Frequency of strongyloidiasis and associated factors: Analysis of 13 years of laboratory results in a tertiary referral hospital in 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%=1.60-3.44), 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, CI95% =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; IC95%=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.

Bioinformatics analysis and prokaryotic expression of Strongyloides stercoralis serine protease inhibitor 1 / 中国血吸虫病防治杂志

Objective To predict the structure and antigenic epitope of the Strongyloides stercoralis serine protease inhibitor 1 (Ss-SRPN-1) protein using bioinformatics tools, and to construct prokaryotic expression plasmids for expression of recombinant Ss-SRPN-1 protein, so as to provide the basis for unraveling the function of the Ss-SRPN-1 protein. Methods The amino acid sequence of the Ss-SRPN-1 protein was downloaded from the NCBI database, and the physicochemical properties, structure and antigenic epitopes of the Ss-SRPN-1 protein were predicted using bioinformatics tools, including ExPASy, SWISS-MODEL and Protean. Primers were designed according to the nucleotide sequences of Ss-SRPN-1, and the Ss-SRPN-1 gene was amplified, cloned and sequenced with genomic DNA extracted from the infective third-stage larvae of S. stercoralis as a template. The Ss-SRPN-1 protein sequence was cloned into the pET28a (+) expression vector and transformed into Escherichia coli BL21 (DE) cells for induction of the recombinant Ss-SRPN-1 protein expression. The recombinant Ss-SRPN-1 protein was then purified and identified using Western blotting and mass spectrometry. Results Bioinformatics analysis showed that the Ss-SRPN-1 protein, which was composed of 372 amino acids and had a molecular formula of C1948H3046N488O575S16, was a stable hydrophilic protein, and the subcellular localization of the protein was predicted to be extracellular. The Ss-SRPN-1 protein was predicted to contain 11 dominant B-cell antigenic epitopes and 20 T-cell antigenic epitopes. The Ss-SRPN-1 gene with a length of 1 119 bp was successfully amplified, and the recombinant plasmid pET28a (+)/Ss-SRPN-1 was constructed and transformed into E. coli BL21(DE) cells. The expressed recombinant Ss-SRPN-1 protein had a molecular weight of approximately 43 kDa, and was characterized as a Ss-SRPN-1 protein. Conclusions The recombinant Ss-SRPN-1 protein has been expressed successfully, and this recombinant protein may be a potential vaccine candidate against strongyloidiasis.

Progress of researches on Strongyloides stercoralis co-infection with other pathogens / 中国血吸虫病防治杂志

Strongyloides stercoralis is an opportunistic pathogenic parasite that can cause severe strongyloidiasis and even death among immunocompromised individuals. Previous clinical studies have reported cases co-infected with S. stercoralis and other pathogens, such as parasites, viruses, bacteria and fungi. This review summarizes strongyloidiasis patients co-infected with pathogens, and analyzes the impact of co-infection on strongyloidiasis, so as to provide insights into the reduction of the morbidity and mortality of disorders associated with S. stercoralis infections.

Sensibilidad de la prueba ELISA para detectar los anticuerpos IgG contra el Strongyloides stercoralis en pacientes inmunocomprometidos

Objetivo: la sensibilidad subóptima de las pruebas coproparasitológicas dificulta el diagnóstico de la estrongiloidiasis. Los métodos serológicos son más sensibles, pero los estudios en pacientes inmunodeprimidos son escasos. El objetivo del estudio fue de evaluar la sensibilidad de una prueba ELISA comercial en pacientes inmunodeprimidos. Métodos: se realizó en Bolivia un estudio multicéntrico en pacientes con cáncer, VIH, enfermedades reumatológicas y hematológicas. 88 pacientes con larvas de S.stercoralis en heces identificadas mediante técnicas coproparasitológicas tuvieron una prueba serológica ELISA (Bordier Affinity Products). Resultados: la sensibilidad de la técnica ELISA fue de 77,3% (61/88) (CI95%: 67,7-85,1). La sensibilidad de este test serológico fue identificada más baja en pacientes HIV+ con CD4300 o una serología VIH desconocida (84,2%) (p=0,035). Conclusiones: la sensibilidad del ELISA es inversamente proporcional al grado de inmunosupresión. Este resultado refuerza la recomendación de diagnosticar la estrongiloidiasis mediante una combinación de técnicas serológicas y coproparasitológicas.

