title: Polymerase chain reaction for the evaluation of Schistosoma mansoni infection in two low endemicity areas of Minas Gerais, Brazil.
abstract: This study aimed to evaluate the occurrence of schistosomiasis in areas with low endemicity using polymerase chain reaction (PCR) as a diagnostic method. We analysed faecal samples from 219 individuals residing in Piau and Coronel Pacheco, state of Minas Gerais, Brazil, using a single faecal sample from each individual and two slides of the Kato-Katz technique as a gold standard. Fifteen out of the 219 samples were positive with both methods of diagnosis. One sample was diagnosed as positive by the Kato-Katz technique only and 61 were diagnosed only by PCR. The positivity rates were 7.3% with the Kato-Katz method and 34.7% with PCR. When both techniques were assumed to have 100% specificity and positive individuals were identified by both methods, the sensitivity of the Kato-Katz method was 20.8% and the PCR sensitivity was 98.7%. The Kappa index between the two techniques was 0.234, suggesting weak agreement. The assessment of a single faecal sample by PCR detected more cases of infection than the analysis of one sample with two slides using the Kato-Katz technique, suggesting that PCR can be a useful diagnostic tool, particularly in areas with low endemicity.
authors.affiliation: Departamento de Parasitologia, Microbiologia e Imunologia, Universidade Federal de Juiz de Fora, MG, Brasil. gabrielbiomed@hotmail.com
authors.forename: Gabriel Costa de
authors.initials: GC
authors.lastname: Carvalho
authors.forename: Letícia Helena dos Santos
authors.initials: LH
authors.lastname: Marques
authors.forename: Luciana Inácia
authors.initials: LI
authors.lastname: Gomes
authors.forename: Ana
authors.initials: A
authors.lastname: Rabello
authors.forename: Luiz Cláudio
authors.initials: LC
authors.lastname: Ribeiro
authors.forename: Kezia Katiane Gorza
authors.initials: KK
authors.lastname: Scopel
authors.forename: Sandra Helena Cerrato
authors.initials: SH
authors.lastname: Tibiriçá
authors.forename: Elaine Soares
authors.initials: ES
authors.lastname: Coimbra
authors.forename: Clarice
authors.initials: C
authors.lastname: Abramo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D005243:Feces / Q000469:parasitology; D005260:Female; D006801:Humans; D007223:Infant; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D012550:Schistosoma mansoni / Q000235:genetics* / Q000302:isolation & purification; D012555:Schistosomiasis mansoni / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D055815:Young Adult