Flu Activity Heats Up Next Month

The month of September 2009 may tell us much more about how serious CDC and outside experts believe the H1N1 influenza will be this fall in the United States. CDC has promised to release updated guidance by Oct. 1 for infection control at health care facilities treating patients confirmed or suspected to be infected, and the Institute of Medicine's expect panel examining PPE needs for health workers against H1N1 will deliver its letter report to CDC and OSHA by Sept. 1.

Audio files and submitted reports from the Aug. 12-13 public meeting are available at this IOM site, giving the public and health professionals the opportunity to assess the various experts' recommendations. The first paper listed is from Dr. Toby L. Merlin, senior medical advisor in CDC's Influenza Coordination Unit, who discussed current guidance -- health care personnel should wear gloves, gown, eye protection, and an N95 respirator when entering the room of a patient with H1N1, and that respirator should be used in accordance with OSHA's regulations requiring medical clearance, fit testing, and training. The patient should wear a surgical mask. Merlin's paper says a 120-day flu pandemic modeled for the U.S. population would require 6.2 billion respirators (of which 2 billion would be used by health care workers) and 26 billion surgical masks; the approximate manufacturing capacity available today for those products is 125 million N95s and 300 million surgical masks per month, according to his paper.

Dr. William G. Lindsley, a biomedical engineer in NIOSH's Health Effects Lab in Morgantown, W.Va., reported results from 10 days of aerosol sampling to measure influenza RNA at a West Virginia University urgent care clinic in February 2009. The sampling confirmed airborne particles containing flu RNA were found throughout the facility, much of it in "particles small enough to be spread throughout waiting and patient rooms and to be inhaled deeply into the respiratory tract," according to this paper, which said surgical masks admitted about 20 percent of the particles, but N95 respirators blocked virtually all particles.

But experts who spoke during the public meeting said health care workers' willingness to wear protective respirators constantly, or for long periods, is a significant issue. Papers presented during the meeting describe H1N1 and seasonal flu levels and fatality rates recorded in several countries in the Southern Hemisphere that already have experienced their normal flu season, and this information is somewhat more encouraging. "Current Clinical and Epidemiological Picture of Novel Influenza A(H1N1) in the Southern Hemisphere," submitted by Sonja J. Olsen, Ph.D., leader of the Global Activities Team for CDC's Division of Emerging Infections and Surveillance Services, shows novel H1N1 declining in Argentina and in two Australian states as of late July but increasing in South Africa as of Aug. 2.

Posted by Jerry Laws on Aug 18, 2009