Objectives: the sensitivity of coproparasitological tests for the diagnosis of strongyloidiasis are suboptimal. Serological methods are more sensitive, but studies among immunocompromised patients are scarce. The aim of this study was to evaluate the sensitivity of a commercial ELISA test among immunocompromised patients. Methods: a multicenter study was conducted in Bolivia among patients with cancer, HIV, rheumatologic or hematologic diseases. 88 patients with S. stercoralis larvae in stool identified by coproparasitological techniques had an ELISA serological test (Bordier Affinity Products). Results: the sensitivity of the ELISA technique was 77,3% (61/88) (CI95%: 67,7-85,1), and was identified lower among HIV+ patients with CD4300 or unknown HIV serology (84,2%) (p=0,035). Conclusions: the sensitivity of ELISA is inversely proportional to the degree of immunosuppression. This result reinforces the recommendation to diagnose strongyloidiasis by a combination of serological and coproparasitological techniques.

Manejo de la estrongiloidiasis: revisión de la literatura con enfoque en la epidemiología en Bolivia

La estrongiloidiasis es una de las enfermedades parasitarias más desatendidas. Tiene una elevada morbilidad y mortalidad en personas tratadas con corticosteroides o con una inmunidad reducida por otros motivos. En Bolivia los estudios realizados han demostrado una alta prevalencia y su transmisión en diversas regiones tropicales y de los valles interandinos. Aunque la enfermedad no se transmite en climas fríos, todas las regiones de Bolivia pueden verse afectadas debido a la migración interna de la población. Las personas pueden infectarse al viajar a regiones endémicas décadas antes de presentar síntomas, porque si se deja sin tratar, puede persistir de por vida La baja sensibilidad de las pruebas diagnósticas coproparasitológicas utilizadas de rutina dificultan su diagnóstico, pero existen técnicas de diagnóstico más eficientes a bajo costo como la técnica de Baermann modificada. La ivermectina es el tratamiento de elección, muy eficaz, bien tolerado cuando es prescrito a dosis adecuada, accesible y disponible en Bolivia.

Strongyloidiasis is one of the neglected parasitosis. Strongyloidiasis has a high morbidity and mortality among people treated with corticosteroids or with reduced immunity for other reasons. In Bolivia, the studies have shown its transmission and high prevalence in various tropical regions and the inter-Andean valleys. Although the disease is not transmitted in cold climates, people living in all regions of Bolivia can be affected due to internal migration. Infection can occur during travel to endemic areas decades before the onset of symptoms, because if left untreated, the strongyloidiasis can persist for life. This disease is one of the most neglected mainly due to the low sensitivity of the coproparasitological tests routinely used in clinical laboratories. There are more efficient diagnostic methods, such as the modified Baermann technique. which can be applied in Bolivia at low cost. Ivermectin is the treatment of choice, effective, well tolerated in adequate dosis, cheap and available in Bolivia.

Nematódeos de interesse médico veterinário em represa urbana no município de Catalão, no sudeste do estado de Goiás, Brasil / Nematodes of veterinary medical interest in an urban reservoir in the municipality of Catalão, southeastern Goiás State, Brazil

Objetivo: realizar análises parasitológicas em amostras de solo provenientes da represa da Bica situada no município de Catalão-GO. Métodos: a área do entorno da represa foi dividida em cinco parcelas, sendo realizadas coletas em dois pontos de cada parcela, superior e inferior. Foram realizadas quatro coletas em dias alternados, totalizando 40 amostras de, aproximadamente, 50g da camada superficial do solo, com profundidade máxima de cinco centímetros. As amostras foram processadas no Setor de Diagnóstico Parasitológico do Laboratório de Biologia Molecular da Universidade Federal de Catalão (UFCAT). Para as análises parasitológicas, foram utilizados cinco métodos encontrados na literatura, Rugai, Willis, Sedimentação espontânea, Ritchie e Ritchie modificado. Resultados: pelo método de Rugai, foi possível detectar larvas rabditoides do gênero Ancylostoma e Strongyloides. Utilizando o método de Ritchie modificado, foram encontrados ovos de Ascaris lumbricoidese Ancylostoma sp. Conclusão: a presença de formas evolutivas no solo da represa indica contaminação por dejetos animais e humanos, favorecendo o estabelecimento de ciclos biológicos das espécies encontradas e de outras diferentes zoonoses. Os dados obtidos demonstram a importância de sensibilizar a população de medidas de promoção da saúde, além de ações preventivas e programas de educação em saúde.

