Imported Lassa fever in Germany: Molecular characterization of a new Lassavirus strain

We describe the isolation and characterization of a new Lassa virus strain imported into Germany by a traveler who had visited Ghana, Cote D'Ivoire, a nd Burkina Faso. This strain, designated "AV," originated from a region in West Africa where Lassa fever has not been reported. Viral S RNA isolated f rom the patient's serum was amplified and sequenced. A long-range reverse t ranscription polymerase chain reaction allowed amplification of the full-le ngth (3.4 kb) S RNA. The coding sequences of strain AV differed from those of all known Lassa prototype strains (Josiah, Nigeria, and LP) by approxima tely 20%, mainly at third codon positions. Phylogenetically, strain AV appe ars to be most closely related to strain Josiah from Sierra Leone. Lassa vi ruses comprise a group of genetically highly diverse strains, which has imp lications for vaccine development. The new method for full-length S RNA amp lification may facilitate identification and molecular analysis of new aren aviruses or arenavirus strains.