While wearing his air tight safety suit in this 2007 image, CDC microbiologist Dr. Scott Smith is in the process of placing a rotor cuff containing tubes of virus particles and cellular debris into a high-speed centrifuge. This activity is taking place inside the confines of the organization?s Biosafety Level 4 (BSL-4) laboratories. The Special Pathogens Branch mission focuses mainly on viral hemorrhagic fevers (VHFs), such as Ebola hemorrhagic fever, Lassa fever, hantavirus pulmonary syndrome (