In this 2007 image. Centers for Disease Control microbiologist Dr. Thomas Stevens. Jr. was showering inside a Biosafety Level 4 (BSL-4) laboratory decontamination booth. prior to exiting the sealed confines of the BSL-4 lab. The process consists of a 4 minute. 5% Microchem wash. which is followed by a 3 minute rinse with water. The Special Pathogens Branch works with BSL-4 viruses. These viruses are highly pathogenic and require handling in special laboratory facilities designed to contain them. The Special Pathogens Branch's (SPB) charter is the study of highly infectious viruses. many of them causing hemorrhagic manifestations in humans. Our daily work involves the investigation of viruses such as Ebola hemorrhagic fever. Marburg hemorrhagic fever. Lassa fever. Rift valley fever virus. Crimean-Congo hemorrhagic fever virus. arenaviruses and hantaviruses. and other recently identified and emerging viral diseases.