What is Influenza (or the flu)?
Influenza, or the flu, is a contagious respiratory illness that can cause mild to severe illness. The flu rapidly produces symptoms such as fever, sore throat, cough, body aches, chills, headaches, and a runny nose. Influenza is highly contagious and is easily passed from person to person, primarily through small droplets produced from a cough or sneeze of an infected individual. In the U.S., on average 5% to 20% of the population gets the flu, more than 200,000 people are hospitalized from flu complications, and ; about 36,000 people die from flu-related causes (www.cdc.gov/flu/, 2009).

What is a Pandemic?
A pandemic is a worldwide outbreak of influenza when a new strain of a virus emerges. In the early stages of the pandemic, people may have little or no natural immunity to the virus; so the disease may spread quickly. Vaccines to protect people from the illness may not be widely available until months after the pandemic begins. Pandemics have occurred throughout history. A pandemic is called based  on its global spread; not the severity of the illness.

There are currently two strains of influenza that are being tracked by national and international health agencies that may have the potential to become pandemic influenza’s. The first is avian influenza (H5N1), found in the eastern hemisphere. This influenza A subtype occurs mainly in birds and can be deadly to them. While H5N1 does not usually infect people, human cases of avian influenza infection have been recorded. Because all influenza viruses have the ability to change, scientists are concerned that the H5N1 virus could one day infect humans and spread person to person. World health officials are monitoring the H5N1 situation and are preparing for the possibility that the virus may begin to spread more freely from human to human.

The second is swine influenza (H1N1) that has emerged in Mexico, primarily around Mexico City. This strain has produced many cases in Mexico and a very limited number of cases in the Americas and Europe. The US Centers for Disease Control and Prevention (CDC) and the US Department of Homeland Security (DHS) are closely tracking the progress of these outbreaks and working to limit the spread of this influenza.

The World Health Organization has issued a Phase 5 alert for both viruses. Phase 5 is characterized by human-to-human spread of the virus into at least two countries in one WHO region, a strong signal that a pandemic is imminent. This is a time to finalize pandemic plans and mitigation measures (www.who.int/en/, 2009).