Horizon investigates an avian flu pandemic.

We are told how birds carry influenza in their bodies as a matter of course; it does not normaly affect them and many birds will live a long and healthy life despite the presence of influenza in their make-up. In 2005, 200,000 birds die from H5N1 in Qinghai lake in China, this is a salt water lake that attracts many migratory birds. This is a cause for concern as the virus desn't normally kill its hosts whereas it had mutated to kill them. Following from the deaths of the many birds in this lake, the virus transmits to an unprecedented number of species. We are told how all the tigers in some chinese zoos die from H5N1 and that human contraction of the virus has an 85% fatality rate in the young.

The programme cut to Mr.Viral Scientist who states that H5N1 is such a cause for concern because "1 or 2 mutations to the virus" would allow it to attack human cells in the nose and mouth, whereas H5N1 at the moment can only harm humans if it gets deep into our lungs.

In 1918, the 'spanish fu' was carried around the world by soldiers from WW1. In 14 months 15 million people had died. The major concern to people of the time was that normally influenza causes fatalities in the elderly , whereas this strain caused deaths in younger people (20-45). Many people who contracted the virus died. 'Spanish flu' is given the scientific name H1N1and we are told this is very similar to H5N1.
H1N1, in its early stage was very quiet, it killed 140 people in the first year, but then went on to cause widespread death. H5N1 caused 148 deaths in its first year, which does not bode well for our future.

A major problem that is highlighted is that the virus is most likely to occur in an asiatic country, where there is poor medical care compared to first-world countries, which would alow the virus to spread more readily throughout their populations. The World Health Organization (WHO) has many teams of scientists already stationed in south-east asia in an attempt to stop the virus at the source of potential outbreaks. We are told that the marker of a pandemic status would be whether there is human to human infection.

WHO's current plan is to quarantine the area of an outbreak and cover the area in an antiviral spray to reduce the number of places the virus has to breed. However H5N1 is said to be very dangerous and easy to spread because the symptoms of the virus take one or two days to come to light, meaning an infected person could have travelled around the globe before the individual discovers they are infected.

We are taken to a family in America who are attempting to prepare for the arrival of the virus. I took a list of what they were stockpiling for a self imposed quarantine:

• Medical supplies.
  
• Enough nonperishable food for four months.
  
• Enough bottled water for four months.
  
• An electric generator.
  
• A water pump connected to an underground resevoir.
  
• Dog food.
  

And then we are warned how the majority of the population aren't prepared or concerened about a possible H5N1 outbreak, but that our governments are taking thos threat very seriously.

We are taken to the Los Alamos National Laboratory in Los Alamos, New Mexico, America. This laboratory studied the effects of a smallpox pandemic but started to focus on the effects of a flu epidemic when it decided that this would be a more real threat. The scientists there have simulated the effects of the H5N1 virus entering the country through airports. There model has markers for every person in the US, with informatoin such as age and travel patterns, making it a pretty realistic model. From first being infected through major airports it takes 3 months for H5N1 to have overrun the whole country.

We are told that in the majority of countries the virus will enter through air travellers. Richer countries will be able (and have in the past with the SARS outbreak) to use infrared cameras to ensure that people running a temperature will not be able to enter the country without thorough checks. However, as was previously stated, it takes one or two days for the virus' symptoms to be visible, meaning someone could catch the virus as they got on the plane and would appear completely healthy when they got of it, or it is also possible (and the programme says inevitable) that people will slip through any checks at airports eventually.

Once the virus reaches pandemic level, we are informed, the rates of new infections and deaths would double every three days.

The Los Alamos National Laboratory is also attempting to determine the ability of Tamiflu to prevent the spread of the virus. Yet it is only effective if taken at the right time, too early or late and it has no ability to fight H5N1.

We are told about the properties of H5N1 that makes it particularly effective in killing the young rather than old.

A normal virus attacking a human's cell will burrow into a cell its receptors can attach to and reproduce itself until the cell is full of the virus. Once the critical mass of the virus within that cell is achieved it will attempt to infect neighbouring cells until the whole body is affected. The body will counteract this using antibodies and sytocines (sy-to-ch-ene, I'm not sure how it's spelt and I can't find a spelling on the internet). The major problem with H5N1 is that it causes a sytocine storm in healthy people, it causes them to overproduce this virus killer which has a negative effect on the body, enabling H5N1 to spread more readily. It causes the body to leak fluids into itslef, ultimately suffocating someone who has contracted H5N1.

Dr. Jim Robertson explains that it is a tiny pice of genetic material that makes H5N1 such an effective killer. It is a highly pathogenic virus because it causes multiple organ failure, especially attacking livers, hearts and brains. He says it is "an utterly evil virus".

We are told that the effects of Tamiflu against H5N1 are completely unknown, and can't be known until an outbreak occurs. A proffesor from the university of london states that once we do know H5N1 we would only be able to produce 600 million vaccines per 6 months, which would be enough for 9% of the population. The programme then moved into the hypothetical 'what-if'. It pointed out the problems in deciding who would recieve the vaccines, and pointed out problems including:

• Riots as people struggle to gain any such vaccine.
  
• The unpreparedness of our medical services, who would end up having to turn sick people away, due to a lack of equipment.
  
• The problem of the innumerable dead bodies.
  

We are told that 1 in 100 of all people will die from such a pandemic.