Prevalence and risk factors of Strongyloides stercoralis in haemodialysis in Cochabamba, Bolivia: a cross-sectional study.

BACKGROUND Strongyloidiasis is an infectious disease that can be fatal in immunocompromised patients. Patients with end-stage renal failure who are on dialysis have a considerably weakened immune system, and organ transplantation is a major risk factor for severe strongyloidiasis. Knowledge of the local epidemiology in tropical and subtropical areas is an essential prerequisite for designing an appropriate strategy to prevent this potentially lethal complication. In this study, we aimed to estimate the prevalence and associated risk factors of S. stercoralis infection in patients on dialysis in Cochabamba, Bolivia. METHODS A cross-sectional study was carried out among patients undergoing haemodialysis in Cochabamba (elevation 2,500 m, temperate climate), collecting information on socio-demographic, lifestyle, and clinical variables, and using one coproparasitological technique (the modified Baermann technique) and one serological (ELISA) test for S.stercoralis diagnosis. RESULTS In total, 149 patients participated in the study (mean age = 51.4 years, 48.3% male). End-stage renal disease was predominantly (59%) of hypertensive and/or diabetic origin. The positive serological prevalence was 18.8% (95% CI: 13.3%-25.9%). Based on the sensitivity and specificity of the ELISA test, the estimate of the actual prevalence was 15.1% (95% CI: 9.4%-20.7%). Stool samples of 105 patients (70.5%) showed a coproparasitological prevalence of 1.9% (95% CI: 0.52%-6.68%). No potential risk factors were significantly associated with S. stercoralis infection. CONCLUSIONS We found a high seroprevalence of S. stercoralis in Bolivian patients undergoing haemodialysis in Cochabamba. We recommend presumptive antiparasitic treatment at regular intervals to avoid the potentially fatal complications of severe strongyloidiasis

A severe clinical phenotype of Noonan syndrome with neonatal hypertrophic cardiomyopathy in the second case worldwide with RAF1 S259Y neomutation

International audienceNoonan syndrome and related disorders are a group of clinically and genetically heterogeneous conditions caused by mutations in genes of the RAS/MAPK pathway. Noonan syndrome causes multiple congenital anomalies, which are frequently accompanied by hypertrophic cardiomyopathy (HCM). We report here a Tunisian patient with a severe phenotype of Noonan syndrome including neonatal HCM, facial dysmorphism, severe failure to thrive, cutaneous abnormalities, pectus excavatum and severe stunted growth, who died in her eighth month of life. Using whole exome sequencing, we identified a de novo mutation in exon 7 of the RAF1 gene: c.776C > A (p.Ser259Tyr). This mutation affects a highly conserved serine residue, a main mediator of Raf-1 inhibition via phosphorylation. To our knowledge the c.776C > A mutation has been previously reported in only one case with prenatally diagnosed Noonan syndrome. Our study further supports the striking correlation of RAF1 mutations with HCM and highlights the clinical severity of Noonan syndrome associated with a RAF1 p.Ser259Tyr mutation

Prévalence et facteurs de risque de <i>Strongyloïdes stercoralis</i> en hémodialyse à Cochabamba, en Bolivie

La strongyloïdose est une infection parasitaire potentiellement fatale chez l’hôte immunosupprimé. Les patients atteints d'insuffisance rénale terminale dialysés présentent un système immunitaire considérablement affaibli et la transplantation rénale est un facteur de risque majeur de strongyloïdose sévère. La connaissance de l'épidémiologie locale dans les zones tropicales et subtropicales est essentielle pour traiter précocement les porteurs de S.stercoralis et prévenir ainsi les complications liées à une strongyloïdose sévère. L’objectif de cette thèse est double. Dans la partie introductive un résumé de la littérature est proposé afin de sensibiliser les cliniciens sur les différents aspects de S.stercoralis. En deuxième partie, une étude transversale est présentée, explorant la prévalence et les facteurs de risque associés à l'infection par S.stercoralis chez des patients hémodialysés à Cochabamba en Bolivie. </p