Introduction:
"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 that the "A" does not stand for "avian").Adaptation is non-exclusive. Being adapted towards a particular species does not preclude adaptations, or partial adaptations, towards infecting different species. In this way strains of influenza viruses are adapted to multiple species, though may be preferential towards a particular host. For example, viruses responsible for influenza pandemics are adapted to both humans and birds. Recent influenza research into the genes of the Spanish flu virus shows it to have genes adapted to both birds and humans; with more of its genes from birds than less deadly later pandemic strains.
Symtoms:
Bird flu in humans can cause a range of serious and potentially fatal complications, including:
If you have recently returned from a country that had an outbreak of bird flu and you get flu symptoms, see your doctor immediately. When making the appointment, tell the clinic staff about your travel including any visits to markets, farms or anywhere else where birds were present.
Influenza viruses can mutate
Influenza viruses that infect animal species can mutate and infect humans. The human immune system may have no defences against viruses that previously only infected animals. That's why infection with these viruses can result in more severe disease in people.
If the H5N1 bird flu virus were to mix with a human influenza virus, such a 'combined' virus could create a new human influenza virus that could spread rapidly.
Health experts are concerned that the current bird flu affecting Asia could become a worldwide pandemic if the virus does mutate. The worst influenza pandemic in modern history was the Spanish flu, which occurred in 1918–19 and killed up to 50 million people.
Measures to contain the spread of the current bird flu virus include identifying and culling affected poultry flocks, research into tests and vaccines, and rigorous quarantine practices.
Treatment options
Several antiviral medications used to treat human influenza are also effective for bird flu. These could be used if a person developed symptoms after possible exposure to bird flu, or to prevent illness in a person who was in close contact with bird flu. Currently testing for bird flu vaccines is an ongoing process.
At the moment, there is no need for people living in USA, or people making short visits to countries with cases of bird flu, to have antiviral medications. Americans living long-term in countries affected by bird flu should consider having a supply of antiviral medications in the home to use on medical advice should the situation change while they are away from the US.
The Federal government is stockpiling Relenza and Tamiflu, two drugs that may be used in the treatment of human cases of bird flu. In the case of an outbreak in humans, these drugs would be used to maintain essential services, prevent transmission and provide treatment for people who are already ill.
A vaccine against bird flu is in development, but is not currently available. The current influenza vaccines will not protect humans against bird flu. However, people who may be exposed to bird flu should consider being vaccinated against human influenza viruses to reduce the risk of the viruses 'mixing' to form a new flu strain.
Advice for travellers
Be aware of the risk of bird flu if you are travelling to a country where outbreaks are occurring. Suggestions include:
"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 that the "A" does not stand for "avian").Adaptation is non-exclusive. Being adapted towards a particular species does not preclude adaptations, or partial adaptations, towards infecting different species. In this way strains of influenza viruses are adapted to multiple species, though may be preferential towards a particular host. For example, viruses responsible for influenza pandemics are adapted to both humans and birds. Recent influenza research into the genes of the Spanish flu virus shows it to have genes adapted to both birds and humans; with more of its genes from birds than less deadly later pandemic strains.
Symtoms:
Bird flu symptoms
Although there have been too few human cases to determine the exact incubation period of bird flu, it would be expected to be from three to 10 days. The symptoms of bird flu in humans are similar to those of regular influenza and include:
- Fever
- Sore throat
- Cough
- Headache
- Aching muscles.
Bird flu in humans can cause a range of serious and potentially fatal complications, including:
- Eye infections
- Pneumonia, including viral pneumonia
- Acute respiratory distress
- Inflammation of the brain and heart.
If you have recently returned from a country that had an outbreak of bird flu and you get flu symptoms, see your doctor immediately. When making the appointment, tell the clinic staff about your travel including any visits to markets, farms or anywhere else where birds were present.
Influenza viruses can mutate
Influenza viruses that infect animal species can mutate and infect humans. The human immune system may have no defences against viruses that previously only infected animals. That's why infection with these viruses can result in more severe disease in people.
If the H5N1 bird flu virus were to mix with a human influenza virus, such a 'combined' virus could create a new human influenza virus that could spread rapidly.
Health experts are concerned that the current bird flu affecting Asia could become a worldwide pandemic if the virus does mutate. The worst influenza pandemic in modern history was the Spanish flu, which occurred in 1918–19 and killed up to 50 million people.
Measures to contain the spread of the current bird flu virus include identifying and culling affected poultry flocks, research into tests and vaccines, and rigorous quarantine practices.
Treatment options
Several antiviral medications used to treat human influenza are also effective for bird flu. These could be used if a person developed symptoms after possible exposure to bird flu, or to prevent illness in a person who was in close contact with bird flu. Currently testing for bird flu vaccines is an ongoing process.
At the moment, there is no need for people living in USA, or people making short visits to countries with cases of bird flu, to have antiviral medications. Americans living long-term in countries affected by bird flu should consider having a supply of antiviral medications in the home to use on medical advice should the situation change while they are away from the US.
The Federal government is stockpiling Relenza and Tamiflu, two drugs that may be used in the treatment of human cases of bird flu. In the case of an outbreak in humans, these drugs would be used to maintain essential services, prevent transmission and provide treatment for people who are already ill.
A vaccine against bird flu is in development, but is not currently available. The current influenza vaccines will not protect humans against bird flu. However, people who may be exposed to bird flu should consider being vaccinated against human influenza viruses to reduce the risk of the viruses 'mixing' to form a new flu strain.
Advice for travellers
Be aware of the risk of bird flu if you are travelling to a country where outbreaks are occurring. Suggestions include:
- Avoid contact with wild or domesticated birds such as chickens, ducks and geese. Don't go to farms or market places, since these are the primary carriers of bird flu
- Stop young children from putting contaminated objects or their own fingers into their mouths.
- Eggshells may be contaminated with bird faeces. Wash eggs thoroughly before breaking and wash your hands thoroughly after handling eggs.
- Avoid foods that contain uncooked egg, such as mayonnaise.
- Wash hands, chopping boards and utensils thoroughly after handling raw poultry.
- Cook poultry at high temperatures. Cooking temperatures of 80°C or higher destroy the bird flu virus in about 60 seconds
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