Bird Flu
Avian influenza or bird flu as it is commonly known, is among the biggest threats to the world today as far as pandemics are concerned. It is caused by influenza viruses that have adapted themselves to birds.
Till date, the virus has been responsible for the death of millions of birds all over the world. Indeed, since the first appearance of the virus in south-east Asia, many countries have reported the outbreak of a bird flu epidemic among the birds.
The virus first affected humans in the year 1996, when 18 case of bird flu was reported in Hong Kong. It resulted in the death of 6 individuals from among them. Next the disease spread to other countries like China and Vietnam. The subsequent years have seen a rise in the number of victims of this disease. Also, the disease spread to a number of other countries during this period. By the year 2007, 270 cases of the disease had been confirmed. Also, 164 deaths had been attributed to the disease.
H5N1 Virus
A variety of viruses are responsible for the 14 different types of avian flu. However, presently, the most prominent one among them is the HPAI A(H5N1) or simply the H5N1 virus. These influenza viruses have specifically adapted themselves to infect birds. However, this does not mean that the H5N1 virus is incapable of infecting other species. In many cases, these viruses can show multiple adaptations i.e. they can adapt themselves to a number of animals.
In general, the H5N1 virus has the following properties:
- It can transmit easily between birds. It is because of this, that the virus has spread itself to many countries within a short period of time.
- Being in its emerging stage, it can undergo mutations to generate strains that can affect other animals, that were not previously known to carry the virus.
- This virus usually binds itself to the galactose receptors present in the respiratory tract of birds. Such receptors are not present in the respiratory tract of humans, but they are present in the lungs around the alveoli. Thus, in case of human infection, the virus is not likely to be coughed out, as it is present deep within the respiratory system.
- Presently, the virus is known to spread, only through poultry and waterfowl. It is known to affect other species of animals and birds as well, however, the role they play in its transmission is unknown.
- Researchers believe, that the virus may exist on the surface of fertilizers as many fertilizers contain poultry products. From the surface, it may get kicked up into the air to affect humans.
- The virus is also undergoing mutations that make it possible for birds to shed it for longer periods of time before their death, thus increasing its pathogenicity.
Bird flu Symptoms
Bird flu causes pneumonia and other breathing problems in birds and thus, proves to be fatal. In humans, the bird flu symptoms are as follows:
- Fever that is persistent for a few days
- Runny nose
- Muscle ache
- Breathing problems and chest pains
- Conjunctivitis and other infections of the eye
- Watery diarrhea
- Coughs
Measures to Prevent Bird Flu
Many agencies, all over the world are collaborating to come up with a solution to curb the spread of bird flu. The major problem they face is the fast mutating nature of H5N1. This makes it impossible to come up with a vaccine for it, as the particular strain is unknown until the time, it affects some individual. The vaccines that have been developed for pre-existing strains have not proved to be very effective.
Some of the steps taken by the various countries to curb the spread of the disease are as follows:
- Mass culling of poultry can help stop the spread of the disease.
- To develop an early warning system in between different countries. Thus, if the virus is detected in one country, information about the same is sent to others.
- Provision of better veterinary services.
- Control over trade of poultry and poultry products.