Prevalence of Strongyloides stercoralis infection among HIV-positive immigrants attending two Italian hospitals, from 2000 to 2009

Human Strongyloides stercoralis infection

Strongyloides stercoralis is an important soil-transmitted helminth occurring world-wide and affecting 30-100 million people. Because many cases are asymptomatic and sensitive diagnostic methods are lacking, S. stercoralis infection is frequently underdiagnosed. The increasing incidence of autoimmune and wasting diseases and increased use of immunosuppressive agents, as well as the increased use of immunosuppressants and cytotoxic drugs, have increased S. stercoralis infection and their mortality. This review provides information about S. stercoralis epidemiology, life cycle, aetiology, pathology, comorbidities, immunology, vaccines, diagnosis, treatment, prevention, control and makes some recommendations for future prevention and control of this important parasite.

Prevalence of neglected tropical diseases among migrants living in Europe: A systematic review and meta-analysis

BACKGROUND

Migration to Europe has intensified due to recent political conflicts, economic crises, and climate change, introducing an increased risk of neglected tropical diseases (NTDs) within this population. While NTDs typically impact tropical regions, their presence among migrants in Europe presents a growing challenge, compounded by limited research in this area. This study provides the first meta-analysis on the prevalence of NTDs in migrants across European nations.

METHODS

A systematic review and meta-analysis was conducted focusing on studies that included NTD prevalence among migrant populations in Europe, with data sourced until July 2024. Cross-sectional and longitudinal studies were eligible, with bias assessed using the Newcastle-Ottawa Scale. Prevalence rates for various NTDs were calculated using a random-effects model, and meta-regressions were performed to assess potential moderators like sample size, age, and gender.

RESULTS

A total of 148 studies comprising 228,798 migrants were analyzed. The most prevalent NTDs were strongyloidiasis (11.53 %) and schistosomiasis (10.8 %), with American trypanosomiasis also present. Dengue and lymphatic filariasis showed significant rates, though high heterogeneity was noted. Data quality was frequently low, with most studies at a high risk of bias.

CONCLUSIONS

This study underscores the need for robust screening and diagnostic protocols in Europe for NTDs, particularly as clinician familiarity with these diseases is limited. Test-and-treat strategies appear promising, yet more comprehensive efforts are necessary. Establishing a European NTD registry could improve monitoring and management. Future studies should prioritize higher-quality data and address the barriers migrants face in accessing health services.

Detection of human strongyloidiasis among patients with a high risk of complications attending selected tertiary care hospitals in Colombo, Sri Lanka using molecular and serological diagnostic tools

BACKGROUND

Strongyloidiasis a neglected tropical disease is known to cause severe disease among immunosuppressed and has not been studied extensively in Sri Lanka. Parasitological diagnostic approaches based on faecal microscopy and culture often fail to detect low-intensity infections. This study investigates the presence of strongyloidiasis among selected immunocompromised individuals using parasitological, molecular and serological techniques.

METHODS

Adult patients with immunocompromising conditions admitted to three tertiary care hospitals in Sri Lanka were recruited. A faecal sample and 2 ml of venous blood were collected. The faecal samples were subjected to direct faecal smear and cultures (agar plate, charcoal and Harada-Mori) and polymerase chain reaction (PCR) using species specific primers designed for Strongyloides stercoralis. The presence of Strongyloides IgG antibodies was tested in the collected serum samples using DRG Strongyloides IgG enzyme-linked immunosorbent assay (ELISA) kits. The PCR products of the positive samples were sequenced using Sanger sequencing method.

RESULTS

A total of 260 patients were recruited to this study, out of which 160 provided faecal samples and 122 provided blood samples. Out of the 160 faecal samples, none were positive for strongyloidiasis by direct smear, charcoal and Harada-Mori cultures. Only one sample (0.6%) was positive by agar plate culture. Out of the 123 samples subjected to PCR, 14 (11.4%), including the culture positive patient, were positive for S. stercoralis. Sequencing results of the PCR products indicated 100% similarity to S. stercoralis. Out of the 122 serum samples subjected to ELISA, 20 (16.4%), including the culture positive patient, were positive for Strongyloides IgG antibodies. However, sociodemographic, exposure factors, clinical features were not significantly associated with the presence of strongyloidiasis infection.

CONCLUSIONS

Strongyloidiasis is present among the immunocompromised population in Sri Lanka, even in the absence of a significant relationship with associated factors. It is advisable to screen such patients with highly sensitive tests such as PCR for early diagnosis and treatment.

Influence of Strongyloides stercoralis Coinfection on the Presentation, Pathogenesis, and Outcome of Tuberculous Meningitis

BACKGROUND

Helminth infections may modulate the inflammatory response to Mycobacterium tuberculosis and influence disease presentation and outcome. Strongyloides stercoralis is common among populations with high tuberculosis prevalence. Our aim was to determine whether S. stercoralis coinfection influenced clinical presentation, cerebrospinal fluid (CSF) inflammation, and outcome from tuberculous meningitis (TBM).

METHODS

From June 2017 to December 2019, 668 Vietnamese adults with TBM, enrolled in the ACT HIV or LAST ACT trials (NCT03092817 and NCT03100786), underwent pretreatment S. stercoralis testing by serology, stool microscopy, and/or stool polymerase chain reaction. Comparisons of pretreatment TBM severity, CSF inflammation (including cytokines), and 3-month clinical end points were performed in groups with or without active S. stercoralis infection.

