Avian Flu is a virus that occurs naturally among birds, which is why it is often referred to as “bird flu.” Wild birds worldwide carry the viruses in their intestines and usually do not get sick from them, however it appears that a new type of avian flu virus does cause disease and death in migratory wild birds.
Avian Flu was first recorded in Italy more than 100 years ago in 1878. As the cause of massive poultry epidemics, this disease was then known as “Fowl Plague”. It came to the United States in 1924-25, and then again in 1929.
Humans can be infected with influenza types A, B, and C viruses, but type A is the most common type to produce serious epidemics in humans—and the only type that affects domestic animals (equine, swine, avian). Influenza type A viruses are categorized by the letter’s H and N—depending on the specific types of proteins on their surface.
The current bird flu in the news is called avian influenza H5N1. There have been a few suspected cases of human to human transmission in Asia, but the bird flu is still spread predominately from infected poultry to people.
Outbreaks of avian influenza H5N1 occurred among poultry in eight countries in Asia (Cambodia, China, Indonesia, Japan, Laos, South Korea, Thailand, and Vietnam) during late 2003 and early 2004. At that time, more than 100 million birds in the affected countries either died from the disease or were killed in order to try to control the outbreaks. By March 2004, the outbreak was reported to be under control. Since late June 2004, however, new outbreaks of influenza H5N1 among poultry were reported by several countries in Asia (Cambodia, China [Tibet], Indonesia, Kazakhstan, Malaysia, Mongolia, Russia [Siberia], Thailand, and Vietnam)—as well as Turkey Romania, and Ukraine. Outbreaks of influenza H5N1 have also been reported among wild migratory birds in China, Croatia, Mongolia, and Romania. (see map)
Avian influenza is very contagious among birds and can make some domesticated birds, including chickens, ducks, and turkeys, very sick and kill them. Infected birds pass the influenza virus through their saliva, nasal secretions, and feces, so susceptible birds become infected when they have contact with contaminated secretions or excretions.
So far, the spread of H5N1 virus from person to person has been limited and has not continued beyond one person. Nonetheless, because all influenza viruses have the ability to change, scientists are concerned that the H5N1 virus will one day be able to infect humans and spread easily from one person to another. Because these viruses do not commonly infect humans, there is little or no immune protection against them in the human population. If H5N1 virus were to gain the capacity to spread easily from person to person, an influenza pandemic (worldwide outbreak of disease) could begin.
The reported symptoms of avian influenza in humans range from typical flu-like symptoms (e.g., fever, cough, sore throat, and muscle aches) to eye infections (conjunctivitis), pneumonia, acute respiratory distress, viral pneumonia, and other severe and life-threatening complications.
Unlike seasonal influenza, in which infection usually causes only mild respiratory symptoms in most people, avian flu infection may follow an unusually aggressive clinical course, with rapid deterioration (1-3 days), and high fatality. Primary viral pneumonia and multi-organ failure have been common among people who have become ill with avian influenza.
Four different influenza antiviral drugs (amantadine, rimantadine, oseltamivir, and zanamivir) are approved by the U.S. Food and Drug Administration (FDA) for the treatment of influenza. However, sometimes influenza strains can become resistant to these drugs, and therefore the drugs may not always be effective. The current avian virus that has caused human illness and death in Asia is resistant to amantadine and rimantadine but oseltamavir and zanamavir would probably work (additional studies still need to be done to demonstrate their effectiveness).
- As is the case with “regular” flu, educate family members about the importance of proper hand washing—which should consist of washing with soap and water for 15-20 seconds.
- Clean and disinfect surfaces that may have become contaminated with flu secretions—using products that are EPA registered disinfectants—such as Lizol Disinfecting Spray and Wipes.
- Thoroughly cook all poultry before eating it. Cooking temperatures kill avian influenza.