Strongyloidiasis in Auckland: A ten-year retrospective study of diagnosis, treatment and outcomes of a predominantly Polynesian and Fijian migrant cohort.

BACKGROUND: Strongyloides stercoralis is not endemic in Aotearoa New Zealand (AoNZ). However, approximately one third of Auckland residents are born in endemic countries. This study aimed to describe the epidemiology and management of strongyloidiasis in Auckland, with a focus on migrants from Pacific Island Countries and Territories. METHODS: This study retrospectively reviewed clinical, laboratory and pharmacy records data for all people diagnosed with strongyloidiasis in the Auckland region between July 2012 and June 2022. People with negative Strongyloides serology were included to estimate seropositivity rate by country of birth. FINDINGS: Over ten years, 691 people were diagnosed with strongyloidiasis. Most diagnoses were made by serology alone (622, 90%). The median age was 63 years (range 15-92), 500 (72%) were male, and the majority were born in Polynesia (350, 51%), Fiji (130, 19%) or were of Pasifika ethnicity (an additional 7%). Twelve participants (1.7%) had severe strongyloidiasis at diagnosis. The total proportion treated with ivermectin was only 70% (484/691), with no differences between immunocompromised and immunocompetent participants, nor by ethnicity. The outcome of treatment (based on a combination of serology and/or eosinophilia and/or stool microscopy) could only be determined in 50% of the treated cohort. One participant failed treatment with ivermectin, experiencing recurrent strongyloidiasis, and another participant died in association with severe strongyloidiasis. The rate of 'positive' Strongyloides serology was highest among participants born in Samoa (48%), Fiji (39%), and Southeast Asian countries (34%). INTERPRETATION: Strongyloidiasis was common and under-treated in Auckland during the study period. Clinicians should have a low threshold for considering strongyloidiasis in migrants from endemic countries, including Polynesia and Fiji.

Evaluation of the SsIR/NIE recombinant antigen ELISA for the follow up of patients infected by Strongyloides stercoralis: a diagnostic study.

Some serology assays demonstrated useful for post-treatment monitoring of Strongyloides stercoralis infection. Serology frequently has low specificity, which might be improved by the use of recombinant antigens. The Strongy Detect ELISA is based on 2 recombinant antigens (SsIR and NIE) and proved good accuracy. Aim of this study was to evaluate the performance of this test for the post-treatment monitoring of strongyloidiasis. We tested 38 paired sera, with matched fecal tests results, stored in our biobank and originating from a randomized controlled trial. At baseline, all patients tested positive for at least 1 fecal assay among PCR, direct stool microscopy and agar plate culture. Patients were re-tested with both serology and fecal assays 12 months after treatment. Primary outcome was the relative reduction in optical density (OD) between baseline and follow up. We observed that about 95% samples showed a reduction between pre and post-treatment OD, with a median relative reduction of 93.9% (IQR 77.3%­98.1%). In conclusion, the test proved reliable for post-treatment monitoring. However, some technical issues, including that the threshold for positivity has not be predefined, and that a substantial number of samples showed overflow signals, need to be fixed to permit use in routine practice.

Epidemiological and clinical trends of imported strongyloidiasis in a referral international health unit, Barcelona, Spain: A 12-year period experience.

BACKGROUND: Imported strongyloidiasis in non-endemic countries has increasingly been diagnosed. The aim of the present study is to describe the main epidemiological and clinical characteristics of patients with imported strongyloidiasis attended in a referral International Health Unit and to detect trend changes over a 12-year period. METHODS: This is an observational retrospective study including all imported strongyloidiasis cases seen at the International Health Unit Vall d'Hebron-Drassanes (Barcelona, Spain) from January 2009 to December 2020. Epidemiological and clinical characteristics from included patients were collected. RESULTS: Overall, 865 cases of imported strongyloidiasis were diagnosed, of whom 472 (54.6 %) were men and mean age was 38.7 (SD 13.4) years. Most cases were diagnosed in migrants (830, 96 %). The distribution of the geographic origin was: Latin America (561, 67.6 %), Sub-Saharan Africa (148, 17.8 %), Asia (113, 13.6 %), North Africa (5, 0.6 %), Eastern Europe (2, 0.2 %), and North America (1, 0.1 %). The main reasons for consultation at the Unit were screening of health status (371, 42.9 %), laboratory test alteration (367, 42.4 %), gastrointestinal symptoms (56, 6.5 %), cutaneous symptoms (26, 3 %), and other clinical symptoms (45, 5.2 %). An increase in the number of cases was observed in the last years of the study period. CONCLUSIONS: Imported strongyloidiasis has increasingly been diagnosed in our referral unit, mostly due to screening strategies implementation. Most of the patients were young migrants coming from Latin America, with no symptoms at the time of diagnosis. The optimization of screening strategies will increase the detection and treatment of cases, reducing potential complications.

