Forensic signatures for Marburgviruses

Marburgvirus is one of the most important hemorrhagic fever viruses with extremely high infectivity and fatality rate (~90%). It is transmitted easily in human populations through a respiratory route and therefore considered as a major biothreat agent. Although detection assays have been developed, no assay is available for forensic analysis. Here we report development of forensic assays for Marburgvirus. We performed detailed phylogenetic analysis of strains and isolates from all known Marburg virus outbreaks as well as from several laboratory strains and identified canonical SNPs for all major clades (outbreaks) and strains. TaqMan-MGB allelic discrimination assays targeting these SNPs were designed and experimentally screened against synthetic RNA templates and genomic RNAs. A total of 45 assays were validated to provide 100% coverage of the clades (outbreaks) and 91% at the strain level (21 out of the 23 targeted Marburgvirus strains) with built-in redundancy for increased robustness. Using these validated assays, we were able to provide accurate forensic analysis on 3 "unknown" Marburgviruses. These high-resolution forensic assays allow rapid and accurate genotyping of Marburgviruses for forensic investigations.