It seems that every day the news contains at least one story about bird flu. With all the news reports and discussion in the media, it’s hard to know how concerned we should be about our health and safety. I think it’s important for health care professionals to be well-informed - for our own sake, as well as that of our patients.
What exactly is avian or bird flu? According to the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO), bird flu, also known as H5N1 virus, is an influenza A subtype that occurs naturally in birds. The virus is shed in the birds’ saliva, nasal secretions and feces. It spreads among birds via contact with surfaces contaminated with these secretions.
What concerns the CDC and WHO about this virus is that it is highly pathogenic and deadly. The most common transmission of avian influenza is currently from bird to bird, and in some cases, from infected birds or contaminated surfaces to humans. It is extremely rare for avian flu to be transmitted from human to human, but scientists fear that this may become common. Viruses, including the H5N1 virus, frequently mutate or change. If this occurs and the virus can be transmitted easily from one human to another, a major world outbreak, or pandemic, could occur.
There have been pandemics of influenza, such as in 1918-1919, which caused an estimated 50 million deaths worldwide. Since January 2004, 140 cases of avian flu in humans have been reported to the WHO. As of early January 2006, the WHO reported 76 avian flu deaths worldwide, primarily in Asian countries. This does not include the deaths of several children and the infection of people in Turkey in mid-January, and possibly more since this writing. Updated information on the avian flu is available on the CDC website at www.cdc.gov.
What is it about the avian flu that leads experts to believe it could become a pandemic? First is the lack of a commercially available vaccine against the H5N1 virus. An effective vaccine has been developed and is in human clinical trials, but, as of this writing, it is not available for distribution. Another concern is that in many of the human infections in Asia, the virus has been resistant to commonly used antiviral agents used to treat other types of influenza. While some antiviral agents, such as Tamiflu™, are effective against the H5N1 virus, it is not known whether the drugs will be effective long term.
This particular type of influenza has especially severe respiratory symptoms. Healthy adults and children normally recover from seasonal influenza (which can also have severe respiratory symptoms). In most cases, deaths from seasonal influenza typically occur in the elderly and people with chronic illnesses. The avian flu has killed healthy adults and children.
Even though cases of avian flu have not been reported in the United States as of this writing, CDC and WHO officials are carefully monitoring outbreaks. The popularity of global travel could contribute to the possibility of outbreaks in the United States and lead to a pandemic. Many countries are ready to implement travel restrictions, if necessary, to prevent sick people from boarding planes. The CDC Web site has recommendations for people who may be traveling to countries where avian flu has been identified. These recommendations are located in the Travelers Health section.
In addition, the U.S. Dept. of Agriculture has instituted an embargo of poultry from Asian countries to prevent possible exposure to birds that may carry the virus. It is important to note, however, that heat from cooking kills viruses. Therefore the CDC believes there is no concern about contracting avian flu by eating poultry or eggs that are well cooked.
What other precautions can be taken to protect ourselves from this deadly flu? According to the CDC and WHO, paying close attention to hand hygiene is, as always, one of the most important precautions we can take. The CDC also recommends that everyone, especially health-care professionals, be vaccinated for seasonal flu, as it is possible to become co-infected with seasonal flu and avian flu and a new strain could be produced. If you experience flu symptoms, seek medical advice.
The good news is that a pandemic has not yet occurred. The bad news is that the possibility continues to grow. Stay informed, and follow the advice and directives from the Centers for Disease Control and Prevention. Oh, and wash your hands!