Bird flu, also called avian influenza, is a viral infection that can also infect humans and other animals. However, most forms of the virus are restricted to birds.
H5N1 is also the most common form of bird flu. Not only is it deadly to birds, but it can easily affect humans and other animals who come in contact with a carrier. According to the Centers for Disease Control and Prevention (CDC), H5N1 was first discovered in humans in 1997, and has killed nearly 60 percent of those infected. An extremely deadly strain of bird flu, H5N1, continues to spread among poultry in Egypt, as well as certain areas of Asia. (CDC, 2010)
Currently, the virus is not known to be spread via human-to-human contact. Still, some experts worry that H5N1 may pose a risk of becoming a pandemic threat to humans.
You may have H5N1 if you experience typical flu-like symptoms that may include:
- respiratory difficulties
- fever (over 100.4°F)
- muscle aches
- runny nose
- sore throat
If you are exposed to bird flu you should notify healthcare providers before you arrive at the doctor's office or hospital. Alerting staff ahead of time will allow them to take precautions to protect staff and other patients before caring for you.
Although there are several types of bird flu, H5N1 was the first avian influenza virus to infect humans. The National Center for Biotechnology Information (NCBI) reports that the first infection occurred in Hong Kong in 1997. The outbreak was linked to handling infected poultry. (NCBI, 2011)
H5N1 occurs naturally in wild waterfowl, but it can spread easily into domestic poultry. The disease is transmitted to humans through contact with an infected birds feces, nasal secretions, or secretions from the mouth or eyes.
Consuming properly cooked poultry or eggs from infected birds does not transmit the bird flu, but eggs should never be served runny. Meat is considered safe if it has been cooked to an internal temperature of 165º F.
H5N1 has the ability to survive for extended periods of time. Birds infected with H5N1 continue to release the virus in feces and saliva for as long as 10 days. The infection may be spread by touching contaminated surfaces.
You may have a greater risk of contracting H5N1 if you are:
- a poultry farmer
- a traveler visiting affected areas
- exposed to infected birds
- someone who eats undercooked poultry or eggs
- a healthcare worker caring for infected patients
- a household member of infected persons
The U.S. Food and Drug Administration has approved a test designed to identify avian influenza. The test is called Influenza A/H5 (Asian lineage) Virus Real-time RT-PCR Primer and Probe Set. It can offer preliminary results in only four hours. Unfortunately, the test is not widely available.
Your doctor may also perform the following tests to look for the presence of the virus that causes bird flu:
- white blood cell differential
- auscultation (a test that detects abnormal breath sounds)
- nasopharyngeal culture
- chest X-ray
Additional tests can be done to ascertain functioning of your heart, kidneys, and liver.
Different types of bird flu can cause different symptoms. As a result, treatments may vary.
In most cases, treatment with antiviral medication such as oseltamivir or zanamivir can help reduce the severity of the disease. However, the medication must be given within 48 hours after the first symptoms appear. Your family or other household members might also be prescribed Tamiflu as a preventive measure, even if they are not sick.
The virus that causes the human form of the flu appears to have developed a resistance to the two most common forms of antiviral medications—amantadine and rimantadine. These medications should not be used to treat the disease.
If you develop a severe infection you may be placed on a breathing machine.
Additionally, if you are infected, you will be placed in isolation to avoid spreading the virus to other patients.
The outlook for bird flu infection depends on the severity of infection and the type and of influenza virus causing it. H5N1 carries a high mortality rate, while other types do not.
Some possible complications you might encounter are:
- sepsis (a potentially fatal inflammatory response to bacteria and other germs)
- organ failure
- acute respiratory distress
You should call your healthcare provider if you have flu symptoms within 10 days of handling infected birds or traveling to areas with known avian flu outbreak.
Your physician may recommend you get a flu shot, so you do not also get a human strain of influenza. If you develop both the avian flu and a human flu at the same time, it could create a new and possibly deadly form of the flu.
The CDC has issued no recommendations against traveling to countries that are affected by H5N1. However, avoiding the following can minimize your risk:
- open air markets
- contact with infected birds
- undercooked poultry
The FDA has approved a vaccine designed to protect against the avian flu, but the vaccine is not currently available to the public. Experts recommend that the vaccine be used if H5N1 begins to spread among people.