Effectiveness of Screening and Treatment Approaches for Schistosomiasis and Strongyloidiasis in Newly-Arrived Migrants from Endemic Countries in the EU/EEA: A Systematic Review

Evaluation of the accuracy of a multi-infection screening test based on a multiplex immunoassay targeting imported diseases common in migrant populations

BACKGROUND

We aimed to evaluate the performance of a novel multiplex serological assay, able to simultaneously detect IgG of six infections, as a screening tool for imported diseases in migrants.

METHODS

Six panels of 40 (n = 240) anonymized serum samples with confirmed infections were used as positive controls to assess the multiplex assay's sensitivity. One panel of 40 sera from non-infected subjects was used to estimate the seropositivity cutoffs, and 32 non-infected sera were used as negative controls to estimate each serology's sensitivity and specificity. The multi-infection screening test was validated in a prospective cohort of 48 migrants from endemic areas. The sensitivity of the Luminex assay was calculated as the proportion of positive results over all positive samples identified by reference tests. The specificity was calculated using 32 negative samples. Uncertainty was quantified with 95 % confidence intervals using receiver operating characteristic analyses.

RESULTS

The sensitivity/specificity were 100 %/100 % for HIV (gp41 antigen), 97.5 %/100 % for Hepatitis B virus (HBV-core antigen), 100 %/100 % for Hepatitis C virus (HCV-core antigen), 92.5 %/90.6 % for strongyloidiasis [31-kDa recombinant antigen (NIE)], 97.5 %/100 % for schistosomiasis (combined serpin Schistosoma mansoni and S.haematobium antigens) and 95 %/90.6 % for Chagas disease [combined Trypanosoma cruzi kinetoplastid membrane protein-11 (KMP11) and paraflagellar rod proteins 2 (PFR2) antigens]. In the migrant cohort, antibody response to the combination of the T.cruzi antigens correctly identified 100 % individuals, whereas HBV-core antigen correctly identified 91.7 % and Strongyloides-NIE antigen 86.4 %.

CONCLUSIONS

We developed a new, robust and accurate 8-plex Luminex assay that could facilitate the implementation of screening programmes targeting migrant populations.

Human strongyloidiasis: complexities and pathways forward

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

Executive summary consensus statement of imported diseases group (GEPI) of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) and the Spanish Society of Tropical Medicine and International Health (SETMSI), on the diagnostic and treatment of imported schistosomiasis

Schistosomiasis is a highly prevalent disease, especially in immigrant populations, and is associated with significant morbidity and diagnostic delays outside endemic areas. For these reasons, the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) and the Spanish Society of Tropical Medicine and International Health (SEMTSI) have developed a joint consensus document to serve as a guide for the screening, diagnosis and treatment of this disease outside endemic areas. A panel of experts from both societies identified the main questions to be answered and developed recommendations based on the scientific evidence available at the time. The document was reviewed by the members from both societies for final approval.

Spectrum of Helminth Infections in Migrants from Sub-Saharan Africa to Europe: A Literature Review

Sub-Saharan Africa (SSA) is endemic to numerous neglected tropical diseases, including many helminth diseases. With the migration of people from this part of the world to Europe, as has been happening on a large scale since 2015, these diseases are becoming more relevant to European physicians. This work aims to summarize the recent literature on this topic and to raise awareness of helminth diseases afflicting SSA migrants. The databases PubMed, Embase, and MEDLINE were screened for literature published in English and German between January 1, 2015 and December 31, 2020. In total, 74 articles were included in this review. The spectrum of helminth infections in migrants from SSA found in the literature review is broad; current research, however, is particularly focused on infections with Schistosoma spp. and Strongyloides stercoralis. Both diseases are often characterized by a long course, with few or no symptoms, with the risk of long-term organ damage. Successful and reliable screening for schistosomiasis and strongyloidiasis is strongly recommended. However, the current diagnostic methods lack sensitivity and specificity, rendering the diagnosis challenging and reliable assessment of disease prevalence difficult. Novel diagnostic methods and a greater awareness of these diseases are urgently needed.

Presumptive treatment or serological screening for schistosomiasis in migrants from Sub-Saharan Africa could save both lives and money for the Italian National Health System: results of an economic evaluation

BACKGROUND

Schistosomiasis can lead to severe irreversible complications and death if left untreated. Italian and European guidelines recommend serological screening for this infection in migrants from Sub-Saharan Africa (SSA). However, studies on clinical and economic impact of this strategy in the Italian and European settings are lacking. This study aims to compare benefits and costs of different strategies to manage schistosomiasis in migrants from SSA to Italy.

METHODS

A decision tree and a Markov model were developed to assess the health and economic impacts of three interventions: (i) passive diagnosis for symptomatic patients (current practice in Italy); (ii) serological screening of all migrants and treating those found positive and (iii) presumptive treatment for all migrants with praziquantel in a single dose. The time horizon of analysis was one year to determine the exact expenses, and 28 years to consider possible sequelae, in the Italian health-care perspective. Data input was derived from available literature; costs were taken from the price list of Careggi University Hospital, Florence, and from National Hospitals Records.

RESULTS

Assuming a population of 100 000 migrants with schistosomiasis prevalence of 21·2%, the presumptive treatment has a greater clinical impact with 86.3% of the affected being cured (75.2% in screening programme and 44.9% in a passive diagnosis strategy). In the first year, the presumptive treatment and the screening strategy compared with passive diagnosis prove cost-effective (299 and 595 cost/QALY, respectively). In the 28-year horizon, the two strategies (screening and presumptive treatment) compared with passive diagnosis become dominant (less expensive with more QALYs) and cost-saving.

CONCLUSION

The results of the model suggest that presumptive treatment and screening strategies are more favourable than the current passive diagnosis in the public health management of schistosomiasis in SSA migrants, especially in a longer period analysis.

Accuracy of Three Serological Techniques for the Diagnosis of Imported Schistosomiasis in Real Clinical Practice: Not All in the Same Boat

Schistosomiasis is a neglected tropical disease despite of being a major public health problem affecting nearly 240 million people in the world. Due to the migratory flow from endemic countries to Western countries, an increasing number of cases is being diagnosed in non-endemic areas, generally in migrants or people visiting these areas. Serology is the recommended method for screening and diagnosis of schistosomiasis in migrants from endemic regions. However, serological techniques have a highly variable sensitivity. The aim of this study was to evaluate retrospectively the sensitivity of three different serological tests used in real clinical practice for the screening and diagnosis of imported schistosomiasis in sub-Saharan migrant patients, using the detection of schistosome eggs in urine, faeces or tissues as the gold standard. We evaluated three different serological techniques in 405 sub-Saharan patients with confirmed schistosomiasis treated between 2004 and 2022: an enzyme-linked immunosorbent assay (ELISA), an indirect haemagglutination assay (IHA) and an immunochromatographic test (ICT). The overall sensitivity values obtained with the different techniques were: 44.4% for IHA, 71.2% for ELISA and 94.7% for ICT, respectively. According to species, ICT showed the highest sensitivity (S. haematobium: 94%, S. mansoni: 93.3%; and S. intercalatum/guineensis: 100%). In conclusion, our study shows that Schistosoma ICT has the best performance in real clinical practice, when compared to ELISA and IHA, in both S. mansoni and S. haematobium infections.

