Bird Flu: Frequently Asked Questions
1. What is seasonal flu?
2. What is the connection between bird flu (H5N1) and a flu pandemic?
3. How do people become infected by diseased birds?
4. How would the influenza virus be spread between humans?
5. What are the likely symptoms of bird flu?
6. What are the most important warning signs that a pandemic is starting?
7. Is there a vaccine to prevent infection with bird flu?
8. What is the treatment for bird flu?
9. How fast could a pandemic spread?
10. Can we still eat chicken?
11. What common sense measures limit the spread of the flu virus?
Seasonal influenza, commonly called "the flu," is a contagious respiratory illness caused by various subtypes of influenza A and B viruses that circulate annually around the world. Influenza A viruses are found in many different animals, including ducks, chickens, pigs, whales, horses, and seals. Influenza B viruses circulate widely only among humans. Most adults have some pre-existing immunity to older forms of influenza but their antibodies don't recognize newer virus strains and infection can occur. Influenza viruses cause a mild to severe illness, sometimes resulting in pneumonia, and even death. The elderly, very young, persons with chronic diseases and persons with weakened immunity are particularly at risk, especially during the cold months of the year.
A "pandemic" is a global outbreak of flu among humans, caused by a new and powerful subtype of the influenza A virus. It causes a highly infectious and serious disease. In past pandemics, influenza has spread worldwide within a year and has had the ability to infect one third of large populations leading to many thousands (even millions) of deaths. It has the potential to overwhelm public health and medical care capacities.
NOTE: It is difficult to determine infection rates for the flu as many people who become ill may recover without seeking medical attention and therefore goes unreported. What may appear to be an extremely high mortality rate would likely be drastically reduced if all cases were reported.
2. What is the connection between bird flu (H5N1) and a flu pandemic?
There are current concerns that, while bird flu is usually limited to birds,
- More humans will be infected by the influenza virus from diseased birds
- The influenza virus will mutate into a form that will spread from person to person
- There then may be serious risk of a flu pandemic as there is little or no immune protection against this virus in the human population
3. How do people become infected by diseased birds?
Bird to human transmission of the disease is not common. It happens mainly through direct contact with infected poultry or with surfaces and objects contaminated by their feces. Meal preparation with poultry and poultry products is safe when done with careful hygiene, when meat juices are kept from contact with other foods usually eaten raw, and when cooking is thorough. The virus is heat sensitive and will not survive when meat is cooked to 180°F.
4. How would the influenza virus be spread between humans?
- Inhaling infected airborne droplets spread by open coughing or sneezing
- Indirect contact with something that is contaminated with germs, then touching one's own eyes, nose, or mouth, eg contaminated door knobs, shopping cart handles, tissues, drinking glasses and hands.
- Direct contact with an infected person, through kissing, for example.
- Approximately 50% of infected people will not develop symptoms but may still carry the virus. Most healthy adults may infect others from 1 day before symptoms develop and up to 5 days after becoming sick. This means that you can pass on the flu to someone before you know you are ill, as well as while you are ill.
People have varying degrees of immunity and it is highly likely that many cases of illness are unreported. What appears to be an extremely high mortality rate in each pandemic and with this subtype of avian flu, is likely to be drastically reduced if all cases were reported.
6. What are the most important warning signs that a pandemic is starting?
In this present situation, it will be when clusters of people who have a connection to an area or to people from an area where there has been an outbreak of avian flu, develop symptoms of severe flu. Immediate investigation will take place to confirm the diagnosis, identify the source and determine whether or not human-to-human transmission is occurring.
7. Is there a vaccine to prevent infection with bird flu?
The viruses in the flu vaccine change each year based on international surveillance and scientists' estimations about which types and strains of viruses will circulate in a given year. Each vaccine contains three influenza viruses-one A (H3N2) virus, one A (H1N1) virus, and one B virus. About 2 weeks after vaccination, antibodies that provide protection against influenza virus infection develop in the body. A bird flu vaccine is still being developed and is not yet available for use.
8. What is the treatment for bird flu?
- Hospitalization: Most patients diagnosed with H5N1 infection have required hospitalization because of the severity of their illness. Antiviral drugs are given to slow down the spread of the virus. Antibiotics are given only to treat secondary infections. Hospitals isolate infected individuals, restrict visitors, and use precautions such as masks, goggles, gowns and gloves to prevent transmission to health care workers and other patients.
- Antiviral drugs: Two antiviral medications are thought to be effective but must be given within 36 hours of symptom development: Zanamivir (marketed as Relenza) and Oseltamivir (marketed as Tamiflu). They interfere with the ability of the virus to replicate and allow time for the body's immune system to respond to, rather than be overwhelmed by, the virus. However, some strains of the virus have already developed resistance to these drugs, which means that they may not be effective.
