Avian influenza is known informally as avian flu or bird flu — refers to “influenza caused by viruses adapted to birds.The version with the greatest concern is highly pathogenic avian influenza (HPAI).Avian influenza (AI) is an infectious viral disease of birds (especially wild water fowl such as ducks and geese), often causing no apparent signs of illness. AI viruses can sometimes spread to domestic poultry and cause large-scale outbreaks of serious disease. Some of these AI viruses have also been reported to cross the species barrier and cause disease or subclinical infections in humans and other mammals.
“Bird flu” is a phrase similar to “swine flu,” “dog flu,” “horse flu,” or “human flu” in that it refers to an illness caused by any of many different strains of influenza viruses that have adapted to a specific host. All known viruses that cause influenza in birds belong to the species influenza A virus. All subtypes (but not all strains of all subtypes) of influenza A virus are adapted to birds, which is why for many purposes avian flu virus is the influenza A virus. (Note, however, that the “A” does not stand for “avian”).
Avian influenza refers to infection of birds with avian influenza Type A viruses. These viruses occur naturally among wild aquatic birds worldwide and can infect domestic poultry and other bird and animal species. Wild aquatic birds can be infected with avian influenza A viruses in their intestines and respiratory tract, but usually do not get sick. However, avian influenza A viruses are very contagious among birds and some of these viruses can sicken and even kill certain domesticated bird species including chickens, ducks, and turkeys.
Infected birds can shed avian influenza A viruses in their saliva, nasal secretions, and feces. Susceptible birds become infected when they have contact with the virus as it is shed by infected birds. They can also become infected by coming in contact with surfaces that are contaminated with virus from infected birds.
AI viruses are divided into 2 groups based on their ability to cause disease in poultry: high pathogenicity or low pathogenicity. Highly pathogenic viruses result in high death rates (up to 100% mortality within 48 hours) in some poultry species. Low pathogenicity viruses also cause outbreaks in poultry but are not generally associated with severe disease.
Causes of bird flu or avian flu :
Bird flu is caused by a virus. After a wild bird infects a farm-raised bird, the virus can easily and quickly spread among hundreds or thousands of birds. Sick birds must then be killed to stop the virus from spreading.People who come into contact with sick chickens, ducks, or turkeys are more likely to get the virus. Bird flu virus can be passed through bird droppings and saliva on surfaces such as cages, tractors, and other farm equipment.
Most people don’t need to worry about getting sick with bird flu virus. You cannot get bird flu from eating fully cooked chicken, turkey, or duck, because heat kills the virus.The H5N1 bird flu virus is spread when wild birds pass the virus along to birds such as chickens or ducks that are being raised for human consumption. While the wild birds do not seem to be affected by the virus, the livestock that contract the virus get very sick and many die.
Typically, avian or bird flu is not passed from birds to humans. However, in the past ten years, there have been hundreds of cases of bird flu in humans, and scientists believe that, if it continues to spread, there could be a flu pandemic. Most cases of H5N1 infection are thought to have occurred as a result of direct or close contact with sick or infected poultry. That’s because there is no natural immunity from bird flu in humans. Your body cannot develop antibodies, and, typically, hospitalization is required. Because of this, anyone is at risk for avian or bird flu, and that’s one thing that raises the concern about a flu pandemic.
Symptoms of bird flu or avian flu:
At first, the symptoms of bird flu can be the same as common flu symptoms, such as:
A sore throat.
Bird flu may also cause an eye infection (conjunctivitis).But bird flu can quickly progress to pneumonia and acute respiratory distress syndrome, a serious lung problem that can be deadly. For the people who die from bird flu, the average length of time from the start of symptoms until death is 9 to 10 days.Call your doctor right away if you have traveled somewhere or live in an area where there is bird flu and you have a fever and a hard time breathing.
Treatment for bird flu or avian flu:
If your doctor thinks that you may have bird flu, he or she will do a physical exam and ask you questions about your symptoms and past health. Your doctor will also ask where you live, where you have traveled recently, and if you have been near any birds. Then your doctor may order blood tests, nasal swabs, or other tests, such as X-rays, to help find out what is making you sick.
Some questions your doctor might ask are:
Have you been within 3 ft (1 m) of live, sick, or dead poultry, or with wild birds?
Have you eaten raw or poorly cooked poultry or eggs?
Have you had close contact (touching or speaking distance) with someone from an area affected with H5N1 bird flu virus who has a severe respiratory illness or who later died from an unknown cause?
Are you a lab or poultry worker who might have been exposed to H5N1 bird flu virus?
How bird flu is treated depends on what the virus is doing to your body. In some cases, antiviral medicines may help you feel better. But experts are concerned that certain antiviral medicines may not work against bird flu. Viruses become resistant when they change over time, and then the medicines that worked in the past no longer work well.
If you have bird flu, you will stay in a private hospital room (isolation room) to reduce the chances of spreading the virus to others. When your doctors and nurses are caring for you, they will wear gloves and gowns. Some people who have bird flu may need a machine called a ventilator to help them breathe better. Other people may need a machine to help the kidneys work better (dialysis). More than half of the time, bird flu leads to death.