Severe strongyloidiasis in corticosteroid-treated patients: case series and literature review

Strongyloides coinfection in COVID-19 patients treated with corticosteroids: A systematic review

The COVID-19 pandemic linked to the virus SARS-CoV-2, which began in China, affected ∼765 million people as of 30 April 2023. The widespread use of corticosteroids for the symptomatic treatment of COVID-19 could lead to the reactivation of infections of opportunistic pathogens, including Strongyloides. We sought to determine the clinical symptoms and demographic characteristics of SARS-CoV-2-Strongyloides co-infection, particularly in patients with severe disease and being treated with immunosuppressive drugs. To do this, we undertook a systematic review of the literature, and searched public accessible scientific databases-the Web of Science, Scopus, PubMed/Medline and Embase -for eligible studies (1 December 2019 to 30 August 2022). The review protocol is registered in PROSPERO (CRD42022377062). Descriptive statistical analyses were used to present the clinical and laboratory parameters of the co-infection; for this, we calculated prevalence using the following formula: positive cases/total number of cases × 100. Of a total of 593 studies identified, 17 studies reporting 26 co-infected patients met the criteria for inclusion in this review. The median age of these patients was 55.14 years. Most of cases (53.8%) were treated with dexamethasone, followed by methylprednisolone (26.9%). Eighteen of 26 patients were immigrants living in European countries or the USA; most of these immigrants originated from Latin America (58%) and South-East Asia (11%). The commonest symptoms of co-infection were abdominal pain (50%), fever (46.1%), dyspnoea (30.7%) and cough (30.7%), and frequently reported laboratory findings were high absolute eosinophil count (38.4%), high white blood cell count (30.7%), high C-reactive protein (23.0%) and high neutrophil count (19.2%). Two of the 26 patients (7.7%) had fatal outcomes. Most of the SARS-CoV-2-Strongyloides coinfected cases were immigrants living in developed countries, emphasising the need for clinicians in these countries to be aware of clinical and laboratory parameters associated with such co-infections, as well as the key importance of rapid and accurate diagnostic tests for timely and effective diagnosis and patient management.

Disseminated Strongyloides stercoralis infection in the setting of Escherichia coli meningitis and bacteraemia in a patient living with HIV on high-dose corticosteroid therapy

Strongyloidiasis, a helminth infection caused by Strongyloides stercoralis, can be complicated by hyperinfection, especially in the setting of immunosuppression; however, many patients go undiagnosed. One clue to diagnosis is unexplained gram-negative bacteraemia or meningitis in patients who are immunosuppressed. Serology can be helpful but may be negative in these patients who are immunocompromised.We present the case of a white cisgender man from Central America in his 40s, living with HIV, with a CD4 count of 77 cells/µL. He was diagnosed with Strongyloides hyperinfection after an increase in his steroid dose. He also had Escherichia coli meningitis and bacteraemia. Strongyloidiasis was diagnosed by stool microscopy despite a negative serology test.This case highlights the challenges in diagnosing strongyloidiasis in the setting of immunosuppression. A high index of clinical suspicion is warranted for patients living with HIV on high-dose corticosteroids. Up to three stool microscopy studies for Strongyloides should be sent in addition to serology.

Intestinal helminthic infections: a narrative review to guide the hepatogastroenterologist

Intestinal helminthic infections are not uncommon in Western Europe, mainly due to modern travel, emigration and globalization. Moreover, some helminthic infections are endemic in Western Europe and are part of the everyday clinical practice. The hepatogastroenterologist should therefore recognize and manage these patients or at least refer them to appropriate reference centers. Signs and symptoms are often unspecific or even absent. Discerning the disease at an early stage avoids expensive diagnostic testing, life-threatening complications and in some cases even further spread of the disease. This review article aims to guide the hepatogastroenterologist when suspecting a helminthic infection by addressing the most prevalent symptoms, summarizing the most probable associated helminthic entities, highlighting practical steps in diagnosis and available treatments.

Coinfection with Strongyloides and SARS-CoV-2: A Systematic Review

BACKGROUND

Treatments for COVID-19, including steroids, might exacerbate Strongyloides disease in patients with coinfection. We aimed to systematically review clinical and laboratory features of SARS-CoV-2 and Strongyloides coinfection, investigate possible interventions, assess outcomes, and identify research gaps requiring further attention.

METHODS

We searched two electronic databases, LitCOVID and WHO, up to August 2022, including SARS-CoV-2 and Strongyloides coinfection studies. We adapted the World Health Organization-Uppsala Monitoring Centre (WHO-UMC) system for standardized case causality assessment to evaluate if using corticosteroids or other immunosuppressive drugs in COVID-19 patients determined acute manifestations of strongyloidiasis.

RESULTS

We included 16 studies reporting 25 cases of Strongyloides and SARS-CoV-2 coinfection: 4 with hyperinfection syndrome; 2 with disseminated strongyloidiasis; 3 with cutaneous reactivation of strongyloidiasis; 3 with isolated digestive symptoms; and 2 with solely eosinophilia, without clinical manifestations. Eleven patients were asymptomatic regarding strongyloidiasis. Eosinopenia or normal eosinophil count was reported in 58.3% of patients with Strongyloides reactivation. Steroids were given to 18/21 (85.7%) cases. A total of 4 patients (19.1%) received tocilizumab and/or Anakirna in addition to steroids. Moreover, 2 patients (9.5%) did not receive any COVID-19 treatment. The causal relationship between Strongyloides reactivation and COVID-19 treatments was considered certain (4% of cases), probable (20% of patients), and possible (20% of patients). For 8% of cases, it was considered unlikely that COVID-19 treatment was associated with strongyloidiasis reactivations; the relationship between the Strongyloides infection and administration of COVID-19 treatment was unassessable/unclassifiable in 48% of cases. Of 13 assessable cases, 11 (84.6%) were considered to be causally associated with Strongyloides, ranging from certain to possible.

