Disseminated strongyloidiasis presenting as purpura

Prevalence of Strongyloides stercoralis infection and associated clinical symptoms among schoolchildren living in different altitudes of Amhara National Regional State, northwest Ethiopia

Background

Strongyloides stercoralis is a parasite that causes strongyloidiasis in humans. It is prevalent in the tropics and sub-tropics where poor sanitation is a common problem. The true prevalence of S. stercoralis in Ethiopia is underestimated due to the lack of a “Gold” standard diagnostic method. Moreover, its prevalence across altitudinal gradient in Amhara Region has not been studied.

Methods

A cross-sectional study was conducted among 844 schoolchildren in Amhara Region from April to December 2019. A stool sample was collected from each study participant and processed using formol ether concentration technique (FECT), spontaneous tube sedimentation technique (STST), Baermann concentration technique (BCT), agar plate culture (APC) and real-time polymerase chain reaction (RT-PCR). Data were entered using EpiData and analyzed by SPSS version 23 statistical software. Prevalence of S. stercoralis infection was determined using a single diagnostic technique and combination of techniques. Association of clinical variables with S. stercoralis infection was assessed by logistic regression and independent variables with p<0.05 were considered statistically significant.

Results

Prevalence of soil-transmitted helminths (STHs) and S. mansoni infections was 38.0% and 20.4%, respectively. Among STHs, the prevalence of hookworm infection was 32.8%. Prevalence of S. stercoralis infection was 39.0%, 28.8%, 10.9%, 10.3%, 4.0% and 2.0% by the respective, combinations of the five methods, RT-PCR, APC, BCT, STST and FECT. The highest prevalence rates, 48.2%, 45.0% and 41.1% of S. stercoralis were recorded in the age group of 12–14 years, males and rural dwellers, respectively. Prevalence rates of S. stercoralis infection in highland, semi-highland and lowland areas were 40.4%, 41.8% and 25.9%, respectively. Having abdominal pain (AOR = 2.48; 95% CI:1.65–3.72), cough (AOR = 1.63;95%CI:1.09–2.42), urticaria (AOR = 2.49;95%CI:1.50–4.01) and being malnourished (AOR = 1.44;95%:1.10–2.01) were significantly associated with strongyloidiasis.

Conclusion

Prevalence of S. stercoralis infection was high and varied across different altitudes in Amhara Region. Some clinical syndromes were found to be significantly associated with S. stercoralis infection. Therefore, proper diagnosis and preventive strategies against S. stercoralis infection are highly recommended to be devised and implemented in Amhara Region.

Prevalence of S. stercoralis is under-reported in many resource-poor countries including Ethiopia. We carried out a school-based cross-sectional study among 844 schoolchildren across highlands, semi-highlands and lowland areas of Amhara Region. We used an approach made of five diagnostic methods, namely, FECT, STST, BCT, APC, and RT-PCR. The total prevalence of S. stercoralis was 39.0%. The highest S. stercoralis prevalence (41.8%) was observed in the semi-highland areas of the region. Strongyloidiasis was significantly higher among 12–14 years age groups, males, and rural dweller children. Clinical symptoms such as presence of abdominal pain, cough, skin rash and malnourishment were significantly associated with strongyloidiasis. We recommend that preventive strategies against strongyloidiasis in Amhara Region should be implemented.