Strongyloidiasis.

Strongyloidiasis is a neglected tropical disease caused primarily by the roundworm Strongyloides stercoralis. Strongyloidiasis is most prevalent in Southeast Asia and the Western Pacific. Although cases have been documented worldwide, global prevalence is largely unknown due to limited surveillance. Infection of the definitive human host occurs via direct skin penetration of the infective filariform larvae. Parasitic females reside in the small intestine and reproduce via parthenogenesis, where eggs hatch inside the host before rhabditiform larvae are excreted in faeces to begin the single generation free-living life cycle. Rhabditiform larvae can also develop directly into infectious filariform larvae in the gut and cause autoinfection. Although many are asymptomatic, infected individuals may report a range of non-specific gastrointestinal, respiratory or skin symptoms. Autoinfection may cause hyperinfection and disseminated strongyloidiasis in immunocompromised individuals, which is often fatal. Diagnosis requires direct examination of larvae in clinical specimens, positive serology or nucleic acid detection. However, there is a lack of standardization of techniques for all diagnostic types. Ivermectin is the treatment of choice. Control and elimination of strongyloidiasis will require a multifaceted, integrated approach, including highly sensitive and standardized diagnostics, active surveillance, health information, education and communication strategies, improved water, sanitation and hygiene, access to efficacious treatment, vaccine development and better integration and acknowledgement in current helminth control programmes.

Examination of Diagnostic Performance of New IgG4 Rapid Test Compared with IgG- and IgG4-ELISAs to Investigate Epidemiology of Strongyloidiasis in Northeast Thailand.

Strongyloidiasis, caused by Strongyloides stercoralis, is a neglected tropical disease with a global distribution. The infection can be fatal in immunocompromised individuals, and accurate diagnosis leading to timely treatment can save lives. Serodiagnosis is a sensitive method for diagnosis and is recommended for screening high-risk individuals. A point-of-care rapid test will facilitate the screening activities, especially in low-resource settings. This study aims to apply a new IgG4 immunochromatographic test using S. stercoralis recombinant antigen (SsRapid® cassette test) and to compare it with in-house IgG and IgG4 enzyme-linked immunosorbent assays (IgG- and IgG4-ELISAs) using native Strongyloides ratti antigen to investigate the epidemiology of strongyloidiasis in northeast Thailand. A total of 300 people participated, with 136 males and 164 females of a similar mean age. The reference tests were fecal examinations using the formalin-ethyl acetate concentration technique and an agar plate culture technique. The prevalence of S. stercoralis determined by SsRapid (81.7%) was significantly higher than that by fecal examinations (43.3%) or by antibody detection by IgG-ELISA (53.0%) or IgG4-ELISA (44.0%). The diagnostic sensitivities of SsRapid, IgG-ELISA, and IgG4-ELISA were found to be 93.9%, 77.7%, and 63.1%, respectively. The rate of positive tests by the SsRapid was significantly correlated to the levels of Strongyloides-specific IgG4 and IgG antibodies. By all diagnostic methods, male participants had a significantly higher prevalence of strongyloidiasis than females. Age was significantly associated with the concentration of specific serum IgG but not with the SsRapid grading score. In conclusion, SsRapid was shown to be a sensitive and valuable diagnostic test for the epidemiology study of strongyloidiasis.

