The Centers for Disease Control and Prevention today updated its H1N1 infection control guidance for health care settings, including use of N95 respirators. The agency continues to recommend that health care workers who are in close contact with patients having suspected or confirmed H1N1 flu use N95s, but acknowledged supply concerns. Where a shortage of respirators exists despite reasonable efforts to obtain them, hospitals may prioritize use of the N95 respirators, especially for aerosol-generating procedures and for health care workers who are at higher risk for H1N1. Hospitals with insufficient supplies of N95 respirators that demonstrate "good faith" efforts to acquire N95s and follow the agency's hierarchy of control recommendations may use surgical masks. During a CDC call with hospitals about the guidance, a representative from the Occupational Safety and Health Administration said OSHA will not deem these hospitals to be out of compliance with its standards, and is preparing a detailed compliance directive outlining how OSHA will enforce the CDC guidance. The CDC also released a document to help health care facilities optimize the implementation of H1N1-related infection control recommendations within the context of equipment shortages. Today's guidance also updates how long health care workers should stay away from work if they develop a fever and respiratory symptoms. Under the new recommendation, these workers should be excluded from work for at least 24 hours after they no longer have a fever without the use of fever-reducing medicines.