The illness

Avian influenza (such as H5N1, H9N2) is a type of influenza A. It was known previously to infect birds only, but 18 human cases caused by the H5N1 strain were documented in Hong Kong in 1997 and another two were documented in 2003.

Human influenza and avian influenza are both caused by influenza viruses. In Hong Kong, human influenza is commonly caused by influenza A (H3N2), influenza A (H1N1) and influenza B viruses, while avian influenza is commonly caused by influenza A (H5N1) and influenza A (H9N2) viruses.

The initial symptoms of avian influenza are similar to those of other influenza viruses, including fever, headache, muscle pain, runny nose, cough and sore throat. However, it is more likely to result in high fever, chest infection, respiratory failure, multi-organ failure, and death.

You cannot differentiate between avian influenza and SARS by symptoms alone. Confirmation of diagnosis will depend on laboratory tests on clinical samples from the patient.

Transmission

Avian influenza is transmitted from infected live birds to humans. Human-to-human transmission is inefficient. Outbreaks of avian influenza in poultry have recently been reported in some Asian and European countries, and some cases of human infection have been reported. Hong Kong has an effective surveillance system for influenza in birds and humans. The Department of Health has been closely monitoring the situation and has adopted appropriate preventive measures to guard against the disease.

Avian influenza is transmitted from infected live birds to humans. Although human-to-human transmission is inefficient, all influenza viruses have the ability to change genetically, and scientists are concerned that the H5N1 virus could one day be able to spread easily from one person to another. Because the virus does not commonly infect humans, there is little or no immune protection against it in the human population. If the H5N1 virus could spread easily from person to person, an influenza pandemic could occur. No one can predict when a pandemic might strike. However, experts from around the world are watching the H5N1 situation very closely and are preparing for the possibility that the virus may begin to spread more easily and widely from person to person.

People in close contact with poultry are more susceptible to contracting avian flu. The elderly, children and people with chronic illness have a higher risk of developing complications such as bronchitis and pneumonia.

Prevention

• Avoid touching live poultry or their droppings because they may carry the avian influenza virus.
• Wash your hands thoroughly with liquid soap and water immediately after contact with live poultry, birds or their droppings.
• Cook poultry and eggs thoroughly before eating.
• Develop good body resistance and have a healthy lifestyle. This can be achieved through a balance diet, regular exercise, adequate rest, reducing stress and no smoking.
• Observe good personal and environmental hygiene.
• Keep hands clean and wash hands properly.
• Cover nose and mouth while sneezing or coughing. Dispose sputum or secretions wrapped in tissue paper into rubbish bins with lids. Wash hands afterwards.
• Maintain good indoor ventilation.
• Avoid crowded places with poor ventilation if you are feeling unwell.

The most effective way to promote your body resistance is to practise healthy lifestyle. You are advised to eat a balanced diet, get regular exercise, not to smoke, and have adequate rest. A balanced diet consists of a variety of food. Whole grains should be consumed as the major component of each meal. You should eat plenty of fruits and vegetables and an adequate amount of lean meat or beans and reduced fat dairy products. Processed or preserved food and food that is rich in fat, cholesterol, salt and sugar should be avoided. Normally, extra supplement is not required.

Your home should be cleaned at least once per week with soapy water or water mixed with 1:99 diluted household bleach solution.

• inspect wash-hand basins/wash-up sinks, bathtubs/shower trays, water closets and floor drains. (Qualified technicians can be hired for inspection and repair)
  Make sure:
• each of the above sanitary fitment is fitted with a trap;
• the trap is fitted properly;
• there is no crack or defect; and
• no leakage.
• pour about half a litre of water into each drain outlet regularly (about once a week). Then, pour a teaspoon of 1:99 diluted household bleach solution into the drain outlet. Finally, spray insecticide into the drain outlet.
• repair immediately if there is defect in the trap or smell of foul air coming out from drain outlets.

You should wash your hands

• before touching eyes, mouth and nose;
• when hands are contaminated by respiratory secretion, e.g., after coughing or sneezing;
• after touching public installations or equipment, such as escalator handrails, elevator control panels or door knobs;
• before handling food or eating; and
• after going to toilet.

