth infections are responsible for a considerable public health burden, yet the current drug armamentarium is small. Given the high cost of drug discovery and development, the high failure rates and the long duration to develop novel treatments, drug repurposing circumvents these obstacles by finding new uses for compounds other than those they were initially intended to treat. In the present review, we summarize in vivo and clinical trial findings testing clinical candidates and marketed drugs against schistosomes, food-borne trematodes, soil-transmitted helminths, Strongyloides stercoralis, the major human filariases lymphatic filariasis and onchocerciasis, taeniasis, neurocysticercosis and echinococcosis. While expanding the applications of broad-spectrum or veterinary anthelmintics continues to fuel alternative treatment options, antimalarials, antibiotics, antiprotozoals and anticancer agents appear to be producing fruitful results as well. The trematodes and nematodes continue to be most investigated, while cestodal drug discovery will need to be accelerated. The most clinically advanced drug candidates include the artemisinins and mefloquine against schistosomiasis, tribendimidine against liver flukes, oxantel pamoate against trichuriasis, and doxycycline against filariasis. Preclinical studies indicate a handful of promising future candidates, and are beginning to elucidate the broad-spectrum activity of some currently used anthelmintics. Challenges and opportunities are further discussed.

Strongyloides stercoralis transmission by kidney transplantation in two recipients from a common donor

Strongyloides stercoralis hyperinfection in an immunocompromised host has a high mortality rate but may initially present with nonspecific pulmonary and gastrointestinal symptoms. Donor-derived S. stercoralis by kidney transplantation is an uncommon diagnosis and difficult to prove. We report two renal allograft recipients on different immunosuppressive maintenance regimens that developed strongyloidiasis after transplantation from the same donor. Recipient 1 presented with a small bowel obstruction. Larvae were demonstrated on a duodenal biopsy and isolated from gastric, pulmonary, and stool samples. Serologic testing for S. stercoralis was negative at a referral laboratory but positive at the Centers for Disease Control. The patient's hospital course was complicated by a hyperinfection syndrome requiring subcutaneous ivermectin due to malabsorption. Recipient 1 survived but the allograft failed. Recipient 2 had larvae detected in stool samples after complaints of diarrhea and was treated. On retrospective testing for S. stercoralis, pretransplant serum collected from the donor and Recipient 1 was positive and negative, respectively. Donor-derived strongyloidiasis by renal transplantation is a preventable disease that may be affected by the immunosuppressive maintenance regimen. Subcutaneous ivermectin is an option in the setting of malabsorption. Finally, routine screening for S. stercoralis infection in donors from endemic areas may prevent future complications.

Strongyloides stercoralis infection in transplanted patients

PATIENT

Male, 36.

FINAL DIAGNOSIS

Strongyloidiasis.

SYMPTOMS

Abdominal pain • anorexia • eosinophilia • fever • letargy • weight loss.

MEDICATION

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CLINICAL PROCEDURE

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SPECIALTY

Infectious diseases.

OBJECTIVE

Challenging differential diagnosis, rare disease.

BACKGROUND

Strongyloidiasis is a worldwide infection, infecting approximately 100 million people in more than 70 countries. It is common in Southeast Asia, Latin America, Papua New Guinea and some parts of the United States. Malnutrition, cancer, organ transplantation, hemodialysis and prolonged use of corticosteroids increase the risk of this opportunistic infection. Undiagnosed and untreated, its mortality rate can be high.

CASE REPORT

We present a 36 year old Black man with history of malignant hypertension and glomerulonephritis who had chronic eosinophilia and vague, poorly localized abdominal pain and tenderness. He received three deceased donor kidney transplants, two of them failed and the third one succeeded. However, after transplantation, his abdominal pain and discomfort increased, became anorexic, lost weight and developed fever and lethargy. Duodenal aspirate examination was positive for strongyloides stercoralis. Immunosuppressant medications were discontinued and he was treated with thiabendazole. In spite of treatment, his condition deteriorated and he expired.

CONCLUSIONS

Due to low sensitivity of stool and serological examinations, diagnosis of strongyloidiasis often is delayed. A high index of suspicion and prompt diagnosis and treatment are essential in decreasing the morbidity and mortality of this infection. Before organ transplantation, every attempt should be made to find the cause of peripheral blood eosinophilia and in endemic areas and among patients coming from countries where the infection is known to exist, organ recipients and donors should be screened for parasitic infections including strongyloidiasis.