RESULTS

Overall, 9.4% participants (63 of 668) tested positive for S. stercoralis. Active S. stercoralis infection was significantly associated with reduced pretreatment CSF neutrophil counts (median [interquartile range], 3/μL [0-25/μL] vs 14 /μL [1-83/μL]; P = .04), and with reduced CSF interferon ɣ, interleukin 2, and tumor necrosis factor α concentrations (11.4 vs 56.0 pg/mL [P = .01], 33.1 vs 54.5 pg/mL [P = .03], and 4.5 vs 11.9 pg/mL [P = .02], respectively), compared with uninfected participants. Neurological complications by 3 months were significantly reduced in participants with active S. stercoralis infection compared with uninfected participants (3.8% [1 of 26] vs 30.0% [33 of 110], respectively; P = .01).

CONCLUSIONS

S. stercoralis coinfection may modulate the intracerebral inflammatory response to M. tuberculosis and improve TBM clinical outcomes.

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.

Strongyloides stercoralis

Strongyloidiasis has been estimated to affect over 600 million people worldwide. It is caused by Strongyloides stercoralis, a roundworm endemic to the tropics and subtropics, especially areas where sanitation is suboptimal Autochthonous transmission has been documented in rural areas of the USA and Europe. Humans are infected when larvae penetrate the skin or are ingested. Autoinfection, in which larvae generated in the host go on to re-infect the host, leads to a state of chronic asymptomatic infection often with eosinophilia. Hyperinfection syndrome may develop when patients develop immune suppression, due to medications such as corticosteroids or following solid-organ transplantation. Hyperinfection is characterized by exponential increase in parasitic burden, leading to tissue invasion and life-threatening disease and associated bloodstream infections due to enteric organisms. Cases following use of corticosteroids for COVID-19 pneumonia have been described. Strongyloidiasis can be diagnosed by direct visualization of larvae in stool or other body fluids, or by serology. Ivermectin is highly effective in treating the disease. Patients with exposure to endemic areas and those expected to become immune suppressed should be screened and treated before starting immune suppressive agents. Empiric treatment should be considered when timely testing is not readily available.

Diagnostic accuracy of a novel enzyme-linked immunoassay for the detection of IgG and IgG4 against Strongyloides stercoralis based on the recombinant antigens NIE/SsIR

Background

The diagnosis of strongyloidiasis is challenging. Serological tests are acknowledged to have high sensitivity, but issues due to cross-reactions with other parasites, native parasite antigen supply and intrinsic test variability do occur. Assays based on recombinant antigens could represent an improvement. The aim of this study was to assess the sensitivity and specificity of two novel immunoglobulin (Ig)G and IgG4 enzyme-linked immunosorbent assays (ELISAs) based on the recombinant antigens NIE/SsIR for the diagnosis of strongyloidiasis.

Methods

This was a retrospective diagnostic accuracy study. We included serum samples collected from immigrants from strongyloidiasis endemic areas for whom there was a matched result for Strongyloides stercoralis on agar plate culture and/or PCR assay, or a positive microscopy for S. stercoralis larvae. For the included samples, results were also available from an in-house indirect fluorescent antibody test (IFAT) and a commercial (Bordier ELISA; Bordier Affinity Products SA) ELISA. We excluded: (i) samples with insufficient serum volume; (ii) samples from patients treated with ivermectin in the previous 6 months; and (iii) sera from patients for whom only routine coproparasitology was performed after formol–ether concentration, if negative for S. stercoralis larvae. The performance of the novel assays was assessed against: (i) a primary reference standard, with samples classified as negative/positive on the basis of the results of fecal tests; (ii) a composite reference standard (CRS), which also considered patients to be positive who had concordant positive results for the IFAT and Bordier ELISA or with a single “high titer” positive result for the IFAT or Bordier ELISA. Samples with a single positive test, either for the IFAT or Bordier ELISA, at low titer, were considered to be “indeterminate,” and analyses were carried out with and without their inclusion.

Results

When assessed against the primary reference standard, the sensitivities of the IgG and IgG4 ELISAs were 92% (95% confidence interval [CI]: 88–97%) and 81% (95% CI: 74–87%), respectively, and the specificities were 91% (95% CI: 88–95%) and 94% (95% CI: 91–97%), respectively. When tested against the CRS, the IgG ELISA performed best, with 78% sensitivity (95% CI: 72–83%) and 98% specificity (95% CI: 96–100%), when a cut-off of 0.675 was applied and the indeterminate samples were excluded from the analysis.

Conclusion

The NIE-SsIR IgG ELISA demonstrated better accuracy than the IgG4 assay and was deemed promising particularly for serosurveys in endemic areas.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04916-x.

Strongyloides stercoralis Infection in Solid Organ Transplant Patients Is Associated With Eosinophil Activation and Intestinal Inflammation: A Cross-sectional Study

BACKGROUND

Strongyloidiasis can cause devastating morbidity and death in immunosuppressed patients. Identification of reliable biomarkers for strongyloidiasis in immunosuppressed patients is critical for the prevention of severe disease.

METHODS

In this cross-sectional study of solid organ transplant (SOT) candidates and recipients, we quantified Strongyloides-specific IgG to the recombinant NIE-Strongyloides antigen and/or to a soluble extract of S. stercoralis somatic antigens ("crude antigen") using enzyme-linked immunosorbent assays (ELISAs). We also measured peripheral eosinophilia, 4 different eosinophil granule proteins, and intestinal fatty acid-binding protein (IFABP).

RESULTS

We evaluated serum biomarkers in 149 individuals; 77 (52%) pre-SOT and 72 (48%) post-SOT. Four percent (6/149) tested positive by NIE ELISA and 9.6% (11/114) by crude antigen ELISA (overall seropositivity of 9.4% [14/149]). Seropositive patients had higher absolute eosinophil counts (AECs) than seronegative patients (P = .004). AEC was positively correlated to the levels of eosinophil granule proteins eosinophil cationic protein (ECP) and eosinophil peroxidase (EPO) (P < .05), while IFABP was positively related to the 2 other eosinophil granule proteins (major basic protein [MBP] and eosinophil-derived neurotoxin [EDN]; Spearman's r = 0.3090 and 0.3778, respectively; P < .05; multivariate analyses slopes = 0.70 and 2.83, respectively).