Evaluation of Two Different Strategies for Schistosomiasis Screening in High-Risk Groups in a Non-Endemic Setting

A consensus on the recommended screening algorithms for schistosomiasis in asymptomatic high-risk subjects in non-endemic areas is lacking. The objective of this study was to evaluate the real-life performance of direct microscopy and ELISA serology for schistosomiasis screening in a high-risk population in a non-endemic setting. A retrospective cohort study was conducted in two out-patient Tropical Medicine units in Barcelona (Spain) from 2014 to 2017. Asymptomatic adults arriving from the Sub-Saharan region were included. Schistosomiasis screening was conducted according to clinical practice following a different strategy in each setting: (A) feces and urine direct examination plus S. mansoni serology if non-explained eosinophilia was present and (B) S. mansoni serology plus uroparasitological examination as the second step in case of a positive serology. Demographic, clinical and laboratory features were collected. Schistosomiasis cases, clinical management and a 24 month follow-up were recorded for each group. Four-hundred forty individuals were included. The patients were mainly from West African countries. Fifty schistosomiasis cases were detected (11.5% group A vs. 4 % group B, p = 0.733). When both microscopic and serological techniques were performed, discordant results were recorded in 18.4% (16/88). Schistosomiasis cases were younger (p < 0.001) and presented eosinophilia and elevated IgE (p < 0.001) more frequently. Schistosomiasis is a frequent diagnosis among high-risk populations. Serology achieves a similar performance to direct diagnosis for the screening of schistosomiasis in a high-risk population.

Development of a Duplex LAMP Assay with Probe-Based Readout for Simultaneous Real-Time Detection of Schistosoma mansoni and Strongyloides spp. -A Laboratory Approach to Point-Of-Care

Loop-mediated isothermal amplification (LAMP) is the most popular technology for point-of-care testing applications due its rapid, sensitive and specific detection with simple instrumentation compared to PCR-based methods. Many systems for reading the results of LAMP amplifications exist, including real-time fluorescence detection using fluorophore-labelled probes attached to oligonucleotide sequences complementary to the target nucleic acid. This methodology allows the simultaneous detection of multiple targets (multiplexing) in one LAMP assay. A method for multiplexing LAMP is the amplification by release of quenching (DARQ) technique by using a 5'-quencher modified LAMP primer annealed to 3'-fluorophore-labelled acting as detection oligonucleotide. The main application of multiplex LAMP is the rapid and accurate diagnosis of infectious diseases, allowing differentiation of co-infecting pathogens in a single reaction. Schistosomiasis, caused among other species by Schistosoma mansoni and strongyloidiasis, caused by Strongyloides stercoralis, are the most common helminth-parasite infections worldwide with overlapping distribution areas and high possibility of coinfections in the human population. It would be of great interest to develop a duplex LAMP to detect both pathogens in the same reaction. In this study, we investigate the use of our two previously developed and well-stablished LAMP assays for S. mansoni and Strongyloides spp. DNA detection in a new duplex real-time eight-primer system based on a modified DARQ probe method that can be performed in a portable isothermal fluorimeter with minimal laboratory resources. We also applied a strategy to stabilize the duplexed DARQ-LAMP mixtures at room temperature for use as ready-to-use formats facilitating analysis in field settings as point-of-care diagnostics for schistosomiasis and strongyloidiasis.

Prevalence of Antimicrobial Resistance and Infectious Diseases in a Hospitalised Migrant Population in Paris, France, a Retrospective Study

Objectives: The aim of this study was to estimate the prevalence of anti-microbial resistance (AMR) carriage and its risk factors in hospitalized migrants. Additionally, the prevalence of infectious diseases was evaluated, as well as symptoms of psychological trauma. Methods: We conducted a retrospective monocentric cross-sectional study including all migrant patients recently arrived and hospitalised over a one-year period. Results: Among 101 patients, seventy-nine percent originated from Sub-Saharan Africa. The overall AMR carriage rate was 20.7% [95% CI: 12.4; 28.9%]. We isolated 5/92 methicillin-resistant Staphylococcus aureus strains (5.4%) and 15/92 extended-spectrum beta-lactamase-producing Enterobacteriaceae (16.4%). AMR carriage was associated with older age, region of origin and length of migration. Rates of HIV, HBV, and HCV infection were 39.6%, 32.7%, and 5%, reflecting sampling bias linked to reasons for hospitalization. Eleven percent had serological evidence of treponemasis and 7.8% had Chlamydia trachomatis infection. Symptoms of depression or post-traumatic stress disorder were observed for more than half the patients. Conclusion: It appears essential to offer a systematic and comprehensive post-arrival screening of AMR carriage, infectious diseases and psychological trauma to subjects who experienced migration.

Usefulness and practicality of a multidisease screening programme targeting migrant patients in primary care in Spain: a qualitative study of general practitioners

OBJECTIVES

Some migrant groups are disproportionately affected by key infectious diseases in European countries. These pose a challenge for healthcare systems providing care to these groups. We aimed to explore the views of general practitioners (GPs) on the acceptability, adaptability and feasibility of a multidisease screening programme based on an innovative clinical decision-support system for migrants (the ISMiHealth tool), by examining the current gaps in healthcare provision and areas of good practice and the usefulness and limitations of training in the health needs of migrants.

METHODS

We undertook a qualitative descriptive study and carried out a series of focus groups (FGs) taking a pragmatic utilitarian approach. Participants were GPs from the four primary healthcare (PHC) centres in Catalonia, Spain, that piloted an intervention of the ISMiHealth tool. GPs were recruited using purposive and convenience sampling. FG discussions were transcribed and analysed using thematic content analysis.

RESULTS

A total of 29 GPs participated in four FGs. Key themes identified were: (1) GPs found the ISMiHealth tool to be very useful for helping to identify specific health problems in migrants, although there are several additional barriers to screening as part of PHC, (2) the importance of considering cultural perspectives when caring for migrants, and of the impact of migration on mental health, (3) the important role of PHC in healthcare provision for migrants and (4) key proposals to improve screening of migrant populations. GPs also highlighted the urgent need, to shift to a more holistic and adequately resourced approach to healthcare in PHC.

CONCLUSIONS

GPs supported a multidisease screening programme for migrant populations using the ISMiHealth tool, which aided clinical decision-making. However, intercultural participatory approaches will need to be adopted to address linguistic and cultural barriers to healthcare access that exist in migrant communities.

Improving the detection of infectious diseases in at-risk migrants with an innovative integrated multi-infection screening digital decision support tool (IS-MiHealth) in primary care: a pilot cluster-randomized-controlled trial

BACKGROUND

There are major shortfalls in the identification and screening of at-risk migrant groups. This study aims to evaluate the effectiveness of a new digital tool (IS-MiHealth) integrated into the electronic patient record system of primary care centres in detecting prevalent migrant infections. IS-MiHealth provides targeted recommendations to health professionals for screening multiple infections, including human immunodeficiency virus (HIV), hepatitis B and C, active tuberculosis (TB), Chagas disease, strongyloidiasis and schistosomiasis, based on patient characteristics (including variables of country of origin, age and sex).

METHODS

A pragmatic pilot cluster-randomized-controlled trial was deployed from March to December 2018. Eight primary care centres in Catalonia, Spain, were randomly allocated 1:1 to use of the digital tool for screening, or to routine care. The primary outcome was the monthly diagnostic yield of all aggregated infections. Intervention and control sites were compared before and after implementation with respect to their monthly diagnostic yield using regression models. This study is registered on international standard randomised controlled trial number (ISRCTN) (ISRCTN14795012).

