Pandemic Alert Levels and Swine Flu Outbreak: Pandemic v Epidemic

by Tina Kells | April 27, 2009 at 10:07 am

8955 views | 66 Recommendations | 5 comments

The Swine Flu outbreak has people around the world in a panic and scary words like pandemic and epidemic don't help. So what is the difference between a pandemic and an epidemic? And does the Swine Flu outbreak really qualify as either one? The WHO raised the pandemic alert level from level 3 t level 4; what does this mean? What are pandemic alert levels?

Epidemics happen all the time and are generally localized but widespread within a specific region. Both the CDC (Centers for Disease Control) and WHO (World Health Organization) claims that there are multiple flu epidemics across the planet in any given year. Pandemics, however, are more rare and are considered to be a global threat, an epidemic that is not contained within any one region and is evidenced across boarders.

According to the WHO flu pandemics strike about once every 10-50 years, or approximately three times per century since the 1500's. In the 20th century there were three flu pandemics; 1918-1919, 1957-1958, and 1968-1969.

The 1918 flu pandemic was devastating and killed 40 million people, primarily of the healthy age demographic 25-40, in less than one year. Barring a preexisting health condition flu viruses rarely kill within this demographic, usually children and the elderly are most vulnerable.

The confusion can be explained by Dictionary.com. In the strictest linguistic terms the definitions of both pandemic and epidemic sound pretty much the same:

pan⋅dem⋅ic(pænˈdɛmɪk / Show Spelled Pronunciation [pan-dem-ik] Show IPA)
–adjective

1. (of a disease) prevalent throughout an entire country, continent, or the whole world; epidemic over a large area.

ep⋅i⋅dem⋅ic(ɛpɪˈdɛmɪk / Show Spelled Pronunciation [ep-i-dem-ik] Show IPA)
–adjective

1. Also, ep⋅i⋅dem⋅i⋅cal. (of a disease) affecting many persons at the same time, and spreading from person to person in a locality where the disease is not permanently prevalent.

Strictly in terms of the English language the words can be used interchangeably, but in CDC and WHO language pandemic and epidemic mean different things. The CDC uses the word pandemic to identify a health crisis situation and has specific courses of action to be taken once pandemic has been declared. There are no such action plans in place for something considered to be an epidemic.

See the CDC Flu Pandemic action plan to understand what can happen once a health situation has been elevated to the level of a pandemic. In terms of a WHO declared pandemic there are six active phases and two post breakout phases.

Pandemic Alert Levels:

Phases 1-3: Predominantly animal infections, few if any human cases
Phases 4: Sustained human to human transmissions
Phases 5-6: Widespread human infection (official Pandemic)
Post Peak: Possibility of recurrent events
Post Pandemic: Disease or illness activity at expected seasonal levels

The WHO (World Health Organization) is set to meet by April 28 to determine if this has reached pandemic proportions. Currently, there are 6 pandemic phases and this crisis has reached stage 3. If the WHO upgraded that status to phase 4, which is marked by a new virus that begins to pass easily enough from person to person that we can detect community-sized outbreaks, such a move would effectively mean that we've got a pandemic on our hands.

2. So what happens if this gets classified as a pandemic?

Moving the world to pandemic phase 4 would be the signal for serious containment actions to be taken on the national and international level. Given that these actions would have major implications for the global economy, not to mention the effects of the public fear that would ensue, there is concern that the WHO may be considering politics along with science.

If this does get declared a pandemic, the WHO and individual countries will work together to try to slow the spread of the virus. However, containment is unlikely, as cases have already been confirmed in several countries.

WebMD offers an excellent analysis of the differences between a pandemic and an epidemic in medical terms.

An epidemic of influenza is different from the dreaded pandemic that scientists and world health officials fear is nigh. We might see an epidemic of seasonal influenza during any given year. In fact, we just had one.

Flu reached epidemic levels in the U.S. for 10 weeks in a row during the 2004-2005 season. Records kept by the CDC show that during the week ending March 5, 2005, 8.9% of all deaths reported in 122 U.S. cities were due to influenza and pneumonia (a common complication of the flu).

The CDC's definition of a flu epidemic relates to the percentage of deaths in a given week caused by influenza and pneumonia. The "epidemic threshold" is a certain percentage above what is considered normal for that period. The normal level, or baseline, is statistically determined based on data from past flu seasons.

Christine Pearson, a spokeswoman for the CDC, cautions that the definition of an influenza epidemic doesn't apply to other diseases.

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mudricky

at 13:18 on April 27th, 2009

Interesting, I must admit I had an idea, but I was off a little.

Cheers for that.

sara star

at 13:37 on April 27th, 2009

I think epidemics will be obsolete with all the travel people do now. If one country gets it, chances are so will others. It is in everyone's best interest that all countries have good sanitation.

Pythiian1

at 14:18 on April 27th, 2009

Thanks, Tina, for further clarification on the terminology, which will hopefully address any confusion that the public might have about the epidemic and pandemic.

445882 (not verified)

at 19:19 on April 28th, 2009

Well fuck.

randallisimo (not verified)

at 15:40 on June 10th, 2009

Anyone who believes the W.H.O. and their vigilance to Baxter Pharmaceuticals, deserves to be shot up with the latest vaccine... Google Simeon Virus 40 and HPV vaccine deaths. Enough said