CONCLUSIONS

This study suggests that, in SOT patients, strongyloidiasis triggers both eosinophilia and eosinophil activation, the latter being associated with intestinal inflammation. These data provide insight into the pathogenesis of S. stercoralis infection in the immunocompromised population at high risk of severe strongyloidiasis syndromes.

HTLV-I and Strongyloides in Australia: The worm lurking beneath

Strongyloidiasis and HTLV-I (human T-lymphotropic virus-1) are important infections that are endemic in many countries around the world with an estimated 370 million infected with Strongyloides stercoralis alone, and 5-10 million with HTVL-I. Co-infections with these pathogens are associated with significant morbidity and can be fatal. HTLV-I infects T-cells thus causing dysregulation of the immune system which has been linked to dissemination and hyperinfection of S. stercoralis leading to bacterial sepsis which can result in death. Both of these pathogens are endemic in Australia primarily in remote communities in Queensland, the Northern Territory, and Western Australia. Other cases in Australia have occurred in immigrants and refugees, returned travellers, and Australian Defence Force personnel. HTLV-I infection is lifelong with no known cure. Strongyloidiasis is a long-term chronic disease that can remain latent for decades, as shown by infections diagnosed in prisoners of war from World War II and the Vietnam War testing positive decades after they returned from these conflicts. This review aims to shed light on concomitant infections of HTLV-I with S. stercoralis primarily in Australia but in the global context as well.

Should We Screen HIV-Positive Migrants for Strongyloidiasis?

BACKGROUND

Strongyloides stercoralis, a nematode endemic in all (sub)tropical regions, can cause life-threatening disease, especially in immunosuppressed patients. Many countries with high HIV-prevalence rates are also highly S. stercoralis endemic, and co-infection may occur.

METHODS

Retrospective study based on serological testing for S. stercoralis in all HIV-infected migrants followed at the Institute of Tropical Medicine, Antwerp, Belgium. If untested, serologic testing was performed on stored samples, dating from the first HIV viral load determination. The epidemiological, clinical and laboratory features of patients with and without strongyloidiasis were retrieved from the electronic medical files.

RESULTS

Of the 2846 HIV patients in active follow-up, 723 (25.4%) had a migration background. Thirty-six patients (5.1%) were diagnosed with Strongyloides co-infection, including 29 during their medical evaluation and seven retrospectively. Patients had a median age of 35.3 years (IQR 30.3-44.4), 28 patients (78%) originated from Sub-Saharan Africa and median time in Belgium was 3.5 years (IQR 0.8-5.7). Symptoms compatible with strongyloidiasis were present in 17 (47%) patients, of whom two were diagnosed retrospectively. Eosinophilia (eosinophil cell count > 450/µL) was observed in 19 (53%) participants. Median CD4 level was 386 /µL (IQR 299-518) at diagnosis of co-infection. Of note, 8 (22%) patients with strongyloidiasis had no reported symptoms nor eosinophilia. None of the patients developed hyperinfection syndrome. There were no differences in age, gender, geographic origin, clinical presentation, CD4 level or viral load between patients with and without strongyloidiasis. Only eosinophilia was strongly correlated with the presence of Strongyloides in multivariate analysis (OR 10.74 (95% CI 5.19-22.25), p < 0.001); the positive likelihood ratio (LR+) of eosinophilia for strongyloidiasis was 5.38 (95% CI 3.66-7.91).

CONCLUSION

Strongyloidiasis was diagnosed in 5.1% of HIV-infected migrants. Eosinophilia had good confirming power for the presence of the disease. However, a sizeable proportion (22%) of co-infected individuals were asymptomatic and had normal eosinophil count, supporting universal screening of all HIV-positive patients native to tropical countries.

Strongyloides stercoralis in Patients on Corticosteroids Therapy Using Enzyme-Linked Immunosorbent Assay and Gelatin Particles Indirect Agglutination Tests: A Diagnostic Approach

INTRODUCTION

Patients on corticosteroids therapy (POCT) are more likely to flare up concealed Strongyloides infection and develop Strongyloides hyperinfection syndrome and/or dissemination. Such critical complications can lead to high mortality rates. Rapid detection methods are, therefore, necessary to detect Strongyloides infection in POCT with the advantage of being applicable in a developing country.

METHODS

Two hundred POCT have been enrolled in this study to determine the rate of infection with Strongyloides. Three different groups of POCT (Strongyloides infected, non-infected, infected with other parasites) were used to evaluate the antibodies detection capability of two serological techniques (enzyme-linked immunosorbent assay (ELISA) and gelatin particles indirect agglutination (GPIAT) against the results of the gold standard agar plate culture (APC).

RESULTS

With APC, the infection rate of Strongyloides stercoralis in POCT was 9.5% (19/200). POCT with Strongyloides infection displayed related risk factors (job, rural settlements, and soil contact) for infection combined with the subtropical nature of Ismailia Governorate. With regard to serology, ELISA detection results were poor compared to APC with sensitivity and specificity of 42.1% and 82.6%, respectively, and positive and negative predictive values of 72% and 30%. GPIAT appeared to be closely related to APC with sensitivity and specificity of 89.4% and 81.8%, respectively, and positive and negative predictive values of 80.9% and 96.7%. Statistical moderate correlation was detected between GPIAT and ELISA.

CONCLUSION

The GPIAT technique is more convenient, easier, cheaper and faster to rule out the infection of Strongyloides in POCT. It might be the test of choice for routine immunodiagnosis of human strongyloidiasis.

