Flu Basics

En Español

What is "the flu?"

The flu (Influenza) is a highly contagious viral infection that usually begins in the nose and throat, but can move to the lungs. It can lead to serious complications, including pneumonia or even death.

Most of the flu currently spreading in the U.S. is the 2009 H1N1 (Swine) flu, Seasonal flu viruses are also present at very low levels, but could increase later in the late fall and winter. A third type of flu (the "bird"flu or H5N1) has been found on other continents but not in the Americas. It is highly lethal but rarely infects humans.

Most healthy people recover from the flu without problems, but certain people are at high risk for serious complications.

What is Seasonal flu?

  • A common disease that occurs each year, usually in the winter months. It causes cough, fever, and body aches.
  • Usually not severe and most people recover on their own.
  • Most serious risk to the very young or old, or those with other chronic medical problems.
  • People usually have some immunity to it from having had flu before or from having received flu shots in the past.
  • An estimated 36,000 people in the U.S. die from flu in an average flu season.

What is H1N1 (Swine) flu?

  • H1N1 (Swine) flu is a new influenza virus causing human illness; young people are more frequently affected than the elderly.
  • H1N1 (Swine) flu is contagious.
  • H1N1 (Swine) flu is NOT caused by eating pork or pork products.
  • Illness with the new H1N1 (Swine) flu virus has ranged from mild to severe.
  • Most people who have gotten H1N1 (Swine) flu have had mild disease and have recovered on their own without need for hospitalization.
  • 70 - 90 percent of people who have been hospitalized with H1N1 (Swine) flu have had one or more medical conditions that placed them in the "high risk" category.

What are the symptoms of flu?

  • Fever
  • Cough
  • Sore throat
  • Body aches
  • Headache
  • Chills
  • Fatigue
  • Some people with H1N1 (Swine) flu also have vomiting and diarrhea.

What is a pandemic?

A pandemic is an outbreak of disease that affects many people at the same time in many parts of the world. According to the World Health Organization, we are currently experiencing a pandemic of H1N1 (Swine) flu.

Pandemic flu:

  • Is a disease in humans. Pandemics can range from mild to severe.
  • It happens when an animal flu virus has changed so that it can infect humans and spread easily from person to person.
  • It could cause serious illness and death because no one has had it before and no one has immunity to it.
  • It is caused by a new virus so there is no vaccine (flu shot) for it. It would take months after a pandemic begins for a vaccine to be ready.

Has a flu pandemic ever happened before?

Yes. There have been outbreaks of pandemic flu in the past and there will be more in the future. In the past century there were three flu pandemics. In 1918 the "Spanish Influenza" killed more than 500,000 people in the United States and, according to some estimates, 50 million people worldwide. In 1957-58 the Asian flu caused approximately 68,000 deaths in the United States, and in 1968-69, the Hong Kong flu caused up to 34,000 deaths in the United States.

Can scientists predict when the next pandemic flu will happen?

No. The current pandemic began in April, 2009 and first showed up in Mexico.

Is Pandemic Flu like the flu that happens every year?

A flu pandemic occurs when a new flu virus emerges (usually coming from an animal) and starts to spread easily between people, who have no prior exposure to the virus and no immunity. Because no one is immune, a much larger number of people are likely to get sick in a pandemic flu year, than in a year with just seasonal flu. The large number of illnesses at one time can stress the health care system, schools and businesses due to demand and high rates of absenteeism. The disease caused by a pandemic virus can have symptoms that are similar to the seasonal flu, or it can be much more severe than the usual flu. After the new flu virus has spread for a year or two, it is no longer "new" to our immune systems. It causes fewer illnesses and becomes one of several flu viruses that cause each year's seasonal flu outbreaks. It can be years until another new flu virus emerges and causes the next pandemic. The last pandemic flu before 2009 was in 1968.

What can I do?

Be informed. The information in this website will help you begin. Be sure to follow the news for public health recommendations for your state and your community.

Be prepared. If you are at high risk of complications from flu, talk to your doctor about whether a prescription for antiviral medicine is appropriate.

Make a plan. Have the things you need readily available to treat someone with flu at home. (Thermometer, tissues, fever-reducing medicine, fluids to drink like sports drinks or Pedialyte, hand sanitizer, disinfectant, etc.) Learn how to take care of someone with flu at home. See www.tinyurl.com/COHomeHealthCare

For more information on pandemic flu, swine flu, bird flu or seasonal flu, visit the following websites:

The Colorado Help Line is now open to answer questions on the swine flu outbreak. Information is available in English and Spanish. 1-877-462-2911