RESULTS

A total of 15 780 migrants registered across the eight centres had at least one visit during the intervention period (March-December 2018), of which 14 598 (92.51%) fulfilled the criteria to be screened for at least one infection. There were 210 (2.57%) individuals from the intervention group with new diagnoses compared with 113 (1.49%) from the control group [odds ratio: 2.08, 95% confidence interval (CI) 1.63-2.64, P < 0.001]. The intervention centres raised their overall monthly diagnosis rate to 5.80 (95% CI 1.23-10.38, P = 0.013) extra diagnoses compared with the control centres. This monthly increase in diagnosis in intervention centres was also observed if we consider all cases together of HIV, hepatitis B and C, and active TB cases [2.72 (95% CI 0.43-5.00); P = 0.02] and was observed as well for the parasitic infections' group (Chagas disease, strongyloidiasis and schistosomiasis) 2.58 (95% CI 1.60-3.57; P < 0.001).

CONCLUSIONS

The IS-MiHealth increased screening rate and diagnostic yield for key infections in migrants in a population-based primary care setting. Further testing and development of this new tool is warranted in larger trials and in other countries.

Schistosomiasis model with treatment, habitat modification and biological control

Schistosomiasis is a parasitic disease caused by Schistosoma worm infection. Some species of snails can serve as the intermediate hosts for the parasite. Numerous interventions have been performed to repress the snail population. One of them is the use of molluscicide. Nevertheless, it is debated that molluscicide intervention has negative impacts on the ecosystem. To investigate the impact of more environmentally friendly interventions, we develop a schistosomiasis model with treatment, habitat modification and biological control. The biological control agent examined in our model is a snail predator. Moreover, to investigate the impact of snail habitat modification, we assume that the snail population grows logistically. We show that all solutions of our model are non-negative and bounded. We also study the existence and stability conditions of equilibrium points. The basic reproduction numbers are determined using the next-generation operator. Linearization combined with the Routh-Hurwitz criterion is used to prove the local stability condition of disease-free equilibrium points. Bifurcation theory is applied to investigate the local stability condition of the endemic equilibrium points. To examine the global behavior of our model, we use asymptotically autonomous system theory and construct a Lyapunov function. We perform several numerical simulations to validate and support our deductive results. Our results show that early treatment can reduce the basic reproduction number and schistosomiasis cases. In addition, modifying snail habitat and releasing the snail predator at the snail habitat can reduce schistosomiasis prevalence. We suggest using snail predators which can hunt and kill snails effectively as a biological control agent.

A simple new screening tool for diagnosing imported schistosomiasis

Objectives

We sought to test the sensitivity and feasibility of a Schistosoma infection screening process consisting of a scored patient consultation questionnaire and a serological diagnostic test.

Study design

Prospective cross-sectional study.

Methods

We collected from Schistosoma-exposed individuals a 14-point check list of clinical and laboratory data related to Schistosoma infection, alongside a serological test to detect Schistosoma spp infection. A check list score was created and compared with the risk of infection and clinical recovery through an agreement analysis.

Results

Two-hundred and fifty individuals were enrolled, of whom 220 (88%) were male and 30 (12%) female. The median age was 39 (range 18–78). One hundred-fifty (60%, 95% CI 54.9%–65.1%) had a check-list score ≥2. Serology test results were positive for 142 (56.8%, 95% CI 51.6%–62%). Chronic complications compatible with long-term Schistosoma infection were detected in 29 out of these 142 (20.4%, 95% CI 13.8%–27%).,. The median score value was 3, the area under the receiver operating characteristic (ROC) curve against serology results was 0.85 and the estimated intercept check-list questionnaire score value was 1.72 (95%, CI: 1.3–2.2). Participants with a positive serological test had a substantially higher check-list score (Cohen's kappa coefficient: 0.62, 95% CI: 0.54–0.70). Ninety four percent patients empirically treated showed a subsequent improvement in clinical and laboratory parameters.

Conclusions

A two-component process consisting of a scored patient consultation questionnaire followed by serological assay can be a suitable strategy for screening populations at high risk of schistosomiasis infection.

Screening for parasites in migrant children

BACKGROUND

Globalization has pushed population movements in the last decades, turning imported diseases into the focus. Due to behavioral habits, children are at higher risk of acquiring iparasitosis. This study aims to investigate the prevalence of parasites in migrant children and factors associated with parasitic diseases.

METHOD

Retrospective cross-sectional study (2014-2018) including children diagnosed with parasitosis. The diagnosis was based on serology and/or microscopic stool-sample evaluation. Epidemiological and clinical data were recorded.

RESULTS

Out of 813 migrant children screened, 241 (29.6%) presented at least one parasite, and 89 (10.9%) more than one. The median age was 6.6 years (IQR: 3.1-11.9) and 58.9% were males. Most cases were referred for a health exam; only 52.3% of children were symptomatic, but 43.6% had eosinophilia. The most common diagnosis were giardiasis (35.3%), schistosomiasis (19.1%), toxocariasis (15.4%), and strongyloidiasis (9.1%). After the multivariate analysis, African origin and presenting with eosinophilia were the main risk factors for parasitism.

CONCLUSIONS

parasitosis are frequent among migrant children. Children are often asymptomatic, and thus active screening for parasitosis should be considered among high-risk populations. Eosinophilia can be useful to guide complimentary tests, as well as geographical origin, but normal eosinophil count does not exclude parasitosis.

Schistosomiasis Among Female Migrants in Non-endemic Countries: Neglected Among the Neglected? A Pilot Study

Background

Schistosomiasis among migrant populations in Europe is an underdiagnosed infection, yet delayed treatment may have serious long-term consequences. In this study we aimed to characterize the clinical manifestations of Schistosoma infection among migrant women, and the degree of underdiagnosis.

Methods

We carried out a prospective cross-sectional study among a migrant population living in the North Metropolitan Barcelona area and coming from schistosomiasis-endemic countries. We obtained clinical, laboratory and socio-demographic data from electronic clinical records, as well as information about years of residence and previous attendance at health services. Blood sample was obtained and schistosomiasis exposure was assessed using a specific ELISA serological test.

Results

Four hundred and five patients from schistosomiasis-endemic regions were screened, of whom 51 (12.6%) were female. Seropositivity prevalence was 54.8%, but considering women alone we found a prevalence of 58.8% (30 out of 51). The median age of the 51 women was 41.0 years [IQR (35–48)] and the median period of residence in the European Union was 13 years [IQR (10–16)]. Schistosoma-positive women (N = 30) showed a higher prevalence of gynecological signs and symptoms compared to the seronegative women (96.4 vs. 66.6%, p = 0.005). Among seropositive women, the median number of visits to Sexual and Reproductive Health unit prior to diagnosis of schistosomiasis was 41 [IQR (18–65)].

Conclusion

The high prevalence of signs and symptoms among seropositive women and number of previous visits suggest a high rate of underdiagnosis and/or delayed diagnosis of Schistosoma infection, particularly female genital schistosomiasis, among migrant females.

Screening for Chronic Infectious Diseases by Serology in Those Presenting with Malaria in London, United Kingdom

The United Kingdom's cases of malaria infection are primarily acquired in sub-Saharan Africa, with the majority of infections presenting in London.1 When patients go to a hospital with malaria, there is a screening opportunity for other geographically associated chronic infections. We identified patients who were diagnosed with malaria after presenting to our emergency department in London over a 2-year period, to assess whether there may be clinical benefit in screening for chronic viral (hepatitis B, hepatitis C, HIV) or parasitic (schistosomiasis, strongyloidiasis) infection in this cohort. Over this period, 131 patients were diagnosed with malaria. Crude seropositivity rates for HIV, hepatitis B, and strongyloidiasis were higher than expected compared with local population estimates, 7 and 28 times higher for HIV and hepatitis B, respectively. Those patients with previously unidentified cases were offered appropriate treatment. These findings support the potential clinical and public health benefits of screening for other infectious diseases in the context of a malaria diagnosis.

