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Consequences: Personal Hygiene


Personal Hygiene

Basics Masks Handwashing Attendance Sneezing Handling Air Travel New Approaches Respiratory Condoms

Basic Flu Personal Hygiene From The CDC

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Filters and infectious particles
Particles greater than 5 microns fall out of the air
Particles 1 – 5 microns in diameter can enter upper airways
0.1 – 1 micron particles enter lower lungs and alveolar ducts

Examples of particle size:

Particulate filter efficiency is based on ability to remove particles greater > than 0.3 microns in diameter (medial aerodynamic diameter of 0.3 um)

It is also very important to note, that although the CDC recommends these products as suitable levels of protection against the H5N1 virus, the testing criteria used to certify these products does not include any biological agents.

NIOSH only tests the filtration efficiencies of N95 facemasks against salt particles, and does not currently employ any standards to test against live agents.

Hard data on masks is hard to come by. WHO recently published two companion papers on non-pharmaceutical interventions by the World Health Organization (WHO) Writing Group.

Data do not exist to quantify the relative efficacy of surgical masks versus respirators in preventing influenza infections in exposed persons, but surgical masks should protect against large droplets, believed to be the major mode of transmission (8).
Wearing Masks in Public
Apparently no controlled studies assess the efficacy of mask use in preventing transmission of influenza viruses. During the 1918 influenza pandemic, mask use was common and even required by law in many jurisdictions. Skepticism arose, however; the medical officer of health for Alberta, Canada, noted that cases of disease continued to increase after mask use was mandated, and public confidence in the measure’s efficacy gave way to ridicule (6).
In Australia, mask-wearing by healthcare workers was thought to be protective, and given evidence of transmission in a closed railway carriage, it was concluded that mask wearing “in closed tramcars, railway carriages, lifts, shops, and other in enclosed places frequented by the public had much to recommend it.” However, mask-wearing in the open air, as initially required in Sydney, was later thought to be unnecessary (24).
In the United States, persons also wore masks as a protective measure. A report from Tucson, Arizona, noted that early measures included “…isolation of ill people, closure of schools, churches, theatres, etc. The epidemic worsened however. As weeks passed, criticism of the measures was expressed, most vocally by businesses losing money but also by religious and educational institutions. To allow some businesses to reopen, city officials ordered ‘masks to be worn in any place where people meet for the transaction of necessary business’ … (and later by) all persons appearing in public places. Within a few days, there was virtually universal compliance with mask wearing, but the epidemic was subsiding” (29).
During the SARS epidemic in 2003, 76% of Hong Kong residents reported wearing masks in public. As noted above, influenza virus isolation rates decreased, but since multiple measures were implemented, the contribution of mask use, if any, is uncertain (20). In case-control studies conducted in Beijing and Hong Kong, wearing masks in public was independently associated with protection from SARS in a multivariate analysis. One study found a dose-response effect (30). Methodologic limitations of the studies (e.g., retrospective questionnaire design) limit drawing conclusions (30,31).

See also:

The Institute of Medicine Committee on Personal Protective Equipment for Healthcare Workers During an Influenza Pandemic held a scientific workshop on February 22, 2007. PowerPoint Slide shows are available at the link.

An example of Hong Kong mask policy can be found here at the Chinese University of Hong Kong (CUHK) web site.

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Low-tech masks

This is an area where some research or innovation is needed. Imagine you’re a mother with a diseased infant in an extremely poor setting. The low-tech approach works for water filters, so wouldn’t it be good if we could have the same for air-filters or masks? Consider bandanas, cloth masks, etc. This is being tried at simple masks which refers to a scientific paper reporting the developement and testing of a low-tech, washable mask which provides a less-than-perfect protection (as all masks do) and might have a role in diminishing transmission.

See also Simple Respiratory Mask from a cotton undershirt.

Microfiber Masks

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Attendance at work/school

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Reduce doorknob handling

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Air travel

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New Approaches to Hygiene

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“Respiratory condoms”

Please take this mostly as a first provocative idea, but maybe a derived idea might have some value. We may need a CopingCreatively section: based on sound scientific knowledge and checking feasibility and real benefits, but also trying to use our brains to find better ways forward.) Bank clerks are behind glass protection - why can’t healthcare providers and cash-counter workers have some kind of plastic wall between clients and themselves? It would just be a couple of long wooden sticks nailed to each wall, and a plastic sheet nailed to the wood. If you want to explore the patients’ belly you can have gloves like those in incubator boxes. I think it would work if the “wall” is tall enough. The concept here is not perfect protection, but reduce unneeded respiratory contacts (say from 10 million contacts a day to 1 million contacts a day) while keeping societies functioning.

Shaking Hands

I do not know of any studies supporting this, but common sense dicates that shaking hands with other people when greeting them should not be done, as virus may be passed that way very directly.

Discuss this entry in the Forum.

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Page last modified on August 14, 2007, at 11:16 PM