Cyclosporin A--a review on fermentative production, downstream processing and pharmacological applications

In present times, the immunosuppressants have gained considerable importance in the world market. Cyclosporin A (CyA) is a cyclic undecapeptide with a variety of biological activities including immunosuppressive, anti-inflammatory, antifungal and antiparasitic properties. CyA is produced by various types of fermentation techniques using Tolypocladium inflatum. In the present review, we discuss the biosynthetic pathway, fermentative production, downstream processing and pharmacological activities of CyA.

Parasitic Infection in Renal Transplant Recipients

The purpose of this study was to evaluate the prevalence of symptomatic parasitic infections in adult renal transplant recipients. We retrospectively analyzed a sample of 657 adult renal transplant recipients performed from January 2001 to December 2005 for immunosuppression protocol, clinical manifestations, parasite diagnosis, treatments, and outcomes. The prevalence of symptomatic parasitosis infections was 2.4% (16/657). None of the infected patients received cyclosporine in their immunosuppression protocol. Most of the infections were caused by Strongyloids stercoralis (n = 11), followed by Giardia lamblia (n = 3), Toxoplasma gondii (n = 1), and Trypanosoma cruzi: (n = 1). Strongyloides stercoralis was the most frequent agent, causing three cases of hyperinfection including one fatal case. With the new immunosuppressive regimes there must be a suspicion of parasitic infection to avoid the diagnostic delay that can be fatal. Strategies, including empiric treatment for S. stercoralis, must be considered.

Parasitic infections in transplant recipients

Parasitic infections are important complications of organ transplantation that are often overlooked in the differential diagnosis of post-transplantation pyrexial illness. Although their frequency is unknown, they seem to be much less prevalent than bacterial and viral infections. Only 5% of human pathogenic parasites have been reported to cause significant illness in transplant recipients. Infection can occur via transmission with the graft or blood transfusion, or be acquired de novo from the environment. Recrudescence of dormant infection can lead to active disease. Post-transplantation parasitic disorders tend to cluster into two clinical profiles. First, an acute systemic illness with anemia, constitutional manifestations and variable stigmata of organ involvement; acute graft dysfunction can lead to confusion and acute rejection. Protozoa including malarial Plasmodium, Leishmania, Trypanosoma and Toxoplasma are associated with this profile. The second typical manifestation encompasses a few localized syndromes, usually associated with the lower gastrointestinal tract, caused by either protozoa (Cryptosporidium and microsporidia) or nematodes (Strongyloides and Ascaris). Dissemination of localized infections can lead to life-threatening systemic manifestations. A high index of suspicion is essential, as diagnosis requires special sampling techniques and laboratory procedures. Definitive diagnosis is usually achieved by detecting the parasite in the patient's tissues or body fluids by histological examination or culture, or by polymerase chain reaction amplification of the parasite-specific antigen sequence. Antibody detection using serological techniques is also possible in a few parasitic infections. Certain lesions have characteristic radiological appearances, hence the value of imaging, particularly in the cerebral syndromes. Treatment is usually straightforward (broad spectrum or specific drugs), yet some species are drug resistant.

Intestinal strongyloidiasis: recognition, management, and determinants of outcome

Significant advances have occurred in our understanding of the biology, immunology, and immunopathology of the usually asymptomatic human infection by the intestinal parasite, Strongyloides stercoralis. Factors that increase the risk for the occurrence of symptomatic intestinal hyperinfection and/or often-fatal disseminated strongyloidiasis have been better defined. The pathophysiology underlying these risk factors, whether disease-related or iatrogenically induced, is a compromised immune system leading to dysfunction of TH-2 helper cells. These specialized lymphocytes are central to maintaining the delicate balance that exists between the infected human host and the stabilized parasite. Recognition of risk factors that impair the function of TH-2 lymphocytes is essential to heightening the index of clinical suspicion enhancing earlier, accurate diagnosis, and the introduction of appropriate therapy. This review summarizes what is understood about infection by S. stercoralis; its focus will be on the epidemiology, diagnosis, clinical presentation patterns in the immunocompetent and immunocompromised human hosts, and recommended treatment regimens.

