Strongyloides stercoralis, Eosinophilia, and Type 2 Diabetes Mellitus: The Predictive Value of Eosinophilia in the Diagnosis of S stercoralis Infection in an Endemic Community

Cross-Sectional Assessment of the Association of Eosinophilia with Intestinal Parasitic Infection in U.S.-Bound Refugees in Thailand: Prevalent, Age Dependent, but of Limited Clinical Utility

The most common causes of eosinophilia globally are helminth parasites. Refugees from high endemic areas are at increased risk of infection compared with the general U.S. population. It is widely accepted that eosinophilia is a good marker for helminth infection in this population, yet its absence has little predictive value for excluding infection. During an enhanced premigration health program, the CDC offered voluntary testing and management of intestinal parasites, among other conditions, to U.S.-bound refugees in Thailand. Stool specimens were tested for Ascaris lumbricoides, Strongyloides stercoralis, Trichuris trichiura, hookworms, Giardia lamblia, Cryptosporidium spp., and Entamoeba histolytica using quantitative polymerase chain reaction. Complete blood counts were performed to identify eosinophilia. Predictive values of eosinophilia for parasitic infections were calculated within nematode groups. Between July 9, 2012 and November 29, 2013, 2,004 participants were enrolled. About 73% were infected with at least one parasite. The overall median eosinophil count was 483 cells/μL (interquartile range [IQR] = 235-876 cells/μL). Compared with participants who did not test positive for any infection, higher eosinophil counts were observed in those infected with A. lumbricoides (RR = 1.3, 95% CI = 1.1-1.4), S. stercoralis (RR = 1.8, 95% CI = 1.4-2.4), Necator americanus (RR = 1.2, 95% CI = 1.1-1.4), and Ancylostoma ceylanicum (RR = 1.8, 95% CI = 1.5-2.2). Eosinophil counts were higher in younger participants (2-4 years versus 65+ years: RR = 4.2, 95% CI = 2.5-6.9), and lower in female participants (RR = 0.9, 95% CI = 0.8-0.9). Sensitivities ranged from 51% to 73%, specificities from 48% to 65%, and predictive values from 4% to 98%. The predictive value of eosinophilia is poor for the most common parasitic infections, and it should not be used alone for screening refugees.

A case of triple infection including strongyloides stercoralis in a microscopic polyangiitis patient

We present the case of a microscopic polyangiitis (MPA) patient who developed strongyloidiasis, nocardia and citrobacter freundii (CF) infection after corticosteroides and immunosuppressant therapy. When digestive, respiratory or other system symptoms consecutively occur in a immunocompromised host who lives in tropical or temperate zone and have close contact with soil, we should take strongyloidiasis into consideration despite absence of eosinophilia. Mixed infection with nocardia cannot be easily excluded. It is essential to search for the etiology proof with multiple approaches positively and repeatedly.

The effects of helminth infections against type 2 diabetes

Type 2 diabetes mellitus (T2D) is a prevalent inflammation-related disease characterized by insulin resistance and elevated blood glucose levels. The high incidence rate of T2D in Western societies may be due to environmental conditions, including reduced worm exposure. In human and animal models, some helminths, such as Schistosoma, Nippostrongylus, Strongyloides, and Heligmosomoides, and their products reportedly ameliorate or prevent T2D progression. T2D induces adaptive immune pathways involved in the inhibition of type 1 immune responses, promotion of type 2 immune responses, and expansion of regulatory T cells and innate immune cells, such as macrophages, eosinophils, and group 2 innate lymphoid cells. Among immune cells expanded in T2DM, type 2 immune cells and macrophages are the most important and may have synergistic effects. The stimulation of host immunity by helminth infections also promotes interactions between the innate and adaptive immune systems. In this paper, we provide a comprehensive review of intestinal helminths' protective effects against T2D.

Strongyloides hyperinfection in an HIV-positive kidney transplant recipient: a case report

BACKGROUND

Strongyloidiasis is caused by the helminth Strongyloides stercoralis and is well-recognised amongst transplant recipients. Serious complications, including Strongyloides hyperinfection which is a syndrome of accelerated autoinfection, or disseminated disease, can occur post-transplantation, resulting in significant morbidity and mortality. Here we present the first published case we are aware of, describing post-transplant Strongyloides hyperinfection in an HIV-positive kidney transplant patient. We discuss the diagnostic challenges and the role of pre-transplant screening.