Strongyloidiasis in immunocompromised migrants to non-endemic countries in the era of COVID-19: what is the role for presumptive ivermectin?

The COVID-19 pandemic has led to widespread use of dexamethasone. Corticosteroid therapy is an important risk factor for Strongyloides hyperinfection. Challenges associated with the performance of Strongyloides tests, and the poor availability of high quality and timely diagnostic testing, makes the use of presumptive ivermectin reasonable in selected situations.

Meta-analysis of variable-temperature PCR technique performance for diagnosising Schistosoma japonicum infections in humans in endemic areas

BACKGROUND

As China is moving onto schistosomiasis elimination/eradication, diagnostic methods with both high sensitivity and specificity for Schistosoma japonicum infections in humans are urgently needed. Microscopic identification of eggs in stool is proven to have poor sensitivity in low endemic regions, and antibody tests are unable to distinguish between current and previous infections. Polymerase chain reaction (PCR) technologies for the detection of parasite DNA have been theoretically assumed to show high diagnostic sensitivity and specificity. However, the reported performance of PCR for detecting S. japonicum infection varied greatly among studies. Therefore, we performed a meta-analysis to evaluate the overall diagnostic performance of variable-temperature PCR technologies, based on stool or blood, for detecting S. japonicum infections in humans from endemic areas.

METHODS

We searched literatures in eight electronic databases, published up to 20 January 2021. The heterogeneity and publication bias of included studies were assessed statistically. The risk of bias and applicability of each eligible study were assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool (QUADAS-2). The bivariate mixed-effects model was applied to obtain the summary estimates of diagnostic performance. The hierarchical summary receiver operating characteristic (HSROC) curve was applied to visually display the results. Subgroup analyses and multivariate regression were performed to explore the source of heterogeneity. This research was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and was registered prospectively in PROSPERO (CRD42021233165).

RESULTS

A total of 2791 papers were retrieved. After assessing for duplications and eligilibity a total of thirteen publications were retained for inclusion. These included eligible data from 4268 participants across sixteen studies. High heterogeneity existed among studies, but no publication bias was found. The pooled analyses of PCR data from all included studies resulted in a sensitivity of 0.91 (95% CI: 0.83 to 0.96), specificity of 0.85 (95% CI: 0.65 to 0.94), positive likelihood ratio of 5.90 (95% CI: 2.40 to 14.60), negative likelihood ratio of 0.10 (95% CI: 0.05 to 0.20) and a diagnostics odds ratio of 58 (95% CI: 19 to 179). Case-control studies showed significantly better performances for PCR diagnostics than cross-sectional studies. This was further evidenced by multivariate analyses. The four types of PCR approaches identified (conventional PCR, qPCR, Droplet digital PCR and nested PCR) differed significantly, with nested PCRs showing the best performance.

CONCLUSIONS

Variable-temperature PCR has a satisfactory performance for diagnosing S. japonicum infections in humans in endemic areas. More high quality studies on S. japonicum diagnostic techniques, especially in low endemic areas and for the detection of dual-sex and single-sex infections are required. These will likely need to optimise a nested PCR alongside a highly sensitive gene target. They will contribute to successfully monitoring endemic areas as they move towards the WHO 2030 targets, as well as ultimately helping areas to achieve these goals.

Strongyloidiasis in Children Outside the Tropics: Do We Need to Increase Awareness?

Strongyloidiasis belongs to the group of neglected tropical diseases, due to diagnostic difficulties and the lack of systematic screening. Studies on strongyloidiasis prevalence are often heterogenous and mainly performed in adults in endemic countries. We retrospectively enrolled 2633 children referred to a tertiary care hospital in Italy between 2009 and 2020 and tested for S. stercoralis infection. Sixty-one (2.3%) had a positive serology and for 55 of them, clinical and epidemiological information were available. Thirteen cases (24%) were diagnosed in Italian children without history residency or travel to foreign countries, while the remaining were internationally adopted or migrant children. Seropositive patients were mostly asymptomatic, and often eosinophilia was the only sign of strongyloidiasis. Sero-reactivity to Toxocara canis was found in 1/3 of patients. Ivermectin was used in 37 (75.5%) treated patients. A significant reduction of eosinophil levels and IgG titer was seen after treatment. Our study confirms that strongyloidiasis is usually asymptomatic in children. However, due to the ability of the parasite to cause a life-long infection together with the risk of a severe form in case of immunosuppression, it is important to identify and treat infected children. Special consideration should be reserved to high-risk groups, such as immigrants and international adoptees, where screening for S. stercoralis is indicated. However, the study highlights that sporadic cases of autochthonous strongyloidiasis in Italy may occur. Therefore, pediatricians should be aware of this condition, which is often under-recognized.

Context-Specific Procedures for the Diagnosis of Human Schistosomiasis – A Mini Review

Schistosomiasis is a parasitic disease caused by trematode blood flukes of the genus Schistosoma, affecting over 250 million people mainly in the tropics. Clinically, the disease can present itself with acute symptoms, a stage which is relatively more common in naive travellers originating from non-endemic regions. It can also develop into chronic disease, with the outcome depending on the Schistosoma species involved, the duration and intensity of infection and several host-related factors. A range of diagnostic tests is available to determine Schistosoma infection, including microscopy, antibody detection, antigen detection using the Point-Of-Care Circulating Cathodic Antigen (POC-CCA) test and the Up-Converting Particle Lateral Flow Circulating Anodic Antigen (UCP-LF CAA) test, as well as Nucleic Acid Amplification Tests (NAATs) such as real-time PCR. In this mini review, we discuss these different diagnostic procedures and explore their most appropriate use in context-specific settings. With regard to endemic settings, diagnostic approaches are described based on their suitability for individual diagnosis, monitoring control programs, determining elimination as a public health problem and eventual interruption of transmission. For non-endemic settings, we summarize the most suitable diagnostic approaches for imported cases, either acute or chronic. Additionally, diagnostic options for disease-specific clinical presentations such as genital schistosomiasis and neuro-schistosomiasis are included. Finally, the specific role of diagnostic tests within research settings is described, including a controlled human schistosomiasis infection model and several clinical studies. In conclusion, context-specific settings have different requirements for a diagnostic test, stressing the importance of a well-considered decision of the most suitable diagnostic procedure.

Molecular approach to the epidemiology of urinary schistosomiasis in France

BACKGROUND

The diagnosis of urogenital schistosomiasis is based on the complementarity of serological technique and microscopic examination (ME). Between 2015 and 2019, the number of urinary schistosomiasis tests received in our laboratory increased sharply from 300 to 900 per year. Therefore, we wanted to evaluate the reliability of urine microscopic examination (ME, reference and routine technique) from urine sample by comparing it to other techniques (antigenic technique and PCR). To this end, we optimized two real-time PCRs targeting respectively Schistosoma haematobium (Sh) and Schistosoma mansoni (Sm).

METHODOLOGY/PRINCIPAL FINDINGS

914 urine samples from 846 patients suspected of urogenital schistosomiasis were prescribed and analyzed by PCR and also by antigenic technique for the first 143 samples. The antigenic technique evaluated was Schisto POC-CCA, Rapid Medical Diagnostics. These results (antigenic technique and PCR) were compared to ME which was performed from all urines. The percentage of 14% (128/914) positive cases with the PCR technique and the percentage of 6.0% (54/914) positive cases with ME is significantly different (Chi 2 test, p<0.001). These 128 positive PCRs correspond to 120 different patients, 88.3% (106/120) of them were young migrants and 11.7% (14/120) were French patients returning from travel. Among these migrants, more than 75% (80/106) came from French-speaking West Africa. In addition, the Schisto POC-CCA showed a specificity of 39% (46/117), too poor to be used as a screening tool in low or non-endemic areas.

