The AHA yesterday urged the Centers for Disease Control and Prevention to revise its hospital infection control guidelines for H1N1 flu to reflect the most recent data on how the virus is transmitted and the limited supply of N-95 respirators. In a letter to the CDC's National Institute for Occupational Safety and Health, the AHA said it supports using a hierarchy of controls to prevent H1N1 infection, and recommends using surgical or procedure masks for most patient contact and N-95 respirators primarily for aerosol-generating procedures. "Current CDC guidance, issued this past Spring before the severity or mechanism of transmission was fully understood, conservatively recommends the use of N-95 (or higher) respirators for routine patient care," the AHA wrote. "However, more recent data suggests that the virus has not changed to become more severe and studies suggest that it transmits much the same way as seasonal flu." The AHA also urged the Department of Health and Human Services to increase funding for research on flu transmission and personal respiratory protection, and for development of a better respirator for health care workers.