CONCLUSIONS

Further research is needed to assess the frequency and risk of Strongyloides reactivation in SARS-CoV-2 infection. Our limited data using causality assessment supports recommendations that clinicians should screen and treat for Strongyloides infection in patients with coinfection who receive immunosuppressive COVID-19 therapies. In addition, the male gender and older age (over 50 years) may be predisposing factors for Strongyloides reactivation. Standardized guidelines should be developed for reporting future research.

A case report: Severe disseminated infection caused by Strongyloides stercoralis in an immunocompromised patient by metagenomic next-generation sequencing

Background

Strongyloides stercoralis (S. stercoralis) is a nematode that is widely distributed in the tropical and subtropical regions of the world and which can cause severe disseminated infection in immunocompromised individuals. However, strongyloidiasis, the disease caused by S. stercoralis, is difficult to diagnose because of its non-specific clinical presentation and the inadequate performance of conventional diagnostic methods.

Case description

We report the case of a 75-year-old male patient with severe disseminated infection caused by S. stercoralis. The patient had a medical history of seasonal bronchitis and, as a consequence, had taken prednisone for many years. Initial clinical tests failed to detect any pathogens, but metagenomic next-generation sequencing (mNGS) resulted in the identification of S. stercoralis in the patient's bronchoalveolar lavage fluid (BALF) and blood. Subsequently, routine testing repeatedly detected nematode larvae in the patient's stool and sputum. Through a combination of mNGS results and clinical symptoms, the patient was finally diagnosed with severe disseminated infection caused by S. stercoralis.

Conclusion

The clinical manifestations of disease caused by infection with S. stercoralis are not specific; therefore, early and accurate diagnosis is very important. mNGS can detect S. stercoralis even when it is present at only a low level. This case report supports the notion that mNGS is a valuable tool in the diagnosis of severe disseminated infections caused by S. stercoralis in immunocompromised patients.

Strongyloidiasis infection in a borderline lepromatous leprosy patient with adrenocorticoid insufficiency undergoing corticosteroid treatment: a case report

BACKGROUND

Strongyloidiasis is a soil-transmitted helminthiasis mainly caused by Strongyloides stercoralis. It is endemic to the tropics and subtropics. Sri Lanka has a 0-1.6% prevalence rate. S. stercoralis infection was identified in a 33-year-old Sri Lankan male patient treated with corticosteroids for borderline lepromatous leprosy with adrenocortical dysfunction.

CASE PRESENTATION

In March 2020, a 33-year-old Sri Lankan (Sinhalese) male patient presented with watery diarrhea, lower abdominal pain, and post-prandial abdominal fullness. Previously, he was diagnosed with borderline lepromatous leprosy and was treated with rifampicin, clofazimine, and prednisolone 60 mg daily since July 2019. After developing gastrointestinal symptoms, he had defaulted leprosy treatment including the prednisolone for 3 months. Duodenal biopsy revealed numerous intraepithelial nematodes within the lumina of glands in the duodenum whose appearance favored Strongyloides. Fecal wet smear revealed numerous Strongyloidis stercoralis L1 rhabditiform larvae. Larval tracks were seen in the agar plate culture. L3 filariform larvae of Strongyloidis stercoralis were seen in the Harada-Mori culture. In addition, the short synacthen test revealed adrenocortical insufficiency, and oral hydrocortisone and fludrocortisone were started with albendazole treatment against strongyloidiasis. Fecal wet smear and culture repeated after treatment with albendazole were negative for Strongyloidis stercoralis. The patient was discharged in July 2020 on oral hydrocortisone. One month later his condition was reviewed and the repeated fecal wet smear and agar plate culture was normal. He is being followed up every 3 months.

CONCLUSION

This is the first case of strongyloidiasis diagnosed in a patient with borderline lepromatous leprosy from Sri Lanka. The patient manifested symptoms of strongyloidiasis while on high-dose steroid therapy for his lepromatous reaction. Subsequently, the patient not only discontinued his steroid therapy, but also developed adrenocortical insufficiency as a complication of leprosy. Therefore, although diagnosis of strongyloidiasis was delayed, his subsequent low steroid levels probably protected him from disseminated disease. This is an interesting case where symptomatic strongyloidiasis was diagnosed in a patient who was initially treated with high-dose steroids but subsequently developed adrenocortical insufficiency. We emphasize the need to screen all patients prior to the commencement of immunosuppressive therapy.

Strongyloides stercoralis: A Neglected but Fatal Parasite

Strongyloidiasis is a disease caused by Strongyloides stercoralis and remains a neglected tropical infection despite significant public health concerns. Challenges in the management of strongyloidiasis arise from wide ranging clinical presentations, lack of practical high sensitivity diagnostic tests, and a fatal outcome in immunocompromised hosts. Migration, globalization, and increased administration of immunomodulators, particularly during the COVID-19 era, have amplified the global impact of strongyloidiasis. Here, we comprehensively review the diagnostic tests, clinical manifestations, and treatment of strongyloidiasis. The review additionally focuses on complicated strongyloidiasis in immunocompromised patients and critical screening strategies. Diagnosis of strongyloidiasis is challenging because of non-specific presentations and low parasite load. In contrast, treatment is simple: administration of single dosage ivermectin or moxidectin, a recent anthelmintic drug. Undiagnosed infections result in hyperinfection syndrome and disseminated disease when patients become immunocompromised. Thus, disease manifestation awareness among clinicians is crucial. Furthermore, active surveillance and advanced diagnostic tests are essential for fundamental management.

