PHILADELPHIA -- A revised analysis of data on the ability of N95 respirators to prevent transmission of viral infections, including influenza, to health care workers raised new doubts about the appropriateness of recent guidance from the Centers for Disease Control and Prevention on N95 use for influenza protection.
The new analysis of results from an Australian and Chinese study that compared the efficacy of N95 respirators and surgical masks in blocking transmission of influenza and other viruses to health care workers showed that the relatively expensive and uncomfortable respirators were not significantly better than surgical masks for preventing transmission, Holly Seale, Ph.D., reported at the annual meeting of the Infectious Diseases Society of America (IDSA).
The report by Dr. Seale revised high-profile findings reported in September by the senior investigator of the study, Dr. C. Raina MacIntyre, at the annual meeting of the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC). Dr. MacIntyre reported that use of N95 respirators led to statistically significant improvement in protection against viral infection, compared with the control, a loose-fitting cloth mask. That analysis failed to show similar benefit from a surgical mask, leading to the inference that N95 respirators had an advantage over surgical masks.
The findings are believed by several infectious diseases experts to have led to controversial guidance on N95 use by health care workers caring for patients infected with pandemic influenza A(H1N1) that the CDC issued on Oct. 14 (www.cdc.gov/h1n1flu/guidelines_infection_control.htm).
The guidance said the CDC recommends "use of respiratory protection that is at least as protective as a fit-tested, disposable N95 respirator for health care personnel who are in close contact with patients with suspected or confirmed 2009 H1N1 infection."
In a second study of N95 respirators and surgical masks, researchers at eight Ontario hospitals randomized 225 nurses to exclusive surgical mask protection and 221 to N95 respirators during a 2.5-month period in fall 2008. The incidence of laboratory-confirmed influenza was nearly identical between the two groups (JAMA 2009;302:1865-71).
"The CDC's current position is that additional data are needed to more clearly determine the most effective methods for protecting health care workers and patients from acquiring influenza infection in the health care setting," CDC spokesperson Thomas W. Skinner said in an interview.
COPYRIGHT 2009 International Medical News Group
COPYRIGHT 2009 Gale, Cengage Learning
article's source : http://bnet/internal medicine news, Nov 15,2009, by Mitchel L. Zoler
The new analysis of results from an Australian and Chinese study that compared the efficacy of N95 respirators and surgical masks in blocking transmission of influenza and other viruses to health care workers showed that the relatively expensive and uncomfortable respirators were not significantly better than surgical masks for preventing transmission, Holly Seale, Ph.D., reported at the annual meeting of the Infectious Diseases Society of America (IDSA).
The report by Dr. Seale revised high-profile findings reported in September by the senior investigator of the study, Dr. C. Raina MacIntyre, at the annual meeting of the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC). Dr. MacIntyre reported that use of N95 respirators led to statistically significant improvement in protection against viral infection, compared with the control, a loose-fitting cloth mask. That analysis failed to show similar benefit from a surgical mask, leading to the inference that N95 respirators had an advantage over surgical masks.
The findings are believed by several infectious diseases experts to have led to controversial guidance on N95 use by health care workers caring for patients infected with pandemic influenza A(H1N1) that the CDC issued on Oct. 14 (www.cdc.gov/h1n1flu/guidelines_infection_control.htm).
The guidance said the CDC recommends "use of respiratory protection that is at least as protective as a fit-tested, disposable N95 respirator for health care personnel who are in close contact with patients with suspected or confirmed 2009 H1N1 infection."
In a second study of N95 respirators and surgical masks, researchers at eight Ontario hospitals randomized 225 nurses to exclusive surgical mask protection and 221 to N95 respirators during a 2.5-month period in fall 2008. The incidence of laboratory-confirmed influenza was nearly identical between the two groups (JAMA 2009;302:1865-71).
"The CDC's current position is that additional data are needed to more clearly determine the most effective methods for protecting health care workers and patients from acquiring influenza infection in the health care setting," CDC spokesperson Thomas W. Skinner said in an interview.
COPYRIGHT 2009 International Medical News Group
COPYRIGHT 2009 Gale, Cengage Learning
article's source : http://bnet/internal medicine news, Nov 15,2009, by Mitchel L. Zoler
Posts
