TB Exposure and Air Purifiers

Tuberculosis (TB) Exposure

The incidence of tuberculosis in the US, despite a spike during the years 1986 to 1992, continuesa downtrend.

Even the multi-drug resistant strains are declining stateside.

Consistent with my so called alarmist views on the environment and the human condition, here is another prediction.

Infectious disease resurgence in the United States in the near future will be led by HIV/AIDS, hepatitis C, tuberculosis (TB), mycoplasmas, and evolving strains of influenza.

Of these, mycoplasma, influenza and tuberculosis are contagious by airborne exposure.

Our purpose here is not a complete review of tuberculosis, but an examination of the airborne route of tb exposure and whether air purifiers may be deployed to control exposure to the tb bug.

This is not medical advice, it is intended for air purifier consumers desiring increased health security.

This is an area where the many weaknesses of mass market air purifiers, as posted everywhere on this site, can really cause injury.

OK Corral Revisited

TB is not a new disease, it is ancient.

The bacterium was isolated in 1882.

Perhaps the most familiar tb victim was the wild west gambler and gunfighter, John Henry "Doc" Holliday, 1851 - 1887.

Despite the gunfight at the OK corral being popularized in print and many films, it was tuberculosis that got Doc Holliday, at the age of 36.

It is believed that Holliday was exposed to TB by close contact with his mother, who died of TB in 1866.

While tuberculosis can be cured by a 9 month course of antibiotics, it has not been eliminated.

TBs comeback is a global emergency according to the World Health Organization.

A new TB infection occurs somewhere every second. About one third of the world’s population is infected.

Airborne TB Exposure

The Tuberculosis mycobacterium is expelled, by victims with TB in the lungs (Pulmonary TB), into the air by coughing, sneezing, talking, singing, or spitting.

To develop TB, exposure generally must come from very close, frequent contact with someone who has an active infection.

Most people get exposed by a partner, family member, or close associate.

As the immunocompromised US population grows, tuberculosis may reverse its US decline.

TB is not spread by casual exposures in public, like the flu or colds.

There are a few freak cases of exposure from direct handling of TB infected tissues; medical waste, funerals, autopsies.

Symptom Based Triage: Torpedo Running

Understanding and control of tuberculosis requires information on TB transmission, how exposure becomes infection, and infection progresses to TB disease.

People who have TB infection but not TB disease are not contagious, but as many as 15 million people in the US carry "latent" TB.

Latent TB can progress to active when the immune system weakens, as happens with malnutrition, AIDS, diabetes, cancer, or many drugs.

As the global demographic bulge known here as the "post-war baby boom" hits the magic 65 yardline, starting in 2013, our collective immunity will cross a threshold.

There is a misconception that since those with the latent form are not contagious they are not "sick."

The principal incubator of developed world disease, a torpedo in the water, is immunocompromised individuals.

The list of groups with impaired immunity continues to grow.

Many will be surprised to find a category fitting them on the list!

Everyone is familiar with the TB needle prick skin test: a positive (red welt) tells who has TB exposure, latent or active. Further testing is required to reveal the extent of the disease.

The Centers for Disease Control (CDC) listed around 14,000 active cases of TB for 2005.

Minorities and immigrants are affected disproportionately, but many new cases are occurring in the over-65 WASP culture.

Air Purifiers Cut TB Risk

Room air purifiers are used to protect health care staff, in hospitals, clinics, and doctors’ offices from exposure to tuberculosis.

The major distinction which separates TB from Influenza and SARS is droplet verses droplet-nuclei transmission.

Following a sneeze, large droplets sink to the floor, smaller droplets quickly dry and collapse to airborne droplet-nuclei.

Flu and SARS are basically spread by direct sneezing: droplet inhalation. That is why the maskswere so popular in China, air purifiers cannot stand between sneezing humans.

In contrast, TB requires long term exposure to airborne droplet nuclei.

Since the TB bacillus is typically in the 1 to 5 micron size range, properly installed and maintained HEPA filters can interdict and contain the threat.

Since germs can accumulate in the filter media, it should be designed to resist microorganism growth.

Ultra violet germicidal irradiation of the filter can prevent it from becoming a reservoir of infectious materials.

Here is where air purifier marketing hype starts to go beyond just lightening consumer's wallets.

There is enormous variation in the quality of UV air purifiers in today's market.

We have $100 machinesadvertised as "germicidal."

Not!

Flu viruses need 3,400 microwatts (per second/cm squared) of UVC dosage for complete elimination, but tuberculosis, with a sturdy cell wall, takes 10,000 microwatts.

A quality HEPA room air purifier with can add extra health security for those with compromised immune systems, like me. Anyone who lives or works with those in the at-risk communities should consider an air purifier for their environment.

To be effective in reducing pathogen exposures, a minimum 12 air changes per hour (ACH) is recommended by the U.S. Centers of Disease Control (CDC).

I constantly harp about the marketing ploy which sells naive consumers cheap air purifiers for application sizes based on one or two (ACH).

Exposure Reducing Air Purifiers

Here is a short list of air cleaners specifically oriented toward sick/safe room particulate reduction. None of these are inexpensive.

IQAir Cleanroom Series

AllerAir Sentinel 5000

NQ Clarifier Medical

End Tuberculosis TB Exposure, Go to Sitemap

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