Objective: to conduct parasitological analyses in soil samples from the Bica reservoir located in the municipality of Catalão-GO. Methods: the area around the dam was divided into five plots, and samples were collected from two points in each plot, upper and lower. Four samples were collected on alternate days, totaling 40 samples of approximately 50g of topsoil, with a maximum depth of five centimeters. The samples were processed in the Parasitological Diagnostic Sector of the Molecular Biology Laboratory of the Federal University of Catalão (UFCAT). For the parasitological analyses, we used five methods found in the literature, Rugai, Willis, spontaneous sedimentation, Ritchie, and modified Ritchie. Results: by the Rugai method, it was possible to detect rhabditoid larvae of the genus Ancylostoma and Strongyloides. Using the modified Ritchie method, eggs of Ascaris lumbricoidesand Ancylostoma sp were found. Conclusion: the presence of evolutive forms in the soil of the reservoir indicates contamination by animal and human waste, favoring the establishment of biological cycles of the species found and of other different zoonoses. The data obtained demonstrated the importance of raising the population's awareness of health promotion measures besides preventive actions and health education programs.

Strongyloides stercoralis en la médula ósea de una persona que vive con VIH: reporte de caso

Strongyloides stercoralis es un nemátodo que se caracteriza por causar infección intestinal, usualmente asintomática, en pacientes inmunocompetentes. Sin embargo, en aquellos que viven con VIH, y de acuerdo con su estado inmune, puede generar un síndrome de hiperinfección con complicaciones diversas por diseminación a diferentes órganos. Se presenta el caso de un paciente de 30 años con diagnóstico de novo de infección por el virus de la inmunodeficiencia humana, con documentación de enfermedad linfoproliferativa. En los estudios complementarios se documenta la presencia de Strongyloides stercoralis de manera inusual en la médula ósea. A pesar de contar con un recuento de linfocitos T CD4+ mayor a 400 células/ µL y de haberse iniciado el manejo para esta condición con ivermectina, el paciente fallece por un estado séptico asociado al síndrome de hiperinfección, por lo cual se considera que este es un caso inusitado que obliga al clínico a tener en cuenta la presencia del nemátodo en pacientes que viven con VIH.

Summary Strongyloides stercoralis is a nematode that is characterized by causing a usually asymptomatic intestinal infection in immunocompetent individuals. However, in patients living with HIV and depending on their immune status, it can generate a hyperinfection syndrome with various complications due to dissemination to different organs. We present the case of a 30-year-old patient with a de novo diagnosis of human immunodeficiency virus infection and lymphoproliferative disease. Within the laboratory workup, the presence of Strongyloides stercoralis was documented in the bone marrow. Despite having a CD4+ T lymphocyte count greater than 400 cells/microliter and having started treatment for this condition with ivermectin, the patient died due to a septic state associated with hyperinfection syndrome, which is why this is considered an unusual case that alerts the clinician to take into account the presence of the nematode in patients living with HIV.

Infección pulmonar por Strongyloides stercoralis en paciente inmunocomprometido. Reporte de caso / Pulmonary infection caused by Strongyloides stercoralis in an immunocompromised patient. Case report

El Strongyloides stercoralis es un nemátodo intestinal capaz de completar su ciclo de vida dentro del huésped humano. Se presenta el caso clínico de una mujer de 57 años con residencia en la zona amazónica por 10 años, la que presenta antecedentes patológicos personales de hiperten-sión arterial, osteoporosis y diabetes mellitus tipo 2, lo que la cataloga como inmunocomprome-tida. Esta asiste a servicios de emergencia con cuadro agudo característico de infección de vías urinarias, recibe tratamiento en la unidad de cuidados intensivos por shock séptico de origen urinario versus pulmonar. La prueba de laboratorio clínico mediante muestra tomada a través de broncoaspiración arroja la existencia de larvas activas de Strongyloides stercoralis. La paciente mejoró sus condiciones de salud luego de un mes de evolución, respondiendo satisfactoriamente a la antibioticoterapia con carbapenémicos y el antiparasitario ivermectina. Los pacientes con factores de riesgo subyacentes tienen alta probabilidad a este tipo de infección agravada. La estrongiloidásis grave tiene una alta tasa de mortalidad, por lo que un diagnóstico temprano es indispensable para mejorar el pronóstico.