Phylogenetic Positioning of a Strongyloides stercoralis Isolate Recovered from a Korean Patient and Comparison with Other Asian Isolates

Strongyloidiasis is caused by Strongyloides stercoralis and is one of the most neglected tropical diseases in tropical and subtropical regions. Although several strongyloidiasis cases have been reported in Korea, genetic analysis of Korean isolates is still incomplete. In this study, a parasite was isolated from a 61-year-old man diagnosed with strongyloidiasis during the treatment of lymphoma on his retroperitoneal lymph node. Diffuse symmetric wall thickening from the ascending to descending colon and a nematode-infected intestine was observed following microscopic examination. Genomic DNA was isolated from a patient tissue block, and S. stercoralis was identified by PCR and sequencing (18S rDNA). In order to determine phylogenetic location of a Korean isolate (named KS1), we analyzed cox1 gene (500-bp) and compared it with that from 47 previous S. stercoralis isolates (28 human isolates and 19 canid isolates) from Asian countries. Our results showed that phylogenetic tree could clearly be divided into 5 different groups according to hosts and regions. KS1 was most closely related with the Chinese isolates in terms of genetic distance.

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.

Umbilical and periumbilical dermatoses

The umbilicus may be the site of congenital and acquired malformations and may harbor clinical clues to the diagnosis of potentially fatal inherited disorders, primary skin conditions, and a variety of infectious diseases. Both benign and malignant tumors may involve the umbilicus, and some are unique to this site. Finally, cutaneous signs localized to this anatomic location may be found in diverse systemic diseases.

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.

Strongyloidiasis--an insight into its global prevalence and management

BACKGROUND

Strongyloides stercoralis, an intestinal parasitic nematode, infects more than 100 million people worldwide. Strongyloides are unique in their ability to exist as a free-living and autoinfective cycle. Strongyloidiasis can occur without any symptoms or as a potentially fatal hyperinfection or disseminated infection. The most common risk factors for these complications are immunosuppression caused by corticosteroids and infection with human T-lymphotropic virus or human immunodeficiency virus. Even though the diagnosis of strongyloidiasis is improved by advanced instrumentation techniques in isolated and complicated cases of hyperinfection or dissemination, efficient guidelines for screening the population in epidemiological surveys are lacking.

METHODOLOGY AND RESULTS

In this review, we have discussed various conventional methods for the diagnosis and management of this disease, with an emphasis on recently developed molecular and serological methods that could be implemented to establish guidelines for precise diagnosis of infection in patients and screening in epidemiological surveys. A comprehensive analysis of various cases reported worldwide from different endemic and nonendemic foci of the disease for the last 40 years was evaluated in an effort to delineate the global prevalence of this disease. We also updated the current knowledge of the various clinical spectrum of this parasitic disease, with an emphasis on newer molecular diagnostic methods, treatment, and management of cases in immunosuppressed patients.

CONCLUSION

Strongyloidiasis is considered a neglected tropical disease and is probably an underdiagnosed parasitic disease due to its low parasitic load and uncertain clinical symptoms. Increased infectivity rates in many developed countries and nonendemic regions nearing those in the most prevalent endemic regions of this parasite and the increasing transmission potential to immigrants, travelers, and immunosuppressed populations are indications for initiating an integrated approach towards prompt diagnosis and control of this parasitic disease.

Gastric strongyloidiasis as multiple small gastric nodules

BACKGROUND

Strongyloidiasis, a common intestinal parasitic infection, is endemic in tropical and subtropical regions and occurs sporadically in temperate areas. It is endemic in Guilan province, Iran, and especially affects the rural population.

CASE REPORT

We report the case of a 43-year-old woman living in Anzali (in the north of Iran), with dyspepsia and epigastric pain for 2 years, unresponsive to H2 receptor antagonists and proton pump inhibitors. Upper gastrointestinal endoscopy was done and showed multiple small nodules at the stomach. The pathologist reported Strongyloides. Treatment with Ivermectin and antibiotic triple therapy was done. She responded well to treatment and 6 months later an upper gastrointestinal endoscopy revealed no significant lesions and all nodules had disappeared. Strongyloidiasis is usually not severe and frequently is nonspecific. For this reason, the infection is easily ignored by both the patients and physicians.

CONCLUSIONS

Although gastric involvement shows nonspecific symptoms, the possibility should be carefully considered by clinicians who practice in endemic areas.

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.