Human T-Cell Lymphotropic Virus Type 1 and Strongyloides stercoralis Co-infection: A Systematic Review and Meta-Analysis

Background

The distribution of human T cell lymphotropic virus type 1 (HTLV-1) overlaps with that of Strongyloides stercoralis. Strongyloides stercoralis infection has been reported to be impacted by co-infection with HTLV-1. Disseminated strongyloidiasis and hyperinfection syndrome, which are commonly fatal, are observed in HTLV-1 co-infected patients. Reduced efficacy of anti-strongyloidiasis treatment in HTLV-1 carriers has been reported. The aim of this meta-analysis and systematic review is to better understand the association between HTLV-1 and S. stercoralis infection.

Methods

PubMed, Embase, MEDLINE, Global Health, Healthcare Management Information Consortium databases were searched. Studies regarding the prevalence of S. stercoralis, those evaluating the frequency of mild or severe strongyloidiasis, and treatment response in people living with and without HTLV-1 infection were included. Data were extracted and odds ratios were calculated. Random-effect meta-analysis was used to assess the pooled OR and 95% confidence intervals.

Results

Fourteen studies were included after full-text reviewing of which seven described the prevalence of S. stercoralis and HTLV-1. The odds of S. stercoralis infection were higher in HTLV-1 carriers when compared with HTLV-1 seronegative subjects (OR 3.2 95%CI 1.7–6.2). A strong association was found between severe strongyloidiasis and HTLV-1 infection (OR 59.9, 95%CI 18.1–198). Co-infection with HTLV-1 was associated with a higher rate of strongyloidiasis treatment failure (OR 5.05, 95%CI 2.5–10.1).

Conclusion

Strongyloides stercoralis infection is more prevalent in people living with HTLV-1. Co-infected patients are more likely to develop severe presentation and to fail treatment. Screening for HTLV-1 and Strongyloides sp. should be routine when either is diagnosed.

Strongyloides hyperinfection syndrome in dermatology in-patients: A case series

Strongyloides stercoralis is a common intestinal pathogen, which often causes disseminated infection in patients on long term immunosuppressive therapy. The features of this syndrome range from subtle abdominal discomfort to fatal infection. Many of the immunologically mediated dermatological conditions need prolonged treatment with Immunosuppressants. Hence there is increased risk of this infestation. In dermatology in-patients, strongyloides stercoralis hyperinfection can be confused with a number of conditions, such as steroid-induced gastritis, corticosteroid withdrawal, electrolyte imbalance, lepra reactions, and erythrodermic enteropathy. In a country like India, where barefoot walking is still prevalent, this condition has been reported less often. We report a series of five patients who were diagnosed with strongyloides hyperinfection syndrome during their admission in the dermatology department during the last year. This case series aims at creating awareness among the dermatologists, so that, this, potentially fatal but easily preventable and treatable condition, can be managed properly.

Atypical pulmonary presentation of Strongyloides stercoralis hyperinfection in a patient with philadelphia chromosome-positive acute lymphoblastic leukemia: Case report

Strongyloides stercoralis is a soil-transmitted helminth endemic to tropical and subtropical regions and can be acquired due to parasite penetration through the skin. It can remain dormant in the gastrointestinal system for decades after the primary infection. In immunocompromised patients, this parasite can cause autoinfection with progression to hyperinfection syndrome. Here we report a unique case of pulmonary strongyloidiasis in a 32-year-old female, originally from Guatemala, with a significant clinical history of Philadelphia chromosome-positive B-cell acute lymphoblastic leukemia diagnosed in 2019. The patient is status post chemotherapy with tyrosine kinase inhibitor plus hyper-CVAD regimen (Cyclophosphamide, Vincristine sulfate, Doxorubicin hydrochloride (Adriamycin), and Dexamethasone). History of drug-induced hyperglycemia and obesity was also noted. Her current chief complaint included dyspnea, tachycardia, and chest pain. Chest computerized tomography (CT) scan showed diffuse interstitial pulmonary edema with septal thickening, scattered ground-glass opacities, and small pericardial effusion. Due to normal ejection fraction, the differential diagnosis included non-cardiogenic pulmonary edema, pneumonitis secondary to chemotoxicity, and infection. She rapidly progressed to acute hypoxic respiratory failure, and a bronchoalveolar lavage study revealed numerous larvae consistent with Strongyloides hyperinfection. Further workup revealed eosinophilia with negative Strongyloides IgG antibody. Given the rarity of this infection in the United States and the patient's place of birth, acquired latent Strongyloides infection is favored as the initial source of infection. The reactivation of the infection process was most likely secondary to her chemotherapy treatment. Strongyloides hyperinfection diagnosis can be challenging to establish and entails a high level of suspicion. Cytology evaluation is an essential factor for diagnosis.

COVID-19-associated opportunistic infections: a snapshot on the current reports

Treatment of the novel Coronavirus Disease 2019 (COVID-19) remains a complicated challenge, especially among patients with severe disease. In recent studies, immunosuppressive therapy has shown promising results for control of the cytokine storm syndrome (CSS) in severe cases of COVID-19. However, it is well documented that immunosuppressive agents (e.g., corticosteroids and cytokine blockers) increase the risk of opportunistic infections. On the other hand, several opportunistic infections were reported in COVID-19 patients, including Aspergillus spp., Candida spp., Cryptococcus neoformans, Pneumocystis jiroveci (carinii), mucormycosis, Cytomegalovirus (CMV), Herpes simplex virus (HSV), Strongyloides stercoralis, Mycobacterium tuberculosis, and Toxoplasma gondii. This review is a snapshot about the main opportunistic infections that reported among COVID-19 patients. As such, we summarized information about the main immunosuppressive agents that were used in recent clinical trials for COVID-19 patients and the risk of opportunistic infections following these treatments. We also discussed about the main challenges regarding diagnosis and treatment of COVID-19-associated opportunistic infections (CAOIs).

