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About Pandemics
A pandemic is a global disease outbreak. It is determined by how the disease spreads, not how many deaths it causes.
When a new influenza A virus emerges, a flu pandemic can occur. Because the virus is new, the human population has little to no immunity against it. With no immunity in the population, the virus spreads quickly from person-to-person worldwide.
Characteristics and Challenges of a Flu Pandemic
- Rapid Worldwide Spread
- When a pandemic flu virus emerges, expect it to spread around the world.
- You should prepare for a pandemic flu as if the entire world population is susceptible.
- Countries may try to delay the pandemic flu’s arrival through border closings and travel restrictions but they cannot stop it.
- Overloaded Health Care Systems
- Most people have little to no immunity to a pandemic virus. Infection and illness rates soar. A substantial percentage of the world’s population will require some form of medical care.
- Nations are unlikely to have the staff, facilities, equipment, and hospital beds needed to cope with the number of people who get the pandemic flu.
- Death rates may be high. Four factors largely determine the death toll:
- The number of people who become infected
- The strength of the virus
- The underlying characteristics and vulnerability of affected populations
- The effectiveness of preventive measures
- Past pandemics spread globally in two or sometimes three waves.
- Past pandemics spread globally in two or sometimes three waves.
- Inadequate Medical Supplies
- The need for vaccines is likely to be larger than the supply. Those at highest risk will likely get the vaccine first.
- Early in a pandemic, the need for antiviral medications is likely to be larger than the supply. Those at highest risk will likely get antiviral medications first.
- A pandemic can create a shortage of hospital beds, ventilators, and other supplies. Alternative sites, such as schools, may serve as medical facilities to manage demand.
- Disrupted Economy and Society
- Travel bans, event cancellations, and school and business closings could have a major impact on communities and citizens.
- Caring for sick family members and fear of exposure could result in significant employee absenteeism.
Seasonal Flu versus Pandemic Flu
Pandemic Flu | Seasonal Flu |
|---|---|
| Rarely happens (three times in 20th century) | Happens annually and usually peaks in January or February |
| People have little or no immunity because they have no previous exposure to the virus | Usually some immunity built up from previous exposure |
| Healthy people may be at increased risk for serious complications | Usually only people at high risk, not healthy adults, are at risk of serious complications |
| Health care providers and hospitals may be overwhelmed | Health care providers and hospitals can usually meet public and patient needs |
| Vaccine probably would not be available in the early stages of a pandemic | Vaccine available for annual flu season |
| Effective antivirals may be in limited supply | Adequate supplies of antivirals are usually available |
| Number of deaths could be high (The U.S. death toll during the 1918 pandemic was approximately 675,000) | Seasonal flu-associated deaths in the United States over 30 years ending in 2007 have ranged from about 3,000 per season to about 49,000 per season. |
| Symptoms may be more severe | Symptoms include fever, cough, runny nose, and muscle pain |
| May cause major impact on the general public, such as widespread travel restrictions and school or business closings | Usually causes minor impact on the general public, some schools may close and sick people are encouraged to stay home |
| Potential for severe impact on domestic and world economy | Manageable impact on domestic and world economy |
Preparing for a Flu Pandemic
Communications and information to educate the population are critical components of pandemic response. Visit Planning and Preparedness for a variety of resources to help you and your community prepare for a flu pandemic.
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