Aids, Sars, Bird Flu and Ebola - a Contrast in Epidemiology

AIDS, SARS, Bird Flu and Ebola - a contrast in epidemiology

Epidemiology, the study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to control health problems, is an ever-growing field of study that has been in effect for many decades. It is an essential field of study for the survival of the human race due to the fact that humans today are, in many places, constantly in close contact with others and the possibility of an epidemic breakout is massive. Historically, epidemics have been known to wipe out millions of people at a time and even kill off an entire colony of people in one clean sweep. To most people an incident like this would be terrifying but to the epidemiologists in the world it is fascinating. Epidemiology has come a long way over the many years and the collective knowledge that has accumulated gives us a great amount of insight on how to go about treating epidemics and even how to prevent future epidemics that can be detrimental to the human race as we know it. When studying epidemics, a few large, special cases draw a large amount of attention. AIDS (acquired immunodeficiency syndrome), SARS (severe acute respiratory syndrome), bird flu and Ebola are all major players in the game of epidemics and have all recently had major impacts on society.

AIDS, as the name infers, is an autoimmune disease that is prevalent worldwide and kills millions of people annually. It is estimated that upwards of 35 million people in the world, 68% (22.9 million) of those 35 million living in the highly infected area of Sub-Saharan Africa, live with AIDS. The disease can affect all people but in the United States, the male homosexual community is statistically at a higher risk for contracting the disease. Those infected by AIDS are of ages ranging from newborn to elderly. The AIDS disease is passed from person to person by the exchange of bodily fluids. Not all bodily fluids can carry the disease. The bodily fluids that do carry the disease are as follows: blood, semen (cum), pre-seminal fluid (pre-cum), rectal fluids, vaginal fluids, and breast milk from an HIV-infected person. As one could see, the main method of transmission is through the exchange of bodily fluids during unprotected sex but it can also be passes to newborn babies by breast feeding from their infected mother. Like many of the infections mentioned in this paper, mucus membranes (ie. mouth, rectum, vagina, external urethral orifice), are the weakness in the human body where the infection can be passed from host to host as well as open wounds or direct injection into the blood stream. Drug abuse across the world is also a large benefactor in the spread of AIDS. It is not uncommon for addicts to share unsanitary needles while injecting methamphetamine or heroin and the AIDS infection can easily be spread this way.

SARS first emerged in 2002 in the southern region of China where it then spread aggressively across Asian countries and even into other countries in a few cases. There were 8422 cases of SARS documented with a case fatality rate of 11% (916 reported deaths). The disease was not age specific but those who were working in a medical institution were affected the harshest since they frequently came into contact with patients who were hosting the SARS virus. SARS, severe acute respiratory syndrome, is caused by one of five coronaviruses, SARS-CoV, being passed from host to host by either direct inoculation or droplets passing through a mucus membrane, much like AIDs. Those who contract the

will be feverous and weak in the early stages but soon after will contract pneumonia. It is at this point where most patients are admitted into hospitals. The original outbreak of SARS was believed to have begun in the rural areas of Guangdong providence, People's Republic of China. As many of these people became sick, they travelled to the more populated areas where there were hospitals thus infecting masses of people both in and out of hospital settings. Unfortunately, currently there is no vaccine to help any future outbreaks. The only means for preventing an outbreak is consolidation and proper education on how to handle a case.

Bird flu, commonly referred to as Avian Influenza (AI), is a virus that affects all different bird species worldwide and can be deadly to humans in close contact with affected birds. The virus typically affects domesticated birds in the largest numbers since domesticated birds are known to be kept in close proximity to one another in less than sterile conditions. Infected