Management of ibrutinib treatment in patients with B-cell malignancies: clinical practice in Portugal and multidisciplinary recommendations

OBJECTIVES

Ibrutinib, a potent inhibitor of the Bruton tyrosine kinase, has revolutionized the treatment of many B-cell malignancies. Ibrutinib has an established favorable toxicity profile with up to 8 years of experience in clinical trials; however, despite ibrutinib's favorable toxicity profile, dose reductions and treatment discontinuations are becoming more evident in clinical practice, particularly in the setting of specific clinical contexts and patient characteristics. This manuscript is set to provide practical recommendations on the management of patients treated with this agent in daily practice.

METHODS

A group of multidisciplinary experts from Portugal met to discuss and highlight practical recommendations, supported on both literature and clinical insights, for the management of the treatment with ibrutinib.

RESULTS/DISCUSSION

Handling of both toxicities and drug-drug interactions during ibrutinib treatment poses several challenges to healthcare providers and can benefit from a multidisciplinary approach. The involvement of specialties, such as cardiology, infectiology and pharmacology, can bring an added value to patient care, not only in anticipating/managing safety issues and dose adjustments but also in enhancing adherence to treatment, ultimately improving the risk/benefit balance.

CONCLUSION

By involving a multidisciplinary group of experts, this work provides a set of key recommendations to optimize care and outcomes for ibrutinib-treated patients. Despite not being a fully comprehensive review on the topic, it is intended as a framework to hematologists and other healthcare professionals who manage these patients in their daily clinical practice.

Strongyloides stercoralis Hyper infection Syndrome

Strongyloides stercoralis is a helminth, widely distributed in tropical and subtropical countries. Its infestation in humans usually does not produce symptoms. However, in some patients, severe and life-threatening forms of this infection can occur, especially in immunocompromised individuals. Severe parasitic infection is triggered by any imbalance in the host’s immunity favouring the auto-infective cycle. This results in an increase in the intraluminal parasitic burden. In addition, tissue infestation is also very common. Clinical presentation is variable, and it is very difficult to diagnose clinically. Diagnosis requires a high index of suspicion. In some cases, the diagnosis is established only on histopathological examination of the excised tissue by the pathologist. Here, the authors report a case of an elderly male diabetic patient, who presented to the emergency department with the features of acute abdomen. On exploratory laparotomy, he was found to have the features suggestive of gangrene of small bowel. Resection of the gangrenous bowel was done, and end-to-end anastomosis was done as the rest of the bowel appeared to be normal. However, the patient died of multi-organ failure and septicaemia on the second postoperative day. The resected intestine showed tissue infestation of Strongyloides stercoralis on histopathological examination. In this review article, the authors summarize a case of hyper infection syndrome of strongyloidiasis and discuss the various aspects of Strongyloides stercoralis infection with emphasis on life cycle of the parasite and different clinical features of the disease.

Post-Renal Transplant Miliary Mottling: Not Always Tuberculosis

A 28-year-old male, 3 years post renal transplant with stable graft function, presented with vomiting for 2 days. He had graft dysfunction and graft biopsy done revealed acute cell - mediated rejection BANFF-IA. After receiving glucocorticoids for rejection, he developed severe enterocolitis and impending respiratory failure. Chest X-ray and computed tomography of the chest revealed miliary mottling. Evaluation showed presence of filariform larvae of Strongyloides stercoralis in the stool and sputum. A diagnosis of Strongyloides Hyperinfection Syndrome (SHS) was made. After a prolonged course of treatment with noninvasive ventilation, broad-spectrum antimicrobials, parenteral ivermectin and oral albendazole therapy, he eventually recovered. This case report is to highlight that Strongyloides Hyperinfection Syndrome should also be considered in the differential in any immunocompromised patient presenting with miliary mottling in imaging.

Clinical Characteristics of Disseminated Strongyloidiasis, Japan, 1975-2017

Clinical characteristics of disseminated strongyloidiasis, the severest form of strongyloidiasis, are not well described. We conducted a retrospective, consecutive chart review of patients with disseminated strongyloidiasis admitted to Okinawa Chubu Hospital in Okinawa, Japan, during January 1975-December 2017. The 70 patients were classified into 3 clinical phenotypes: dissemination (32 patients [45.7%]), occult dissemination with meningitis caused by enteric organisms (12 patients [17.1%]), and occult dissemination with culture-negative suppurative meningitis (26 patients [37.1%]). Associated mortality rates were 56.3%, 16.7%, and 11.5%, respectively, and sepsis occurred in 40.6%, 58.3%, and 11.5% of cases, respectively. Common symptoms included fever (52.9% of patients), headache (32.9%), and altered mental status (24.3%). Patients were treated with thiabendazole (before 2003) or ivermectin (after 2003). Our findings show that disseminated strongyloidiasis has clinical phenotypes in terms of severity and that identification of occult dissemination, a mild form with prominent neurologic manifestations, is lifesaving.

Severe Strongyloides stercoralis infection in kidney transplant recipients: A multicenter case-control study

BACKGROUND

Severe Strongyloides stercoralis infection in kidney transplant recipients is associated with considerable morbidity and mortality, although little is known about the risk factors for such infection.

