title: Comparison between PCR and larvae visualization methods for diagnosis of Strongyloides stercoralis out of endemic area: A proposed algorithm.
abstract: Underdiagnosis of chronic infection with the nematode Strongyloides stercoralis may lead to severe disease in the immunosuppressed. Thus, we have set-up a specific and highly sensitive molecular diagnosis in stool samples. Here, we compared the accuracy of our polymerase chain reaction (PCR)-based method with that of conventional diagnostic methods for chronic infection. We also analyzed clinical and epidemiological predictors of infection to propose an algorithm for the diagnosis of strongyloidiasis useful for the clinician. Molecular and gold standard methods were performed to evaluate a cohort of 237 individuals recruited in Buenos Aires, Argentina. Subjects were assigned according to their immunological status, eosinophilia and/or history of residence in endemic areas. Diagnosis of strongyloidiasis by PCR on the first stool sample was achieved in 71/237 (29.9%) individuals whereas only 35/237(27.4%) were positive by conventional methods, requiring up to four serial stool samples at weekly intervals. Eosinophilia and history of residence in endemic areas have been revealed as independent factors as they increase the likelihood of detecting the parasite according to our study population. Our results underscore the usefulness of robust molecular tools aimed to diagnose chronic S. stercoralis infection. Evidence also highlights the need to survey patients with eosinophilia even when history of an endemic area is absent.
authors: Departamento de Microbiología, Parasitología e Inmunología, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), Facultad de Medicina, Universidad de Buenos Aires (UBA), Paraguay 2155, CC1121ABG Buenos Aires, Argentina; Hospital de Clínicas José de San Martín, Universidad de Buenos Aires, Av. Córdoba 2351, C1120AAF Buenos Aires, Argentina. Electronic address: silvia_repetto@yahoo.com.ar.
authors: Silvia A
authors: SA
authors: Repetto
authors: Departamento de Microbiología, Parasitología e Inmunología, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), Facultad de Medicina, Universidad de Buenos Aires (UBA), Paraguay 2155, CC1121ABG Buenos Aires, Argentina.
authors: Paula
authors: P
authors: Ruybal
authors: Departamento de Microbiología, Parasitología e Inmunología, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), Facultad de Medicina, Universidad de Buenos Aires (UBA), Paraguay 2155, CC1121ABG Buenos Aires, Argentina.
authors: María Elisa
authors: ME
authors: Solana
authors: Hospital General de Agudos Carlos G. Durand, Sección Infectología, Av. Díaz Vélez 5044, C1405DCS Buenos Aires, Argentina.
authors: Carlota
authors: C
authors: López
authors: Instituto de Investigaciones, Biomédicas sobre Retrovirus y SIDA (INBIRS), Facultad de Medicina, Universidad de Buenos Aires, Argentina.
authors: Carolina A
authors: CA
authors: Berini
authors: Departamento de Microbiología, Parasitología e Inmunología, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), Facultad de Medicina, Universidad de Buenos Aires (UBA), Paraguay 2155, CC1121ABG Buenos Aires, Argentina.
authors: Catalina D
authors: CD
authors: Alba Soto
authors: Departamento de Microbiología, Parasitología e Inmunología, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), Facultad de Medicina, Universidad de Buenos Aires (UBA), Paraguay 2155, CC1121ABG Buenos Aires, Argentina.
authors: Stella M González
authors: SM
authors: Cappa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D000818:Animals; D001118:Argentina; D015331:Cohort Studies; D003955:Diagnostic Tests, Routine; D019353:Endemic Diseases; D004802:Eosinophilia / Q000097:blood*; D005243:Feces / Q000469:parasitology*; D005260:Female; D006801:Humans; D007814:Larva; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D015203:Reproducibility of Results; D017171:Strongyloides stercoralis / Q000235:genetics* / Q000302:isolation & purification*; D013322:Strongyloidiasis / Q000175:diagnosis*; D055815:Young Adult
keywords: Endemic areas; Eosinophilia; Helminthiasis diagnosis; Nematode infections; PCR in stool samples molecular diagnosis; S. stercoralis; Strongyloidiasis