Identification and treatment of Strongyloides stercoralis infection in a Boston Terrier dog from south-eastern Australia.

Strongyloides stercoralis, the causative agent of strongyloidiasis, is a potentially zoonotic intestinal nematode endemic to northern Australia. Strongyloidiasis is typically observed in immunocompromised hosts and is characterised by gastrointestinal signs, respiratory symptoms and a failure to thrive. In immunocompromised hosts, hyperinfection syndrome and disseminated infections can prove life-threatening. A 24-month-old Boston Terrier dog was referred for investigation of chronic small and large intestinal watery hematochezic diarrhoea, emaciation and hematemesis. Small intestinal histology identified a nematode despite consecutive negative faecal flotations. A real-time polymerase chain reaction and Baermann test subsequently confirmed infection with S. stercoralis. The dog had received an oral parasiticide comprising milbemycin oxime and afoxolaner every month for the 11 months prior to this diagnosis. Despite fenbendazole being reported as successful in the treatment of canine strongyloidiasis, a course of fenbendazole failed to clear the infection. Eradication of S. stercoralis infection was confirmed after the administration of off-label ivermectin fortnightly for 12 doses. Attention should be paid to this nematode as the failure of routine copromicroscopic methods to diagnose S. stercoralis infections can result in misdiagnosis, mistreatment and progression of the disease. Off-label ivermectin may be an alternative to fenbendazole for the treatment of Strongyloides spp. infection in dogs.

A severe case of hyperinfection by Strongyloides stercoralis in a pet dog from Romania.

Strongyloides stercoralis is a zoonotic soil-transmitted nematode affecting mainly humans and dogs but identified also in non-human primates, cats and wild carnivores. It has a cosmopolitan distribution being endemic in tropical and subtropical areas. In Romania, the infection was reported on several occasions in dogs with low prevalence (3.5% -3.8%), assessed by coproscopy and it was confirmed in human patients with no travel history. A 2-year-old male Boston Terrier dog presented to a private clinic due to severe digestive problems, in July 2022. The animal had a long history of health problems. The dog was in a very bad clinical condition with severe abdominal pain, bloody diarrhea, and weight loss. Coproparasitological examinations using the saline flotation method and the modified Baermann's technique were done, both being negative. In addition, an intestinal biopsy was performed during the second endoscopy. Nematodes were collected and identified morphologically and molecularly confirmed. Histology revealed severe inflammation of the duodenal mucosa with areas of edema, necrosis, and hemorrhage, and in the intestinal glands, there were numerous nematodes suggesting a parasitic infection by Strongyloides spp. PCR followed by sequencing confirmed the infection with S. stercoralis. The dog was treated with a combination of oral fenbendazole and milbemycin oxime for 5 months. No relapse was observed 3 months after negativity was attained. This case describes a severe clinical infection by Strongyloides stercoralis in a domestic dog from Romania and the recovery after long-term treatment.

Improved diagnostic sensitivity of human strongyloidiasis using point-of-care mixed recombinant antigen-based immunochromatography.

Strongyloidiasis is a neglected tropical disease that can cause fatal complications due to hyperinfection and disseminated strongyloidiasis in immunocompromised patients. We used two Strongyloides stercoralis recombinant antigenic proteins, L3NieAg.01 (NIE) and IgG-immunoreactive antigen (SsIR), to develop the recombinant antigen-based immunochromatography test (ICT) kit. We constructed and compared kits using either the NIE (NIE ICT kit) or the SsIR (SsIR ICT kit) antigens and a kit using a mixture of both (NIE-SsIR ICT kit) for detection of anti-Strongyloides IgG antibody in human serum samples. Serum samples from normal healthy individuals (Group I, n = 40), proven strongyloidiasis patients (Group II, n = 100), and those with other parasitic infections (Group III, n = 154) were evaluated. Sensitivity and specificity were 81.0% and 84.0% for the NIE ICT kit, 89.0% and 83.5% for the SsIR ICT kit, and 95.0% and 90.2% for the NIE-SsIR ICT kit, respectively. The NIE-SsIR ICT kit provided the best diagnostic results; it can supplement stool examination for clinical diagnosis and can be used to screen for asymptomatic S. stercoralis infection in people at risk in endemic areas. The NIE-SsIR ICT kit can also be used in large-scale sero-epidemiological investigations in endemic areas without the need for additional facilities or ancillary supplies.

