• Introduction
• Symptoms
• Causes
• Diagnosis
• Treatment
• Prevention
  

Introduction

Avian influenza (or "bird flu") is a highly infectious disease affecting many species of birds, including chickens, duck, turkeys and geese.  It can affect commercial, wild and pet birds. There are 15 types of bird flu, but the type that is causing concern at the moment is the deadly strain H5N1.

Avian flu passes from bird to other birds but there have also been human cases. There have been over 100 confirmed human cases of avian flu with the H5N1 strain, in people from Indonesia, Thailand and Cambodia, which has led to 60 deaths.  All the victims are thought to have been in close or direct contact with infected birds. Millions of poultry have been killed in South East Asia and other countries with outbreaks, to prevent the spread of the disease among birds, which would stop it being passed on to people.

The concern is that the H5N1 strain may undergo genetic changes making it able to spread easily from person to person. If these changes occur, then there would be a greater risk. So far, this has not occurred. And it is important to note that at present, there is no firm evidence that H5N1 strain has the ability to pass from one person to another.

The H5N1 strain of bird flu has also been confirmed in birds in Turkey and Romania. Reports have shown that a parrot died in UK quarantine due the H5N1 strain of bird flu.  It is thought that the parrot may have contracted the virus from other birds while in quarantine.  The UK's disease-free status is still unchanged and further checks are being made in 8 quarantine facilities in the UK.

There have been no reports of wild or domestic birds being infected with avian influenza ‘bird flu’ in the UK. According to The Department for Food and Rural Affairs (DEFRA), the risk of anyone catching it is extremely low.

Symptoms

The time from infection to the start of symptoms is usually between 3 and 5 days, although in some cases can be up to 7 days.  And the symptoms can last for a week.

Symptoms of avian flu are similar to other types of flu, including:

• fever,
• aching muscles,
• sore throats,
• runny nose,
• breathing problems,
• chest pains,
• watery diarrhoea,
• conjunctivitis (eye infection), and
• coughs.

The symptoms can come on suddenly and the infection is very aggressive. Avian flu can cause rapid deterioration, pneumonia and multiple organ failure, which can be fatal.

Causes

People can catch the disease by being close to live infected birds and include any of the following types of contact:

• touching infected birds,
• being in contact with their saliva or fluids from their nose,
• being in contact with, or inhaling dried dust from their droppings

Droppings can also contaminate dust, soil, water, feed, equipment, vehicles, clothing and shoes, which can cause the spread of avian flu.  The virus can also be carried on the feet and bodies of animals, which can cause the disease to spread. Another source can be live markets where birds are sold in crowded and sometimes unsanitary (unclean) conditions, so avoid visiting these if you are travelling in countries that have had an outbreak.

Exposure to the virus is considered likely during slaughter, de-feathering, butchering and preparation of infected poultry for cooking.

Although there have been over 100 confirmed human cases, this is a small number compared to the huge number of birds affected. It is not yet understood why some people and not others have become infected following similar exposure.

Diagnosis

Although there have been no cases of anyone with avian flu in the UK, the Health Protection Agency (HPA) have plans in place to manage any cases of suspected avian flu.

The initial assessment will be made by telephone, at a GP surgery, at home or in a side room at the hospital. A diagnosis is made when the following symptoms, information and potential risk has been considered:

• Fever of 38C or higher,
• Respiratory problems, for example, shortness of breath, breathing problems

The doctor will ask if you have travelled in the 7 days prior to symptoms starting, to an area affected by avian flu. And if you have been close (to within 1 metre) of live or dead domestic fowl, wild birds, including those at bird markets.

You will also be asked if you have had close contact (touching/speaking distance) with anyone who has a severe respiratory illness. Or if you had contact with anyone who had an unexplained death from an area that has had an outbreaks.

The following tests will be done to establish whether you have avian flu:

• chest X-ray,
• liver function tests,
• nose and throat swab,
• blood tests, and
• gram stain (a process that detects different bacteria)

If laboratory tests and chest X-ray is normal, then it is unlikely to be avian flu.

Treatment

Although there have been no cases of anyone with avian flu in the UK, the Health Protection Agency (HPA) have plans in place to manage any cases of suspected avian flu.

Patients who have suspected symptoms of avian flu will be advised to stay at home or will be cared for in hospital (in isolation from other patients). The patient may be kept in isolation for 7 to 10 days but it does depend on the type of flu.

The main forms of treatment include:

• rest,
• drinking plenty of fluids combined with proper nutrition, and
• taking medications to help with fever and pain such as aspirin (but not in children) and paracetamol.

Complications, such as bacterial pneumonia, can develop in some people and can be treated with antibiotics.

Those who are severely affected may need to receive extra oxygen to aid breathing and/or respiratory support through artificial ventilation.

Prevention

As birds carry the virus, there is no way of preventing it spreading, although monitoring the migratory patterns of wild birds should provide early warnings of the arrival of infected flocks.  This means that the birds could be targeted and collected on arrival to prevent the virus spreading to other birds.

The current flu vaccinations will not protect against disease caused by the H5N1 strain.  Various worldwide organisations are working together towards producing a vaccine against avian flu.

There are many other ways that individuals can take to protect themselves and others from all types of respiratory disease. For example:

• good hygiene, such as regular hand washing,
• turn away from other people and cover your mouth with tissues when coughing or sneezing,
• put the tissues in the bin straight away after use and wash your hands,
• keep away from public places if you are ill and avoid contact with children or people with underlying illnesses,
• when attending a medical practice, alert the receptionist to your symptoms so you can be seated away from others and possibly be given a surgical mask, and
• maintain good general health and stay up-to-date with the recommended vaccinations, such as the pneumococcal and seasonal flu vaccine for those in high risk groups, for example, asthma and the over 65s.

Avian flu is not transmitted through cooked food. In areas that have experienced outbreaks of bird flu, poultry and eggs can be safely consumed.  It is advisable that the food is handled and cooked properly, for example there are no “pink” parts on the poultry and the egg yolks are not runny.

The outbreak does not pose a food safety risk for UK consumers because the virus is not blood borne and is not transferred through cooked food. As a precaution, the UK has banned poultry imports from all the countries that have had bird flu outbreaks. And farmers in the UK have been given advice to minimise any possible risk of infection.

If you are travelling in a country that has had avian flu outbreaks, stay away from live animal markets and poultry farms.  Avoid bird droppings, keep away from any dead birds you may see, and don’t bring any live birds or poultry products back with you, including feathers.

The Government and National Health Service have plans in place on how to manage the possibility of an outbreak in the UK, although this is thought to be highly unlikely.

Glossary

Source: NHS Direct Online Health Encyclopedia (Last Updated: 06/03/2006 10:59:38)