CONCLUSION/SIGNIFICANCE

Targeted Sh and Sm PCRs in urine are reliable techniques compared to ME (reference technique). In view of our results, we decided to screen urinary schistosomiasis by direct ME always coupled by the PCR technique, which has shown better reliability criteria.

Cost-effectiveness of different strategies for screening and treatment of Strongyloides stercoralis in migrants from endemic countries to the European Union

BACKGROUND

The best strategy for controlling morbidity due to imported strongyloidiasis in migrants is unclear. We evaluate the cost-effectiveness of six possible interventions.

METHODS

We developed a stochastic Markov chain model. The target population was adult migrants from endemic countries to the European Union; the time horizon, a lifetime and the perspective, that of the health system. Average and incremental cost-effectiveness ratios (ACER and ICER) were calculated as 2016 EUR/life-year gained (LYG). Health interventions compared were: base case (no programme), primary care-based presumptive treatment (PCPresTr), primary care-based serological screening and treatment (PCSerTr), hospital-based presumptive treatment (HospPresTr), hospital-based serological screening and treatment (HospSerTr), hospital-based presumptive treatment of immunosuppressed (HospPresTrim) and hospital-based serological screening and treatment of the immunosuppressed (HospSerTrim). The willingness to pay threshold (WTP) was €32 126.95/LYG.

RESULTS

The base case model yielded a loss of 2 486 708.24 life-years and cost EUR 3 238 393. Other interventions showed the following: PCPresTr: 2 488 095.47 life-years (Δ1 387.23LYG), cost: EUR 8 194 563; ACER: EUR 3573/LYG; PCSerTr: 2 488 085.8 life-years (Δ1377.57LYG), cost: EUR 207 679 077, ACER: EUR 148 407/LYG; HospPresTr: 2 488 046.17 life-years (Δ1337.92LYG), cost: EUR 14 559 575; ACER: EUR 8462/LYG; HospSerTr: 2 488 024.33 life-years (Δ1316.08LYG); cost: EUR 207 734 073; ACER: EUR 155 382/LYG; HospPresTrim: 2 488 093.93 life-years, cost: EUR 1 105 483; ACER: EUR -1539/LYG (cost savings); HospSerTrim: 2 488 073.8 life-years (Δ1365.55LYG), cost: EUR 4 274 239; ACER: EUR 759/LYG. One-way and probabilistic sensitivity analyses were undertaken; HospPresTrim remained below WTP for all parameters' ranges and iterations.

CONCLUSION

Presumptively treating all immunosuppressed migrants from areas with endemic Strongyloides would generate cost savings to the health system.

Development of rSs-NIE-1 and rSs-IR Recombinant Antigen-Based Immunoblot for Detection of Antibody to Strongyloides stercoralis

Strongyloides stercoralis is a soil-transmitted nematode that can cause life-threatening conditions in immunocompromised persons. In the United States, strongyloidiasis should be considered mainly in immigrants, refugees, or travelers. The confirmatory laboratory diagnosis is usually performed by detecting larvae from the stool, duodenal material, and sputum. In persons who are immunocompromised with severe strongyloidiasis, adult worms and eggs can be detected from duodenal material. For serological diagnosis, most assays use crude antigens to detect anti-S. stercoralis IgG. Recently, recombinant proteins such as rSs-NIE-1 and rSs-IR have been used to detect IgG antibodies. We used rSs-NIE-1 and rSs-IR recombinant antigens to develop a biplex Western blot assay to detect the IgG4 antibody in individuals with strongyloidiasis. The sensitivities of rSs-NIE-1 and rSs-IR were 97.4% and 90.8%, respectively, whereas the specificities were 97.6% and 98%, respectively. In conclusion, the biplex rSs-NIE-1 and rSs-IR immunoblot performs well in detecting IgG4 antibody in S. stercoralis-infected persons.

Seropositivity and geographical distribution of Strongyloides stercoralis in Australia: A study of pathology laboratory data from 2012-2016

Background

There are no national prevalence studies of Strongyloides stercoralis infection in Australia, although it is known to be endemic in northern Australia and is reported in high risk groups such as immigrants and returned travellers. We aimed to determine the seropositivity (number positive per 100,000 of population and percent positive of those tested) and geographical distribution of S. stercoralis by using data from pathology laboratories.

Methodology

We contacted all seven Australian laboratories that undertake Strongyloides serological (ELISA antibody) testing to request de-identified data from 2012–2016 inclusive. Six responded. One provided positive data only. The number of people positive, number negative and number tested per 100,000 of population (Australian Bureau of Statistics data) were calculated including for each state/territory, each Australian Bureau of Statistics Statistical Area Level 3 (region), and each suburb/town/community/locality. The data was summarized and expressed as maps of Australia and Greater Capital Cities.

Principal findings

We obtained data for 81,777 people who underwent serological testing for Strongyloides infection, 631 of whom were from a laboratory that provided positive data only. Overall, 32 (95% CI: 31, 33) people per 100,000 of population were seropositive, ranging between 23/100,000 (95% CI: 19, 29) (Tasmania) and 489/100,000 population (95%CI: 462, 517) (Northern Territory). Positive cases were detected across all states and territories, with the highest (260-996/100,000 and 17–40% of those tested) in regions across northern Australia, north-east New South Wales and north-west South Australia. Some regions in Greater Capital Cities also had a high seropositivity (112-188/100,000 and 17–20% of those tested). Relatively more males than females tested positive. Relatively more adults than children tested positive. Children were under-represented in the data.

Conclusions/Significance

The study confirms that substantial numbers of S. stercoralis infections occur in Australia and provides data to inform public health planning.

Strongyloides stercoralis, a parasitic roundworm, is endemic in many countries world-wide. In Australia, groups at risk for strongyloidiasis include Aboriginal and/or Torres Strait Islander people, who acquired this parasite locally, and immigrants and returned travellers who acquired the infection outside Australia. We obtained deidentified results of ELISA IgG antibody tests for Strongyloides from diagnostic pathology laboratories during 2012 to 2016 and calculated the number of people who were positive at least once and the number who never had a positive result. We drew maps showing the number positive per 100,000 of population, the percent positive of those tested, and the number tested/100,000 for each region and the number positive in each suburb of residence according to the Australian Bureau of Statistics. The highest seropositivity (260-996/100,000 of population) was in Northern Australia, north-west South Australia and north-east New South Wales where many Aboriginal and Torres Strait Islander people live in remote communities. There were also some regions in Greater Capital Cities with a high number of people positive per 100,000 of population (112-188/100,000), likely reflecting higher populations of immigrants and returned travellers who were infected outside Australia.

Challenges of Managing Skin Diseases in Refugees and Migrants

"Currently, an estimated 70.8 million individuals worldwide are forcibly displaced due to war, violence, and persecution. Barriers to providing dermatologic care include the large number of affected people, their movement within and across international borders, security issues, and limited access to dermatology expertise and formularies. Screening protocols for skin diseases and sexually transmitted infections differ worldwide, raising the need for shared guidelines to assess migrants' health. This article reviews the literature of skin and sexually transmitted infections in migrants and displaced persons, highlighting the impact of social determinants on skin health and challenges faced in providing care."