Schistosoma and Other Relevant Helminth Infections in HIV-Positive Individuals-an Overview

For many years, researchers have postulated that helminthic infections may increase susceptibility to HIV, and that immune activation may have contributed to the extensive spread of HIV in sub-Saharan Africa. In the meantime, immunological studies have provided some evidence in support of this hypothesis, while cross-sectional clinical studies were able to further support the assumed association between HIV infection and selected helminthic co-infections. However, as many of the helminthic infections relevant to HIV-infected patients belong to the group of “neglected tropical diseases”, as defined by the World Health Organization, a certain lack of attention has inhibited progress in fully scaling up treatment and prevention efforts. In addition, despite the fact that the challenges of co-infections have preoccupied clinicians for over two decades, relevant research questions remain unanswered. The following review aims to provide a concise overview of associations between HIV and selected helminthic co-infections concerning aspects of HIV acquisition and transmission, clinical and immunological findings in co-infected individuals, as well as treatment and prevention efforts.

Epidemiology of Strongyloides stercoralis infection in Bolivian patients at high risk of complications

Background

Strongyloidiasis can be fatal in immunocompromised patients, but few epidemiological studies investigated the burden of this neglected tropical disease among these populations, particularly in low- and middle-income countries such as Bolivia. This study aimed to fill in this gap by estimating prevalence rate and risk factors associated with strongyloidiasis among patients at high risk of complications

Methods

A cross-sectional study was carried out in Santa Cruz (elevation 400 meters, tropical climate) and Cochabamba (elevation 2,500 meters, temperate climate), among patients with cancer, HIV infection and rheumatic or hematologic disease, using four coproparasitological techniques and one serological (ELISA) test.

Results

In total, 1,151 patients participated in this study, including individuals who were HIV-positive (30%) or with rheumatic (29%), oncologic (32%) or hematologic (9%) diseases. The serological and coproparasitological prevalence was 23.0% (95% confidence interval [CI], 20.7–25.5; n = 265/1151) and 7.6% (95% CI, 6.2–9.3; n = 88/1151), respectively, with an estimated actual prevalence of 20.2% (95% CI, 17.9–22.5). Positive serology and positive coproparasitology were associated with younger age and lower education levels. There was no significant difference in prevalence between Cochabamba and Santa Cruz as defined by coproparasitology (6.4% vs. 8.9%; p = 0.11) or serology (24.0% vs. 22.0%; p = 0.4). Among 64 patients in Cochabamba who had never travelled to the tropical lowlands, 5 (7.8%) had a positive coproparasitology.

Conclusions

Strongyloidiasis is widely prevalent in Bolivia among vulnerable patients at increased risk of life-threatening complications. Transmission of the parasite occurs both in tropical lowlands and temperate elevation (≥ 2,500 m). Control strategies to prevent transmission and complications of this serious parasitic disease should be urgently reinforced.

Strongyloidiasis is an understudied chronic intestinal infection and one of the most overlooked of the neglected tropical diseases, particularly in countries such as Bolivia. The strongyloidiasis usually remains paucisymptomatic for decades in immunocompetent persons, but may lead to severe conditions with high mortality rates in immunocompromised individuals. We carried out a study to explore the epidemiology of strongyloidiasis among Bolivian patients with cancer, HIV infection, and rheumatic or hematologic diseases. Our study highlighted that strongyloidiasis was widely prevalent in tropical and inter-Andean temperate areas of Bolivia among patients at high risk of life-threatening complications. One in five participants was infected. We showed that strongyloidiasis was highly prevalent in both tropical and temperate regions. Improved access to adequate diagnosis, treatment, and preventive measures are therefore urgently required in Bolivia, and most likely elsewhere in the region. Treatment of uncomplicated strongyloidiasis is simple, highly effective, and potentially life-saving.

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.

Coinfections between Persistent Parasitic Neglected Tropical Diseases and Viral Infections among Prisoners from Sub-Saharan Africa and Latin America

In Swiss prisons, more than 70% of detained people are foreigners and over one-third originate from sub-Saharan Africa or Latin America. These two regions are endemic for various tropical diseases and viral infections, which persist after migration to nonendemic countries. Parasitic infections (schistosomiasis; strongyloidiasis) and cooccurrent viral infections (HIV, hepatitis B (HBV), and hepatitis C (HCV)) are especially of concern for clinical care but have been neglected in empirical research. These diseases often remain silent for years before causing complications, especially if they occur concomitantly. Our research aimed to study the prevalence rates and coinfections of two neglected tropical diseases, namely, Strongyloides stercoralis and Schistosoma sp. and viral infections among sub-Saharan Africans (SSA) and Latin Americans (LA) in Switzerland's largest pretrial prison. We carried out a cross-sectional prevalence study using a standardized questionnaire and serological testing. Among the 201 participants, 85.6% were SSA and 14.4% LA. We found the following prevalence ratios: 3.5% of HIV (4.1% in SSA, 0% in LA), 12.4% of chronic HBV (14.5% in SSA, 0% in LA), 2.0% of viraemic HCV (1.7% in SSA, 3.4% in LA), and 8.0% of strongyloidiasis (8.1% in SSA, 6.9% in LA). The serological prevalence of schistosomiasis among SSA was 20.3% (not endemic in Latin America). Two infections were simultaneously detected in SSA: 4.7% were coinfected with schistosomiasis and chronic HBV. Four other coinfections were detected among SSA: schistosomiasis-HIV, HIV-chronic HBV, HIV-HCV, and schistosomiasis-strongyloidiasis. To conclude, the high prevalence rates of persistent viral and parasitic infections and their potential coinfections among SSA and LA detained migrants highlight the need to implement control strategies and programs that reach people in detention centers in nonendemic countries.

