kevinbui

Pandemic influenza is by no means anything new, both in the United States as well as for the rest of the world. In fact, pandemics of influenza occur roughly every decade or so, with mild outbreaks of influenza occurring every other year. Many of you are probably well aware of the infamous Spanish Flu, which occurred back in 1918, that killed approximately 25-50 million people worldwide, with no less than 500 thousand deaths in the

United States alone.¹ Unfortunately, influenza, like any other virus, is continuously mutating into many different forms, which is the culprit of the many mild/severe outbreaks of influenza that we experience. While we may be able to make a vaccine for a specific strain of influenza once it has already entered our population, we are always threatened by new strains for which we have yet to make a vaccine. Therefore, one of the fears that we are currently pondering concerning H5N1 (the designation for avian influenza) is that a mass outbreak will occur within certain human populations before an appropriate vaccine is made.

At this point in time, avian influenza has not bridged the gap between animals (mostly birds) and humans in such a way as to create a pandemic. A handful of cases where humans have either suffered from H5N1 or have died from H5N1 have been reported in several countries throughout Eurasia (concentrated heavily in Southeast Asia), but all of these cases were a result from direct, prolonged contact with infected birds, specifically with butchered birds. However, human to human transmission of H5N1 has yet to occur. It is important to have a basic understanding of how viruses, specifically avian influenza, are transmitted from one species to another. The virus H5N1 has receptor proteins called hemagglutinin, which are located on the outer coating of the virus. These receptors are very specific to certain cells, and in the case of H5N1, are specific to bird cells. However, a mutation to the receptors, which is very feasible, could allow them to bind to human cells. If this were to happen, a pandemic of H5N1 would occur.

As previously touched upon, there is no vaccine at this point for H5N1. If we were to make a vaccine, it would take approximately six months, which leaves ample time for a pandemic to occur and take a hefty toll before those who have yet to be infected can become vaccinated. A fear that goes along with vaccinations is the allocation of these vaccines: Will we have enough vaccines for everybody? Who will get vaccinated if there are shortages? Who should be responsible for making/distributing these vaccines (i.e. which countries, which companies, etc.)? Another method of controlling the spread of the virus is to use the drug Tamiflu^®. Tamiflu^®inhibits neuraminidase, which are protein receptors located on H5N1 that allow the virus to spread. While this does not prevent influenza infection, it helps keep the virus from spreading exponentially.

In the advent of modern transportation, if/when H5N1 becomes communicable between humans, a pandemic could occur within a matter of days. Because a person does not show symptoms of the virus for roughly two days while remaining infectious from the point of becoming infected, there is no way of determining with certainty who does and does not have H5N1, making the idea of monitoring an infected person’s travel impossible. An interesting component of H5N1 is that unlike most illnesses, whose high risk populations are often young children and the elderly, H5N1 is projected to cause the highest rates of illness/death in persons between the ages of 19-64.² More alarming is the current death rate of H5N1. Although only a handful of cases have been reported to date, specifically in the countries of Azerbaijan, Cambodia, China, Djibouti, Egypt, Indonesia, Iraq, Thailand, Turkey, and Vietnam, the current death rate stands at 584 per 1,000 infected.³ With this preliminary data already at our disposal, it is vital for community’s to become more aware of the looming threats of avian influenza. Emergency plans, stocked resources (i.e. food, medical supplies, etc.), knowing how to reduce the spread of germs, and a general knowledge of what is at stake are all important things for us to have when preparing for the more than probable arrival of an avian flu pandemic.

² A Maine Epidemic. Retrieved October 12, 2006 from <http://www2.cdc.gov/od/fluaid/fluAID>.

³ Global Epidemic. Retrieved October 12, 2006 from <http://www.who.int/csr/disease/avian_influenza/en/>.

Picture from: http://english.aljazeera.net/mritems/images/2006/11/25/1_202257_1_5.jpg