Successful use of parenteral ivermectin in an immunosuppressed patient with disseminated strongyloidiasis and septic shock

Severe strongyloidiasis: a systematic review and meta-analysis of 339 cases

Strongyloidiasis is a parasitosis representing a significant public health problem in tropical countries. It is often asymptomatic in immunocompetent individuals but its mortality rate increases to approximately 87% in severe forms of the disease. We conducted a systematic review, including case reports and case series, of Strongyloides hyperinfection and dissemination from 1998 to 2020 searching PubMed, EBSCO and SciELO. Cases that met the inclusion criteria of the Preferred Reported Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist were analysed. Statistical analysis was performed using Fisher's exact test and Student's t-test and a Bonferroni correction for all the significant values. A total of 339 cases were included in this review. The mortality rate was 44.83%. The presence of infectious complications, septic shock and a lack of treatment were risk factors for a fatal outcome. Eosinophilia and ivermectin treatment were associated with an improved outcome.

Disseminated Strongyloidiasis in Renal Transplant Recipient Complicated with Neurological Manifestations

Introduction: Infections caused by Strongyloides stercoralis are quite difficult to detect. It can remain silent long before manifesting, which used to occur when patients were under immunosuppressed conditions. This scenario makes the patient’s treatment and recovery hard to deal with. Case Presentation: This paper reports the case of a renal transplant patient who presented disseminated strongyloidiasis infection complicated with neurological manifestations. In order to eliminate Strongyloides stercoralis, the patient initially received oral Ivermectin treatment, and as the infection persisted, parenteral treatment was provided. The patient developed flaccid tetraparesis and increased cerebrospinal fluid protein with albumin- cytological dissociation, initially suggesting the diagnosis of Guillain-Barré syndrome. Conclusions: This clinical report highlights the need for early diagnosis and treatment in cases of immunosuppressed patients with strongyloidiasis infection, as the diagnosis might be neglected.

Nebulized ivermectin for COVID-19 and other respiratory diseases, a proof of concept, dose-ranging study in rats

Ivermectin is a widely used antiparasitic drug with known efficacy against several single-strain RNA viruses. Recent data shows significant reduction of SARS-CoV-2 replication in vitro by ivermectin concentrations not achievable with safe doses orally. Inhaled therapy has been used with success for other antiparasitics. An ethanol-based ivermectin formulation was administered once to 14 rats using a nebulizer capable of delivering particles with alveolar deposition. Rats were randomly assigned into three target dosing groups, lower dose (80–90 mg/kg), higher dose (110–140 mg/kg) or ethanol vehicle only. A toxicology profile including behavioral and weight monitoring, full blood count, biochemistry, necropsy and histological examination of the lungs was conducted. The pharmacokinetic profile of ivermectin in plasma and lungs was determined in all animals. There were no relevant changes in behavior or body weight. There was a delayed elevation in muscle enzymes compatible with rhabdomyolysis, that was also seen in the control group and has been attributed to the ethanol dose which was up to 11 g/kg in some animals. There were no histological anomalies in the lungs of any rat. Male animals received a higher ivermectin dose adjusted by adipose weight and reached higher plasma concentrations than females in the same dosing group (mean C_max 86.2 ng/ml vs. 26.2 ng/ml in the lower dose group and 152 ng/ml vs. 51.8 ng/ml in the higher dose group). All subjects had detectable ivermectin concentrations in the lungs at seven days post intervention, up to 524.3 ng/g for high-dose male and 27.3 ng/g for low-dose females. nebulized ivermectin can reach pharmacodynamic concentrations in the lung tissue of rats, additional experiments are required to assess the safety of this formulation in larger animals.

Ivermectin: From theory to clinical application

Approximately 250 million people have been using ivermectin (IVM) annually to combat many parasitic diseases including filariasis, onchocerciasis, strongyloidiasis, scabies and pediculosis. Many clinical studies have proven its efficacy against these diseases and have reported the optimum dose and duration of treatment. Moreover, its antiparasitic range has increased to cover more parasitic infections, but it still requires further exploration, e.g. for trichinosis and myiasis. Furthermore, IVM showed high efficacy in killing vectors of disease-causing parasites such as mosquitoes, sandflies and tsetse flies. The World Health Organization (WHO) has managed many control programmes involving the use of IVM to achieve elimination of onchocerciasis and lymphatic filariasis and to reduce malaria transmission. However, IVM is not exempt from the possibility of resistance and, certainly, its intensive use has led to the emergence of resistance in some parasites. Recent research is investigating the possibility of novel drug delivery systems for IVM that increase its potential to treat a new range of diseases and to overcome the possibility of drug resistance. This review highlights the most common human uses of IVM, with special reference to the new and promising properties of IVM.