1. Wet hands under running water.
2. Apply liquid soap and rub hands together to make a soapy lather.
3. Away from the running water, rub the front and back of hands. Massage all the finger tips properly including the thumb, the web of finger, around and under the nails. At last, don't forget to wash your wrist. Do this for at least 20 seconds.
4. Rinse hands thoroughly under running water.
5. Dry hands thoroughly with either a clean cotton towel, a paper towel, or a hand dryer.
6. The cleaned hands should not touch the water tap directly again. The tap may be turned off by using towel wrapping the faucet.

You should wear a mask if you have a fever or respiratory symptoms, if you are going to a hospital or clinic, or if you are caring for a patient with fever or respiratory symptoms.

Wash hands before putting on a mask, and before and after taking one off.

1. The mask should fit snugly over the face:
• The coloured side of the mask faces outwards, with the metallic strip uppermost.
• The strings or elastic bands are positioned properly to keep the mask firmly in place.
• The mask should fully cover the nose, mouth and chin.
• The metallic strip moulds to the bridge of the nose and the mask should fit snugly over the face.
2. Try not to touch the mask once it is secured on your face as frequent handling may reduce its protection. If you must do so, wash your hands before and after touching the mask.
3. When taking off the mask, avoid touching the outside of the mask as this part may be covered with germs.
4. After taking off the mask, put the mask into a plastic or paper bag before putting it into a lidded rubbish bin.
5. A surgical mask should be changed at least daily. Replace the mask immediately if it is damaged or soiled.

At present there is no vaccine for preventing avian influenza in humans.

Influenza vaccine cannot prevent avian influenza as the vaccine was meant for human influenza. However, the vaccine can help reduce the chance of complications and hospitalization from human influenza; hence it is recommended for the elderly and patients with chronic illnesses. Influenza vaccine can also reduce the chance of genetic re-assortment and subsequent emergence of influenza strain with pandemic potential. People should seek medical advice if they are considering getting the vaccination.

When buying and handling live chickens, try not to touch them or their droppings. Do not blow at their bottoms. Egg shells may have been contaminated with bird faeces. Wash the outside of eggs and wipe them dry before putting into the refrigerator for storage. Observe food hygiene when cooking chickens and eggs. Always wash your hands thoroughly with liquid soap and water after handling chickens and eggs.

There is no evidence that avian influenza can be transmitted through eating poultry or eggs. However, make sure poultry and eggs have been thoroughly cooked.

Do not eat raw eggs or dip cooked food into any sauce containing raw eggs. Eggs should be cooked until the white and yolk become firm. Poultry should be cooked thoroughly. The centre of the poultry should reach 70°C continuously for at least two minutes during cooking. If there are pinkish juices running from the cooked poultry or the middle part of its bone is still red in colour, the poultry should be cooked again until fully done.

You should postpone your trip if you feel unwell, particularly if you have a fever or respiratory symptoms. If you feel unwell when outside Hong Kong, especially if you have a fever or cough, wear a mask and inform the hotel staff or tour leader. See a doctor at once.

Travellers are advised to avoid contact with birds and poultry, and avoid going to bird parks, poultry markets and farms. Do not feed pigeons or other birds. If you have been in contact with birds or poultry, immediately wash you hands thoroughly with liquid soap and water. Observe food hygiene and eat only poultry and eggs that have been thoroughly cooked.

If you develop flu-like symptoms after a trip, you should put on a mask and consult a doctor immediately, and let your doctor know your travel history.

Antiviral Drugs

Whether a doctor prescribes antiviral drugs to a patient will depend on the circumstances and health needs of the patient, taking into consideration the presence of any contraindication and balancing the benefits of taking the antiviral drugs against the possible adverse side effects. Indiscriminate use of antiviral drugs may give rise to drug resistance.

For prophylaxis, its effectiveness lasts as long as the drugs are being taken and ceases once the drugs are stopped. Self-medication is not encouraged because of potential side effects and possibility of emergence of antiviral resistance.

Prophylaxis should be prescribed by registered doctors.

Contingency Plan

The government has established an overall contingency mechanism to set a clear command and response coordination structure for making and implementing decisions. Central to this contingency mechanism is a three-tier response system to ensure the government's swift formulation of strategies in handling major infectious disease outbreaks. With reference to this three-tier response system, government departments will draw up their contingency plans.