Strongyloides stercoralis is an intestinal nematode capable of completing its life cycle within the human host. The clinical case of a 57-year-old woman who has lived in the Amazon region for 10 years is presented. She has a personal pathological history of arterial hypertension, osteopo-rosis, and type 2 diabetes mellitus, which classifies her as immunocompromised. She attends emergency services with acute symptoms characteristic of urinary tract infection, receives treat-ment in the intensive care unit for septic shock of urinary versus pulmonary origin. The clinical laboratory test using a sample taken through bronchial aspiration shows the existence of active larvae of Strongyloides stercoralis. The patient's health conditions improved after a month of evolution, responding satisfactorily to antibiotic therapy with carbapenems and the antiparasitic ivermectin. Patients with underlying risk factors are at high risk for this type of aggravated infection. Severe strongyloidiasis has a high mortality rate, so early diagnosis is essential to improve prognosis

Evaluation of Strongyloides stercoralis infection in patients with HTLV-1 / Evaluación de la infestación por Strongyloides stercoralis en pacientes con HTLV-1

Introduction: Individuals infected with the human T-lymphotropic virus type 1 (HTLV-1) may present severe and disseminated forms of Strongyloides stercoralis infection with low therapeutic response. Objective: To investigate the S. stercoralis infection and the seroprevalence of IgG anti-S. stercoralis antibodies in individuals infected with HTLV-1 attending the Reference Center for HTLV-1 (CHTLV) in Salvador, Bahia, Brazil. Materials and methods: We conducted a cross-sectional study in 178 HTLV-1-infected individuals treated at the HTLV specialized center between January, 2014, and December, 2018. The parasitological diagnosis of S. stercoralis was performed using the Hoffman, Pons and Janer, agar plate culture, and Baermann-Morais methods. The IgG anti-S. stercoralis detection was performed using an in house enzyme-linked immunosorbent assay (ELISA). The HTLV-1 infection was diagnosed using a commercial ELISA and confirmed by Western blot. Results: The frequency of S. stercoralis infection was 3.4% (6/178). Individuals infected with S . stercoralis from rural areas (50.0%; 3/6) also showed S. stercoralis hyperinfection (>3,000 larvae/gram of feces). The frequency of circulating anti-S. stercoralis IgG antibodies was 20.8% (37/178). Conclusions: HTLV-1-infected people living in precarious sanitary conditions are more prone to develop severe forms of S. stercoralis infection. Considering the high susceptibility and unfavorable outcome of the infection in these individuals, the serological diagnosis for S. stercoralis should be considered when providing treatment.

Introducción. Los individuos infectados por el virus linfotrópico T humano tipo 1 (HTLV-1) pueden presentar formas graves y diseminadas de infestación por Strongyloides stercoralis con poca mejoría terapéutica. Objetivo. Investigar la infestación por S. stercoralis y la seroprevalencia de IgG anti-S. stercoralis en individuos infectados por HTLV-1 atendidos en el Centro de Referencia para HTLV-1 (CHTLV), en Salvador, Bahía, Brasil. Materiales y métodos. Se hizo un estudio transversal con 178 individuos infectados por HTLV-1 atendidos en el centro especializado de HTLV entre enero de 2014 y diciembre de 2018. El diagnóstico parasitológico de S. stercoralis se hizo mediante los métodos de Hoffman, Pons y Janer, cultivo en placa de agar y Baermann-Morais. Para la detección de IgG anti-S. stercoralis, se utilizó una prueba casera de inmunoabsorción ligada a enzimas (ELISA). La infección por HTLV-1 se diagnosticó usando un ELISA comercial y se confirmó mediante Western blot. Resultados. La frecuencia de infestación por S. stercoralis fue del 3,4 % (6/178). Además, los individuos infestados por S. stercoralis provenientes de la zona rural (50,0 %; 3/6) también mostraron hiperinfestación por S. stercoralis (>3.000 larvas/gramo de heces). La frecuencia de anticuerpos IgG anti-S. stercoralis fue del 20,8 % (37/178). Conclusiones. Las personas infectadas por HTLV-1 que viven en condiciones sanitarias precarias son más propensas a desarrollar formas graves de infestación por S. stercoralis. Teniendo en cuenta la gran vulnerabilidad y el resultado desfavorable de la infección en estos individuos, se debe considerar el diagnóstico serológico de S. stercoralis para administrar el tratamiento

Hallazgo histopatológico de Strongyloides stercoralis en enfermedad de Crohn: reporte de caso / Histopathologic finding of Strongyloides stercoralis in a patient with Crohn's disease: Case report

Resumen Caso clínico: Se describe un caso clínico poco frecuente en un paciente inmunocomprometido con hallazgo histopatológico de infestación parasitaria. Es un paciente masculino de edad media que habita en zona subtropical con diagnóstico de enfermedad de Crohn tratado con corticoide e inmunomoduladores, presentaba dolor abdominal y anemia crónica de 1 año de evolución, analítica negativa para parásitos, reactantes de fase aguda normales, gastroscopia y colonoscopia previas (6 meses) sin hallazgos relevantes. Por la persistencia del cuadro clínico se repitieron los estudios endoscópicos en los que se visualizaron hemorragias subepiteliales con resultados histopatológicos de Strongyloides stercoralis. Conclusión: En el contexto de un paciente inmunocomprometido, en zona endémica y con evolución tórpida, debe obligar a realizar un diagnóstico diferencial en el que se debe sospechar siempre de infestación parasitaria. Aunque la endoscopia no se necesita para el diagnóstico de estrongiloidiasis, su intervención puede ser oportuna.