Title: Amélioration de la sensibilité diagnostique de l'anguillulose humaine grâce à l'immunochromatographie à base d'antigènes recombinants mixtes sur le lieu d'intervention. Abstract: La strongyloïdose est une maladie tropicale négligée qui peut entraîner des complications mortelles dues à une hyperinfection et à une strongyloïdose disséminée chez les patients immunodéprimés. Nous avons utilisé deux protéines antigéniques recombinantes de Strongyloides stercoralis, L3NieAg.01 (NIE) et l'antigène immunoréactif IgG (SsIR), pour développer un kit de test d'immunochromatographie (TIC) basé sur les antigènes recombinants. Nous avons construit et comparé des kits utilisant les antigènes NIE (kit NIE ICT), SsIR (kit SsIR ICT) ou un mélange des deux (kit NIE-SsIR ICT) pour la détection des anticorps IgG anti-Strongyloides dans des échantillons de sérum humain. Des échantillons de sérum provenant d'individus normaux en bonne santé (groupe I, n = 40), de patients atteints d'anguillulose avérée (groupe II, n = 100) et de patients atteints d'autres infections parasitaires (groupe III, n = 154) ont été évalués. La sensibilité et la spécificité étaient respectivement de 81,0 % et 84,0 % pour le kit NIE ICT, 89,0 % et 83,5 % pour le kit SsIR ICT, et 95,0 % et 90,2 % pour le kit NIE-SsIR ICT. Le kit NIE-SsIR ICT a fourni les meilleurs résultats de diagnostic ; il peut compléter l'examen des selles pour le diagnostic clinique et peut être utilisé pour dépister une infection asymptomatique à S. stercoralis chez les personnes à risque dans les zones d'endémie. Le kit NIE-SsIR ICT peut également être utilisé dans des enquêtes séro-épidémiologiques à grande échelle dans les zones endémiques sans nécessiter d'installations supplémentaires ou de fournitures auxiliaires.

Frequency of strongyloidiasis and associated factors: Analysis of 13 years of laboratory results in a tertiary referral hospital in Honduras, 2010-2022. / Frecuencia de estrongiloidiasis y factores asociados: análisis de 13 años de resultados de laboratorio en un hospital de tercer nivel de Honduras, 2010-2022

INTRODUCTION: The frequency of detected strongyloidiasis is affected by the selected laboratory method in the studied population. Considering that Honduras has few community-based studies, the analysis of the laboratory record data can provide information helping to understand this parasitosis. OBJECTIVE: To estimate the frequency and to identify the factors associated with strongyloidiasis, analyzing the laboratory records of the Servicio de Parasitología at Hospital Escuela in Tegucigalpa (Honduras) between 2010 and 2022. MATERIALS AND METHODS: We carried out a descriptive, cross-sectional, analytical study. The laboratory diagnosis consisted of stool samples' examination by direct smear and modified Baermann technique. We estimated frequencies and percentages. The statistical association was calculated with prevalence ratios and a 95% confidence interval. Software R, version 4.2.0, and epiR package, version 2.0.46, were used to perform the analysis. RESULTS: The frequency of strongyloidiasis was 0.29% (112/38,085). It was higher with the modified Baermann technique (0.87%; 40/4,575) among male patients (0.44%; 70/15,758). Regarding the age, strongyloidiasis was higher in the 20-40 years old group (0.41%; 28/6,886) with direct smear and 41-61 years old (1.14%; 14/1,232) group with the modified Baermann technique. Among the factors associated with strongyloidiasis were age between 20 and 61 years old (PR=2.26, CI 95%=1.53-3.31), male patients (PR=2.34, CI 95%=1.60­3.44), mucus (PR=1.86, CI 95%=1.22-2.83) and Charcot-Leyden crystals in stool (PR=8.47, CI 95%=5.14-13.96); watery stool (PR=2.39, CI 95%=1.55-3.68), and other helminthiases (PR=6.73, CI 95%=3.98-11.38). Associated factors to cases detected with the modified Baermann technique were outpatient consultation (PR=4.21, CI 95%=1.91-9.28) and formed stools (PR=3.99, CI 95%=1.94-8.19). CONCLUSIONS: The modified Baermann technique increased the detection of strongyloidiasis almost four times. Most cases were distributed among male adults. The cases diagnosed exclusively with the modified Baermann technique have differences from those with observed larvae in the direct smear. It is necessary to develop community-based population studies.