METHODOLOGY/PRINCIPAL FINDINGS

This was a retrospective, multicenter, case-control study in which we assessed the risk factors for and clinical outcomes of severe S. stercoralis infections in kidney transplant recipients in Brazil. We included 138 kidney transplant recipients: 46 cases and 92 controls. Among the cases, the median number of days from transplantation to diagnosis was 117 (interquartile range [IQR], 73.5-965) and the most common clinical findings were gastrointestinal symptoms (in 78.3%) and respiratory symptoms (in 39.1%), whereas fever and eosinophilia were seen in only 32.6% and 43.5%, respectively. The 30-day all-cause mortality among the cases was 28.3% overall and was significantly higher among the cases of infection occurring within the first three months after transplantation (47% vs. 17.2%, P = 0.04). The independent risk factors were receiving a transplant from a deceased donor (odds ratio [OR] = 6.16, 95% confidence interval [CI] = 2.05-18.5), a history of bacterial infection (OR = 3.04, 95% CI = 1.2-7.5), and a cumulative corticosteroid dose (OR = 1.005, 95% CI = 1.001-1.009). The independent predictors of mortality were respiratory failure (OR = 98.33, 95% CI = 4.46-2169.77) and concomitant bacteremia (OR = 413.00, 95% CI = 4.83-35316.61).

CONCLUSIONS/SIGNIFICANCE

Severe S. stercoralis infections are associated with considerable morbidity and mortality after kidney transplantation. In endemic areas, such infection may occur late after transplantation, although it seems to be more severe when it occurs earlier after transplantation. Specific risk factors and clinical manifestations can identify patients at risk, who should receive prophylaxis or early treatment.

Infectious Lung Disease

Infectious diseases are one of the main causes of morbidity and mortality worldwide. With new pathogens continuously emerging, known infectious diseases reemerging, increasing microbial resistance to antimicrobial agents, global environmental change, ease of world travel, and an increasing immunosuppressed population, recognition of infectious diseases plays an ever-important role in surgical pathology. This becomes particularly significant in cases where infectious disease is not suspected clinically and the initial diagnostic workup fails to include samples for culture. As such, it is not uncommon that a lung biopsy becomes the only material available in the diagnostic process of an infectious disease. Once the infectious nature of the pathological process is established, careful search for the causative agent is advised. This can often be achieved by examination of the hematoxylin and eosin-stained sections alone as many organisms or their cytopathic effects are visible on routine staining. However, ancillary studies such as histochemical stains, immunohistochemistry, in situ hybridization, or molecular techniques may be needed to identify the organism in tissue sections or for further characterization, such as speciation.

Strongyloidiasis in northern Vietnam: epidemiology, clinical characteristics and molecular diagnosis of the causal agent

Background

Strongyloidiasis is a health problem in Vietnam, but appropriate information is still limited. The aim of this study was to determine the prevalence, geographical distribution, epidemiological aspects, symptoms and other health indicators of Strongyloides stercoralis infections in patients from 27 provinces of northern Vietnam attending the Hanoi Medical University Hospital during 2016 and 2017.

Methods

Blood samples of 2000 patients were analyzed for S. stercoralis infection with an IgG ELISA test. Seroprevalence was analyzed by gender, age group, locality of origin (rural or urban areas) and symptoms. Stools from the seropositive patients were examined for the detection of worms which were subsequently used for species identification by morphology and rDNA ITS1 sequencing.

Results

A seroprevalence of 20% was detected, showing an increasing prevalence from young to older age groups but without significant gender difference. Seroprevalence was higher in rural areas than in urban areas, both in general and individually in all provinces without exception, and lower in the mountainous areas than in the large valley lowlands. The follow-up of the 400 patients showed eosinophilia in 100% of cases, diarrhoea in 64.5%, digestion difficulties in 58.0%, stomachache in 45.5%, stomach and duodenal ulcers in 44.5%, itching in 28.0% and fever in 9.5%. The prevalence of symptoms and signs were also higher in older age groups than in younger age groups. Worms were detected in stools of 10.5% of the patients. Sequencing of a 501-bp nuclear ribosomal DNA ITS1 fragment allowed for the verification of infection by Strongyloides stercoralis.

Conclusions

To our knowledge, this study is the largest survey of human strongyloidiasis in Vietnam so far and the first molecular identification of this nematode species in this country. Long-term chronicity may probably be usual in infected subjects, mainly in the older age groups.

Strongyloidiasis hyperinfection after renal transplant presenting as diffuse alveolar hemorrhage with respiratory failure

Strongyloides stercoralis is a helminthic enteric parasite estimated to infect at least 30 to 100 million people globally. It is transmitted via contaminated soil with a unique ability to complete its entire life cycle in the human host. It is common in humid, tropical, and subtropical regions of the world and is endemic in the Southeastern United States. Strongyloidiasis hyperinfection has been described in a variety of conditions that impair host immunity, including immunosuppression after transplantation. The syndrome has a high mortality rate but may initially present with nonspecific symptoms. A high degree of clinical suspicion coupled with early detection and aggressive therapeutic measures is paramount to a successful outcome.

Is Strongyloides seropositivity associated with diabetes mellitus? A retrospective case-control study in an East London NHS Trust

BACKGROUND

The association between diabetes and Strongyloides stercoralis remains controversial. We conducted a case-control study examining the association between diabetes and Strongyloides seropositivity in a large UK centre.

METHODS

Between January 2013 and October 2016, cases and controls were identified by positive and negative Strongyloides serology, respectively. Demographic, clinical and microbiological data were retrospectively collected. Multivariate logistic regression analysis was performed.

