In the absence of primary prevention, plans must be made to delay the entry of a novel pandemic virus into the population and to employ measures that prevent or slow transmission of the virus in both the healthcare and community sectors. Such measures can be deployed at the community level, for example, by closing schools and other public places. In addition, these measures can be implemented at the individual level by isolating patients, limiting contacts with infected persons, and otherwise minimizing the likelihood of exposure to the virus. These steps can be voluntary, such as respiratory hygiene/cough etiquette and frequent hand washing, or mandatory, such as by requiring infected individuals to be quarantined or equipped with medical masks that might limit respiratory transmission of the virus.
Clearly there is widespread public interest and concern about pandemic influenza, its transmission, the probability that it will occur, and what can be done to protect the public’s health. Public health officials and organizations throughout the world remain on high alert because of increasing concerns about the prospect of an influenza pandemic, which many experts believe to be inevitable. Most of the current fear of a potential pandemic stems from an outbreak of avian influenza in Asia, Africa, and Europe; infected birds are known to be in 45 countries at the time of this writing (CIDRAP, 2006). Hundreds of millions of wild and domesticated fowl have died from this virus, either through illness or culling. According to the U.S. Department of Homeland Security (DHS), despite the use of traditional control measures, the avian virus is “now endemic in Southeast Asia, present in long-range migratory birds, and unlikely to be eradicated soon” (DHHS, 2006). At this point, the reported number of humans infected remains low in comparison to the number of birds infected—192 confirmed cases in 9 countries over the past 4 years. Of those cases there have been 109 reported deaths (WHO, 2006). The committee found no estimates of the number of cases not reported. As the reported cases stem from those seeking medical care, the death rate may be artificially high.
The H5N1 virus can infect a variety of hosts, including birds and humans, but has not yet demonstrated the ability to be transmitted efficiently among humans. However, via genetic mutation or exchange of genetic material with a human influenza virus, it may develop this capability. Such a change may lead to devastating consequences. And, if mutation and human-to-human transmission do not ensue with the current H5N1 strain, there is a great likelihood that another strain will lead to a pandemic. During the 20th century, there were three pandemics that arose as a result of