CASE PRESENTATION

A 58-year-old African-American male, originally from the Caribbean, received a deceased donor kidney transplant for presumed focal segmental glomerulosclerosis. He was known to be HIV-positive, with a stable CD4 count, and an undetectable viral load. Five months post-transplant, he developed gastrointestinal symptoms and weight loss. He had a normal eosinophil count (0.1-0.2 × 109/L), negative serum cytomegalovirus DNA, and negative blood and stool cultures. His Strongyloides serology remained negative throughout. A diagnosis of Strongyloides hyperinfection was made by the histological examination of his duodenum and lung, which identified the parasites. He completed his course of treatment with Ivermectin but exhibited profound deconditioning and required a period of total parenteral nutrition. He was subsequently discharged after a prolonged hospital admission of 54 days.

CONCLUSIONS

This case highlights the challenges in diagnosing Strongyloides infection and the need to maintain a high index of clinical suspicion. Non-invasive techniques for the diagnosis of Strongyloides may be insufficient. Routine pre-transplant serological strongyloidiasis screening is now performed at our centre.

[Acute renal failure and rare severe complication of systemic steroid treatment in a 73-year-old woman]

This article reports about a 73-year-old woman of Bosnian descent who presented with acute renal failure. A renal biopsy was diagnostic for a postinfect necrotizing and extracapillary proliferative glomerulonephritis. The patient reported a febrile infection fever 2 weeks previously. The diagnostics did not reveal any indications of an ongoing infection. The glomerulonephritis responded to treatment with systemic steroids. The patient was readmitted to hospital 6 weeeks later in a severely ill condition. A gastric biopsy revealed a Strongyloides stercoralis infestation. Due to the systemic steroid therapy the patient had developed a so-called hyperinfection syndrome and died despite treatment on the intensive care unit. This case illustrates the need for awareness of this rare parasitosis, particularly in patients from endemic areas. A likely causal relationship with the glomerulonephritis is discussed and an overview of the diagnostics, course of the disease and treatment of this parasitosis is given.

Eosinophilia and Kidney Disease: More than Just an Incidental Finding?

Peripheral blood eosinophilia (PBE), defined as 500 eosinophils or above per microliter (µL) blood, is a condition that is not uncommon but often neglected in the management of patients with chronic kidney disease (CKD), acute kidney injury (AKI), or patients on renal replacement therapy (RRT). The nature of PBE in the context of kidney diseases is predominantly secondary or reactive and has to be distinguished from primary eosinophilic disorders. Nonetheless, the finding of persistent PBE can be a useful clue for the differential diagnosis of underdiagnosed entities and overlapping syndromes, such as eosinophilic granulomatosis with polyangiitis (EGPA), IgG4-related disease (IgG4-RD), acute interstitial nephritis (AIN), or the hypereosinophilic syndrome (HES). For patients on RRT, PBE may be an indicator for bio-incompatibility of the dialysis material, acute allograft rejection, or Strongyloides hyperinfection. In a subset of patients with EGPA, eosinophils might even be the driving force in disease pathogenesis. This improved understanding is already being used to facilitate novel therapeutic options. Mepolizumab has been licensed for the management of EGPA and is applied with the aim to abrogate the underlying immunologic process by blocking interleukin-5. The current article provides an overview of different renal pathologies that are associated with PBE. Further scientific effort is required to understand the exact role and function of eosinophils in these disorders which may pave the way to improved interdisciplinary management of such patients.

Strongyloides stercoralis hyperinfection in an unconscious diabetic patient with dermatomyositis

A case of Strongyloides stercoralis hyperinfection in a patient with dermatomyositis and diabetes mellitus is herein reported. The case was a 60-year-old female admitted due to watery diarrhea and unconsciousness. She had a 10-year history of chronic immunosuppressive therapy including methotrexate and prednisolone for dermatomyositis. Stool parasitological examination revealed numerous rhabditiform larvae of threadworm "S. stercoralis." Larva in stool sample was characterized by sequencing of mitochondrial DNA. After treatment with ivermectin, the patient recovered without evidence of S. stercoralis in follow-up stool samples. In endemic areas, stool examination for detection of S. stercoralis should be performed on a regular basis for all patients receiving immunosuppressive therapy, as early detection and treatment are necessary to minimize complications of severe strongyloidiasis.