Abstract Clinical case: The following is a rare clinical case in an immunocompromised patient with histopathological findings of parasitic infestation. The patient is a middle-aged male who lives in a subtropical area and has a diagnosis of Crohn's disease treated with corticosteroids and immunomodulators. The patient presented with abdominal pain and chronic anemia for 1 year, with negative laboratory tests for parasites and normal acute phase reactants. Gastroscopy and colonoscopy were performed before the consultation (6 months) without relevant findings. Due to the persistence of the symptoms, endoscopic studies were repeated, finding subepithelial bleeding with histopathological results of Strongyloides stercoralis. Conclusion: In the context of an immunocompromised patient living in an endemic area and with a torpid evolution, a differential diagnosis should be made always suspecting a parasitic infestation. Although endoscopy is not necessary to diagnose strongyloidiasis, its use may be convenient.

Innovative approaches to improve serodiagnosis of Strongyloides stercoralis infection

ABSTRACT Strongyloidiasis is a helminthiasis of neglected condition that has no gold standard parasitological diagnosis due to the intermittent release of larvae in feces. This study aimed to use an scFv (single chain variable fragment) obtained by Phage Display, previously validated to detect immune complexes in serum samples from individuals infected with Strongyloides stercoralis by enzyme-linked immunosorbent assay (ELISA). Now the ability of scFv to detect the immune complexes was verified by immunofluorescence, flow cytometry using magnetic beads and surface plasmon resonance (SPR). As ELISA, the SPR, immunofluorescence and flow cytometry demonstrated the ability of scFv to detect immune complexes in sera from individuals with strongyloidiasis and discriminate them from sera of individuals with other parasitic diseases and healthy individuals. Besides de conventional ELISA, the novel approaches can also be promptly applied as auxiliary diagnostic tools to the existing parasitological method for accurate diagnosis of human strongyloidiasis.

Fatal Strongyloides stercoralis hyperinfection syndrome in an alcoholic diabetic patient from México / Síndrome de hiperinfección mortal por Strongyloides stercoralis en un paciente diabético y alcohólico de México

Strongyloides stercoralis hyperinfection syndrome is a medical emergency that requires a high level of suspicion. Immunocompromised patients are at high risk of hyperinfection syndrome; however, malnutrition, alcoholism, and diabetes mellitus also need to be considered as predisposing factors. The diagnosis and treatment of Strongyloides hyperinfection are challenging and patients often have severe complications. Consequently, mortality is overwhelmingly high, with proportions above 60%. Herein, we report a case of Strongyloides hyperinfection in a 40-year-old alcoholic diabetic patient living in México. Unfortunately, the late diagnosis resulted in his death despite the treatment and supportive measures. Increased awareness is needed to prevent the dire consequences of strongyloidiasis.

El síndrome de hiperinfección por Strongyloides stercoralis es una emergencia médica que requiere una aguda sospecha clínica. Los pacientes inmunocomprometidos tienen alto riesgo de sufrir el síndrome de hiperinfección; sin embargo, la desnutrición, el alcoholismo y la diabetes mellitus también deben considerarse factores predisponentes. El diagnóstico y el tratamiento de la hiperinfección por S. stercoralis constituyen un desafío y los pacientes a menudo tienen complicaciones graves. Como consecuencia, la mortalidad es abrumadoramente alta, con proporciones superiores al 60 %. Se presenta un caso de hiperinfección por S. stercoralis en un paciente diabético y alcohólico de 40 años que vivía en México. Infortunadamente, el diagnóstico tardío causó su muerte a pesar del tratamiento y las medidas de soporte. Se necesita un mayor conocimiento para prevenir las terribles consecuencias de la estrongiloidiasis.

