About Influenza (The Flu)

Seasonal Influenza
Seasonal influenza, commonly known as the "flu", is caused by influenza viruses that attack a person’s respiratory system. Influenza viruses can be spread from person to person when viruses are released into the air from an infected person’s cough or sneeze. Sometimes people can get infected if they touch contaminated surfaces (e.g. including others' hands) and transfer the viruses from their hands to their nose, mouth, or eyes. Symptoms can include fevers, headaches, dry coughs, extreme tiredness, sore throat, runny or stuffy nose, and muscle aches. Stomach-related symptoms (e.g., nausea, vomiting, and diarrhea) are more common in children than adults. Symptoms of the flu may not appear until 1 day after a person has been infected with the influenza virus. Therefore, people may pass the flu to other people before they know they are sick.

Techniques to prevent catching or spreading the seasonal influenza include getting annual flu shots (when recommended) and practicing healthy habits, such as:

• Staying home when you are sick
• Avoiding close contact with people who are sick, as well as with people when you are sick
• Covering your mouth and nose when sneezing or coughing
• Washing your hands often and using proper hand washing techniques
• Not touching your eyes, nose, or mouth because you can pass germs into your body from your hands and fingers

For more information on prevention tips and vaccinations, visit the Centers for Disease Control and Prevention (CDC) website on "Preventing the Flu".

Not only are there different influenza viruses that currently exist, but influenza viruses are also constantly changing and evolving. For this reason, people can get sick with the "flu" more than once, and the flu shot is updated annually. A more in-depth discussion of influenza viruses can be found on the CDC website.

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Avian influenza (Bird Flu)

Avian influenza, or "bird flu", is an infection caused by naturally occurring influenza viruses that are within birds. While wild birds usually do not get sick from the influenza viruses that are in their intestines, avian influenza is extremely contagious among birds and varies in its effect on domesticated birds depending on virus type. The current avian influenza virus of concern is a strain of H5N1 that is highly lethal to both birds and to the few humans who have so far been infected (virtually all from direct contact with infected birds). Sick birds can pass the avian influenza viruses through their saliva, nasal secretions, and feces. The current risk of humans getting the bird flu is low. However, human cases have been reported among people who have direct or close contact with infected birds or contaminated surfaces. Infection between humans has been rare and has not passed beyond one person. Human symptoms of avian influenza can range from typical flu symptoms to more life-threatening complications, such as severe respiratory distress. The symptoms depend on the particular type or strain of the avian influenza virus. Currently, there is no vaccine or "flu shot" that would protect humans from the avian influenza virus. However, avian influenza vaccine research and development have begun. The CDC website provides more detailed information about H5N1 avian influenza.

"We face two threats. The first is spread of highly pathologic avian influenza to California and its establishment in wild birds and domestic poultry. The odds of this happening are rather high - likely greater than 90%. The second is that one or more mutations of avian H5N1 influenza will spontaneously arise (somewhere in the world through the ongoing processes of viral reproduction, mutation, and selection) that enables avian H5N1 to spread efficiently from human to human. The odds of this happening are unknown and there is insufficient scientific information on influenza viruses on which to base reliable estimates. But even if the odds are relatively low - say less than 10% - they are not grounds for complacency."

Dr. Scott Layne, Associate Professor of Epidemiology at UCLA’s School of Public Health, while testifying before the California Assembly. Download his complete testimony.

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What is an influenza pandemic?
An influenza pandemic is a worldwide outbreak of infection among humans that occurs when three criteria are met when:

1. a new form of the influenza virus appears
2. the virus infects humans and cause serious illness, and
3. the virus is easily spreads and continues to infect people without interruption

In some parts of Asia and Europe, the first two criteria above have been met with the avian influenza virus known as “H5N1”. However, as described above, the avian influenza virus currently cannot be easily transmitted between humans. Since influenza viruses are constantly changing and evolving, experts fear that viruses like “H5N1” could one day change and have the ability to more easily infect humans and spread the disease. Thus, cases of avian influenza are monitored very closely and preparations are being made to combat any possible global influenza pandemics. The CDC website has more information about where avian influenza outbreaks have occurred globally.

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For more information on seasonal influenza, avian influenza, and influenza pandemics, please visit the links below:

• Centers for Disease Control and Prevention
  An in-depth site that reviews the key facts, common questions and answers, and instances of human infection, as well as information on what the virus is, how it is spread, and current prevention efforts
  
  Seasonal Influenza
  
  Avian Influenza
  
  Pandemic Influenza
  
  
• World Health Organization (WHO) - Avian Influenza
  Current reports and updates on the avian influenza, as well as tracking reports that show the current number of confirmed human cases.
  
  Frequently Asked Questions
  
  Avian Influenza Fact Sheet
  
  Confirmed Human Cases of Avian Influenza (H5N1)
  
  
• County of Los Angeles Department of Health Services - Influenza
  Contains influenza information specific to Los Angeles County, as well as general influenza resources, such as an "Avian Influenza Presentation", Avian Influenza Fact Sheet, and links to other websites.
  
  
• United States Department of Agriculture (USDA) - Avian Influenza
  Information on how the USDA have responded to bird flu in the United States, such as the monitoring and surveillance of live bird markets and migratory birds.

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