title: Improved detection of Lassa virus by reverse transcription-PCR targeting the 5' region of S RNA.
abstract: The method of choice for the detection of Lassa virus is reverse transcription (RT)-PCR. However, the high degree of genetic variability of the virus poses a problem with the design of RT-PCR assays that will reliably detect all strains. Recently, we encountered difficulties in detecting some strains from Liberia and Nigeria in a commonly used glycoprotein precursor (GPC) gene-specific RT-PCR assay (A. H. Demby, J. Chamberlain, D. W. Brown, and C. S. Clegg, J. Clin. Microbiol. 32:2898-2903, 1994), which prompted us to revise the protocol. The design of the new assay, the GPC RT-PCR/2007 assay, took into account 62 S RNA sequences from all countries where Lassa fever is endemic, including 40 sequences generated from the strains in our collection. The analytical sensitivity of the new assay was determined with 11 strains from Sierra Leone, Liberia, Ivory Coast, and Nigeria by probit analysis; the viral loads detectable with a probability of 95% ranged from 342 to 2,560 S RNA copies/ml serum, which corresponds to 4 to 30 S RNA copies/assay. The GPC RT-PCR/2007 assay was validated with 77 serum samples and 1 cerebrospinal fluid sample from patients with laboratory-confirmed Lassa fever. The samples mainly originated from Liberia and Nigeria and included strains difficult to detect in the assay of 1994. The GPC RT-PCR/2007 assay detected virus in all clinical specimens (100% sensitivity). In conclusion, a new RT-PCR assay, based in part on the protocol developed by Demby et al. in 1994, for the detection of Lassa virus is described. Compared to the assay developed in 1994, the GPC RT-PCR/2007 assay offers improved sensitivity for the detection of Liberian and Nigerian Lassa virus strains.
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, Department of Virology, Bernhard-Nocht-Strasse 74, Hamburg 20359, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Olschläger
authors.forename: Michaela
authors.initials: M
authors.lastname: Lelke
authors.forename: Petra
authors.initials: P
authors.lastname: Emmerich
authors.forename: Marcus
authors.initials: M
authors.lastname: Panning
authors.forename: Christian
authors.initials: C
authors.lastname: Drosten
authors.forename: Meike
authors.initials: M
authors.lastname: Hass
authors.forename: Danny
authors.initials: D
authors.lastname: Asogun
authors.forename: Deborah
authors.initials: D
authors.lastname: Ehichioya
authors.forename: Sunday
authors.initials: S
authors.lastname: Omilabu
authors.forename: Stephan
authors.initials: S
authors.lastname: Günther
mesh_terms: D017931:DNA Primers / Q000235:genetics*; D006801:Humans; D007835:Lassa Fever / Q000175:diagnosis* / Q000821:virology; D007836:Lassa virus / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D012367:RNA, Viral / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D014773:Virology / Q000379:methods*
chemical_list: D017931:DNA Primers; D012367:RNA, Viral