Human infection with Strongyloides stercoralis and other related Strongyloides species

The majority of the 30-100 million people infected with Strongyloides stercoralis, a soil transmitted intestinal nematode, have subclinical (or asymptomatic) infections. These infections are commonly chronic and longstanding because of the autoinfective process associated with its unique life cycle. A change in immune status can increase parasite numbers, leading to hyperinfection syndrome, dissemination, and death if unrecognized. Corticosteroid use and HTLV-1 infection are most commonly associated with the hyperinfection syndrome. Strongyloides adult parasites reside in the small intestine and induce immune responses both local and systemic that remain poorly characterized. Definitive diagnosis of S. stercoralis infection is based on stool examinations for larvae, but newer diagnostics - including new immunoassays and molecular tests - will assume primacy in the next few years. Although good treatment options exist for infection and control of this infection might be possible, S. stercoralis remains largely neglected.

Ivermectin versus albendazole or thiabendazole for Strongyloides stercoralis infection

BACKGROUND

Strongyloidiasis is a gut infection with Strongyloides stercoralis which is common world wide. Chronic infection usually causes a skin rash, vomiting, diarrhoea or constipation, and respiratory problems, and it can be fatal in people with immune deficiency. It may be treated with ivermectin or albendazole or thiabendazole.

OBJECTIVES

To assess the effects of ivermectin versus benzimidazoles (albendazole and thiabendazole) for treating chronic strongyloides infection.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register (24 August 2015); the Cochrane Central Register of Controlled Trials (CENTRAL), published in the Cochrane Library; MEDLINE (January 1966 to August 2015); EMBASE (January 1980 to August 2015); LILACS (August 2015); and reference lists of articles. We also searched the metaRegister of Controlled Trials (mRCT) using 'strongyloid*' as a search term, reference lists, and conference abstracts.

SELECTION CRITERIA

Randomized controlled trials of ivermectin versus albendazole or thiabendazole for treating chronic strongyloides infection.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias in the included trials. We used risk ratios (RRs) with 95% confidence intervals (CIs) and fixed- or random-effects models. We pooled adverse event data if the trials were sufficiently similar in their adverse event definitions.

MAIN RESULTS

We included seven trials, enrolling 1147 participants, conducted between 1994 and 2011 in different locations (Africa, Southeast Asia, America and Europe).In trials comparing ivermectin with albendazole, parasitological cure was higher with ivermectin (RR 1.79, 95% CI 1.55 to 2.08; 478 participants, four trials, moderate quality evidence). There were no statistically significant differences in adverse events (RR 0.80, 95% CI 0.59 to 1.09; 518 participants, four trials, low quality evidence).In trials comparing ivermectin with thiabendazole, there was little or no difference in parasitological cure (RR 1.07, 95% CI 0.96 to 1.20; 467 participants, three trials, low quality evidence). However, adverse events were less common with ivermectin (RR 0.31, 95% CI 0.20 to 0.50; 507 participants; three trials, moderate quality evidence).In trials comparing different dosages of ivermectin, taking a second dose of 200 μg/kg of ivermectin was not associated with higher cure in a small subgroup of participants (RR 1.02, 95% CI 0.94 to 1.11; 94 participants, two trials).Dizziness, nausea, and disorientation were commonly reported in all drug groups. There were no reports of serious adverse events or death.

AUTHORS' CONCLUSIONS

Ivermectin results in more people cured than albendazole, and is at least as well tolerated. In trials of ivermectin with thiabendazole, parasitological cure is similar but there are more adverse events with thiabendazole.

CATMAT statement on disseminated strongyloidiasis: Prevention, assessment and management guidelines

Background

Strongyloides stercoralis is a parasitic nematode found in humans, with a higher prevalence in tropical and sub-tropical regions worldwide. If untreated, the infection can progress to disseminated strongyloidiasis, a critical illness which may be fatal.

Objective

To provide clinical guidance on the prevention, assessment and management of disseminated strongyloidiasis.

Methods

A literature review was conducted to evaluate the current evidence and to identify any systematic reviews, case reports, guidelines and peer reviewed and non-peer reviewed medical literature. The Committee to Advise on Tropical Medicine and Travel (CATMAT) assembled a working group to develop this statement, which was then critically reviewed and approved by all CATMAT members.

Recommendations

CATMAT recommends that screening for strongyloidiasis should be considered for individuals with epidemiologic risk and/or co-morbidities that place them at risk for Strongyloides hyperinfection and dissemination. Those at highest risk of hyperinfection and dissemination are individuals born in a Strongyloides-endemic area who undergo iatrogenic immunosuppression or have intercurrent human T-lymphotropic virus (HTLV-1) infection. Diagnosis of strongyloidiasis is based on serologic testing and/or examination of stools and other clinical specimens for larvae. Referral to a tropical medicine specialist with expertise in the management of strongyloidiasis is recommended for suspected and confirmed cases. A diagnosis and treatment algorithm for strongyloidiasis has been developed as a reference tool.

Conclusion

Strongyloidiasis is relatively widespread in the global migrant population and screening for the disease should be based on an individual risk assessment. A practical tool for the clinician to use in the prevention, assessment and management of disseminated strongyloidiasis in Canada is now available.