Impact of Enhanced Health Interventions for United States-Bound Refugees: Evaluating Best Practices in Migration Health

With an unprecedented number of displaced persons worldwide, strategies for improving the health of migrating populations are critical. United States-bound refugees undergo a required overseas medical examination to identify inadmissible conditions (e.g., tuberculosis) 2-6 months before resettlement, but it is limited in scope and may miss important, preventable infectious, chronic, or nutritional causes of morbidity. We sought to evaluate the feasibility and health impact of diagnosis and management of such conditions before travel. We offered voluntary testing for intestinal parasites, anemia, and hepatitis B virus infection, to U.S.-bound refugees from three Thailand-Burma border camps. Treatment and preventive measures (e.g., anemia and parasite treatment, vaccination) were initiated before resettlement. United States refugee health partners received overseas results and provided post-arrival medical examination findings. During July 9, 2012 to November 29, 2013, 2,004 refugees aged 0.5-89 years enrolled. Among 463 participants screened for seven intestinal parasites overseas and after arrival, helminthic infections decreased from 67% to 12%. Among 118 with positive Strongyloides-specific antibody responses, the median fluorescent intensity decreased by an average of 81% after treatment. The prevalence of moderate-to-severe anemia (hemoglobin < 10 g/dL) was halved from 14% at baseline to 7% at departure (McNemar P = 0.001). All 191 (10%) hepatitis B-infected participants received counseling and evaluation; uninfected participants were offered vaccination. This evaluation demonstrates that targeted screening, treatment, and prevention services can be conducted during the migration process to improve the health of refugees before resettlement. With more than 250 million migrants globally, this model may offer insights into healthier migration strategies.

The relationship between treatment for Strongyloides stercoralis infection and type 2 diabetes mellitus in an Australian Aboriginal population: A three-year cohort study

AIM

To determine the effect of treatment for Strongyloides stercoralis infection on type 2 diabetes mellitus in an Australian Aboriginal population.

METHODS

A three-year cohort study of 259 Aboriginal adults living in northern Australia. Subjects were tested for S. stercoralis infection, diabetic status and HbA1c at recruitment. 92 subjects were ELISA positive for S. stercoralis and 91 were treated with two doses of ivermectin 0.2mg/kg. Serological cure was assessed after 6months and those who remained positive were retreated. All subjects then underwent the same testing at 3years follow up.

RESULTS

Follow up was successful in 80% of subjects. Eight new cases of T2DM were recorded, 7 in the treatment group and 1 in the non-treatment group (Unadjusted RR 7.71, CI 0.98-60.48, p=0.052. Adjusted RR 5.45, CI 075-35.92, p=0.093). In addition, worsening glycemic control (T2DM or newly diagnosed glucose intolerance) was recorded in 13 cases (10 treatment group, 3 non treatment. Adjusted RR 3.74, CI 1.06-13.20, p=0.04). There was a significant improvement in glycemic control in the patients with pre-existing T2DM when treated for S. stercoralis compared to the non-treatment group (Diff. -1.03, p=0.009).

CONCLUSION

This study demonstrated a differential effect of treatment for S. stercoralis on glucose metabolism in patients with and without T2DM. It showed a significant effect on the development of T2DM and glucose intolerance in those without T2DM, while improving glycemic control in subjects with pre-existing T2DM. Although numbers in this study are small, it suggests that larger studies may be of interest.

Strongyloides stercoralis in solid organ transplantation: early diagnosis gets the worm

PURPOSE OF REVIEW

Strongyloidiasis is a parasitic infection affecting millions of people worldwide. Complications of infection are strongly associated with alcoholism, immunosuppression, and organ transplantation. Delayed diagnosis results in hyperinfection syndrome and disseminated strongyloidiasis leading to mortality rates approaching 80%. Early detection, and prevention of infection and transmission are key to diminish this illness.

RECENT FINDINGS

In this review, we cover the basic concepts in immunity, immunosuppression, and disorder necessary for understanding the infectious syndromes associated with Strongyloides stercoralis infection. Focused discussion on donor-derived transmission and recipient risk in solid organ transplantation is presented. Current methodology for diagnosis, screening algorithms, and treatment are also reviewed.

SUMMARY

Strongyloidiasis complicated by hyperinfection and dissemination remains associated with a poor outcome. The poor outcome pleads for a high level of suspicion and aggressive treatment in at-risk patients. As the population of transplant patients continues to increase, the risk of infection also increases, compelling us to address this highly fatal infectious complication in solid organ transplantation (SOT). Here we review the pathology, immunology, diagnosis, and treatment of strongyloides infection in the immunosuppressed SOT population.

