Strongyloides hyperinfection presenting with petechiae and purpura

Human strongyloidiasis: complexities and pathways forward

Strongyloidiasis is a World Health Organization neglected tropical disease usually caused by Strongyloides stercoralis, a parasitic worm with a complex life cycle. Globally, 300-600 million people are infected through contact with fecally contaminated soil. An autoinfective component of the life cycle can lead to chronic infection that may be asymptomatic or cause long-term symptoms, including malnourishment in children. Low larval output can limit the sensitivity of detection in stool, with serology being effective but less sensitive in immunocompromise. Host immunosuppression can trigger catastrophic, fatal hyperinfection/dissemination, where large numbers of larvae pierce the bowel wall and disseminate throughout the organs. Stable disease is effectively treated by single-dose ivermectin, with disease in immunocompromised patients treated with multiple doses. Strategies for management include raising awareness, clarifying zoonotic potential, the development and use of effective diagnostic tests for epidemiological studies and individual diagnosis, and the implementation of treatment programs with research into therapeutic alternatives and medication safety.

A comprehensive review of Strongyloides stercoralis infection after solid organ and hematopoietic stem cell transplantation

BACKGROUND

We reviewed the scientific literature to gain insight on the epidemiology and outcome of Strongyloides stercoralis infections after transplantation.

METHODS

CINAHL, PUBMED, and OVID/MEDLINE were reviewed from inception through March 31, 2022 using key words Strongyloides and transplantation.

RESULTS

Our review identified 108 episodes of Strongyloides infection among 91 solid organ transplant (SOT) and 15 hematopoietic cell transplant (HCT) recipients. Median time to infection was 10.8 (range, .14-417) and 8.8 (range, 0-208) weeks after SOT and HCT, respectively. Gastrointestinal symptoms were frequent (86/108 [79.6%]), while skin rash (22/108 [20.3%]) and fever (31/103 [30%]) were less common. Peripheral eosinophilia was observed in half of patients (41/77 [53.2%]). Bacteremia (31/59 [52.5%]) was frequently due to Gram-negative organisms (24/31 [77.4%]). Abnormal chest radiologic findings were reported in half (56/108 [51.9%]). The majority had hyperinfection syndrome (97/108 [89.8%]) while disseminated strongyloidiasis was less common (11/108 [10.2%]). Thirty-two cases were categorized as donor-derived infection (DDI), with donors (23/24 [95.8%]) who had traveled to or lived in endemic areas. Median time to DDI was 8 weeks (range .5-34.3 weeks) after transplantation. Treatment consisted of ivermectin (n = 26), a benzimidazole (n = 27), or both drugs (n = 28). There was high all-cause mortality (48/107, 44.9%) and a high Strongyloides-attributable mortality (32/49, 65.3%).

CONCLUSIONS

Strongyloidiasis should be strongly considered among recipients with epidemiologic risk factors for infection, even in the absence of eosinophilia or rash. A policy that provides guidance on pro-active screening is needed, to ensure preventive measures are provided to recipients at increased risk.

Modeling strongyloidiasis risk in the United States

OBJECTIVES

To provide a spatial risk assessment for the neglected disease strongyloidiasis in the United States by prioritizing areas with high probability of Strongyloides stercoralis presence and to offer recommendations for targeted screening and surveillance.

METHODS

The risk assessment was based on a species distribution model with parasite occurrence data and ecologically important environmental variables as input and local habitat suitability for the species as output. The model used a maximum entropy algorithm and occurrence records and environmental data from public sources. This ecological risk assessment was coupled to socioeconomic factors using multi-criteria analysis.

RESULTS

The model predicts suitable habitat for the parasite in ten states beyond the southeastern United States where it has been recorded including states in the south, east and northeast, and west coasts.

CONCLUSIONS

We recommend strongyloidiasis should be reportable in 16 states at high risk and uniform, near universal solid organ transplant screening should be implemented alongside approaches to heighten clinical suspicion.

Strongyloides stercoralis larvae in the urine of a patient with transitional cell carcinoma of the bladder: a case report

Disseminated infection with Strongyloides stercoralis refers to the massive migration of infective larvae from the gastrointestinal tract to other organs that are not involved in the normal life cycle of the parasite. We describe the case of a Nigerian male with transitional cell carcinoma of the bladder in whom larvae of S. stercoralis was identified in the urine. This report involves a 60-year old male Nigerian presenting to the Urology clinic of the Jos University teaching hospital, Nigeria with disseminated S. stercoralis. The index patient presented with a 5 month history of total haematuria, urinary frequency, urgency, nocturia, straining to pass urine, feeling of incomplete voiding and terminal dribbling. He also had episodes of suprapubic pain. Physical examination revealed a cachexic patient who had mild suprapubic tenderness. Urinary examination showed numerous red blood cells and rhabditiform larvae of S. stercoralis. Abdominal ultrasound revealed a heterogeneous mass in the urinary bladder measuring 4.0 × 3.3 cm. Abdominal computed tomography also showed an irregular mass measuring 4.2 × 3.8 cm with HU of 41 projecting into the bladder from the posterior wall towards the dome. Histology of the biopsy specimen revealed transitional cell carcinoma. The patient was treated with a single dose of oral ivermectin but died 1 week later. Physicians working in areas that are endemic for S. stercoralis should consider investigating immunocompromised patients for S. stercoralis infection given the poor prognosis of disseminated infection in this group of patients.

Mucocutaneous manifestations of helminth infections: Nematodes

In the 21st century, despite increased globalization through international travel for business, medical volunteerism, pleasure, and immigration/refugees into the United States, there is little published in the dermatology literature regarding the cutaneous manifestations of helminth infections. Approximately 17% of travelers seek medical care because of cutaneous disorders, many related to infectious etiologies. This review will focus on the cutaneous manifestations of helminth infections and is divided into 2 parts: part I focuses on nematode infections, and part II focuses on trematode and cestode infections. This review highlights the clinical manifestations, transmission, diagnosis, and treatment of helminth infections. Nematodes are roundworms that cause diseases with cutaneous manifestations, such as cutaneous larval migrans, onchocerciasis, filariasis, gnathostomiasis, loiasis, dracunculiasis, strongyloidiasis, ascariasis, streptocerciasis, dirofilariasis, and trichinosis. Tremadotes, also known as flukes, cause schistosomiasis, paragonimiasis, and fascioliasis. Cestodes (tapeworms) are flat, hermaphroditic parasites that cause diseases such as sparganosis, cysticercosis, and echinococcus.

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.

Skin infections and infestations in geriatric patients

Geriatric patients develop infections, but many have a different appearance from what usually is expected. The difference depends on the age and immune status of the patient and the virulence of the organism. Differences may make recognition more difficult. Therapy may require different doses. Examples of the more common infections are detailed in this article.

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.