A mixed-method analysis of screening for Strongyloides stercoralis prior to immunosuppression: A problem of limited bandwidth?

BACKGROUND

Guidelines recommend screening for strongyloidiasis prior to immunosuppression in those at epidemiological risk, as hyperinfection following immunosuppression is often fatal. The uptake of this recommendation is unknown, and we aimed to explore this in our setting.

AIMS

Determine the proportion of adult patients at epidemiological risk for strongyloidiasis who were screened prior to immunosuppression at the Royal Melbourne Hospital, Explore the factors that influenced clinicians' decision to screen for strongyloidiasis prior to immunosuppression.

METHODS

This study used a mixed-methods approach. First, a 12-month (1 January 2018 to 1 January 2019) retrospective observational study was used to quantify the proportion of those at epidemiological risk who were screened prior to immunosuppression, while also identifying variables that were positively or negatively associated with screening. Second, clinicians from relevant specialties were recruited for focus group sessions to explore factors that influenced their decision to screen according to an interpretivist framework.

RESULTS

230 newly immunosuppressed patients at epidemiological risk of strongyloidiasis were identified, of whom 87 (37.8%) were screened prior to immunosuppression. In multivariate analysis, older patients, outpatients and people from non-English speaking backgrounds were significantly less likely to be screened. In focus groups, a number of barriers and enablers to screening were identified. Notably, clinicians reported that a major barrier was the cognitive load required to clinically reason about this uncommon disease, in addition to other priorities.

CONCLUSION

We identified many missed opportunities to screen patients at risk of hyperinfection, particularly those most vulnerable. To improve screening, this study highlights the importance of reducing cognitive load by using decision-support tools, which may facilitate screening in vulnerable patients and in time-constrained settings. This article is protected by copyright. All rights reserved.

Strategies for management of strongyloidiasis in migrants from Sub-Saharan Africa recently arrived in Italy: A cost-effectiveness analysis

BACKGROUND

The Italian and the European Centre for Disease Control and Prevention guidelines both recommend a systematic serological screening for strongyloidiasis in sub-Saharan migrants (SSA), however, studies on clinical and economic impact of this strategy in the Italian and European settings are lacking.

METHODS

A population of 100,000 migrants from SSA to Italy was considered and a Markov decision tree model was developed to assess the clinical and economic impact of two interventions for strongyloidiasis compared with the current practice (passive diagnosis of symptomatic cases): a) universal serological screening and treatment with ivermectin in case of positive test b) universal presumptive treatment with ivermectin. One and 10-year time horizon in the health-care perspective were considered.

RESULTS

In the one and 10-year time horizon respectively the costs for passive diagnosis was €1,164,169 and €9,735,908, those for screening option was € 2,856,011 and € 4,959,638 and those for presumptive treatment was €3,538,474 and € 4,883,272. Considering the cost per cured subject in the one-year time horizon, screening appears more favorable (€209.53), than the other two options (€232.55 per presumptive treatment and €10,197.29 per current strategy). Incremental cost-effectiveness ratio (ICERs) of screening strategy and presumptive treatment were respectively 265.27 and 333.19. The sensitivity analysis identified strongyloidiasis' prevalence as the main driver of ICER.

CONCLUSIONS

Compared to the current practice (passive diagnosis) both screening and presumptive treatment strategies are more favorable from a cost-effectiveness point of view, with a slight advantage of the screening strategy in a one-year time horizon.

Asymptomatic Strongyloidiasis among Latin American Migrants in Spain: A Community-Based Approach

Strongyloides stercoralis infection is frequently underdiagnosed since many infections remain asymptomatic. Aim: To estimate the prevalence and characteristics of asymptomatic S. stercoralis infection in Latin American migrants attending a community-based screening program for Chagas disease in Spain. Methodology: Three community-based Chagas disease screening campaigns were performed in Alicante (Spain) in 2016, 2017, and 2018. Serological testing for S. stercoralis infection was performed using a non-automatized IVD-ELISA detecting IgG (DRG Instruments GmbH, Marburg, Germany). Results: Of the 616 migrants from Central and South America who were screened, 601 were included in the study: 100 children and adolescents (<18 years of age) and 501 adults. Among the younger group, 6 participants tested positive (prevalence 6%, 95% confidence interval [CI] 2.5% to 13.1%), while 60 adults did so (prevalence 12%, 95% CI 9.3% to 15.3%). S. stercoralis infection was more common in men than in women (odds ratio adjusted [ORa] 2.28, 95% CI 1.289 to 4.03) and in those from Bolivia (ORa 2.03, 95% CI 1.15 to 3.59). Prevalence increased with age (ORa 1.02, 95% CI 0.99 to 1.05). In contrast, a university education had a protective effect (ORa 0.29, 95% CI 0.31 to 0.88). Forty-one (41/66; 62.1%) of the total cases of S. stercoralis infection were treated at the health care center. Positive stool samples were observed in 19.5% of the followed-up positive cases. Conclusion: Incorporating serological screening for S. stercoralis into community-based screening for Chagas disease is a useful intervention to detect asymptomatic S. stercoralis infection in Central and South American migrants and an opportunity to tackle neglected tropical diseases in a transversal way. The remaining challenge is to achieve patients’ adherence to the medical follow-up.

Clinical Features Associated with Strongyloidiasis in Migrants and the Potential Impact of Immunosuppression: A Case Control Study

Strongyloides stercoralis is a widely distributed nematode more frequent in tropical areas and particularly severe in immunosuppressed patients. The aim of this study was to determine factors associated with strongyloidiasis in migrants living in a non-endemic area and to assess the response to treatment and follow-up in those diagnosed with the infection. We performed a multicenter case-control study with 158 cases and 294 controls matched 1:2 by a department service. Participants were recruited simultaneously at six hospitals or clinics in Spain. A paired-match analysis was then performed looking for associations and odds ratios in sociodemographic characteristics, pathological background, clinical presentation and analytical details. Cases outcomes after a six-month follow-up visit were also registered and their particularities described. Most cases and controls came from Latin America (63%-47%) or sub-Saharan Africa (26%-35%). The number of years residing in Spain (9.9 vs. 9.8, p = 0.9) and immunosuppression status (30% vs. 36.3%, p = 0.2) were also similar in both groups. Clinical symptoms such as diffuse abdominal pain (21% vs. 13%, p = 0.02), and epigastralgia (29% vs. 18%, p < 0.001); along with a higher eosinophil count (483 vs. 224 cells/mL in cases and controls, p < 0.001) and the mean total Immunoglobulin E (IgE) (354 U/L vs. 157.9 U/L; p < 0.001) were associated with having strongyloidiasis. Finally, 98.2% percent of the cases were treated with ivermectin in different schedules, and 94.5% met the cure criteria at least six months after their first consultation. Abdominal pain, epigastralgia, eosinophilia, increased levels of IgE and Latin American origin remain the main features associated with S. stercoralis infection, although this association is less evident in immunosuppressed patients. The appropriate follow-up time to evaluate treatment response based on serology titers should be extended beyond 6 months if the cure criteria are not achieved.

