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

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.

Physical and pharmacokinetic characterization of Soluvec™, a novel, solvent-free aqueous ivermectin formulation

Purpose: To describe application of the Quicksol™ solvent-free approach to solubilize ivermectin (IVM). Methods: Lyophilized IVM complexed with hydroxypropyl-β-cyclodextrin (HP-β-CD) was resolubilized in aqueous polysorbate-80, generating Soluvec™. Lyophilizate was examined by Fourier-transform infrared spectroscopy and differential scanning calorimetry; Soluvec, by dynamic light scattering. Pharmacokinetics was evaluated in dogs allocated to subcutaneous (SC) or intramuscular (IM) Soluvec or oral IVM. Results: IVM in Soluvec was tightly bound by HPβCD, forming nearly monodisperse 28 nm particles with solubility ∼2500-times that of free IVM. SC and IM Soluvec increased IVM exposure, peak IVM and extended duration of IVM exposure, versus oral dosing. Conclusion: The Quicksol method generated Soluvec, a concentrated aqueous parenteral IVM formulation with pharmacokinetic properties suitable for veterinary or human use.

Oral myiasis: Analysis of cases reported in the English literature from 1990 to 2020

Myiasis is an infection caused by the deposition of fly larvae in tissues, and its involvement in the human oral cavity is uncommon. Herein, we have performed a data analysis of published cases of oral myiasis. A search was performed in PubMed, Ovid, Web of Science, Scopus, and LILACS. Geographic distribution, demographic data, associated factors, clinical features, fly types, treatment, and presence of sequelae were analyzed. A total of 122 articles reported the cases of 157 infected individuals. The most affected countries were India (41%) and Brazil (29.5%). Male predominance (67.5%) and a mean of 41.9 years of age were observed. The gingiva (29%) was the most affected site, followed by palate (25%) and lip (21%). There were different forms and combinations of treatments: manual removal of larvae and surgical debridement, application of asphyxiating substances, antibiotic therapy, and use of ivermectin. The condition predominantly affects individuals with neurological and/or locomotor disabilities, of low socioeconomic status, with poor oral hygiene and chemical dependence and individuals with previous injuries or with the absence of lip sealing. The establishment of a standard treatment protocol, enabling comparison in future studies and providing uniformity in treatment strategies offered by health services is strongly recommended.

Intestinal parasites including Cryptosporidium, Cyclospora, Giardia, and Microsporidia, Entamoeba histolytica, Strongyloides, Schistosomiasis, and Echinococcus: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of intestinal parasites in the pre- and post-transplant period. Intestinal parasites are prevalent in the developing regions of the world. With increasing travel to and from endemic regions, changing immigration patterns, and the expansion of transplant medicine in developing countries, they are increasingly recognized as a source of morbidity and mortality in solid-organ transplant recipients. Parasitic infections may be acquired from the donor allograft, from reactivation, or from de novo acquisition post-transplantation. Gastrointestinal multiplex assays have been developed; some of the panels include testing for Cryptosporidium, Cyclospora, Entamoeba histolytica, and Giardia, and the performance is comparable to conventional methods. A polymerase chain reaction test, not yet widely available, has also been developed to detect Strongyloides in stool samples. New recommendations have been developed to minimize the risk of Strongyloides donor-derived events. Deceased donors with epidemiological risk factors should be screened for Strongyloides and recipients treated if positive as soon as the results are available. New therapeutic agents and studies addressing the optimal treatment regimen for solid-organ transplant recipients are unmet needs.

Case Report: Ivermectin and Albendazole Plasma Concentrations in a Patient with Disseminated Strongyloidiasis on Extracorporeal Membrane Oxygenation and Continuous Renal Replacement Therapy

Disseminated strongyloidiasis is often fatal, despite treatment with oral albendazole and parenteral ivermectin (IVM). Here, we report elevated plasma IVM and albendazole sulfoxide concentrations in the context of extracorporeal membrane oxygenation and continuous renal replacement therapy in a patient with disseminated strongyloidiasis treated with subcutaneous IVM and nasogastric albenzadole. Despite elevated drug plasma concentrations, live filariform larvae were detected in endotracheal aspirates after 2 weeks of treatment.

Successful use of subcutaneous ivermectin for the treatment of Strongyloides stercoralis hyperinfection in the setting of small bowel obstruction and paralytic ileus in the immunocompromised population

Severe Strongyloides stercoralis, such as hyperinfection syndrome, carries a high mortality risk. Even with appropriate treatment, patients may experience infectious complications and failure of therapy. Currently, there are no Food and Drug Administration–approved parenteral therapies available for treatment in patients who develop gastrointestinal complications from hyperinfection, including small bowel obstruction. A veterinary form of ivermectin is available as a subcutaneous injection, although current literature in humans is limited. We report on the successful treatment of two surviving immunocompromised patients with S. stercoralis hyperinfection syndrome after prompt recognition and initiation of veterinary subcutaneous ivermectin therapy.