Introducción: La detección de estrongiloidiasis depende del método de diagnóstico utilizado y la población estudiada. Dado que en Honduras hay pocos estudios poblacionales, el análisis de los datos de laboratorio puede generar información que ayude a entender esta parasitosis. Objetivo: Estimar la frecuencia e identificar los factores asociados a la estrongiloidiasis mediante el análisis de los registros de laboratorio del Servicio de Parasitología del Hospital Escuela en Tegucigalpa (Honduras) durante el periodo 2010-2022. Materiales y métodos: Se llevó a cabo un estudio descriptivo, transversal y analítico. El diagnóstico de laboratorio consistió en el análisis de muestras de heces con los métodos directo y Baermann modificado. Se estimaron frecuencias y porcentajes, y la asociación estadística se calculó con razón de prevalencia e intervalos de confianza del 95 %. Se utilizaron los programas R, versión 4.2.0, y el paquete epiR, versión 2.0.46, para ejecutar los análisis estadísticos. Resultados: La frecuencia general de estrongiloidiasis fue 0,29 % (112/38.085). Dicha frecuencia de detección fue mayor con el método de Baermann modificado (0,87 %; 40/4.575), entre pacientes masculinos (0,44 %; 70/15.758). También fue mayor en el rango de edad 20-40 años (0,41%; 28/6.886) por examen directo y entre los 41-61 años (1,14%; 14/1.232) con el método de Baermann modificado. Entre los factores asociados con la estrongiloidiasis se encontraron: edad entre los 20 y los 61 años (RP=2,26; IC 95%=1,53-3,31), sexo masculino (RP=2,34; IC 95% =1,60-3.44), moco (RP=1,86; IC 95%=1,22-2,83) y cristales de Charcot-Leyden en heces (RP=8,47, IC 95%=5,14-13,96), heces líquidas (RP=2,39, IC 95%=1,55-3,68) y otras helmintiasis (RP=6,73, IC 95%=3,98-11,38). Como factores asociados a los casos detectados con el método de Baermann modificado están consulta externa (RP=4,21, IC 95%=1,91-9,28) y heces formadas (RP=3,99, IC 95%=1,94-8,19). Conclusiones: El método de Baermann modificado aumentó la frecuencia de detección de estrongiloidiasis casi cuatro veces. La mayoría de los casos se distribuyeron entre pacientes masculinos adultos. Los casos diagnosticados exclusivamente con el método de Baermann modificado tuvieron diferencias con los casos diagnosticados por examen directo. Es necesario realizar estudios poblacionales.

First field study using Strong-LAMP for diagnosis of strongyloidiasis in Cubal, Angola.

