Nosocomial buffalopoxvirus infection, Karachi, Pakistan.

During 5 months in 2004-2005, buffalopoxvirus infection, confirmed by virus isolation and limited nucleic acid sequencing, spread between 5 burns units in Karachi, Pakistan. The outbreak was related to movement of patients between units. Control measures reduced transmission, but sporadic cases continued due to the admission of new patients with community-acquired infections.