Australian Screen

Teacher’s notes

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This clip shows how it was established that an outbreak of avian (bird) influenza in Hong Kong in 1997 crossed over into the human population and resulted in the death of, among others, the 3-year-old boy depicted here. It includes a representation of the hospitalisation of the boy and footage of dead and dying poultry. About 1.5 million chickens were killed in an effort by authorities in Hong Kong to contain the outbreak. Virologist Albert Osterhaus describes how, with the help of fellow virologist Robert Webster, he identified that the boy was infected with the H5N1 strain of avian influenza, the first time this strain was seen to jump directly to humans.

Educational value points

• Avian influenza, or 'bird flu’, is a contagious viral disease that usually only infects birds but has been known to cross the species barrier and infect humans. While some strains of avian flu cause only mild symptoms, the highly pathogenic strains, including H5N1, can spread rapidly through poultry flocks causing a severe and fast-acting disease that affects multiple internal organs and can lead to death within 48 hours. There are some recorded cases of pigs, tigers, leopards and domestic cats being infected with the virus.

• The 3-year-old boy who died from avian flu in 1997 was the first confirmed case of a human contracting the disease. During the 1997 outbreak 18 people in Hong Kong were infected by the H5N1 strain, six of whom died. The current outbreak of H5N1, which began in South-East Asia in 2003, is the most widespread to date and human cases have been confirmed in Cambodia, Indonesia, Thailand and Vietnam. In this outbreak 150 million birds have either died or been destroyed in a bid to control the spread of the virus. Although it is considered endemic in some parts of Asia, it has also appeared in Europe and the Middle East.

• Avian flu does not spread easily from birds to humans but there is concern that it could mutate into a highly contagious strain which may result in a pandemic (global outbreak). With the H5N1 strain being a new virus for humans and one that causes serious illness, two of the three conditions for a pandemic have already been met. The third is that the virus is able to spread easily among humans, who in the case of H5N1 have little or no immunity to it. Migratory birds and international air travel could aid the spread of the virus.

• People who have contracted the H5N1 strain of avian flu have been infected via direct contact with infected poultry. There have been no confirmed cases of human-to-human transmission. As is the case with poultry, the H5N1 strain has a rapid and debilitating effect on infected humans. It usually causes viral pneumonia and multi-organ failure. Fatality rates among humans are also high, with 59 per cent of those infected having died from the virus. Each time a human is infected via poultry, the virus has a chance of mutating to become more easily transmitted between humans.

• The World Health Organization (WHO) believes that there is a high risk of an avian flu pandemic. Past influenza epidemics have affected between 25 and 35 per cent of the population worldwide, and WHO estimates that an avian flu pandemic that caused even mild disease could result in up to 7.4 million deaths. The great influenza pandemic of 1918, coming as it did at the very end of the First World War, killed between 20 and 40 million people in less than a year. Previously it was thought that this type of global phenomenon was unlikely to recur given advances in public health that have successfully controlled other diseases such as smallpox and tuberculosis.

• Australia is working with other countries and organisations such as WHO to prevent an influenza pandemic, by, for example, improving systems to detect influenza outbreaks. Global cooperation is seen as key to containing the virus. This clip shows how virologists in Hong Kong, Rotterdam and Memphis cooperated to identify the H5N1 strain. The development of a H5N1 vaccine is seen as the best way of minimising death from a pandemic, but global research is also focused on learning more about the virus and its spread in order to develop effective ways to combat it.

• Steps have been taken to reduce the risk of an avian flu outbreak in Australia. The chicken-meat and egg industries have adopted bio-security arrangements to keep wild birds such as waterfowl, which carry the disease, away from farmed birds. In the event of an outbreak there are plans for the mass destruction of poultry. The Australian Government is stockpiling antiviral drugs in case of a pandemic, and a vaccine against H5N1, which may help contain the virus, is being developed. The vaccine would have to match closely the pandemic virus, so large-scale commercial production would not start until the new virus had emerged and a pandemic had been declared.

• Super Flu: Race Against a Killer is an example of a documentary made in the 'expository’ style. Expository documentaries rely on the spoken word to advance an argument, and use images to support this argument. In this clip rapid edits are used to convey the sense of a drama unfolding and the urgency of the need to identify the virus. This is reinforced in the hospital scene by the use of a handheld camera that ranges jerkily from the boy hooked to a respirator to the doctor at his bedside, while the laboratory scenes have been sped up to suggest a race against time.