BACKGROUND: Strongyloides stercoralis infection is a common neglected tropical disease distributed worldwide, mainly in tropical and subtropical climates. The impact of S. stercoralis infections on human health ranges from mild asymptomatic infections to chronic strongyloidiasis unnoticeable until the host is immunosuppressed. In severe strongyloidiasis, a syndrome of hyperinfection and larval dissemination to various organs can occur with high mortality rates. The diagnosis of strongyloidiasis is challenging because of the absence of a single standard reference test with high sensitivity and specificity, which also makes it difficult to estimate the accuracy of other diagnostic tests. This study aimed to evaluate, for the first time, the use of an easy-to-perform loop-mediated isothermal amplification (LAMP) colorimetric assay (named Strong-LAMP) for the molecular screening of strongyloidiasis in stool samples from patients in a low-resource endemic area in Cubal, Angola. To compare different LAMP application scenarios, the performance of the Strong-LAMP under field conditions in Angola was reassessed in a well-equipped reference laboratory in Spain and compared with a quantitative polymerase chain reaction (qPCR) method. METHODS: A total of 192 stool samples were collected from adult population in Cubal, Angola, and examined by parasitological methods (direct saline microscopy and Baermann's technique). DNA was extracted from each stool sample using a commercial kit and tested by the colorimetric Strong-LAMP assay for the detection of Strongyloides spp. under field conditions. Furthermore, all samples were shipped to a well-equipped laboratory in Spain, reanalysed by the same procedure and compared with a qPCR method. The overall results after testing were compared. RESULTS: Strongyloides stercoralis larvae were identified by direct saline microscopy and Baermann in a total of 10/192 (5.2%) and 18/192 (9.4%) stool samples, respectively. Other helminth and protozoan species were also identified. The Strong-LAMP-positive results were visually detected in 69/192 (35.9%) stool samples. The comparison of Strong-LAMP results in field conditions and at a reference laboratory matched in a total of 146/192 (76.0%) samples. A total of 24/192 (12.5%) stool samples tested positive by qPCR. CONCLUSIONS: This is the first study in which colorimetric Strong-LAMP has been clinically evaluated in a resource-poor strongyloidiasis endemic area. Strong-LAMP has been shown to be more effective in screening for strongyloidiasis than parasitological methods under field conditions and qPCR in the laboratory. Our Strong-LAMP has proven to be a field-friendly and highly accurate molecular test for the diagnosis of strongyloidiasis.

Comparison of different PCR amplification targets for molecular diagnosis of Strongyloides stercoralis.

Molecular techniques are an alternative for the diagnosis of strongyloidiasis, produced by Strongyloides stercoralis. However, it is necessary to determine the best amplification target for the populations of this parasite present in a geographical area and standardize a polymerase chain reaction (PCR) protocol for its detection. The objectives of this work were the comparison of different PCR targets for molecular detection of S. stercoralis and the standardization of a PCR protocol for the selected target with the best diagnostic results. DNA extraction was performed from parasite larvae by saline precipitation. Three amplification targets of the genes encoding ribosomal RNA 18S (18S rDNA) and 5.8S (5.8S rDNA) and cytochrome oxidase 1 (COX1) of S. stercoralis were compared, and the PCR reaction conditions for the best target were standardized (concentration of reagents and template DNA, hybridization temperature, and number of cycles). The analytical sensitivity and specificity of the technique were determined. DNA extraction by saline precipitation made it possible to obtain DNA of high purity and integrity. The ideal target was the 5.8S rDNA, since the 18S rDNA yielded non-reproducible results and COX1 never amplified under any condition tested. The optimal conditions for the 5.8S rDNA-PCR were: 1.5 mM MgCl2, 100 µM dNTPs, 0.4 µM primers, and 0.75 U DNA polymerase, using 35 cycles and a hybridization temperature of 60 °C. The analytical sensitivity of the PCR was 1 attogram of DNA, and the specificity was 100%. Consequently, the 5.8S rDNA was shown to be highly sensitive and specific for the detection of S. stercoralis DNA.

Clinical presentation and diagnosis of imported strongyloidiasis at a tertiary hospital, Stockholm, Sweden.

BACKGROUND: Since Strongyloides can persist in its host for decades, and cause life threatening infections data on prevalence, the burden and risk factors for infection is crucial in migrant populations. METHODS: In this observational retrospective cohort study, we describe the epidemiological, clinical, and microbiological characteristics of imported strongyloidiasis diagnosed at the Karolinska University Hospital, Stockholm, Sweden, during 2010-2021. RESULTS: We identified 98 individuals with strongyloidiasis, 89 (90.8%) born in endemic and 9 (9.2%) in non-endemic countries. Sub-Saharan Africa was the most common origin among the group born in endemic countries (62, 69.7%), (p < 0.005). There were 22 individuals with an underlying immunosuppressive condition. Gastrointestinal symptoms (53/98, 54.1%) were the symptoms most frequently described, and were more frequent in adults (57.0%) vs children (0%) (p = 0.013). Eosinophilia was detected in 74 (75.5%), being more frequent in the endemic-borne group (79.8% vs 33.3%, p = 0.002). Eight persons developed complications of strongyloidiasis because of either hyperinfection or disseminated disease. No people living with HIV with CD4 <500/mm3 (n = 6) developed severe strongyloidiasis. CONCLUSION: A limited number of strongyloidiasis cases was identified, with few complicated cases in immunosuppressed patients. Further studies focusing on identifying and exploring the risk of complicated strongyloidiasis in immunosuppressed patients are needed.

