I often talk about threats to our food supply and control measures that should be taken to reduce the risk of foodborne illness. We all play a part in keeping the food supply safe from “farm to fork.” Let’s look at a potentially huge threat not only to the food supply but the human race in general and see what is being done to keep this threat in check—and what we can do to keep our food supply safe.
What is this threat? It is viral. Remember viruses? They are smaller than bacteria with a simple biological structure. They are hard to inactivate/kill within a biological system. They need a living host to reproduce, and they mutate into new forms. They’re back in the news and giving the world a wake-up call, especially if you are a domesticated chicken, duck, or turkey in certain parts of the world.
Avian Influenza (AI), or the bird flu, causing concern worldwide comes in two forms: a highly pathogenic viral strain (HPAI) known as H5N1 HPAI (also known as Asian bird flu virus) and LPAI. The other strains of AI are considered far less pathogenic, hence the acronym LPAI. The FDA notes (as of March 21, 2006) that LPAI poses little health risks to humans.
Let’s look at some facts about H5N1 HPAI, both from a bird’s perspective and from the human’s. HPAI is a form of bird flu that can potentially spread rapidly in wild and domesticated flocks and cause high mortality in infected birds. Wild birds carry the viruses in their intestines but usually do not get sick. Transmission of the viruses via these highly mobile animals is of concern. The virus is found in their respiratory systems and intestines. Transmission bird to bird is done via droplets of moisture and other secretions. Domesticated flocks of chickens, ducks, and turkeys infected with the virus usually get severely diseased. Control measures being carried out in regions of the world affected have been to destroy poultry flocks with confirmed H5N1. From late 2003 into 2004, over 100 million birds in these areas have died as a result of the disease or have been destroyed to control the spread. Since 2003 countries including Cambodia, Indonesia, Japan, Laos, South Korea, Thailand, and Vietnam have experienced outbreaks. Spread of the disease has continued into Europe, Africa, and the Near East. Destruction of these flocks is critical not only to contain the spread within the poultry industry but also to limit the potential for the virus to mutate into a strain that crosses over and becomes a human form.
Humans infected with the virus generally have been tending to small flocks of free-ranging poultry. Bird-to-human transmission has occurred within environments where the persons have been in direct contact with live birds, their waste products, and the byproducts of processing them into raw food products. These persons (adults and children) have been in direct contact with infected birds. The World Health Organization reports that since 2003 approximately 150 human cases have been reported with around 50 percent being fatal.
Human-to-human transmission of this virus has occurred but is rare. When we hear the word pandemic the fear is that this virus will mutate into a form easily transferred from human to human. There is no currently available vaccine to protect humans from the H5N1 virus. Development is underway, however. The good news is that transmission of the disease from live birds to humans is relatively easy to control with good personal hygiene and basic handling procedures. The millions of birds culled to help control the spread of the disease have not resulted in any known cases of the disease within the population of workers. How is the United States and the U.S. poultry industry controlling transmission of H5N1? The National Chicken Council notes:
- Transmission from live animals. The importation of birds or bird products from affected areas of the world has been banned or placed under strict control.
- Transmission from poultry products. None of the affected countries in Southeast Asia is permitted to export poultry products to the United States. The U.S. imports very little poultry product.
- Transmission via human beings.While it is possible infected humans could bring H5N1 strain to the United States from an infected region, President Bush added this strain of influenza to the list of diseases for which a person can be quarantined.
- Bio-security. Poultry companies and farmers practice strict bio- security at all times and it is heightened during an outbreak of avian influenza. Trucks carrying feed are hosed down, personnel wear protective clothing and plastic boots and go through footbaths, farmers stay away from community gatherings, and farmers generally keep their farms locked down until problems have passed.
AVIAN FLU AND FOOD SAFETY
There’s good news for all of us in food service. Based on the latest information, the avian flu virus is controlled using the same handling and cooking procedures used to control Salmonella Enteritidis infections. So it’s back to basics to control this threat. Good management practices include consistent appropriate personal hygienic practices, knowing your critical control points and associated critical limits.
According to the FDA, “there is no evidence anyone has been infected with Asian Bird Flu or other bird flu virus by eating properly cooked eggs or other cooked poultry products derived from infected birds. Cooking eggs until the whites and yolks are firm and cooking poultry to 165°F (74°C) kills the bird flu virus if it is present.”
While at this time this virus is relatively easy to control in poultry products by cooking and appropriate handling, millions of domesticated birds have died or been culled to control viral spread and potential mutation of the virus. The food supply in many areas of the world has been affected, especially in small subsistence agricultural areas where the loss of even a few chickens and/or ducks means the difference between adequate nutrition or the lack thereof. The high- density growing practices of the U.S. poultry industry coupled with the biosecurity protocols noted may keep the supply safer. This is not to say we can let our guard down. The viruses are mutating as you read this. We must be vigilant, proactive, and support basic research.
Learn More
Norm Faiola, Ph.D., is associate dean and associate professor, Department of Nutrition and Hospitality Management, Syracuse University. Email Dr. Faiola with questions or comments: nafaiola@syr.edu.
|