Strongyloides hyperinfection in a patient with solid malignant tumor a case report

Strongyloides stercoralis is unique among the nematodes, in which it completes its life cycle inside a single human host by causing autoinfection in the host, and it causes hyperinfection leading to persistent and fatal disseminated infections in immunocompromised hosts. The present case report is about strongyloidiasis fatal hyperinfection in a patient with malignant tumor of the tongue on radiotherapy treatment, to highlight the need for clinical suspicion of strongyloidiasis in an immunocompromised host. As per the Centers for Disease Control and Prevention, the mortality in strongyloides hyperinfection syndrome is alarmingly high, a case fatality rate that is almost 90%. Hence, the clinicians should be well equipped to diagnose, treat, and also prevent the fatal consequences of this lethal nematode. Detailed workup for this parasitic infection is crucial, and this case report emphasizes that a simple wet mount stool microscopic examination can clinch the diagnosis.

Strongyloides stercoralis como causa infrecuente de infección de líquido ascítico en cirrosis / Strongyloides stercoralis as uncommon cause of ascitic fluid infection in cirrhosis

Resumen Se comunica el caso clínico de un varón, con antecedentes de una cirrosis hepática alcohólica y gota, usuario crónico de antiinflamatorios, incluyendo corticoesteroides. Consultó por una melena secundaria a una úlcera bulbar. Durante su internación presentó fiebre, tratándose con ceftriaxona por un probable foco urinario. Por persistir febril, se realizó una paracentesis diagnóstica. En la muestra de líquido ascítico se observaron larvas de Strongyloides stercoralis. Recibió tratamiento antiparasitario con ivermectina, con buena respuesta clínica. Aunque la infección por S. stercoralis es relativamente frecuente en pacientes con cirrosis hepática alcohólica, la ascitis infectada por Strongyloides corresponde a una forma de presentación infrecuente. Este caso muestra la importancia de la paracentesis diagnóstica en todo paciente con ascitis secundaria a una cirrosis. Es importante considerar la presentación atípica de la infestación por Strongyloides en el contexto del paciente inmunocomprometido, ya que sin tratamiento puede tener una alta mortalidad.

Abstract Male patient, with a history of alcoholic cirrhosis frequent user of anti-inflammatory drugs including corticosteroids. He consulted for digestive bleeding secondary to a bulbar ulcer. During the admission, he had fever and antibiotic treatment with ceftriaxone is started, for a urinary infection. Fever persisted for 48 hours, so a diagnostic paracentesis was made: Strongyloides stercoralis larvae were seen in the direct microscopic exam. The patient started antiparasitic treatment with ivermectin. He was discharged and did not returned for follow up. Although infection with S. stercoralis is relatively common in patients with alcoholic liver cirrhosis, ascites infected with Strongyloides corresponds to an infrequent form of presentation. This case shows the importance of diagnostic paracentesis in every cirrhotic patient. It is important to consider atypical presentation of Strongyloides infection in the immunocompromised host, considering it could be fatal without treatment.

Hemorragia digestiva ocasional em criança por estrongiloidíase: importância do exame parasitológico / Occasional digestive hemorrhage in children due to strongyloidiasis: importance of parasitologic testing

RESUMO Objetivo: Descrever um caso incomum de infecção por Strongyloides stercoralis (S. stercoralis) em paciente de quatro meses de idade e ressaltar a importância do diagnóstico precoce. Descrição do caso: Paciente masculino, procedente e residente de Videira, Santa Catarina, Brasil, nasceu pré-termo, parto cesárea, peso de nascimento 1.655 g, e permaneceu na Unidade de Terapia Intensiva neonatal e intermediária por 20 dias. Aos quatro meses de idade, começou a evacuar fezes sanguinolentas e foi feita hipótese de alergia à proteína do leite de vaca, em razão da sintomatologia e do uso da fórmula infantil para o primeiro semestre, para o qual foi indicada a substituição por fórmula infantil com proteína hidrolisada. Foram solicitados a pesquisa de leucócitos e o exame parasitológico das fezes). Ambos se mostraram positivos e o parasitológico revelou a presença de larva rabditoide de S. stercoralis. O clínico manteve a hipótese inicial e a dieta, mas solicitou a coleta de três amostras de fezes, que resultaram em uma amostra para larvas rabditoide, em muda, de S. stercoralis. Como a criança apresentava dor abdominal, vômito e as fezes permaneciam sanguinolentas, foi iniciado o tratamento com tiabendazol - duas vezes/dia por dois dias -, repetido após sete dias, e, em seguida, realizado o exame parasitológico de fezes, tendo sido negativo. Comentários: A estrongiloidíase, apesar de ser uma infecção parasitária frequentemente leve, em pacientes imunocomprometidos pode se apresentar de forma grave e disseminada. Deve-se suspeitar desse agente em pacientes que vivem em áreas endêmicas, sendo o diagnóstico estabelecido por meio da pesquisa das larvas do S. stercoralis na secreção traqueal e nas fezes.

