As quickly as swine flu is popping up around the globe, “news” about swine flu is being consumed at an even faster pace. If you ever played Whisper Down the Lane, you know that information often changes as it passes from person to person. With the advent of social networks such as Twitter, basic facts can morph into panicky fiction as quickly as a text message is transmitted.
It is at times like these that we need to carefully search out credible sources of information. Let’s take a moment to look at two authoritative sources of international health news and the arbiters of the term “pandemic”: the United Nations World Health Organization (WHO) and the U.S. Centers for Disease Control (CDC).
In an effort to provide meaningful and consistent characterization of flu outbreaks, both the WHO and the CDC have formulated rating systems. The WHO rates the severity of an outbreak of a new contagion using a six-phase system ranging from no-risk (Level 1) to pandemic (Level 6):
1. No animal virus has caused human infection
2. An animal influenza virus has caused at least one human to become ill
3. An animal influenza virus has caused sporadic cases or small clusters of people to become ill, but there is no sustained human to human transmission (current level of avian or “bird’ flu worldwide)
4. Verified human-to-human transmission of enough volume to cause community level outbreaks (such as the swine flu outbreak at the school in Queens, New York)
5. Human-to-human spread into at least two countries in close proximity without a known host travelling from one country to another (Tourists who return home from Mexico and become ill do not meet this test)
6. Community level outbreaks on at least two continents (Pandemic)
Don’t even try to “tweet” this important information on Twitter.
Once a pandemic has been declared by the WHO, the CDC uses a “Pandemic Severity Index” to rate flu outbreaks based on the number of anticipated deaths. Category 1 outbreaks have an expected death toll limited to less than 90,000, while category 5 puts the number at almost 2 million. The CDC developed this system in response to the Avian Flu threat in 2007 in order to standardize the level response taken by public health agencies around the U.S. and the world.
Word is just in that the WHO has raised its pandemic alert to Level 5. Let’s keep the WHO criteria firmly in mind as the contagion spreads. There are 36,000 deaths in the U.S. each year from flu complications, and we have a long way to go to reach Category 2.