Microemulsion composed of combination of skin beneficial oils as vehicle: Development of resveratrol-loaded microemulsion based formulations for skin care applications

Microemulsion can be a potential delivery vehicle to deliver skin care actives to deep skin layer for chronic skin care benefits. On top of skin care active, microemulsion vehicle composed of multiple skin beneficial oils can deliver additional skin care efficacies. In this study, microemulsions were developed using combinations of two skin beneficial oils, tea tree oil and medium chain triglyceride instead of single oil. For that, pseudo ternary phase diagrams were constructed on these oil combinations at different ratios of surfactant/co-surfactants. Ratio of oils and surfactant/co-surfactant combinations exhibited significant impact on the microemulsion region. A few compositions were selected from the single phase microemulsion regions of these phase diagrams for the preparation of resveratrol-loaded microemulsion and microemulsion gel formulations. The particle size of the resveratrol-loaded microemulsions were <50 nm. Cryogenic scanning electron microscope image clearly showed nano-droplets dispersed in continuous phase. Both physical and chemical stability of the formulations varied depending on their compositions, such as surfactant/co-surfactant combination and % total oil. The presence of chelating agent and anti-oxidant was also crucial to stabilize the formulations. The selected formulations demonstrated good physicochemical stability at 5 °C, 25 °C, and 40 °C/75 % RH (relative humidity) stability conditions. The results further showed that the % total oil and surfactant phase composition had huge influence on resveratrol release and skin permeation patterns from the microemulsion gels. In vitro skin permeation result indicated that the microemulsion gels can help resveratrol penetration into deep skin layer. Therefore, the developed resveratrol-loaded microemulsion gels can be utilized as skin care product with multiple skin care benefits.

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.

Comprehensive infectious disease screening in a cohort of unaccompanied refugee minors in Germany from 2016 to 2017: A cross-sectional study

BACKGROUND

Information regarding the prevalence of infectious diseases (IDs) in child and adolescent refugees in Europe is scarce. Here, we evaluate a standardized ID screening protocol in a cohort of unaccompanied refugee minors (URMs) in a municipal region of southwest Germany.

METHODS AND FINDINGS

From January 2016 to December 2017, we employed a structured questionnaire to screen a cohort of 890 URMs. Collecting sociodemographic information and medical history, we also performed a standardized diagnostics panel, including complete blood count, urine status, microbial stool testing, tuberculosis (TB) screening, and serologies for hepatitis B virus (HBV) and human immunodeficiency virus (HIV). The mean age was 16.2 years; 94.0% were male, and 93.6% originated from an African country. The most common health complaints were dental problems (66.0%). The single most frequent ID was scabies (14.2%). Of the 776 URMs originating from high-prevalence countries, 7.7% and 0.4% tested positive for HBV and HIV, respectively. Nineteen pathogens were detected in a total of 119 stool samples (16.0% positivity), with intestinal schistosomiasis being the most frequent pathogen (6.7%). Blood eosinophilia proved to be a nonspecific criterion for the detection of parasitic infections. Active pulmonary TB was identified in 1.7% of URMs screened. Of note, clinical warning symptoms (fever, cough >2 weeks, and weight loss) were insensitive parameters for the identification of patients with active TB. Study limitations include the possibility of an incomplete eosinophilia workup (as no parasite serologies or malaria diagnostics were performed), as well as the inherent selection bias in our cohort because refugee populations differ across Europe.

CONCLUSIONS

Our study found that standardized ID screening in a URM cohort was practicable and helped collection of relevant patient data in a thorough and time-effective manner. However, screening practices need to be ameliorated, especially in relation to testing for parasitic infections. Most importantly, we found that only a minority of infections were able to be detected clinically. This underscores the importance of active surveillance of IDs among refugees.

Strongyloidiasis screening in migrants living in Spain: systematic review and meta-analysis

OBJECTIVES

To provide information regarding the prevalence of strongyloidiasis among migrants coming from Strongyloides stercoralis-endemic areas who reside in Spain.

METHODS

Systematic review of the literature and meta-analysis of studies showing prevalence of S. stercoralis infection among migrants from Latin America, Africa, Eastern Europe, Asia and Oceania who reside in Spain. We included articles published until 30 April 2019 without language restriction. The keywords used for the search included 'Strongyloides stercoralis', 'strongyloidiasis', 'Spain', 'screening' and 'migrants'.

RESULTS

Twenty-four studies were included in the review and meta-analysis, comprising 12 386 screened people. Eleven studies (7020 patients) evaluated the presence of S. stercoralis infection only through investigation of larvae in faeces, showing an overall prevalence of 1% (95%CI 1-1%). Thirteen studies (5366 patients) used a serological test, showing an overall prevalence of 14% (95%CI 11-17%). Strongyloidiasis seroprevalence was 20% (95%CI 15-24%) among migrants from sub-Saharan Africa, 14% (95%CI 10-18%) among those from Latin America and 8% (95%CI 5-11%) among migrants from North Africa.

CONCLUSIONS

Migrants coming from strongyloidiasis-endemic areas living in Spain had a high S. stercoralis infection prevalence, particularly those from sub-Saharan Africa and Latin America. This population should be screened using serology as the most sensitive test for S. stercoralis infection. This could be easily implemented at primary care level.

High Prevalence of Strongyloidiasis in Spain: A Hospital-Based Study

Introduction: Strongyloidiasis is a prevailing helminth infection ubiquitous in tropical and subtropical areas, however, seroprevalence data are scarce in migrant populations, particularly for those coming for Asia. Methods: This study aims at evaluating the prevalence of S. stercoralis at the hospital level in migrant populations or long term travellers being attended in out-patient and in-patient units as part of a systematic screening implemented in six Spanish hospitals. A cross-sectional study was conducted and systematic screening for S. stercoralis infection using serological tests was offered to all eligible participants. Results: The overall seroprevalence of S. stercoralis was 9.04% (95%CI 7.76-10.31). The seroprevalence of people with a risk of infection acquired in Africa and Latin America was 9.35% (95%CI 7.01-11.69), 9.22% (7.5-10.93), respectively. The number of individuals coming from Asian countries was significantly smaller and the overall prevalence in these countries was 2.9% (95%CI -0.3-6.2). The seroprevalence in units attending potentially immunosuppressed patients was significantly lower (5.64%) compared with other units of the hospital (10.20%) or Tropical diseases units (13.33%) (p < 0.001). Conclusions: We report a hospital-based strongyloidiasis seroprevalence of almost 10% in a mobile population coming from endemic areas suggesting the need of implementing strongyloidiasis screening in hospitalized patients coming from endemic areas, particularly if they are at risk of immunosuppression.

High Prevalence of Strongyloides among South Asian Migrants in Primary Care-Associations with Eosinophilia and Gastrointestinal Symptoms

Gastrointestinal (GI) symptoms are a frequent reason for primary care consultation, and common amongst patients with strongyloidiasis. We conducted a prospective cohort and nested case control study in East London to examine the predictive value of a raised eosinophil count or of GI symptoms, for Strongyloides infection in South Asian migrants. We included 503 patients in the final analyses and all underwent a standardised GI symptom questionnaire, eosinophil count and Strongyloides serology testing. Positive Strongyloides serology was found in 33.6% in the eosinophilia cohort against 12.5% in the phlebotomy controls, with adjusted odds ratio of 3.54 (95% CI 1.88-6.67). In the GI symptoms cohort, 16.4% were seropositive but this was not significantly different compared with controls, nor were there associations between particular symptoms and Strongyloidiasis. Almost a third (35/115) of patients with a positive Strongyloides serology did not have eosinophilia at time of testing. Median eosinophil count declined post-treatment from 0.5 cells × 109/L (IQR 0.3-0.7) to 0.3 (0.1-0.5), p < 0.001. We conclude Strongyloides infection is common in this setting, and the true symptom burden remains unclear. Availability of ivermectin in primary care would improve access to treatment. Further work should clarify cost-effectiveness of screening strategies for Strongyloides infection in UK migrant populations.