Efeitos da ciclosporina A e betametasona na toxocaríase murina experimental

Estudou-se o efeito de ciclosporina A ou betametasona em camundongos experimentalmente infectados por larvas de Toxocara canis administrados 15 dias antes ou 45 dias após infecção por esse ascarídeo. Nos animais infectados determinou-se a cinética da resposta humoral por IgG 60 e 90 dias após infecção por meio de pesquisa de anticorpos anti-Toxocara, utilizando teste imunoenzimático, em amostras de sangue obtidas por punção do plexo orbitário. No 90º dia após a infecção todos os animais sobreviventes foram sacrificados e submetidos a digestão ácida da carcaça, pulmões, fígado e cérebro para recuperação de larvas de Toxocara canis encistadas nesses órgãos. Observou-se retardo na produção de anticorpos IgG anti-Toxocara nos animais tratados com ciclosporina A ou betametasona 15 dias antes da infecção, além de aumento significativo na quantidade de larvas de Toxocara canis recuperadas no grupo de animais que foi tratado com ciclosporina A 15 dias antes da infecção pelo ascarídeo.

Strongyloidiasis pre and post autologous peripheral blood stem cell transplantation

Hyperinfection with strongyloides stercolis occurs in the setting of chronic strongyloides infection in conjunction with immune suppression. Although malnutrition remains the major secondary cause worldwide in the developed world, iatrogenic immune suppression is an important precipitant. Autologous stem cell transplantation recipients are significantly immunocompromised albeit temporarily. Despite the increasing use of haemopoetic stem cell transplantation, hyperinfection with strongyloides has rarely been reported. We describe two cases of patients transplanted with chronic strongyloidiasis. In one case eradication therapy was given prior to the transplant which was uncomplicated. In the second case strongyloidiasis was diagnosed post transplant which was complicated by infection and respiratory compromise. Fatal hyperinfection subsequently developed after corticosteroid therapy was started for a disease progression in the CNS.

Effect of multidrug resistance modulators on the activity of ivermectin and moxidectin against selected strains of Haemonchus contortus infective larvae

Nematode parasites have shown resistance to the anthelmintics, ivermectin and moxidectin, and there is evidence that the over-expression of parasite P-glycoprotein (P-gp) may account, at least in part, for resistance to ivermectin. The objective of this study was to evaluate whether the multidrug resistance (MDR) modulators, verapamil, CL 347.099 (an analog of verapamil) and cyclosporin A, would enhance the efficacy of ivermectin and moxidectin against selected strains of Haemonchus contortus using an in vitro larval migration assay. The modulators had no effects on the number of migrating larvae when used alone. Ivermectin and moxidectin showed a significant (P<0.05) increase in its efficacy by 52.8 and 58.5% respectively, when used in association with verapamil against a moxidectin-selected strain. CL 347,099 also increased significantly (P<0.05) the ivermectin and moxidectin efficacy by 24.2 and 40.0% respectively, against an ivermectin-selected strain and by 40.0 and 75.6% respectively, against an moxidectin-selected strain. At the concentrations tested cyclosporin A showed a variable effect on increasing the efficacy of the anthelmintics against the susceptible and resistant strains.

Immunosuppressive and antiparasitic effects of cyclosporin A on Hymenolepis nana infection in mice

The effect of cyclosporin A, which is known to act both as immunosuppressant and as an antiparasitic drug in many host-parasite systems, was examined in a mouse-Hymenolepis nana system. When BDF1 mice were injected s.c. with cyclosporin A (100 mg kg-1 day-1) every 48 h from 11 days p.i. with eggs, expulsion of the adult worms from the intestines of mice was prevented completely until at least 30 days p.i. Worm burden, dry weight and the number of gravid proglottids were not significantly reduced. By contrast, in untreated mice most of the worms were eliminated by 19 days p.i. The drug also completely abolished acquired resistance to a challenge infection with eggs when mice were injected s.c. with cyclosporin A (100 mg kg-1 day-1) around the time of challenge infection (Days -2, -1, 0, 1 and 2 relative to challenge). Such immunosuppressive effects of cyclosporin A on worm expulsion and protective immunity to reinfection were similar to those of another immunosuppressant, cyclophosphamide. As for the antiparasitic action of cyclosporin A against H. nana, a smaller number of cysticercoids developed from eggs in mice given cyclosporin A (100 mg kg-1 day-1) for 5 days beginning 1 day before infection, than in untreated controls.