MOLECULAR-DETECTION AND CHARACTERIZATION OF YELLOW-FEVER VIRUS IN BLOOD AND LIVER SPECIMENS OF A NON-VACCINATED FATAL HUMAN CASE

A yellow fever virus of a South American genotype was identified in th e liver and blood samples of a non-vaccinated European patient after h is return from Brazil. ELISA tests were negative for IgG and positive for IgM against yellow fever. Yellow fever proteins in the formalin-fi xed and paraffin-embedded liver biopsy were detected by immunohistoche mical procedures. Viral RNA extracted from the liver tissue was also d etected using an RT-semi-nested PCR procedure and molecular hybridizat ion. Alignment of the sequence obtained from a gene fragment amplified by RT-semi-nested PCR directly from a blood sample with those of Afri can and South American yellow fever virus strains identified a Brazili an topotype as being responsible for the disease. RT-semi-nested PCR m ay be used advantageously for clinical specimens for rapid and specifi c diagnosis, and with archival biopsy material for retrospective studi es. (C) 1997 Wiley-Liss, Inc.