Human strongyloidiasis: complexities and pathways forward.

SUMMARYStrongyloidiasis 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.

First identification of Strongyloides stercoralis infection in a pet dog in Argentina, using integrated diagnostic approaches.

BACKGROUND: Strongyloides stercoralis is a soil-transmitted intestinal nematode with a complex life cycle that primarily affects humans, non-human primates, dogs, and occasionally cats. This study presents, to the best of our knowledge, the first case of S. stercoralis infection and its genotyping in a domestic dog from Argentina. METHODS: The patient was a female wired-haired Teckel dog exhibiting recurrent coughing. Coproparasitological analysis using the Baermann technique revealed the presence of rhabditiform larvae morphologically compatible with S. stercoralis. To confirm this finding, molecular diagnosis (18S ribosomal RNA) and analysis of the cox1 gene were performed. RESULTS: We identified a haplotype (HP20) that has previously only been related to S. stercoralis infection in dogs, but was found in the present study to be highly related to the haplotype (HP16) of a zoonotic variant and divergent from those previously described from human patients in Argentina. Furthermore, unlike in human cases following treatment with ivermectin, the dog was negative after moxidectin treatment according to polymerase chain reaction of the sampled faeces. CONCLUSIONS: This case report shows the importance of further investigation into potential transmission events and prevalences of S. stercoralis in dogs and humans in South America. The results reported here should also encourage future work that examines different scenarios of infection with S. stercoralis in dogs and humans with the aim of integrating clinical management, diagnosis, treatment and follow-up strategies in the quest for new approaches for the treatment of this disease in animals and humans. The findings support the adoption of a One Health approach, which recognizes the interconnectedness between animal and human health, in addressing parasitic infections such as strongyloidiasis.

Strongyloidiasis in humans and dogs in Southern Italy: an observational study.

Strongyloidiasis is a clinical issue both in humans and in dogs. Moreover, there are concerns about its zoonotic potential. We aimed to explore Strongyloides stercoralis epidemiology in Southern Italy in humans and dogs sharing the same environment in three different settings: (1) kennels (group K); (2) livestock farms (group L) and (3) agricultural farms (group A). For humans, a commercial ELISA test was used for screening. RT-PCR on faecal samples was done for people testing positive or equivocal at serology. On dog's faecal samples, Baermann test and RT-PCR were performed. A total of 145 dogs and 139 persons were tested. Based on faecal tests in dogs and serology in humans, a S. stercoralis positivity of 4.1% and 6.5% was revealed, respectively. The sites where cases were found were different for animals and humans. In dogs the highest positivity was in group K (6.7% against 2% and 0% in L and A). Differently, in humans the proportion of positive results was similar between the groups (p = 0.883). Fifty percent (3/6) of positive dogs were healthy; the other dogs presented weight loss and/or diarrhoea. ELISA-positive persons (n=9) were all in health, but abdominal pain (37.5%), urticaria (22.2%) and asthma (22.2%) were reported, resolving after treatment with oral ivermectin 200 µg/kg. RT-PCR performed on 13 human faecal samples resulted negative. These findings suggest that strongyloidiasis is present in humans and dogs in Southern Italy, and screening in larger cohorts would be needed for more accurate estimates.

Strongyloides infection screening in transplant candidates: What is the best strategy?