RESULTS

Over the study period, 532 samples were serologically tested for Strongyloides. After exclusion of duplicates and cases with missing data, 100 (22.3%; 95% CI 18.5-26.4%) out of 449 tested positive. Of seropositive cases, the mean age was 57 years (SD 16), 71 (71%) were male, 94 (94%) were migrants and 92 (92%) had eosinophilia.Univariate logistic regression analysis demonstrated a significant association between Strongyloides seropositivity and age (OR 1.04, 95% CI 1.02-1.05), male sex (OR 2.22, 95% CI 1.37-3.59), migration (OR 5.36, 95% CI 2.27-12.67), eosinophilia (OR 4.36, 95% CI 2.04-9.33) and diabetes (OR 3.52, 95% CI 2.19-5.66). In multivariate analysis, there remained a significant association between diabetes and Strongyloides seropositivity (OR 1.81, 95% CI 1.04-3.16).

CONCLUSIONS

We demonstrated a high rate of Strongyloides seropositivity in our East London cohort and a significant association with diabetes.

The Worm that Clogs the Lungs: Strongyloides Hyper-Infection Leading to Fatal Acute Respiratory Distress Syndrome (ARDS)

BACKGROUND Strongyloides stercoralis is an intestinal helminth. Parasitism is caused by penetration of the larvae through the skin. It is endemic in tropical and subtropical regions of the world and in the United States occurs in the southeastern region. It has a tendency to remain dormant or progress to a state of hyper-infection during immunosuppression. CASE REPORT We present the case of a 70-year-old Nigerian who developed fatal ARDS secondary to Strongyloides infection after been treated with steroids for treatment of autoimmune necrotizing myopathy. Despite adequate management with mechanical ventilation and appropriate antifungal therapy, the patient died on day 19 of hospitalization. CONCLUSIONS S. stercoralis is known to affect every organ in the body. ARDS is often an overlooked complication of Strongyloides hyper-infection, which is often deadly. Immediate diagnosis and treatment are important for patient survival.

Severe strongyloidiasis and systemic vasculitis: comorbidity, association or both? Case-based review

A possible association between strongyloidiasis and systemic vasculitis is rarely reported in the literature. We report the case of a patient with severe strongyloidiasis and an angiographic finding consistent with polyarteritis nodosa. Diagnosis of strongyloidiasis was made by finding of larvae and adult parasites in samples of the upper gastrointestinal tract mucosa and stool. The patient was treated with albendazole, ivermectin and corticosteroid withdrawal. This therapy led to the resolution of symptoms, with repeated stool samples negative for S. stercoralis. However, the clinical course was complicated with pulmonary tuberculosis. Despite tuberculostatic therapy and supportive measures, a lethal outcome occurred. The report is followed by a focused review of the available literature on the association of strongyloidiasis and systemic vasculitis.

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.

Argument for Inclusion of Strongyloidiasis in the Australian National Notifiable Disease List

Strongyloidiasis is an infection caused by the helminth, Strongyloides stercoralis. Up to 370 million people are infected with the parasite globally, and it has remained endemic in the Indigenous Australian population for many decades. Strongyloidiasis has been also reported in other Australian populations. Ignorance of this disease has caused unnecessary costs to the government health system, and been detrimental to the Australian people's health. This manuscript addresses the 12 criteria required for a disease to be included in the Australian National Notifiable Disease List (NNDL) under the National Health Security Act 2007 (Commonwealth). There are six main arguments that provide compelling justification for strongyloidiasis to be made nationally notifiable and added to the Australian NNDL. These are: The disease is important to Indigenous health, and closing the health inequity gap between Indigenous and non-Indigenous Australians is a priority; a public health response is required to detect cases of strongyloidiasis and to establish the true incidence and prevalence of the disease; there is no alternative national surveillance system to gather data on the disease; there are preventive measures with high efficacy and low side effects; data collection is feasible as cases are definable by microscopy, PCR, or serological diagnostics; and achievement of the Sustainable Development Goal (SDG) # 6 on clean water and sanitation.

Chronic strongyloidiasis with recurrent asthma exacerbations and steroid-associated 'hives'

A 74-year-old man experienced worsening asthma for several years. Oral steroids were required on multiple occasions for asthma treatment. During his steroid courses, he developed a hive-like rash, which would resolve after completion of each steroid course. He was from Romania, and had lived in the USA for many years. Laboratory testing had shown eosinophilia. He was eventually diagnosed with strongyloidiasis by serology. Treatment with ivermectin led to marked improvement but not resolution of his long-term asthma. His hive-like rash, which was likely larva currens, did not recur with a subsequent steroid course. Improved recognition of strongyloidiasis, particularly in steroid-treated patients, is needed.

Strongyloides stercoralis and hookworm co-infection: spatial distribution and determinants in Preah Vihear Province, Cambodia

BACKGROUND

Strongyloides stercoralis and hookworm are two soil-transmitted helminths (STH) that are highly prevalent in Cambodia. Strongyloides stercoralis causes long-lasting infections and significant morbidity but is largely neglected, while hookworm causes the highest public health burden among STH. The two parasites have the same infection route, i.e. skin penetration. The extent of co-distribution, which could result in potential high co-morbidities, is unknown in highly endemic settings like Cambodia. The aim of this study was to predict the spatial distribution of S. stercoralis-hookworm co-infection risk and to investigate determinants of co-infection in Preah Vihear Province, North Cambodia.

METHODS

A cross-sectional survey was conducted in 2010 in 60 villages of Preah Vihear Province. Diagnosis was performed on two stool samples, using combined Baermann technique and Koga agar culture plate for S. stercoralis and Kato-Katz technique for hookworm. Bayesian multinomial geostatistical models were used to assess demographic, socioeconomic, and behavioural determinants of S. stercoralis-hookworm co-infection and to predict co-infection risk at non-surveyed locations.