Strongyloides stercoralis in the Immunocompromised Population

Strongyloides stercoralis is an intestinal nematode of humans that infects tens of millions of people worldwide. S. stercoralis is unique among intestinal nematodes in its ability to complete its life cycle within the host through an asexual autoinfective cycle, allowing the infection to persist in the host indefinitely. Under some conditions associated with immunocompromise, this autoinfective cycle can become amplified into a potentially fatal hyperinfection syndrome, characterized by increased numbers of infective filariform larvae in stool and sputum and clinical manifestations of the increased parasite burden and migration, such as gastrointestinal bleeding and respiratory distress. S. stercoralis hyperinfection is often accompanied by sepsis or meningitis with enteric organisms. Glucocorticoid treatment and human T-lymphotropic virus type 1 infection are the two conditions most specifically associated with triggering hyperinfection, but cases have been reported in association with hematologic malignancy, malnutrition, and AIDS. Anthelmintic agents such as ivermectin have been used successfully in treating the hyperinfection syndrome as well as for primary and secondary prevention of hyperinfection in patients whose exposure history and underlying condition put them at increased risk.

Purpura in infants and children

Hemorrhage into the skin (purpura) may result from abnormalities in any of the three components of hemostasis: platelets, plasma coagulation factors, and blood vessels. The morphology, size, and distribution of the hemorrhagic lesions are helpful diagnostic features. The main causes of purpura in the newborn and the more common hemorrhagic disorders in children are reviewed.

Strongyloides stercoralis eosinophilic granulomatous enterocolitis

Six patients suffering from an unusual form of colitis produced by Strongyloides stercoralis hyperinfection are described. In contrast to the usual Strongyloides hyperinfection syndrome, in which small intestinal and pulmonary manifestations are seen in patients with some forms of immunodeficiency, the patients described here presented with only a characteristic transmural eosinophilic granulomatous inflammation affecting mostly the colonic wall and clinically mimicking ulcerative colitis or Crohn's disease. This Strongyloides eosinophilic granulomatous enterocolitis apparently results from a florid inflammatory response by eosinophils, histiocytes, and giant cells with formation of granulomas that destroy the larvae entering the colon. This morphologic picture differs from that of the well-described hyperinfection syndrome, in which the bulk of the larvae pass through the colonic wall to complete the life cycle, with only a few larvae destroyed in the colon. The probable pathophysiologic mechanism of this unusual manifestation of hyperinfection is discussed based on the anatomic and clinical observations of patients who presented at different stages in the evolution of their condition and whose length of follow-up varied.

Case report: purpura in disseminated strongyloidiasis

Purpuric lesions have been described previously in 10 patients with disseminated strongyloidiasis. We identified three additional patients in whom purpura developed as a manifestation of disseminated strongyloidiasis. Nine (69%) of the 13 patients were men, and the median age of patients was 61 years (range, 32-75 years). Six patients were from the southeastern United States. Six patients had underlying malignancy and four patients had chronic lung disease. All patients had received prior corticosteroids. The parasite was identified in 11 (92%) of 12 patients where stool or sputum examination was performed. Skin biopsies of purpuric lesions were obtained in 12 patients, in 10 (83%) of which larvae were found. Despite recommended treatment with thiabendazole in 12 of 13 patients, 11 (85%) of the patients died, and at least 6 died within 16 days of onset of purpura. Physicians, particularly those in the southeastern United States, should strongly consider the diagnosis of disseminated strongyloidiasis in patients receiving corticosteroids and in whom purpura and systemic toxicity develops.

Disseminated strongyloidiasis with cutaneous manifestations in an immunocompromised host

Recognition of the characteristic cutaneous eruption of disseminated strongyloidiasis can be crucial for early diagnosis and treatment of this potentially fatal infestation. We describe a corticosteroid-dependent elderly man who had a purpuric eruption. Filariform larvae of Strongyloides stercoralis were found in dermal granulomas and also in the sputum.