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

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

Evidence-Based Guidelines for Screening and Management of Strongyloidiasis in Non-Endemic Countries

Strongyloidiasis is an intestinal parasitic infection becoming increasingly important outside endemic areas, not only because of the high prevalence found in migrant populations, but also because immunosuppressed patients may suffer a potentially fatal disseminated disease. The aim of these guidelines is to provide evidence-based guidance for screening and treatment of strongyloidiasis in non-endemic areas. A panel of experts focused on three main clinical questions (who should be screened and how, how to treat), and reviewed pertinent literature available in international databases of medical literature and in documents released by relevant organizations/societies. A consensus of the experts' opinion was sought when specific issues were not covered by evidence. In particular, six systematic reviews were retrieved and constituted the main support for this work. The evidence and consensus gathered led to recommendations addressing various aspects of the main questions. Grading of evidence and strength of recommendation were attributed to assess the quality of supporting evidence. The screening of individuals at risk of the infection should be performed before they develop any clinical complication. Moreover, in immunosuppressed patients, the screening should be mandatory. The screening is based on a simple and widely accessible technology and there is now a universally accepted treatment with a high efficacy rate. Therefore, the screening could be implemented as part of a screening program for migrants although further cost-effectiveness studies are required to better evaluate this strategy from a public health point of view.

Epidemiology of Strongyloides stercoralis in northern Italy: results of a multicentre case-control study, February 2013 to July 2014

Strongyloides stercoralis is a soil-transmitted helminth widely diffused in tropical and subtropical regions of the world. Autochthonous cases have been also diagnosed sporadically in areas of temperate climate. We aimed at defining the epidemiology of strongyloidiasis in immigrants and Italians living in three northern Italian Regions. Screening for S. stercoralis infection was done with serology, confirmation tests were a second serological method or stool agar culture. A case–control approach was adopted and patients with a peripheral eosinophil count ≥ 500/mcL were classified as cases. Of 2,701 individuals enrolled here 1,351 were cases and 1,350 controls; 86% were Italians, 48% women. Italians testing positive were in 8% (97/1,137) cases and 1% (13/1,178) controls (adjusted odds ratio (aOR) 8.2; 95% confidence interval (CI): 4.5–14.8), while positive immigrants were in 17% (36/214) cases and in 2% (3/172) controls (aOR 9.6; 95% CI: 2.9–32.4). Factors associated with a higher risk of infection for all study participants were eosinophilia (p < 0.001) and immigration (p = 0.001). Overall, strongyloidiasis was nine-times more frequent in individuals with eosinophilia than in those with normal eosinophil count.

Diagnosis of Strongyloides stercoralis by morphological characteristics combine with molecular biological methods

Strongyloidiasis is one of the neglected tropical diseases caused by infection with the nematode Strongyloides genus and distributed worldwide. Strongyloidiasis can be fatal in immunosuppressed patients induced hyperinfection or disseminated strongyloidiasis. Unfortunately, until now, due to the unspecific clinical symptom in infected individuals and the low sensitivity diagnosis of strongyloidiasis, many patients were misdiagnosed every year. Furthermore, the larvae of the Strongyloides stercoralis (S. stercoralis) is similar to other nematodes such as hookworm, Trichostrongylus increased the difficulty of diagnosis. In this case, the patient is a 63-year-old male person, who had a nearly 30 years medical history of asthma and emphysema, and 4-5-year medical history of diabetes. The sputum examination found some parasite larvae, then we identify the larvae using clinical observation and morphological characteristics combine with examined cytochrome oxidase subunit 1 (COX1) and 18S rRNA genes by PCR, sequence analysis and finally classified by phylogenetic analysis, the larvae were diagnosed as S. stercoralis. Our results showed that diagnosis with strongyloidiasis by morphological characteristics combine with molecular biological methods can improve the sensitive of diagnosis and provide a final diagnosis for the disease in the clinics.

Strongyloidiasis-Related IRIS

Helminthic infection and HIV have been reported to coexist, particularly in sub-Saharan African patients living with HIV. Strongyloidiasis is one of the most common helminths, usually leading to cutaneous and gastrointestinal (GI) symptoms. In the immunocompromised host, this infection can lead to strongyloidiasis hyperinfection syndrome (SHS), not common in HIV-infected patients. Immune reconstitution inflammatory syndrome (IRIS) can follow the initiation of antiretroviral therapy (ART), with a variety of presentations. The authors present here a 32-year-old HIV-infected female who was recently diagnosed with AIDS, started ART, and recovered from SHS. Her upper endoscopy revealed severe duodenitis but no causal agent per biopsy or stool examination. After receiving symptomatic therapy, she showed improvement, a course of events that fit the diagnosis of GI-related IRIS.

DIAGNOSIS OF Strongyloides stercoralis INFECTION IN IMMUNOCOMPROMISED PATIENTS BY SEROLOGICAL AND MOLECULAR METHODS

Strongyloidiasis is a potentially serious infection in immunocompromised patients. Thus, the availability of sensitive and specific diagnostic methods is desirable, especially in the context of immunosuppressed patients in whom the diagnosis and treatment of strongyloidiasis is of utmost importance. In this study, serological and molecular tools were used to diagnose Strongyloides stercoralis infections in immunosuppressed patients. Serum and stool samples were obtained from 52 patients. Stool samples were first analyzed by Lutz, Rugai, and Agar plate culture methods, and then by a quantitative real time polymerase chain reaction (qPCR). Serum samples were evaluated by an enzyme-linked immunosorbent assay (ELISA) using a soluble (AS) or a membrane fractions antigen (AM) obtained from alkaline solutions of the filariform larvae of Strongyloides venezuelensis. Of the 52 immunosuppressed patients, three (5.8%) were positive for S. stercoralis by parasitological methods, compared to two patients (3.8%) and one patient (1.9%) who were detected by ELISA using the AS and the AM antigens, respectively. S. stercoralis DNA was amplified in seven (13.5%) stool samples by qPCR. These results suggest the utility of qPCR as an alternative diagnostic tool for the diagnosis of S. stercoralis infection in immunocompromised patients, considering the possible severity of this helminthiasis in this group of patients.