RESULTS

Of the 2576 participants included in the study, 48.6% and 49.0% were infected with S. stercoralis and hookworm, respectively; 43.8% of the cases were co-infections. Females, preschool aged children, adults aged 19-49 years, and participants who reported regularly defecating in toilets, systematically boiling drinking water and having been treated with anthelmintic drugs had lower odds of co-infection. While S. stercoralis infection risk did not appear to be spatially structured, hookworm mono-infection and co-infection exhibited spatial correlation at about 20 km. Co-infection risk was positively associated with longer walking distances to a health centre and exhibited a small clustering tendency. The association was only partly explained by climatic variables, suggesting a role for underlying factors, such as living conditions and remoteness.

CONCLUSIONS

Both parasites were ubiquitous in the province, with co-infections accounting for almost half of all cases. The high prevalence of S. stercoralis calls for control measures. Despite several years of school-based de-worming programmes, hookworm infection levels remain high. Mebendazole efficacy, as well as coverage of and compliance to STH control programmes should be investigated.

Immune complex detection in saliva samples: an innovative proposal for the diagnosis of human strongyloidiasis

Human strongyloidiasis is caused by helminth Strongyloides stercoralis. It has a worldwide distribution, often neglected and cause of severe morbidity. The parasitological diagnosis is hindered by the low and irregular amount of larvae in feces. The goal of the present study was to detect IgG and IgG immune complex using conventional serum samples and saliva as alternative samples. We collected samples from 60 individuals, namely: group I composed of 30 healthy individuals; and group II composed of 30 individuals eliminating S. stercoralis larvae in feces. We calculated the area under the curve, general index of diagnostic accuracy, Kappa index and determined the correlations between different diagnostic tests. The detection of IgG levels was performed by an immunoenzymatic assay with alkaline extract of S. venezuelensis larvae as antigen. Positivity of anti-S. stercoralis IgG in serum samples from group I was 3·3%, and from group II 93·3%. The detection of immune complex indicated that group I exhibited 3·3% and group II 56·7%. In the saliva samples, IgG detection was 26·7% for group I and 43·3% for group II. Immune complex was detected in 20% of group I, and 30% of group II. IgG immune complex in conventional serum samples and saliva as alternative samples can be considered biomarkers for the diagnosis of active strongyloidiasis.

Pulmonary strongyloidiasis: assessment between manifestation and radiological findings in 16 severe strongyloidiasis cases

Background

Strongyloidiasis is a chronic parasitic infection caused by Strongyloides stercoralis. Severe cases such as, hyperinfection syndrome (HS) and disseminated strongyloidiasis (DS), can involve pulmonary manifestations. These manifestations frequently aid the diagnosis of strongyloidiasis. Here, we present the pulmonary manifestations and radiological findings of severe strongyloidiasis.

Methods

From January 2004 to December 2014, all patients diagnosed with severe strongyloidiasis at the University of the Ryukyus Hospital or affiliated hospitals in Okinawa, Japan, were included in this retrospective study. All diagnoses were confirmed by the microscopic or histopathological identification of larvae. Severe strongyloidiasis was defined by the presence of any of the following: 1) the identification of S. stercoralis from extra gastrointestinal specimens, 2) sepsis, 3) meningitis, 4) acute respiratory failure, or 5) respiratory tract hemorrhage. Patients were assigned to either HS or DS. Medical records were further reviewed to extract related clinical features and radiological findings.

Results

Sixteen severe strongyloidiasis cases were included. Of those, fifteen cases had pulmonary manifestations, eight had acute respiratory distress syndrome (ARDS) (53%), seven had enteric bacterial pneumonia (46%) and five had pulmonary hemorrhage (33%). Acute respiratory failure was a common indicator for pulmonary manifestation (87%). Chest X-ray findings frequently showed diffuse shadows (71%). Additionally, ileum gas was detected for ten of the sixteen cases in the upper abdomen during assessment with chest X-ray. While, chest CT findings frequently showed ground-glass opacity (GGO) in 89% of patients. Interlobular septal thickening was also frequently shown (67%), always accompanying GGO in upper lobes.

Conclusions

In summary, our study described HS/DS cases with pulmonary manifestations including, ARDS, bacterial pneumonia and pulmonary hemorrhage. Chest X-ray findings in HS/DS cases frequently showed diffuse shadows, and the combination of GGO and interlobular septal thickening in chest CT was common in HS/DS, regardless of accompanying pulmonary manifestations. This CT finding suggests alveolar hemorrhage could be used as a potential marker indicating the transition from latent to symptomatic state. Respiratory specimens are especially useful for detecting larvae in cases of HS/DS.

Enterococcal meningitis in association with Strongyloides hyperinfection syndrome

INTRODUCTION

Strongyloidiasis can cause hyperinfection or disseminated infection in an immunocompromised host, and is an important factor linked to enterococcal bacteremia and meningitis.

CASE REPORTS

We report two cases highlighting the importance of suspecting Strongyloides hyperinfection syndrome in patients with enterococcal meningitis.

CONCLUSION

Our cases highlight the importance of suspecting Strongyloides hyperinfection syndrome in cases of community acquired enterococcal bacteremia and meningitis.

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.

Ivermectin Treatment and Sanitation Effectively Reduce Strongyloides stercoralis Infection Risk in Rural Communities in Cambodia

BACKGROUND

Strongyloides stercoralis is the only soil-transmitted helminth with the ability to replicate within its host, leading to long-lasting and potentially fatal infections. It is ubiquitous and its worldwide prevalence has recently been estimated to be at least half that of hookworm. Information on the epidemiology of S. stercoralis remains scarce and modalities for its large-scale control are yet to be determined.