Control of chronic Strongyloides stercoralis infection in an endemic community may be possible by pharmacological means alone: Results of a three-year cohort study

Objectives

To assess the effect of treatment with ivermectin on the prevalence of S. stercoralis infection in an Australian Aboriginal population over a three year period, and to assess the validity of using a lower ELISA cut-off in diagnosis.

Methods

A three-year cohort study of 259 adult Australian Aboriginals living in a remote community in northern Australia. S stercoralis infection was diagnosed using commercial ELISA testing, and employed a lower threshold for treatment than that recommended. Follow up was conducted at 6 months and 3 years following ivermectin treatment.

Findings

Treatment with ivermectin was highly effective and resulted in a sustained fall in the prevalence of infection in the study group (Initial prevalence 35.3%, 3 year prevalence 5.8%, McNemar’s chi² = 56.5, p<0.001). Results of treatment suggested use of a lower ELISA threshold for treatment was valid in this setting. Follow up identified a small group of subjects with persistently positive ELISA serology despite repeated treatment.

Interpretation

Control of S. stercoralis infection in this cohort appears to be feasible using pharmacological treatment alone.

Infection with the worm Strongyloides stercoralis is common throughout the developing world, and in some resource poor communities living within developed societies, such as the Aboriginal communities of northern Australia. It is generally agreed that reliable diagnosis of this infection is possible by blood tests, and that the medication ivermectin represents the best available treatment, however questions remain over how to best control and eliminate the infection in areas where it is common. Strongyloides infections may be asymptomatic, and may persist indefinitely without the need for re-infection. The worm is transmitted by contact with contaminated soil. Suggested strategies for control have therefore included mass administration of ivermectin in affected areas, and environmental measures to prevent the contamination of soil. In this study we follow up a group of subjects living in an endemic community three years after they were tested and treated for strongyloides infection. We find a persisting low prevalence of infection in this group in the absence of any environmental changes or further treatment, suggesting that control of the infection in this community might be achieved through simple case finding and treatment alone. In addition, we suggest the use of a lower cut-off value for serological testing in these communities, in order to avoid missing cases of infection.

Trends in Strongyloides stercoralis Faecal Larvae Detections in the Northern Territory, Australia: 2002 to 2012

Strongyloides stercoralis is a soil-transmitted helminth (STH) endemic to tropical and subtropical areas. We reviewed the temporal detection trends in patients with S. stercoralis larvae present in faecal samples, in Northern Territory (NT) Government Health facilities, between 2002 and 2012. This was a retrospective observational study of consecutive patients with microbiologically confirmed detection of S. stercoralis in faeces. The presence of anaemia, eosinophilia, polyparasitism, and geographic and demographic data, were included in the assessment. S. stercoralis larvae were present in 389 of 22,892 faecal samples (1.7%) collected across the NT over 11 years, examined by microscopy after formol ethyl acetate concentration. 97.7% of detections were in Indigenous patients. Detections, by number, occurred in a biphasic age distribution. Detections per number of faecal samples collected, were highest in the 0–5 year age group. Anaemia was present in 44.8%, and eosinophilia in 49.9% of patients. Eosinophilia was present in 65.5% of the ≤5 age group, compared to 40.8% of >5 year age (p < 0.0001). Polyparasitism was present in 31.4% of patients. There was an overall downward trend in larvae detections from 2.64% to 0.99% detections/number of faecal samples year between 2002 and 2012, consistent with the trends observed for other local STHs. S. stercoralis remains an important NT-wide pathogen.

Infections: A Possible Risk Factor for Type 2 Diabetes

Diabetes mellitus is one of the biggest challenges to human health globally, with an estimated 95% of the global diabetic population having type 2 diabetes. Classical causes for type 2 diabetes, such as genetics and obesity, do not account for the high incidence of the disease. Recent data suggest that infections may precipitate insulin resistance via multiple mechanisms, such as the proinflammatory cytokine response, the acute-phase response, and the alteration of the nutrient status. Even pathogen products, such as lipopolysaccharide and peptidoglycans, can be diabetogenic. Therefore, we argue that infections that are known to contribute to insulin resistance should be considered as risk factors for type 2 diabetes.