The year 2007 marks 10 years since the H5N1 avian influenza virus (often called bird flu) was first reported, and it is getting more difficult to contain with every passing year. The virus has killed 202 people, and more than 50 million chickens infected with the virus or suspected of being infected have been killed or culled in more than 50 countries.
Explore this issueDecember/January 2008
The infection is caused by influenza virus type A, which normally infects birds and is highly contagious. The first case of human infection with highly pathogenic H5N1 avian influenza was reported in Hong Kong in 1997. In 2003, the most devastating and widespread outbreak of H5N1 to date emerged in Asia before spreading to Europe, Africa, and North America. The most obvious victim of bird flu is the multibillion-dollar poultry industry. Estimates of global losses due to outbreaks amount to hundreds of billions of dollars.
The biggest threat to the poultry industry is the backlash due to customer fears. Several polls conducted in 2006 in the United States found that more than 40% of people thought they could get bird flu by eating poultry. Poultry sales in France fell by 30% following an outbreak last year. Consumer reaction was even more severe in Romania, which witnessed an 80% drop in poultry sales in May 2006; in Italy, sales fell by 70% after wild swans were infected. Early in 2007, the price of chicken in Indonesia dropped by 50%. Early victims of bird flu scares have also included global fast food chains. In 2005, a Japanese fast food chain slashed its profit forecast by 60% and spent £2 million on safety campaigns after bird flu was reported in Japan. When a bird flu outbreak in a region is contained, however, sales of poultry do bounce back, albeit slowly.
A Food Safety Risk?
But does H5N1 really pose a food safety risk? It is clear that globalization of food production and trade has made food safety an issue of international importance. Food safety must be tackled not only at the national level; it now requires international collaboration between food safety authorities.
Continuing outbreaks of bird flu in poultry in Asia, Europe, and Africa have raised concern about the various sources of infection and risks to humans. Based on current evidence, direct contact with infected live or dead poultry is responsible for a majority of infections in humans. There is also concern that the virus could spread to humans through contact with contaminated poultry products.
In developed countries, meat is bought, either refrigerated or frozen, from a butcher or supermarket. In Asia, however, it is common practice to buy chickens and other live animals at the market and slaughter them in kitchens. As a result of this practice, Asians have a high level of exposure to potentially disease-carrying animals, both in their homes and as they pass through the markets that line the streets of densely packed urban centers. Wet markets have been identified as one of the sources of H5N1 infection in humans.
Most recently, a nine-month-old in Hong Kong who was frequently taken to a wet market selling live poultry was infected with a mild form of bird flu. It is this kind of event that raises a number of questions about food safety during an influenza outbreak.
Proper Cooking Key to Safety
H5N1 is sensitive to heat; thus, it is safe to consume poultry as long as it has been cooked properly (70°C in all parts of the food). Consumers should also be aware of the risk of cross-contamination. Raw poultry juices and poultry products should never touch items that are eaten raw. People involved in the preparation of raw/frozen poultry products should thoroughly wash their hands and disinfect all utensils that contact the poultry. Hot water and soap are sufficient for this purpose.