METHODOLOGY/PRINCIPAL FINDINGS

A community-based two-year cohort study was conducted among the general population in a rural province in North Cambodia. At each survey, participants infected with S. stercoralis were treated with a single oral dose of ivermectin (200μg/kg BW). Diagnosis was performed using a combination of the Baermann method and Koga agar plate culture on two stool samples. The cohort included participants from eight villages who were either positive or negative for S. stercoralis at baseline. Mixed logistic regression models were employed to assess risk factors for S. stercoralis infection at baseline and re-infection at follow-up. A total of 3,096 participants were examined at baseline, revealing a S. stercoralis prevalence of 33.1%. Of these participants, 1,269 were followed-up over two years. Re-infection and infection rates among positive and negative participants at baseline were 14.4% and 9.6% at the first and 11.0% and 11.5% at the second follow-up, respectively. At follow-up, all age groups were at similar risk of acquiring an infection, while infection risk significantly decreased with increasing village sanitation coverage.

CONCLUSIONS/SIGNIFICANCE

Chemotherapy-based control of S. stercoralis is feasible and highly beneficial, particularly in combination with improved sanitation. The impact of community-based ivermectin treatment on S. stercoralis was high, with over 85% of villagers remaining negative one year after treatment. The integration of S. stercoralis into existing STH control programs should be considered without further delay.

In vitro and in vivo evaluation of 2-aminoalkanol and 1,2-alkanediamine derivatives against Strongyloides venezuelensis

Background

Strongyloidiasis is a parasitic disease widely present in tropical and subtropical areas. Strongyloides stercoralis represents the main species that infects human beings. Ivermectin is the current drug of choice; however, issues related with treatment failure in patients with diabetes or infected with T-lymphotropic virus-1 make the identification of new molecules for alternative treatment a priority. In the present study, the activity of sphingosine-related aminoalcohol and diamine were evaluated against Strongyloides venezuelensis third-stage larva (L3) cultures and experimental infections in mice.

Methods

The efficacy of each compound against L3 was assessed using both XTT (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) assay and microscopic observation with concentrations ranging from 1 to 350 μM. Cytotoxicity was evaluated using J774.2 macrophage cell line and XTT assay. Lethal concentration 50 (LC₅₀), selectivity index (SI) and structure-activity relationships were established. The activity compounds 4 (2-(ethylamino) hexadecan-1-ol), 6 (2-(butylamino) hexadecan-1-ol), 17 (tert-butyl N-(1-aminododecan-2-yl) carbamate) and 18 (tert-butyl N-(1-aminohexadecan-2-yl) carbamate) were further assessed against experimental S. venezuelensis infections in CD1 mice measuring reductions in the numbers of parthenogenetic females and egg passed in faeces. Mice were infected with 3,000 L3 and treated with 20 mg/kg/day for five days.

Results

In the screening study of 15 aminoalcohols [lauryl (n = 9); palmityl (n = 13); stearyl (n = 15) and alcohol derivatives], the presence of a palmitol chain was associated with the highest efficacy against L3 (LC₅₀ 31.9–39.1 μM). Alkylation of the 2-amino group with medium size fragments as ethyl or n-butyl showed the best larvicidal activity. The dialkylation did not improve efficacy. Aminoalcohols 4 and 6 showed the highest SI (1.5 and 1.6, respectively). With respect to diamine derivative compounds, a chain size of sixteen carbon atoms (palmitoyl chain, n = 13), and the alkylation of the 2-amino group with medium-sized fragments, were associated with the highest lethal activities. The presence of carbamoyl group in diamines 17 and 18 yielded high SI (1.7 and 1.4, respectively). Infected mice treated with aminoalcohol 6 showed reduction in parthenogenetic females (59 %) and eggs in faeces (51 %).

Conclusions

These results support the potentiality of aminoalcohol and diamine sphingosine-related compounds as suitable prototypes for developing new promising drugs against strongyloidiasis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-016-1648-5) contains supplementary material, which is available to authorized users.

Unsuspected Strongyloides stercoralis infection in hospital patients with comorbidity in need of proper management

BACKGROUND

Investigate the role of latent strongyloidiasis infection in patients at the University Hospital, Honduras.

METHODS

Prospective observational cohort study during 20 non consecutive months from March 2009 to February 2011. Epidemiological and clinical data obtained from patients excreting Strongyloides stercoralis larvae in stool who consulted at the hospital were recorded and analyzed.

RESULTS

Thirty five (5 %) of 712 patients had S. stercoralis larvae in one stool sample; 62.8 % came from rural areas and 91.7 % were poor; 68.5 % (24/35) were 21 years old or older. Eight patients (22.8 %) had no predisposing illness; 3 (8.6 %) received steroid treatment, 29/35 (82.8 %) presented with persistent diarrhea and 24/35 (68.5 %) presented following comorbidities: HIV/AIDS (31.4 %), alcoholism alone (11.4 %) or with other associated illness (8.6 %), malignancy (8.6 %), renal failure (5.7 %) and hyperthyroidism (2.8 %). A combination of symptoms suggestive of strongyloidiasis but indistinguishable from those potentially associated to their comorbid condition included severe epigastric pain, diarrhea of weeks duration, peripheral eosinophilia, astenia, adynamia, fever, anemia and weight loss in 85.7 % of the cases, 3 of whom described skin lesions compatible with larva currens. None of the diagnostic clinical impressions mentioned Strongyloides infection. Ten strongyloidiasis patients received partial treatment with albendazole or ivermectin. Incomplete data, underestimation of the parasitic infection and no laboratory follow-up of the patients limited our observations.

CONCLUSIONS

Strongyloides stercoralis is an unsuspected and neglected parasitic infection by health personnel in Honduras. Lack of awareness of its importance represents a strong barrier to proper treatment and follow-up, posing a threat of possible fatal complications in patients with comorbid conditions.