ABSTRACT Objective: To describe an uncommon case of infection by Strongyloides stercoralis (S. stercoralis) in a 4-month-old child and to highlight the importance of early diagnosis. Case description: The patient was a male child from the city of Videira, State of Santa Catarina, Southern Brazil, who was born preterm by Cesarean-section, weighing 1,655 g, and stayed in the neonatal intensive care unit for 20 days. At four months of age, the child started presenting blood in stools and the possibility of cow's milk protein allergy was considered, given the symptoms and the use of infant formula in his 1st semester of life, which was then replaced by infant formula with hydrolyzed protein. White blood cell count and a parasitological stool sample were requested. Both tested positive and the stool ova and parasite examination showed a rhabditoid larva of S. stercoralis. The clinician maintained the initial hypothesis and diet, but requested three new stool samples, which tested positive for rhabditoid larvae of S. stercoralis. Since the child presented abdominal pain and vomiting, and there was still blood in stools, treatment with thiabendazole was initiated twice a day for two days. Treatment was repeated after seven days along with a new parasitological examination, which was then negative. Comments: Although strongyloidiasis is usually a mild parasitic infection, it may be severe and disseminated in immunocompromised patients. This agent must be considered in patients who live in endemic areas, and the diagnosis should be established by searching S. stercoralis larvae in tracheal secretions and in stools.

A Case of Chronic Strongyloidiasis with Recurrent Hyperinfection

Strongyloides stercoralis is an intestinal nematode that often causes chronic diarrhea and may develop severe complicated form of hyperinfection or disseminated infection in immunocompromised patients. Here, we report a case of recurrent strongyloidiasis presenting with pulmonary and meningeal involvement. A 55-year-old male diagnosed with pancreatic cancer 4 months ago was admitted due to chronic diarrhea, abdominal pain, and weight loss for 2–3 months. He had been treated with albendazole for chronic recurrent strongyloidiasis 13 years ago and again 2 years ago. He developed sepsis of Klebsiella pneumoniae and Escherichia coli on Days 3 and 7, respectively, and then meningitis of E. coli on Day 42. Strongyloidiasis was diagnosed by detection of abundant filariform larvae in sputum specimens on Day 15. He was treated for disseminated strongyloidiasis with albendazole and ivermectin for five weeks until clearance of larvae was confirmed in sputum and stool specimens. Laboratory diagnosis is important to guide appropriate treatment and to prevent chronic and recurrent strongyloidiasis.

Epidemiology and immunodiagnostics of Strongyloides stercoralis infections among migrant workers in Malaysia

To investigate the status of Strongyloides(S.) stercoralis infections among migrant workers in Malaysia for the first time and identify risk factors. Methods: Four diagnostic methods were employed for the detection of S. stercoralis including microscopy, enzyme-linked immunosorbent assay (ELISA) using a commercial kit, ELISA using the rSs1a antigen and polymerase chain reaction (PCR). Low and semi-skilled workers from five working sectors (i.e. manufacturing, food service, agriculture and plantation, construction and domestic service) were tested on a voluntary basis. Results: The overall seroprevalence of S. stercoralis from 483 workers employing the ELISA commercial kit for IgG was 35.8% (n=173; 95% CI: 31.5%-40.1%) whereas seroprevalence using the rSs1a-ELISA was 13.0% (n=63; 95% CI: 10.0%-16.0%). Cross tabulation between the ELISA commercial kit and rSs1a-ELISA showed that only 6.4% (n=31; 95% CI: 4.2%-8.6%) of the samples were positive in both tests. Microscopic examination of all 388 fecal samples were negative; however subsequent testing by a nested PCR against DNA from the same samples successfully amplified DNA from three male subjects (0.8%; 3/388). Male workers, India and Myanmar nationality, food service occupation and those living in the hostel were statistically significant with seroprevalence (P<0.005). Conclusion: This is the first report on the epidemiology of S. stercoralis infections among the migrant workers in Malaysia. Our results highlight the importance of using appropriate diagnostic tools for detection. The presence of anti-S. stercoralis antibodies in the study population calls for improvements in personal hygiene and sanitation standards among migrant workers in Malaysia through control strategies including health education campaigns and programs aimed at increasing awareness and healthy behaviors.

