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สื่อประชาสัมพันธ์ -> คำแนะนำนักท่องเที่ยว

คำแนะนำนักท่องเที่ยว

02/02/2011

1. What is avian influenza (bird flu)?

           Avian influenza is the occurrence of flu in bird. Therefore it is also called bird flu. This is caused by influenza virus in birds and is currently occurring in an epidemic form in many countries of Asia. The disease in domesticated or wild birds may occur in a mild form or a severe form. When severe it kills nearly all the affected birds. The current epidemic of bird flu is causing deaths in a large number of birds in the affected countries. At present the disease has been reported amongst the domesticated poultry(chicken, turkey and eggs).

2. What causes the bird flu?

          Bird flu is caused by influenza virus type A. There are about 15 different sub types of the virus though bird flu is caused by subtypes H5 or H7 strain. These sub types cause a severe disease in birds especially chicken and turkeys. That is why they are called highly pathogenic avian influenza. Occasionally the infection jumps from infected birds or their infected material to human beings. Even though there are large epidemics of the disease in birds, there are very few affected human beings in some countries who have suffered from the infection. Most countries are confirming the occurrence of H5 N1 influenza A as the cause of bird flu.

3. How does bird flu spread amongst the birds and in human beings?

            Migratory water fowl- the wild ducks carry the virus but do not suffer from disease. Epidemics of bird flu occur when domesticated birds like chicken or turkey come in contact with wild ducks carrying the virus. Bird flu may start as a mild illness but after some months due to changes in the virus may become serious and kill nearly all the affected birds. This has been seen in many countries in the past where the disease remained mild for several months and then became serious leading to the deaths of a large number of birds. The infection can also affect the eggs. From the poultry the infection can affect the human beings by affecting those who come in contact with the infected material like the droppings or the virus sticking to the hair or other parts of the body of the infected animal.

4. Is the current epidemic of bird flu the first time occurrence of the disease like SARS?

            This is not a new disease. The first epidemic was reported from Italy about 100 years back. Since then the disease has been reported often from many countries. In recent years the epidemic in Hong Kong was of concern but it was controlled by killing a large number of birds rapidly from the infected farms.

5. Can the spread of bird flu occur from one human being to another?

             At present there is no indication for spread of bird flu from one human being to the other However, this can happen in future. The influenza virus type A and its various subtypes can in the presence of another influenza virus merge with it through mixing and reassortment. This can lead to appearance of a new virus with characteristics that are different from the parent viruses. Since the population has no immunity to the new virus subtype it can appear as a serious life threatening disease. Human beings and pigs serve like mixing vessels where the mixing of type A influenza virus acquired from the birds with human influenza (also called flu virus) can occur. This can lead to human to human transmission of the disease in future.

6. Why is there so much concern about bird flu in the countries in Asia?

            There are several countries where large epidemics of bird flu are being reported. These countries have reported the infection over a few weeks time. At present these countries include Indonesia, thland, Viet Nam, Hong Kong, Pakistan, Japan and Taiwan. There are fears that the virus may jump from birds to human beings in larger numbers. According to current information the infection does not spread from an infected human to another but this is a possibility. If this occurs then a large of epidemic of bird flu may occur that can prove to be devastating.

7. What are the countries affected by bird flu?

            Since the beginning of the present epidemic, several countries in Asia are affected by bird flu. These include DPR Korea, Republic of Korea, Viet Nam, thland, Japan, Indonesia, Pakistan, and Indonesia. This list of countries is changing all the time. Although bird flu is being reported from a number of countries in Asia, definite occurrence of bird flu in human beings is reported from thland and Viet Nam.

8. How is bird flu suspected in human beings?

             Bird flu in human beings resembles an acute respiratory infection which can be caused by flu (influenza). Bird flu in human beings is recognized when the patient has fever 38 C, cough, sore throat, sore eyes, muscle aches, pneumonia, acute respiratory distress (breathing difficulty), or renal problems. In addition there should be contact with a patient of bird flu.

9. How can the diagnosis of bird flu in human beings confirmed?

              The diagnosis of bird flu can be confirmed in only a few laboratories in the world that are well equipped to do it. This is done by the finding of the virus from the patient’s samples or by blood tests that can be done in selected laboratories. The information about these laboratories is provided by the national government and support is provided by WHO to the government to make arrangements in selected laboratories to confirm the diagnosis of bird flu in human beings.

10. Is there any age or sex predilection for bird flu?

               The answer to this question is not final since there have been very few cases of bird flu in humans till now. More information will be required to be certain. The current information suggests that it occurs more in children and younger people than in older people. There is no sex predilection.

11. How soon can bird flu appear in humans after being exposed to the disease in birds ?

                Bird flu can appear within 1-3 days after contact with the infected material. This is termed as incubation period for the disease.

12. Who is at risk of getting bird flu?

                In the affected countries, people who work in the poultry farms are at risk. Those who are selling birds and eggs are also at risk of getting the disease. Staff members who visit the affected country to investigate the epidemic can come in contact with the droppings of birds during their field visits and are therefore at greater risk of getting the disease. People who work in the laboratory who handle the infected material are also at risk.

13. Who is more susceptible to develop bird flu?

                Persons who work and live in farms where domesticated birds like chicken and turkey are raised are susceptible. There are markets where these birds are sold. People coming in contact with sick birds can get this infection. Veterinarians and people working in laboratories with the type A influenza virus are likely to get the disease. People who transport these birds can also suffer from bird flu. Until there is evidence for human to human transmission, the disease will most likely remain confined to those who come in contact with sick birds or their droppings. If the egg and chicken/turkey that is consumed is not fully cooked then there are chances of getting the infection although the risk is minimal from eating the food.