Strongyloides stercoralis Hyperinfection in an HIV-Infected Patient Successfully Treated with Subcutaneous Ivermectin

A 39-year-old Ethiopian HIV-positive man with peripheral T-cell lymphoma developed Strongyloides stercoralis hyperinfection. The patient was initially treated with oral ivermectin for three weeks without response, most likely due to malabsorption because of concomitant paralytic ileus. Given the persistence of larvae in the body fluids, the worsening respiratory status and clinical malabsorption, veterinary parenteral formulation of ivermectin was administered. The very high plasma concentration of ivermectin achieved in the patient after parenteral administration led to a rapid improvement in his clinical condition and rapid disappearance of the parasite from biological samples, without any adverse reaction.

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.

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.

Failure of ivermectin per rectum to achieve clinically meaningful serum levels in two cases of Strongyloides hyperinfection

Two cases of Strongyloides hyperinfection are presented. Ivermectin was initially administered orally and per rectum pending the availability of subcutaneous (SC) preparations. In neither case did rectal suppositories of ivermectin achieve clinically meaningful serum values. Clinicians should use SC preparations of ivermectin as early as possible in Strongyloides hyperinfection and dissemination.

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.

Screening, prevention, and treatment for hyperinfection syndrome and disseminated infections caused by Strongyloides stercoralis

PURPOSE OF REVIEW

This review discusses the latest approaches to the diagnosis and treatment of patients with strongyloidiasis, with an emphasis on infection in the immunocompromised host and the risk for disseminated strongyloidiasis.

RECENT FINDINGS

The differences in acute, chronic, accelerated autoinfection, and disseminated disease in Strongyloides stercoralis infection are explored with particular emphasis on early diagnosis, treatment, and prevention. The goals of treatment are investigated for the different infection states. Predisposing risks for dissemination are delineated, and the roles played for newer diagnostics in the identification of at-risk individuals are detailed.

SUMMARY

The use of newer diagnostic tests and broader screening of immunocompromised patients from Strongyloides-endemic areas is of paramount importance, particularly if prevention of life-threatening dissemination is the goal.

Update on strongyloidiasis in the immunocompromised host

Immunocompromised persons are the most vulnerable population at risk for developing life-threatening clinical syndromes associated with strongyloidiasis, such as hyperinfection syndrome (HS) or dissemination. This review focuses on describing Strongyloides infection in the immunocompromised host, including immune response against this infection, analyzing the cases with HS published during the past 4 years in the United States, and describing the most sensitive diagnostic tools and the most effective treatment for each clinical syndrome. Strongyloidiasis is becoming an important parasitic disease in the United States, especially in the immunocompromised immigrant population. Because the transplant population is particularly at risk for developing HS, both recipients and donors should be screened for Strongyloides. Clinicians should also be aware that the development of HS can follow unexpectedly a few days after appropriate anthelminthic therapy. Highly sensitive screening tests are still not available in the major tertiary medical centers. Parenteral ivermectin has been used in some severe cases. Further therapy developments and improving diagnostic tools are warranted.

Non-oral treatment with ivermectin for disseminated strongyloidiasis

Critically ill patients with disseminated strongyloidiasis may not be candidates for oral treatment. We report four patients with disseminated strongyloidiasis, believed to be unable to absorb oral therapy, who were treated with ivermectin by rectal and/or subcutaneous administration. Obtaining subcutaneous ivermectin and dosing it appropriately is a challenge. These cases underscore the need for improved access to subcutaneous ivermectin and more pharmacological data to guide use of this treatment approach.

Duodenal obstruction - an unusual presentation of Strongyloides stercoralis enteritis: a case report

Background

Intestinal obstruction is a poorly recognized and probably underreported complication of strongyloidiasis. We present herein an unusual case, of complete duodenal obstruction caused by S. stercoralis.

Methods

A systematic review of the literature examining the clinical course, diagnostic methods, and outcome of this rare complication of strongyloidiasis was performed.

Results

A 42-year-old woman presented with a 5-month history of abdominal pain, vomit, and weight loss. An abdominal CT scan showed an obstruction of the third part of the duodenum. Segmental intestinal resection was carried out and histopathology examination revealed heavy Strongyloides stercoralis infestation. Duodenal obstruction is a rare complication of S. stercoralis infection, with only 8 cases described in the literature since 1970. Most of the patients are males, middle-aged, and the diagnosis was made by duodenal aspirate/biopsy, or analysis of surgical specimen.

Conclusions

Duodenal obstruction is an unusual, but potential fatal, complication of S. stercoralis infection. The large spectrum of clinical manifestation and lack of classic clinical syndrome make the final diagnosis of strongyloidiasis extremely difficult. A high index of suspicion, mainly in patients from endemic areas, is needed for correct and early diagnosis of this uncommon presentation of Strogyloides stercoralis enteritis.