Which mask?

Bird flu, swine flu, seasonal flu, winter flu and more! After the SARS incident of 2003, everyone has become more vigilant about self protection. The most recent swine flu or H1N1 incident has focused our attention on another potential communicable disease in the community. Consequently one can notice more people wearing a mask in the streets. Some would wear a simple mask, some a proper surgical face mask and not infrequently you see someone donning the N-95 mask. The N-95 mask was standard issue for all heath care workers during the SARS period. It offers the best protection provided it is fitted properly and worn properly. If the H1N1 swine flu becomes a pandemic, there won’t be enough N-95 masks for everyone. In a more practical setting, is the N-95 mask much better than a surgical mask in stopping you from picking up the flu?

Researchers from the McMaster University compared the effectiveness of the surgical mask against the N95 mask in protecting 446 nurses against influenza (JAMA 2009; 302: 1865 – 1871). These nurses were working in emergency departments, medical and paediatric units in 8 tertiary care hospitals in Ontario, Canada. They were randomly assigned to wear surgical mask (n=225) or N-95 mask (n=221). Influenza infection occurred in 50 nurses (23.6%) in the surgical mask group and in 48 (22.9%) in the N95 mask group. There was no statistical difference in the influenza infection rate between the 2 types of mask.

If you are going to wear a mask, please make sure that you wear it properly. I have seen quite a number of people walking around with an N95 mask on their face but it was put on wrongly. In such cases the thought that you have an N95 mask on your face will certainly make you feel more secure psychologically but in reality it will not reduce your risk of getting a flu. If you are going to wear a mask, at least make sure you learn how to wear it properly.