An Introduction to Epidemiology
Understanding the how’s and why’s of becoming sick is very important to keep us healthy. There are “disease detectives” called epidemiologists who specialize in understanding disease patterns, so that we know which precautions to take to keep ourselves and everyone around us healthy.
The spread of communicable or infectious disease evolved into what we now call “the germ theory”. Before the 1850’s, people used to think that foul smelling vapors called miasma caused illness. However, John Snow, the father of Epidemiology, challenged the miasma theory by mapping a cholera epidemic in Soho, London, from water sources and claimed that cholera must be water-borne, not air-borne. Since then, disease mapping has become very important in understanding disease patterns. A great interactive and up-to-date map can be found at www.healthmap.org.
The rates of transmission of specific diseases is also important to understand. Endemic diseases, or diseases that are steady and do not fluctuate in a society (so transmission is only from one person to another), are not as much of a threat as epidemics or pandemics. Epidemics spread faster in a specific location, meaning that one person can infect multiple people, and can cause many people to become sick at once. Pandemics are epidemics on a global scale. And though infection from person to person is fairly common, the students learned that the most deadly animal is actually the mosquito, a vector (or carrier) for diseases.
In today’s lesson, the students modeled an epidemic through an activity where they spread an “infection” through the class by sharing contents of a cup with one another. They graphed their results and noticed the rate of infection was exponential, or an epidemic. At the start of the activity, only one of the students was “infected” and through multiple rounds, the infection spread. By the third round, eight students were infected! They realized that “patient zero”, or the first person to catch and spread the infection, is usually difficult to isolate and aside from prevention methods, these considerations are challenges epidemiologists face.
We ended the lesson by focusing on healthy habits or methods of prevention and elimination efforts. So far, only one human disease has been successfully eradicated through vaccination: smallpox. Guinea worm, though not through vaccinations, is also very close to being eradicated!