title: Improved detection of dengue-1 virus from IgM-positive serum samples using C6/36 cell cultures in association with RT-PCR.
abstract: Dengue is the most important arboviral disease in the world, and its diagnosis is primarily made by serology. Virus isolation has been successful mainly in clinical samples obtained during the acute phase of illness, and is carried out through inoculation of clinical samples into C6/36 cell monolayers followed by the detection of infection by indirect immunofluorescence assay (IFA). We compared the efficiency of RT-PCR and IFA in the detection of dengue-1 virus after inoculation of C6/36 cells with samples obtained in the convalescent period of dengue infection. Out of 75 IgM-positive samples inoculated into C6/36 cells, 2 were positive by IFA while 17 were positive by RT-PCR. The 2 IFA-positive samples were collected during the acute phase of the illness; 17 positive samples were found by RT-PCR, including the 2 detected by IFA. For both methods, we also investigated the time necessary for viral detection using a fixed dose of 1 x 10(4) viruses/ml. RT-PCR and IFA detected the dengue virus 1 and 4 days after virus inoculation, respectively. The results obtained here indicate that RT-PCR is the most sensitive method in the detection of dengue viruses using C6/36 cells for viral isolation.
authors.affiliation: Department of Clinical Medicine, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: Sérgio
authors.initials: S
authors.lastname: Oliveira De Paula
authors.forename: Danielle
authors.initials: D
authors.lastname: Malta Lima
authors.forename: Marilidia
authors.initials: M
authors.lastname: Clotteau
authors.forename: Roberto da Justa
authors.initials: Rda J
authors.lastname: Pires Neto Rd
authors.forename: Benedito Antônio
authors.initials: BA
authors.lastname: Lopes da Fonseca
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D001483:Base Sequence; D002460:Cell Line; D004279:DNA, Viral / Q000097:blood / Q000235:genetics; D003715:Dengue / Q000175:diagnosis* / Q000276:immunology / Q000821:virology; D003716:Dengue Virus / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification*; D019084:Fluorescent Antibody Technique, Indirect / Q000706:statistics & numerical data; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000706:statistics & numerical data; D012680:Sensitivity and Specificity
chemical_list: D000914:Antibodies, Viral; D004279:DNA, Viral; D007075:Immunoglobulin M