14. Can bird flu be prevented by medicines?

            Antibiotics are not advised in the prevention of bird flu since they do not work. Similarly anti viral medicines are not advised. Personal protection measures and food safety are the best ways to protect against bird flu.

15. Is there a vaccine to prevent bird flu?

           At present there is no vaccine for bird flu. It will take about 4 months to produce a vaccine that can be available in the market. Influenza vaccine is available but it will not protect against the bird flu. This vaccine is different from year to year. The change becomes necessary since influenza viruses tend to undergo frequent and permanent changes. This requires laboratory monitoring of the viruses and the vaccine has to be prepared on the basis of the common influenza viruses that are circulating.

16. Is there any role for influenza vaccine in control of bird flu?

           There is no specific vaccine to prevent bird flu although influenza vaccine for the country where you live in is available. Influenza vaccine is recommended for people at risk. This will help in prevention of reassortment and mixing up of the genetic material between influenza (flu) viruses and reduce the risk of human to human transmission. It is also likely to prevent the occurrence of severe forms of the disease. The people who should be considered for influenza vaccine are those persons who are likely to come in contact with the infected material. These include WHO staff, laboratory workers who come in contact with the infected material, people working in the poultry farms and people in the markets where poultry is sold.

17. What are the precautions at personal level to avoid getting bird flu?

           Avoid going to markets where birds are sold, and do not visit the poultry farms during the epidemic. There is a greater risk of getting bird flu while handling the infected bird or infected eggs than eating these foods. If the food is well cooked, there is hardly any risk of getting bird flu. Frequent and thorough hand washing is to be observed to avoid getting the disease.

18. I have chickens in my house and a couple of other birds as pets. What is your advice to me for the protection against bird flu?

             The risk of getting bird flu from birds at home is small unless the disease spreads from poultry farms to homes. However, you should observe all precautions to protect yourself and the family from getting the disease. You should practice thorough hand washing while handling the birds or their droppings. Watch your birds if they are getting sick and ensure that they are killed as soon as the disease is suspected.

19. Is the bird flu contracted by eating the infected birds?

             There is minimal risk from consuming the infected eggs or infected meat provided it is well cooked. The danger is greater if the human beings come in contact with their droppings by inhaling them or by coming in contact with any material that is infected with the virus. At present there is no risk of transmission of the disease from another infected person since human transmission of the disease is not known to date.

20. What is your advice on eating food that is imported from countries where bird flu is occurring? Should my government not impose a ban on the import of meat?

            There is no evidence that bird flu is a food borne disease. The disease does not occur from eating infected food. However it is important to be sure that meat or meat products that you eat are properly cooked in a hygienic way. This would also help in protection against other infections that are food borne. The consumption of raw poultry, eggs and pork is not advised because of the risk of salmonella and campylobacter infections. The normal advice on food hygiene should be followed. This includes thorough hand washing, thorough cooking of poultry products and prevention of cross contamination. The bans on imports are decisions made by the government. The intention of this decision is to minimize the risk of release of the virus particles in the country to infect the wild and domestic poultry.

21. What is your advice about the disposal of infected birds?

            The birds that are infected should be disposed off carefully. They should either be burnt or buried. The persons who are responsible for disposing of the birds or possibly infected eggs should be careful to avoid coming in contact with them or their droppings. They should observe infection control measures and wash their hands grequently and thoroughly.

22. Are there any travel restrictions imposed to prevent the spread of bird flu?

            WHO is not recommending any restrictions on travel to the affected countries. This is because the reported cases acquire the infection through direct contact with infected poultry on the farms or in live bird market. There is no evidence for human to human transmission of the infection. The current infection is spreading through trade of domesticated birds or through the natural flight route of infected birds. Isolation of affected countries is not advisable since it will create unwarranted panic and adversely affect the trade and economy.

23. What is your advice on screening of the passengers coming from other countries?

            WHO does not advise screening of passengers for the symptoms of bird flu. This is because influenza is known to spread before the first symptoms appear. Therefore routine screening of passengers will not help in controlling the spread of the disease. It is advised that travellers should avoid visiting markets where chicken and birds are sold and not go to poultry farms in the countries they are visiting.

24. Environmentalists always resist the killing of birds and animals. What is your guidance to them on control of bird flu?

            The concern of environmentalists about the wanton killing of birds and animals is normally justified. At present many countries are in the midst of an epidemic of bird flu. This disease at present is not being transmitted from one human being to another but if this does happen then we may have to face a pandemic of influenza which can be devastating. The past experience shows that culling of birds is an effective way to control the epidemic. Therefore doing this when it is required to avert a major disaster is justified. This issue should be taken up with the environmentalists and they should be convinced about the need for such an action.

25. What is your advice to the countries on prevention of spread of bird flu in the animals?

              Avoid selling of raw vegetable near the areas where these might come in contact with droppings of birds in cages or with drains that might carry the infected material. The slaughter of birds should be done in a hygienic way. The persons responsible for handling of raw poultry products should observe hygienic measures and cleanliness to prevent them from getting infected. The government should consider the separation of sale of live birds and animals from ready to eat foods prepared from meat and meat products.

26. What is the role of WHO in controlling the bird flu epidemic ?

             WHOs objective is to reduce the risk to humans from bird flu to prevent it from recombining with human influenza virus in which case it will not only spread rapidly but may also become more severe. To avert an influenza pandemic, it is helping to support countries so that every one in contact with affected poultry is adequately protected. WHO is taking the lead helping to lead the development of a vaccine against avian flu. It is advising the authorities to increase their surveillance of affected poultry stocks.

Source : World Health Organization (WHO)