December 2008Volume 12, Supplement 1, Page e328
The First Randomized, Controlled Clinical Trial of Mask Use in Households to Prevent Respiratory Virus Transmission
Background: Observational epidemiologic data suggest that transmission of viral respiratory infection was significantly reduced during the SARS epidemic with the use of face masks as well as other infection control measures. However, there are no prospective randomised control trials on face masks in prevention of viral respiratory infections Aims: To determine the efficacy of surgical masks and P2 masks in households on the interruption of transmission of respiratory viruses.
Methods: Prospective cluster randomized trial comparing surgical masks, non-fit-tested P2 (respirator) masks with no masks in interruption of viral transmission between household members. Families of children presenting to emergency department with influenza like illness (ILI) were randomised to one of the three groups and followed up for development of respiratory illness in other family members. Nasopharyngeal swabs of index patients and contacts that developed ILI were tested with a multiplex respiratory viral PCR for influenza A and B, parainfluenza, RSV, picornavirus, enterovirus, rhinovirus, adenovirus, coronaviruses human metapneumovirus.
Results: We recruited 286 adults with exposure to respiratory infections in the Australian winters of 2006 and 2007 - 94 adults were randomized to surgical masks, 90 to P2 masks and 102 to the control group. Using intention to treat analysis, we found no significant difference in the relative risk of respiratory illness in the mask groups compared to control group. However, compliance with mask use was less than 50%. In an adjusted analysis of compliant subjects, masks as a group had protective efficacy in excess of 80% against clinical influenza-like illness. The efficacy against proven viral infection and between P2 masks (57%) and surgical masks (33%) was non-significant.
Conclusions: This is the first RCT on mask use to be conducted and provides data to inform pandemic planning. We found compliance to be low, but compliance is affected by perception of risk. In a pandemic, we would expect compliance to improve. In compliant users, masks were highly efficacious. A larger study is required to enumerate the difference in efficacy (if any) between surgical and non-fit tested P2 masks.
Steross...thanks for digging out this report. The problem as I see it is that there was very poor compliance (50%) to wear the mask. Then too is the problem is that infected patients usually shed the virus several days before they become symptomatic so that masks would have to be worn by people at all times to lesson their risks. Finally some viruses are so highly communicable even when completely air tight protection systems are used such as those used such as those used in the US transmission has occurred to those caring for the patient. The only real solution as I see it for the CDC to develop a more rapid way of identification of these viruses and then to.rapidly make effective vaccines. As of now we are way too slow of finding and making vaccines. A worldwide flu 1918 type epidemic that will kill millions is thus widely predicted by public health experts.
We require of our students 300 hours during their didactic training, and then 1770 during their advance experientials, for a total of 2070 hours. If they do a residency you can add 2000 to it. If they then do a fellowship add another 4000.
I've done a residency and a fellowship. 2070+2000+4000= 8070 hours of clinical training. Not quite the 15k, but still a smurfload more than a PA or NP.