Q&A: Bird flu
What is avian flu?
Avian influenza, also known as bird flu, is a contagious viral disease in animals, caused by a virus loosely related to human influenza. While all bird species and - less commonly - pigs are thought to be susceptible, domestic poultry flocks are especially vulnerable to infection, which can rapidly result in epidemics among their populations. Since bird flu was first recognised, in Italy, a century ago, there have been more than a dozen strains of the virus. Some are almost harmless, while others result in death within hours. The H5N1 form of bird flu is the most dangerous. It is highly pathogenic and extremely contagious among birds, both by air and contact with faeces. Mortality is close to 100%, with many birds dying on the same day they were infected.
Which countries have been affected?
The latest bird flu outbreak, which started in 2003, has mostly affected Asia, where millions of birds have died after contracting the disease, or have been destroyed in measures to prevent it spreading. As of April 4 2006, cases in animals have been recorded in 46 countries, according to the World Organisation for Animal Health. These countries are: Afghanistan, Albania, Austria, Azerbaijan, Bosnia and Herzegovina, Bulgaria, Burkina Faso, Cambodia, Cameroon, China, Croatia, Denmark, Egypt, France, Georgia, Germany, Greece, Hong Kong, Hungary, Kazakhstan, South Korea, India, Indonesia, Iran, Israel, Italy, Jordan, Malaysia, Mongolia,Myanmar, Niger, Nigeria, Pakistan, Poland, Romania, Russia, Serbia and Montenegro, Slovakia, Slovenia, Sweden, Switzerland, Thailand, Turkey, Ukraine and Vietnam. There have also been H5 outbreaks in the Czech Republic, Iraq, Laos and the Philippines.
What about Britain?
On October 21 2005, British authorities confirmed that a parrot from Surinam had died in quarantine in Essex after being infected with bird flu, which was later confirmed as the H5N1 strain. On April 7 2006, Scottish police said tests were being carried out on a dead swan infected with bird flu. It was discovered a week earlier in Cellardyke, a coastal village nine miles from St Andrews. If the swan tested positive for H5N1, it would be the first wild bird in Britain to be discovered carrying the most lethal for of avian flu. A protection zone with a minimum radius of 1.8 miles (3km) was set up, as well as a surveillance zone of six miles. The Cabinet Office activated its civil contingencies committee (Cobra).
If it just affects birds, why the panic?
According to the World Health Organisation (WHO), as of April 4 2006, more than 191 people around the world had been infected by the H5N1 strain, of whom 108 had died. So far, most human deaths have been in Asia in communities in which people live in close proximity to poultry.
WHO scientists believe it is likely that the virus is carried by migrating birds. Although it does not easily infect humans, every time it does, it increases the chance that the virus could mutate into a form which could be passed from one infected human to another.
WHO says that would probably be how a flu pandemic would start. Pandemics have occurred every 20 to 30 years, but it has been almost 40 years since the last one happened. The most severe pandemic occurred in 1918-1919 and is estimated to have killed around 50 million people worldwide. On September 29 2005, David Nabarro, the WHO expert appointed to coordinate the international response to a pandemic, said a pandemic would cause anything from 5 million to 150 million human deaths.
The Department of Health's contingency plan says that between 21,000 and 700,000 deaths could be expected in Britain from a flu pandemic. One-quarter of the population could become infected, and another quarter would need to care for them.
What measures is the UK taking?
In common with other countries, the British government's plan to tackle bird flu is characterised by surveillance and containment. The Department for Environment, Food and Rural Affairs has asked birdwatchers to help provide an early warning against the arrival of the infection and has issued guidelines accordingly. Scientists are also involved in examining bird droppings for signs of the influenza virus.
The EU says communication between the public, vets and doctors is essential in alerting authorities to any outbreak of flu.
As occurred in Turkey, when an outbreak is confirmed, authorities slaughter poultry in an attempt to contain the spread of the virus. Were it to mutate into a form contagious among humans, authorities would begin a programme of mass treatment, using antiviral drugs and flu vaccines.
The British government is spending £200m on stockpiling antiviral drugs to treat one in four of the population and on 2m doses of vaccines to protect medical and emergency staff in the event of the disease turning into a global pandemic.
What drug treatments are available?
Tamiflu, made by the Swiss pharmaceutical company Roche, is the antiviral drug favoured by most governments. It can be taken as a preventative treatment but there is no evidence it will stop people being infected. Doctors believe it could relieve flu symptoms and help the body to fight the virus. However, there have been concerns that H5N1 is developing resistance to Tamiflu. In December 2005, research published by the New England Journal of Medicine, showed that two out of eight patients being treated for bird flu in Vietnam died despite receiving Tamiflu.
Tamiflu is only available in the UK on prescription and, with governments around the world ordering it, it has become very scarce. It might be possible to obtain online but since prices have increased the British government has warned that fakes are in circulation.
Another antiviral drug, Relenza, is available but it has to be inhaled and is harder to store over long periods.
Stockpiles of the vaccine against H5N1 could be a first line of defence for priority groups while scientists develop a vaccine against the exact strain responsible for the pandemic. The British government will buy sufficient vaccine for the entire population should a pandemic begin and the strain of flu be identified, but it would take around seven to nine months to produce.
The government is briefing doctors on how to deal with any mass outbreak, and the Department of Health has made information available to the public, as has the World Health Organisation.
What other measures are being taken?
The EU has banned imports of poultry products from countries with bird flu outbreaks. Britain's health secretary, Patricia Hewitt, told the House of Commons on October 17 2005 there was no danger to people of contacting bird flu by eating poultry. The Food Standards Agency says there is no evidence to suggest bird flu can be passed on by eating poultry or eggs, but it recommends ensuring they are properly cooked. The Australian government has recommended washing eggs before breaking them and washing hands afterwards.
What if the pandemic happens anyway?
The Department of Health (DoH) would have the main responsibility for coordinating the UK's emergency response, with the support of the Health Protection Agency (HPA) - the UK-wide authority responsible for combating the spread of infectious disease. The DoH would establish a national operations room to support the local response to outbreaks and coordinate vaccine distribution to affected areas.
Devolved administrations in Wales, Scotland and Northern Ireland have been asked to coordinate the response in their regions. The HPA has also published an updated influenza pandemic contingency plan, which makes up part of the DoH's overall plan.
In the event of a pandemic, the HPA would set up a strategic emergency coordination centre. It would coordinate clinical surveillance, provide infection control advice, analyse flu strains and issue information to the public and healthcare professionals. It would also advise the DoH on the use of vaccines.
In December 2005, a House of Lords science and technology committee report said it did not believe the Department of Health could provide strong enough leadership in the event of a flu pandemic. It recommended that the government appoint a cabinet-level minister to coordinate the implementation of the contingency plan.
How would the response work on the ground?
Strategic health authorities would receive support through regional public health groups, which would coordinate the work of primary care trusts and hospitals in responding to cases.
All hospital and ambulance service trusts would be expected to put in place the necessary resources to care for people affected by a pandemic in their area, as well as offering help to other NHS trusts.
It is likely that areas would be put under quarantine, travel restrictions imposed, schools closed and public meetings banned.
However, British peers have concerns about whether the health infrastructure could cope with the 1 million new cases expected every day at the height of a pandemic. Panic-buying and food shortages are expected and it is likely that Cobra would be called into action to coordinate responses to the crisis.
Police would probably need to use stringent powers granted under the Civil Contingencies Act 2004 and the military could be called upon to replace police and other emergency service personnel too ill to work.