Subcutaneous ivermectin use in the treatment of severe Strongyloides stercoralis infection: two case reports and a discussion of the literature

BACKGROUND

Strongyloides stercoralis infection presents with varying degrees of severity, but it often primarily involves the small bowel. In severe infection and cases of hyperinfection, ileus and small-bowel obstruction may prevent enteral absorption of anthelminthics such as ivermectin. At present there are no parenteral anthelminthics licensed for use in humans.

METHODS

Here, we describe two cases of severe S. stercoralis infection treated with an unlicensed veterinary preparation of subcutaneous ivermectin, and we discuss the published reports of the use of this treatment elsewhere.

RESULTS

Both patients were successfully treated with subcutaneous ivermectin, and both recovered completely.

CONCLUSIONS

Despite the limited published experience of parenteral ivermectin use, there is evidence that it may be a safe and effective treatment for severe strongyloidiasis. However, more data are needed to guide dosing schedules and monitoring for toxicity.

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.

Infections of the developing world

Access to critical care is rapidly growing in areas of the world where it was previously nonexistent and where infectious diseases often comprise the largest disease burden. Additionally, with crowding, mass migrations, and air travel, infectious diseases previously geographically confined are quickly spread across the planet, often in shorter time frames than disease incubation periods. Hence, critical care practitioners must be familiar with infectious diseases previously confined to the developing world. This article reviews selected tropical diseases that are seen in diverse locales and often require critical care services.

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.

Salvage treatment of disseminated strongyloidiasis in an immunocompromised patient: therapy success with subcutaneous ivermectin

Disseminated strongyloidiasis is a disease with high mortality rate, especially in immunocompromised individuals. Paralytic ileus and intestinal malabsorption are frequent symptoms caused by this severe disease. As there are no licensed parenteral anthelmintic drugs for human use, off-label formulations are often used in the treatment of this disease. In this case report, the use of subcutaneous ivermectin is described as a successful therapy for this life-threatening infection.

Serum ivermectin levels after enteral and subcutaneous administration for Strongyloides hyperinfection: a case report

An AIDS patient was diagnosed with Strongyloides stercoralis hyperinfection complicated by ileus. Serum ivermectin concentrations were very low after rectal administration, but increased after subcutaneous doses. Absorption of rectal ivermectin appears poor, and subcutaneous administration can increase serum levels quickly, which may improve treatment in critically ill patients.

Hyperinfection strongyloidiasis in a liver transplant recipient treated with parenteral ivermectin

Severe strongyloidiasis, including hyperinfection and dissemination, is a recognized complication of solid organ transplantation. However, the development of strongyloidiasis in a liver transplant recipient has not been previously described. We present a case of severe strongyloidiasis occurring in a patient 4 months after liver transplantation and 1 month after receiving treatment for acute rejection. We assess the management challenges in this patient who remained symptomatic despite oral treatment with ivermectin and albendazole and eventual successful treatment with parenteral ivermectin. We review the published experience with alternative methods of ivermectin administration. We also investigate the possible source of infection, as the patient was not from an endemic area.

Fatal relapse of disseminated strongyloidiasis in an HIV-positive patient, despite ivermectin treatment

There are no established guidelines for the treatment of disseminated strongyloidiasis in immunosuppressed patients, and many different treatment regimens have been used. Here, the case of a 48-year-old, HIV-positive, Congolese man, who was hospitalized for disseminated tuberculosis but developed life-threatening disseminated strongyloidiasis, is described. This patient died, with relapsing disseminated strongyloidiasis, 3 months after being treated with ivermectin. The reasons for this poor outcome and the various treatment options for strongyloidiasis in HIV-infected patients are discussed.

Ivermectin: uses and impact 20 years on

PURPOSE OF REVIEW

Ivermectin was first discovered and used in veterinary medicine over 20 years ago. This review highlights some of the recent published research from 2005 through June 2006 on the use of ivermectin in both helminth and arthropod infection.

RECENT FINDINGS

In recent years, several published studies have detailed the expanding role for ivermectin in multiple endo and ectoparasitic infections, including scabies, pediculosis, soil transmitted helminths, gnathostomiasis and myiasis. In addition, there is increasing experience with parenteral ivermectin for the treatment of disseminated strongyloidiasis. The success of ivermectin in reducing Onchocerca volvulus and Wuchereria bancrofti transmission through universal treatment in disease control programs continues to be well documented, but recent epidemiologic data describe suboptimal response to ivermectin by O. volvulus in a minority of individuals, the molecular markers for which are currently under investigation.

SUMMARY

Over 20 years of research and clinical use have advanced ivermectin from its beginnings as a veterinary anthelmintic to its significant role in several successful disease control programs. Nevertheless, further research is needed to understand the basis for suboptimal response and to better define optimal drug regimens for varying diseases.