BACKGROUND: The potential that Strongyloides stercoralis infection has to cause major morbidity and high mortality when the disseminated form occurs in transplant patients is of particular concern. METHODS: In this study, the objective was to observe S. stercoralis infection in patients who are candidates for transplantation by using parasitological, serological, and molecular techniques and to propose an algorithm for the detection of that infection in transplant candidates. RESULTS: By parasitological techniques, 10% of fecal samples were positive. Anti-Strongyloides antibodies immunoglobulin G were detected in 19.3% and 20.7% of patients by immunofluorescence assay and enzyme-linked immunosorbent assay, respectively. S. stercoralis DNA was observed in 17.3% of samples by conventional polymerase chain reaction and 32.7% of samples by quantitative polymerase chain reaction (qPCR). CONCLUSION: The set of results allows us to reinforce that a positive result by parasitological techniques and/or qPCR indicates that the specific treatment should be applied. However, the improvement of diagnostic techniques may suggest changes in the screening for strongyloidiasis in these patients.

Fatal Disseminated Strongyloidiasis in an Immunosuppressed Patient During COVID-19 Pandemic.

INTRODUCTION: This report presents a fatal case of disseminated strongyloidiasis in a patient with myasthenia gravis and diabetes mellitus who had received corticosteroid therapy. CASE REPORT: The patient was a 67-year-old woman living in a rural area endemic for Strongyloides stercoralis in northern Iran. Disseminated strongyloidiasis was diagnosed in the advanced stage of the disease, with enormous numbers of larvae demonstrated in direct smears prepared from stool samples and stomach biopsy. Despite treatment with ivermectin and antibiotics, the patient succumbed to the severity of the infection. CONCLUSION: Clinicians working in endemic areas should be mindful of the possibility of gastric involvement in strongyloidiasis, even if symptoms are nonspecific. We recommend that high-risk individuals be screened for S. stercoralis prior to immunosuppressive therapy in endemic regions to raise awareness and prevent similar cases.

Recurrent Klebsiella bacteremia due to chronic strongyloidiasis in the context of cirrhotic hepatopulmonary syndrome.

A woman in her 50s with a medical history of cirrhosis, alcohol use disorder, primary biliary cholangitis and extended spectrum beta lactamase (ESBL) Klebsiella presented with weakness, cough and abdominal pain with positive blood cultures for ESBL Klebsiella, and was treated with intravenous meropenem and patient symptoms improved. Testing for Strongyloides antibodies was positive, so she was treated with ivermectin. Strongyloidiasis-associated Gram-negative rod (GNR) bacteremia are rare conditions; however, it is important to consider an underlying strongyloidiasis in recurrent GNR bacteremia to prevent recurrent hospitalisation and morbidity.

Multiple Stool Sampling and Specific Parasitological Technique are Crucial to Diagnose Strongyloidiasis in Alcoholic Patients.

PURPOSE: Chronic alcoholism is a well-known risk factor for strongyloidiasis, in these patients the disease is potentially more severe, probably due to the breakdown of local protective barriers and immunosuppression caused by alcohol, which can lead to autoinfection and dissemination. The aim of this study was to evaluate multiple stool sampling and a specific parasitological assay agar plate culture (APC) for the diagnosis of Strongyloides stercoralis in alcoholics. METHODS: APC was compared to sedimentation technique (HPJ; Hoffman, Pons and Janer), as parasitological methods to detect S. stercoralis infection in alcoholic individuals. Three stool samples from 60 alcoholic and 60 non-alcoholic individuals were analyzed. RESULTS: S. stercoralis larvae were observed in 11 (18.3%) alcoholic individuals and 1 (1.7%) nonalcoholic individual (P = 0.0042). In view of the combined results, sensitivity for the APC method was 63.6% (CI 31.6-87.6%) with the first sample reaching 100% (CI 67.8-100%) after analyzing three fecal samples. The HPJ sensitivity was 36.4% (CI 12.4-68.4) in the first sample, reaching 72.7% (CI 39.3-92.7) after three samples analyzed. CONCLUSION: The present results suggest that in alcoholic patients, it is important to repeat stool sampling with specific techniques, especially using the APC method, to avoid misdiagnosis in cases that could evolve to disseminated strongyloidiasis.