title: Application of real-time PCR for the detection of Strongyloides spp. in clinical samples in a reference center in Spain.
abstract: Strongyloidiasis is one of the major intestinal helminthic infections in humans with a worldwide distribution, affecting especially tropical and subtropical regions. This disease can occur without any symptoms or as a potentially fatal hyperinfection or disseminated infection. Definitive diagnosis of Strongyloides stercoralis infection relies mainly on demonstration of larvae in stool, but at present there is no gold standard for this diagnosis. Our main objective was to evaluate a real-time PCR targeting the 18S rRNA gene of Strongyloides spp. and to compare it with routine parasitological methods. DNA from Strongyloides venezuelensis was used to optimize PCR protocols obtaining an analytical sensitivity of 0.1 pg of parasite DNA per sample. Sensitivity and specificity of real-time PCR on fecal samples from 231 patients screened for suspected strongyloidiasis attending two hospitals in Madrid were 93.8% and 86.5%, respectively. No significant differences were found when comparing Ct-values of positive PCR between parasitological positive and negative samples. This study showed that real-time PCR is an effective tool for diagnosing strongyloidiasis and could be applied in association with parasitological methods in epidemiological studies in endemic areas. It would be also important to assess its performance in immunocompromised populations who are at risk of fatal disease.
authors.affiliation: Department of Parasitology, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid 28220, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: Saugar
authors.affiliation: Department of Microbiology and Parasitology, Hospital Universitario Severo Ochoa, Leganés, Madrid 28911, Spain.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Merino
authors.affiliation: Division of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, 28007 Madrid, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Martín-Rabadán
authors.affiliation: IBSAL-CIETUS (Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca), Facultad de Farmacia, Universidad de Salamanca, 37007 Salamanca, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Fernández-Soto
authors.affiliation: Department of Parasitology, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid 28220, Spain.
authors.forename: Sheila
authors.initials: S
authors.lastname: Ortega
authors.affiliation: Department of Parasitology, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid 28220, Spain.
authors.forename: Teresa
authors.initials: T
authors.lastname: Gárate
authors.affiliation: Department of Parasitology, National Centre for Microbiology, Instituto de Salud Carlos III, Majadahonda, Madrid 28220, Spain. Electronic address: erodrgez@isciii.es.
authors.forename: Esperanza
authors.initials: E
authors.lastname: Rodríguez
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D005243:Feces / Q000469:parasitology; D005260:Female; D006373:Helminthiasis / Q000175:diagnosis* / Q000453:epidemiology / Q000469:parasitology; D006801:Humans; D016867:Immunocompromised Host; D007411:Intestinal Diseases, Parasitic / Q000175:diagnosis* / Q000453:epidemiology / Q000469:parasitology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D012337:RNA, Ribosomal, 18S / Q000032:analysis*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D013030:Spain / Q000453:epidemiology; D013321:Strongyloides / Q000235:genetics* / Q000302:isolation & purification; D017171:Strongyloides stercoralis / Q000235:genetics / Q000302:isolation & purification; D013322:Strongyloidiasis / Q000175:diagnosis* / Q000453:epidemiology / Q000469:parasitology; D055815:Young Adult
chemical_list: D012337:RNA, Ribosomal, 18S
keywords: Diagnosis; Melting curve analysis; Real-time PCR; Spain; Strongyloides spp.; Strongyloidiasis