Strongyloidiasis: A Disease of Socioeconomic Disadvantage

Strongyloidiasis is a disease caused by soil transmitted helminths of the Strongyloides genus. Currently, it is predominately described as a neglected tropical disease. However, this description is misleading as it focuses on the geographical location of the disease and not the primary consideration, which is the socioeconomic conditions and poor infrastructure found within endemic regions. This classification may result in misdiagnosis and mistreatment by physicians, but more importantly, it influences how the disease is fundamentally viewed. Strongyloidiasis must be first and foremost considered as a disease of disadvantage, to ensure the correct strategies and control measures are used to prevent infection. Changing how strongyloidiasis is perceived from a geographic and clinical issue to an environmental health issue represents the first step in identifying appropriate long term control measures. This includes emphasis on environmental health controls, such as better infrastructure, sanitation and living conditions. This review explores the global prevalence of strongyloidiasis in relation to its presence in subtropical, tropical and temperate climate zones with mild and cold winters, but also explores the corresponding socioeconomic conditions of these regions. The evidence shows that strongyloidiasis is primarily determined by the socioeconomic status of the communities rather than geographic or climatic conditions. It demonstrates that strongyloidiasis should no longer be referred to as a "tropical" disease but rather a disease of disadvantage. This philosophical shift will promote the development of correct control strategies for preventing this disease of disadvantage.

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.

Prevalence of chronic infections and susceptibility to measles and varicella-zoster virus in Latin American immigrants

Background

Large numbers of Latin American immigrants recently arrived in Western Europe. Curative and preventive programmes need to take account of their risk of suffering and transmitting imported chronic infections and of their susceptibility to cosmopolitan infections. We aimed to assess the prevalence and co-occurrence of imported chronic infections among Latin American immigrants, and their susceptibility to highly prevalent cosmopolitan infections.

Methods

Adult participants were recruited in the community and in a primary health centre in Geneva in 2008. Serological tests were performed on stored sera for HIV, HBV, syphilis, Strongyloides stercoralis, Trypanosoma cruzi, varicella and measles. We considered only chronic active infections in the analysis.

Results and discussion

The 1 012 participants, aged 37.2 (SD 11.3) years, were mostly female (82.5 %) and Bolivians (48 %). Overall, 209 (20.7 %) had at least one and 27 (2.7 %) two or more chronic infections. T. cruzi (12.8 %) and S. stercoralis (8.4 %) were the most prevalent chronic active infections compared to syphilis (0.4 %), HBV (0.4 %) and HIV (1.4 %). Concomitant infections affected 28.2 and 18.5 % of T. cruzi and S. stercoralis infected cases. Bolivian origin (aOR: 13.6; 95 % CI: 3.2–57.9) was associated with risk of multiple infections. Susceptibilities for VZV and measles were 0.7 and 1.4 %, respectively. Latin American immigrants are at risk of complications and possible reactivation of chronic parasitic infections but have overall low risks of chronic viral and syphilitic active infections.

Conclusions

Systematic screening for chronic active parasitic infections is therefore necessary especially among Bolivians. The high protection rate against measles and VZV doesn’t require specific preventive interventions.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-016-0136-7) contains supplementary material, which is available to authorized users.

Novel approaches to the diagnosis of Strongyloides stercoralis infection

Strongyloides stercoralis differs from the other soil-transmitted helminths because it puts infected subjects at risk of a fatal syndrome (in cases of immunosuppression for medical conditions, immunosuppressant therapies, or both). Chronic strongyloidiasis is often a non-severe condition, or is sometimes even asymptomatic, but diagnosis and effective therapy are essential in order to eradicate the infection and the life-long risk involved. Therefore, diagnostic methods need to be highly sensitive. Stool microscopy and the Kato-Katz technique are commonly used in prevalence studies, but they are inadequate for S. stercoralis detection. This is probably the main reason why the global prevalence has long been underestimated. Concentration methods, the Baermann technique and Koga agar plate culture have better, but still unsatisfactory, sensitivity. Serological tests have demonstrated higher sensitivity; although some authors have concerns about their specificity, it is possible to define cut-off values over which infection is almost certain. In particular, the luciferase immunoprecipitation system technique combined with a recombinant antigen (NIE) demonstrated a specificity of almost 100%. ELISA coproantigen detection has also shown promising results, but still needs full evaluation. Molecular diagnostic methods are currently available in a few referral centres as in-house techniques. In this review, on the basis of the performance of the different diagnostic methods, we outline diagnostic strategies that could be proposed for different purposes, such as: prevalence studies in endemic areas; individual diagnosis and screening; and monitoring of cure in clinical care and clinical trials.

Hyperinfection strongyloidiasis in renal transplant recipients

Strongyloidiasis is infection caused by the nematode Strongyloides stercoralis. Chronic uncomplicated strongyloidiasis is known to occur in immunocompetent individuals while hyperinfection and dissemination occurs in selective immunosuppressed hosts particularly those on corticosteroid therapy. We report two cases of hyperinfection strongyloidiasis in renal transplant recipients and document endoscopic and pathological changes in the involved small bowel. One patient presented with features of dehydration and malnutrition while another developed ileal obstruction and strangulation, requiring bowel resection. Oesophagogastroduodenoscopy showed erythematous and thickened duodenal mucosal folds. Histopathological examination of duodenal biopsies revealed S. stercoralis worms, larvae and eggs embedded in mucosa and submucosa. Wet mount stool preparation showed filariform larvae of S. stercoralis in both cases. Patients were managed with anthelmintic therapy (ivermectin/albendazole) and concurrent reduction of immunosuppression. Both patients had uneventful recovery. Complicated strongyloidiasis should be suspected in immunocompromised hosts who present with abdominal pain, vomiting and diarrhoea, particularly in endemic areas.

