An important aspect of virological surveillance is the identification of the detected viruses. Broad surveillance, that typically employs deep sequencing of collected tissue samples, provides the investigator with many sequence files constructed from overlapping stretches of DNA sequences. Directed surveillance for viruses of a specific taxonomic group provides the investigator with sequence files from cDNA amplified using specific primers to conserved viral regions. Here we will describe general approaches to identify hemorrhagic viral agents through phylogenetic analysis of cDNA sequences obtained during surveillance activities.