Dr Klena is a PhD infectious diseases microbiologist whose professional career began in 1992. He has extensive experience in microbial genetics, microbial genomics and pathogenicity studies. Through his work and research, John has been fortunate to be able to work across the world, although the focus of much of his team’s recent efforts are in Bangladesh (Nipah virus and Crimean-Congo haemorrhagic fever (CCHF) virus), Colombia (New World hantaviruses and New World arenaviruses) and Uganda (CCHF, filoviruses including Ebola, Bundibugyo, Sudan and Marburg, and Rift Valley Fever virus). At CDC, Dr Klena supervises a team that develops and provides diagnostic assays (nucleic-acid-based and serological) to national and international partners and has extensive experience in viral isolation, phylogenetic analysis of viral genomes and the safe handling and manipulation of high-consequence viral pathogens.