Development of a rapid serological assay for the diagnosis of strongyloidiasis using a novel diffraction-based biosensor technology

BACKGROUND

Strongyloidiasis is a persistent human parasitic infection caused by the intestinal nematode, Strongyloides stercoralis. The parasite has a world-wide distribution, particularly in tropical and subtropical regions with poor sanitary conditions. Since individuals with strongyloidiasis are typically asymptomatic, the infection can persist for decades without detection. Problems arise when individuals with unrecognized S. stercoralis infection are immunosuppressed, which can lead to hyper-infection syndrome and disseminated disease with an associated high mortality if untreated. Therefore a rapid, sensitive and easy to use method of diagnosing Strongyloides infection may improve the clinical management of this disease.

METHODOLOGY/PRINCIPAL FINDINGS

An immunological assay for diagnosing strongyloidiasis was developed on a novel diffraction-based optical bionsensor technology. The test employs a 31-kDa recombinant antigen called NIE derived from Strongyloides stercoralis L3-stage larvae. Assay performance was tested using retrospectively collected sera from patients with parasitologically confirmed strongyloidiasis and control sera from healthy individuals or those with other parasitoses including schistosomiasis, trichinosis, echinococcosis or amebiasis who were seronegative using the NIE ELISA assay. If we consider the control group as the true negative group, the assay readily differentiated S. stercoralis-infected patients from controls detecting 96.3% of the positive cases, and with no cross reactivity observed in the control group These results were in excellent agreement (κ = 0.98) with results obtained by an NIE-based enzyme-linked immunosorbent assay (ELISA). A further 44 sera from patients with suspected S. stercoralis infection were analyzed and showed 91% agreement with the NIE ELISA.

CONCLUSIONS/SIGNIFICANCE

In summary, this test provides high sensitivity detection of serum IgG against the NIE Strongyloides antigen. The assay is easy to perform and provides results in less than 30 minutes, making this platform amenable to rapid near-patient screening with minimal technical expertise.

Diagnostic accuracy of five serologic tests for Strongyloides stercoralis infection

Background

The diagnosis of Strongyloides stercoralis (S. stercoralis) infection is hampered by the suboptimal sensitivity of fecal-based tests. Serological methods are believed to be more sensitive, although assessing their accuracy is difficult because of the lack of sensitivity of a fecal-based reference (“gold”) standard.

Methods

The sensitivity and specificity of 5 serologic tests for S. stercoralis (in-house IFAT, NIE-ELISA and NIE-LIPS and the commercially available Bordier-ELISA and IVD-ELISA) were assessed on 399 cryopreserved serum samples. Accuracy was measured using fecal results as the primary reference standard, but also using a composite reference standard (based on a combination of tests).

Results

According to the latter standard, the most sensitive test was IFAT, with 94.6% sensitivity (91.2–96.9), followed by IVD-ELISA (92.3%, 87.7–96.9). The most specific test was NIE-LIPS, with specificity 99.6% (98.9–100), followed by IVD-ELISA (97.4%, 95.5–99.3). NIE-LIPS did not cross-react with any of the specimens from subjects with other parasitic infections. NIE-LIPS and the two commercial ELISAs approach 100% specificity at a cut off level that maintains ≥70% sensitivity.

Conclusions

NIE-LIPS is the most accurate serologic test for the diagnosis of S. stercoralis infection. IFAT and each of the ELISA tests are sufficiently accurate, above a given cut off, for diagnosis, prevalence studies and inclusion in clinical trials.

The diagnosis of Strongyloides stercoralis infection is usually made by finding larvae of the parasite in the feces. The larval output is orders of magnitude lower than, say, the egg output of Ancylostoma duodenale, therefore the sensitivity of conventional techniques is poor. Sensitivity is enhanced by specific techniques, but the infection can still be missed. Several serologic methods (Strongyloides antibody detection in blood) are considered more sensitive, but they have been assessed so far with fecal tests as the gold standard, which is obviously unsatisfactory considering, precisely, their suboptimal sensitivity. Using a bank of sera from patients surely infected, not infected or doubtful, we assessed the accuracy of five different serologic tests also using a composite reference standard, obtained by combining the results of different tests. The recently developed NIE-LIPS resulted virtually 100% specific, with sensitivity >80%. Two commercially available ELISA tests were also highly specific above a given cut-off. Cross reactions with other parasitic infections were rarer than in previous studies. In conclusion, serologic tests are accurate tools, both for diagnostic purposes and for prevalence studies. Whether or not they can also be reliable markers of cure is currently under study.

Three cases of imported neurocysticercosis in Northern Italy

BACKGROUND

Neurocysticercosis (NCC) is an important cause of adult-onset seizures in endemic areas, whereas it is emerging in some nonendemic areas as well because of extensive immigration.

METHOD

We describe three cases of imported NCC recently admitted to San Bortolo Hospital in Vicenza, located in Northern Italy.

RESULTS

All patients were immigrants. One patient was human immunodeficiency virus positive with severe immunosuppression. The diagnosis of NCC was made on the basis of magnetic resonance results; failure of anti-Toxoplasma, antitubercular, and antifungal therapy; and regression of the cystic lesions after empiric therapy with albendazole. Serology was positive in only one case. In one patient, NCC was diagnosed by biopsy of the brain lesion.

CONCLUSION

In nonendemic countries, NCC should be included in the differential diagnosis of all patients coming from endemic areas with seizures, hydrocephalus, and compatible lesions on brain imaging. Long-term follow-up is required but may be difficult to implement because these patients tend to move in search of employment. Screening of patient's household contacts for Taenia solium infection should always be carried out.