Molecular identification of Strongyloides stercoralis infection in a severe pulmonary patient with pemphigus from Hainan Province of China

Objective: To describe a case of Strongyloides (S.) stercoralis infestation with severe lung involvement in a patient who had pemphigus and treated with prednisone and to analyze the molecular characteristics of the S. stercoralis isolate. Methods: A 54-year-old Chinese man living in rural area of the Hainan Province, China. He had a 1-year history of pemphigus and took prednisone for more than six month. He was admitted to the hospital with a 1-week history of abdominal pain, nausea and vomiting. Two days before admission, he presented with cough, expectoration, and shortness of breath after activity accompanied by fever. Computed tomography (CT) of the chest was performed at different stage of admission. Gastric juice, sputum and stool sample smears were examined under light microscope. The larvae of Strongyloides were found from gastric juice, sputum and stool samples of the patient and the genomic DNA of the larvaes was extracted. PCR amplification of the cytochrome c oxidase subunit 1 (cox1) gene was carried out for the DNA sample and the products were sequenced. Results: CT of the chest on day 1 of admission showed inflammation in the tongue segment of the upper lobe of the left lung and the lower lobe of both lungs and the subsequent CT of the chest revealed extensive bilateral pulmonary infiltrates. PCR amplification and sequencing analysis of the Strongyloides larvae directly colleted from the gastric juice, sputum and stool samples on day 10 of admission showed that 100% homology with the sequence of S. stercoralis isolated in a human from Iran (GenBank No. MG995852). Clinical and imageologicalimprovement was achieved after treatement of albendazole (600 mg/day). Conclusions: This is the first case report of pulmonary S. stercoralis infection in a patient with pemphigus treated with prednisone in Hainan Province of China. We suggested that strongyloidiasis should be routinely investigated in patients presenting with nausea, vomiting, diarrhea, cough or expectoration which were accompanied by fever, especially for patients with low immune function or immune deficiency. .

Epidemiology and immunodiagnostics of Strongyloides stercoralis infections among migrant workers in Malaysia

To investigate the status of Strongyloides(S.) stercoralis infections among migrant workers in Malaysia for the first time and identify risk factors. Methods: Four diagnostic methods were employed for the detection of S. stercoralis including microscopy, enzyme-linked immunosorbent assay (ELISA) using a commercial kit, ELISA using the rSs1a antigen and polymerase chain reaction (PCR). Low and semi-skilled workers from five working sectors (i.e. manufacturing, food service, agriculture and plantation, construction and domestic service) were tested on a voluntary basis. Results: The overall seroprevalence of S. stercoralis from 483 workers employing the ELISA commercial kit for IgG was 35.8% (n=173; 95% CI: 31.5%-40.1%) whereas seroprevalence using the rSs1a-ELISA was 13.0% (n=63; 95% CI: 10.0%-16.0%). Cross tabulation between the ELISA commercial kit and rSs1a-ELISA showed that only 6.4% (n=31; 95% CI: 4.2%-8.6%) of the samples were positive in both tests. Microscopic examination of all 388 fecal samples were negative; however subsequent testing by a nested PCR against DNA from the same samples successfully amplified DNA from three male subjects (0.8%; 3/388). Male workers, India and Myanmar nationality, food service occupation and those living in the hostel were statistically significant with seroprevalence (P<0.005). Conclusion: This is the first report on the epidemiology of S. stercoralis infections among the migrant workers in Malaysia. Our results highlight the importance of using appropriate diagnostic tools for detection. The presence of anti-S. stercoralis antibodies in the study population calls for improvements in personal hygiene and sanitation standards among migrant workers in Malaysia through control strategies including health education campaigns and programs aimed at increasing awareness and healthy behaviors.

Estrongiloidiasis gastrointestinal en paciente inmunocompetente: a propósito de un caso / Gastrointestinal strongyloidosis in an immunocompetent patient: a case report

Intestinal parasitic infections cause a not insignificant number of chronic diarrhea in children, however, with the sociodemographic change that our country has experienced, the number of cases and new parasites (immigration from tropical endemic areas) could increase. We report the case of an immunocompetent patient who presents with chronic diarrhea associated with Strongyloides stercoralis infection. The patient migrated two years ago from an endemic area for this helminth. The diagnosis is challenging, and the chances of a successful outcome depend on the administration of the antiparasitic.

Las infecciones parasitarias intestinales provocan un número no despreciable de causas de diarrea crónica en niños, sin embargo, con el cambio sociodemográfico que ha vivido nuestro país se podría incrementar el número de casos y de nuevos parásitos (inmigración de áreas endémicas tropicales). Reportamos el caso de un paciente inmunocompetente, que presenta cuadro de diarrea crónica asociada a infección por Strongyloides stercoralis. El paciente habría migrado hace dos años desde zona endémica para este helminto. El diagnóstico es desafiante y las posibilidades de un resultado exitoso dependen de la administración del antiparasitario.