Urogenital schistosomiasis detected in sub-Saharan African migrants attending primary healthcare consultations in Paris, France: a 14-year retrospective cohort study (2004-2017)

Urogenital schistosomiasis (UGS) remains common in sub-Saharan African migrants. The aim of the study was to describe UGS cases detected among patients attending primary healthcare consultations in free outpatient clinics in Paris. This retrospective cohort study included all cases of active UGS from 2004 to 2017. Cases were defined by the presence of Schistosoma haematobium typical ova at urine microscopy. Primary care physicians prescribed it on the basis of epidemiological or clinical criteria. Demographic, clinical, biological, and imaging data were retrieved. Active UGS was diagnosed in 105 cases. The sex ratio (F/M) was 3/102 with a median age of 25. Most cases came from West Africa and recently arrived in Europe (median delay, 1 year). Patients under 18 (23%) were more frequent after 2011. Compatible symptoms were reported in 63/104 patients (60%), hematuria being the most frequent (43/104). Urine dipstick detected micro-hematuria in 42/60 patients screened (70%). In 73 cases, urine microscopy was performed from either one, two, or three micturitions on separate days. The rate of positive urine microscopy increased from one (69.2%) to two micturitions (95.4%). All patients except three received praziquantel. Among those who underwent ultrasonography, 30/86 (35%) had abnormalities, 28/30 at the bladder. A step-by-step clinical assessment led to the detection of active UGS: questions on age, location in childhood and hematuria, physical examination, and urine dipstick. A prospective study in primary care is needed for protocol-based management of active UGS to be part of a socio-medical program for migrants.

Development of microemulsion based topical ivermectin formulations: Pre-formulation and formulation studies

The aim of this work was to develop microemulsions and microemulsion gels which can be used as vehicles for the topical delivery of ivermectin. Tea tree oil and ethyl butanoate were found to be suitable for ivermectin-loaded microemulsion formulations due to the higher solubility of ivermectin in these two oils than other tested oils. The pseudo-ternary phase diagrams were constructed based on these selected oils and combination of different surfactant/co-surfactant at different ratios. Ivermectin-loaded stable microemulsions and microemulsion gels were successfully formulated based on the selected compositions from the phase diagrams. Ivermectin-loaded microemulsions showed spherical nano-droplets dispersed in the continuous phase (via cryogenic field emission scanning electron microscope image) and the particle size was less than 100 nm (via dynamic light scattering measurement). Ethyl butanoate based microemulsion appeared to be the best microemulsion formulation considering the stability and permeation profiles while tea tree oil based microemulsion showed the best stability profile. Overall, microemulsion gel formulations exhibited better stability profiles than their microemulsion counterparts. All microemulsion gel formulations demonstrated significantly faster in vitro membrane permeation (release) rate of ivermectin than Soolantra cream (reference marketed product by Galderma, USA).The developed microemulsion and microemulsion gel formulations appear to be promising vehicles for topical delivery of ivermectin.

Overcoming challenges in the diagnosis and treatment of parasitic infectious diseases in migrants

Introduction: Recent increases in population movements have created novel health challenges in many areas of the World, and health policies have been adapted accordingly in several countries. However, screening guidelines for infectious diseases are not standardized and generally do not include comprehensive screening for parasitic infections.Areas covered: Malaria, Chagas disease, leishmaniasis, amebiasis, filariases, strongyloidiasis, and schistosomiasis are reviewed, focusing on the challenges posed for their diagnosis and management in vulnerable populations such as migrants. The methodology included literature searches in public databases such as PubMed.gov and Google Scholar and search of the US National Library of Medicine online database of privately and publicly funded clinical studies (ClinicalTrials.gov) until November 2019.Expert opinion: Parasitic infections which may remain asymptomatic for prolonged periods, leading to chronic infection and complications, and/or may be transmitted in non-endemic areas are ideal candidates for screening. Proposed strategies to improve diagnosis in vulnerable groups such as migrants include facilitating access to healthcare in a multi-dimensional manner considering location, individual characteristics, and timing. Limitations and availability of specific diagnostic techniques should be addressed and focus on drug and vaccine development for these neglected infections should be prioritized through collaborative initiatives with public disclosure of results.

High-dose or multi-day praziquantel for imported schistosomiasis? A systematic review

BACKGROUND

Schistosomiasis affects more than 260 million people worldwide, mostly in sub-Saharan Africa, where more than 280 000 deaths per year are estimated. In the past few years, the increasing flow of migrants from endemic areas and the upward number of international travels have caused the emergence of the disease also in non-endemic areas. A single course of praziquantel (PZQ) 40 mg/kg is the first-line treatment recommended by the World Health Organization, mainly based on clinical trials conducted in endemic countries. No trials have been performed in non-endemic areas.

METHODS

We carried out a systematic review of case reports and case series published between 1956 and August 2017 on cases of chronic schistosomiasis (infection acquired >3 months before) diagnosed in non-endemic areas and treated with PZQ. Primary outcome was to assess the number of different therapeutic regimens deployed and their frequency of use, calculated as the number of reports for each regimen over the total number of included cases.

RESULTS

The final database included 99 case reports and 51 case series, for a total of 1433 patients. In 57 of the 150 records (38%) the administered treatment was different from the one recommended by the World Health Organization. The proportion of 'alternative' regimens included increased doses of PZQ (up to 80 mg/kg) and/or prolonged duration of treatment and/or doses repeated some days/weeks apart. About 50% of the records regarding Western short-term travellers reported a non-standard treatment.

CONCLUSION

This is the first complete catalogue of the published experience with PZQ outside of endemic areas in the situation where reinfection is not an issue. We found a wide heterogeneity of the therapeutic regimens reported. Multicenter clinical trials conducted in non-endemic areas and guidelines specifically addressing the treatment of imported cases of chronic schistosomiasis are needed.

Real-time PCR for diagnosis of imported schistosomiasis

BACKGROUND

The diagnosis of schistosomiasis currently relies on microscopic detection of schistosome eggs in stool or urine samples and serological assays. The poor sensitivity of standard microscopic procedures performed in routine laboratories, makes molecular detection methods of increasing interest. The aim of the study was to evaluate two in-house real-time Schistosoma PCRs, targeting respectively S. mansoni [Sm] and S. haematobium [Sh] in excreta, biopsies and sera as potential tools to diagnose active infections and to monitor treatment efficacy.

METHODS

Schistosoma PCRs were performed on 412 samples (124 urine, 86 stools, 8 biopsies, 194 sera) from patients with suspected schistosomiasis, before anti-parasitic treatment. Results were compared to microscopic examination and serological assays (enzyme-linked immunosorbent assay (ELISA), indirect haemagglutination (HA) and Western Blot (WB) assay).

RESULTS

Compared to microscopy, PCRs significantly increased the sensitivity of diagnosis, from 4% to 10.5% and from 33.7% to 48.8%, for Sh in urine and Sm in stools, respectively. The overall sensitivity of PCR on serum samples was 72.7% and reached 94.1% in patients with positive excreta (microscopy). The specificity of serum PCR was 98.9%. After treatment, serum PCR positivity rates slowly declined from 93.8% at day 30 to 8.3% at day 360, whereas antibody detection remained positive after 1 year.

CONCLUSION

Schistosoma PCRs clearly outperform standard microscopy on stools and urine and could be part of reference methods combined with WB-based serology, which remains a gold standard for initial diagnosis. When serological assays are positive and microscopy is negative, serum PCRs provide species information to guide further clinical exploration. Biomarkers such as DNA and antibodies are of limited relevance for early treatment monitoring but serum PCR could be useful when performed at least 1 year after treatment to help confirm a cured infection.