Seroprevalence of Schistosomiasis and Strongyloides infection in HIV-infected patients from endemic areas attending a European infectious diseases clinic

Background

Although the Centres for disease Control and Prevention (CDC) recommends empiric treatment for schistosomiasis and strongyloidiasis (prevalent but treatable parasitic infections) in some refugee groups it is unclear if these guidelines should be extended to non-refugee immigrants from endemic areas. We aimed to assess seroprevalence of, and risk factors for, positive schistosomiasis and strongyloides serology in HIV-infected patients from endemic areas attending a European Infectious Diseases clinic.

Methods

In a prospective cohort study, HIV-infected patients from helminth endemic areas underwent clinical assessment and blood draw for schistosomiasis and strongyloides serology, routine haematology and inflammatory markers (ESR and CRP). Between-group differences were analyzed by Wilcoxin Signed Rank and Fisher’s t tests as appropriate.

Results

Ninety HIV-infected patients (mean [standard deviation (SD)] age 34 [6] years, 29% male) were recruited from May 2008 to June 2009. Nine (10%) subjects tested positive for helminth infections. Seven tested positive for schistosomiasis (8%) while two tested positive for strongyloides (2%). Seropositive subjects were more likely to have higher eosinophil counts (mean [SD]) (0.3 [0.3] vs. 0.15 [0.2] x10³cells/cm, P = 0.021) with a trend towards lower CD4+ T-cell counts (mean [SD]) (280 [218] vs. 395 [217] cells/mm³, P = 0.08).

Conclusion

The high prevalence of helminth infections (10%) in asymptomatic HIV infected adults identified in this study supports routine screening of immigrants from helminth endemic areas or with exposure history.

HOOKWORM AND THREADWORM INFECTIONS AND THEIR ASSOCIATION WITH HEMOGLOBIN AND EOSINOPHIL CONCENTRATIONS IN RESIDENTS OF SALVADOR-BAHIA, BRAZIL

SUMMARY Parasitic infections are responsible for substantial mortality and morbidity worldwide. In most healthy individuals, little overt pathology is observed during infection with S. stercoralis. However, the symptoms in advanced cases may include gastrointestinal bleeding. Anemia is most commonly associated with hookworm infection, especially when several hundred worms are present. Our study evaluates the relationship between the hookworm or S. stercoralis infection status and the hemoglobin concentration of individuals examined by a private network of laboratories in Salvador, Bahia, Brazil. We examined 374,120 samples from middle-class individuals living in Salvador City from January 2004 to April 2008. The stool samples were analyzed by the Lutz and Baermann-Moraes methods, and the blood samples were analyzed for hemoglobin concentration and eosinophil counting. The prevalence of hookworm and S. stercoralis were 0.27% (1,027) and 0.34% (1,286), respectively. The prevalence of hookworm and S. stercoralis infection was significantly higher in males than in females and increased with age. Eosinophilia was a common laboratorial finding in individuals infected with hookworm and S. stercoralis. The hemoglobin concentration was lower in the hookworm-infected individuals than in non-infected ones, but none of the examined patients were anemic. Lack of anemia could be a consequence of the socioeconomic status of these patients.

Strongyloides stercoralis, the hidden worm. Epidemiological and clinical characteristics of 70 cases diagnosed in the North Metropolitan Area of Barcelona, Spain, 2003-2012

BACKGROUND

The nematode Strongyloides stercoralis has a very particular autoinfection life-cycle which leads to chronic infections remaining undetected for decades. However, hyperinfection can occur in patients receiving immunotherapy resulting in high mortality rates. The main objective of this study was to assess the results of a 10-year multicenter surveillance program performed in an area with dense immigration in Barcelona, Spain.

METHODS

From January 2003 to December 2012, all individuals with Strongyloides stercoralis infection attending the four centers with diagnostic capability in the North Metropolitan area of Barcelona were recorded.

RESULTS

The annual detection rate was 0.2 new diagnosed cases x10 000 inhabitants/year and 1 case x10 000 immigrants/year. Many patients were immigrants (63; 90.0%), asymptomatic (45; 64.3%) and with a high eosinophil count (63; 90.0%). Immunosuppression was present in 11 (15.7%) patients, among whom two (2.8%) cases of disseminated hyperinfection were recorded. Ivermectin was prescribed in 45 (76.3%) and albendazole in 14 (23.7%). Following treatment seven patients (11.9%) receiving albendazole presented relapse, that is, albendazole failed to clear the parasite in 50% of these drug-treated patients (p < 0.001).

CONCLUSIONS

During the study period, 90% of the cases of Strongyloides stercoralis diagnosed could be considered as imported by immigrants, most being asymptomatic and with eosinophilia. The infection is probably largely underestimated and population-based studies are needed to determine its true prevalence. Meanwhile, diagnosis must be based on active investigation of the helminth (serology and feces culture), especially in immunocompromised patients. The implementation of pre-immunosuppression protocols with the aim of identifying Strongyloides stercoralis is encouraged with empirical treatment with ivermectin being recommended in sites without diagnostic facilities.

Imported strongyloidiasis: epidemiology, presentations, and treatment

Strongyloidiasis is extremely more frequent in immigrants than in travellers. Clinical presentations do not differ significantly between the two groups, and the most frequent picture is a chronic infection characterized by intermittent, mild, non-specific symptoms. Acute presentation is rare but it has been reported in travellers. Screening of asymptomatic subjects is not generally recommended, while a presumptive treatment with ivermectin might be justified for all travellers and immigrant patients presenting unexplained eosinophilia and/or compatible symptoms, even in case of negative test results. In fact, delayed diagnosis and treatment has life-threatening consequences in patients with conditions predisposing to development of hyperinfection and dissemination.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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