Throughout history, there have always been diseases; however, the widespread transmission of diseases and plagues did not appear until around 8000 BCE. These epidemics likely began to spread because of the change from hunting and gathering, to farming and domesticating animals. This change allowed groups to settle into one area; thus, allowing for population to significantly increase. The birth interval was reduced to just two years for farmers. This makes sense because as hunter-gatherers, they had to carry everything—including children. Hunter-gatherers also had different types of diseases. For instance, they faced intestinal worms, lice, fleas, and microbes from wild animals. However, the entire group was never affected because the means of transmission were not available. Once the change from hunter-gatherer occurred, individuals began living in close proximity to one another, they used human excrement and animal feces for fertilizer, and lived closely with domesticated animals. All of this allowed for diseases to quickly be transmitted from person to person.

These villages were often heaven for rats, mice, ticks, flies, mosquitoes, and other vectors due to the lack of sanitation. Since most villages only grew one crop, individuals also suffered from a lack of nutrition. Domesticated animals typically lived in the house with people, thus further subjecting individuals to vectors. Domesticated animals also brought a lot to the table as far as contributions go. They provided milk, meat, manure for fertilizer, wool for clothes, and a mode of transportation. Although these benefits from animals were great, epidemics evolved from animals, making them the main cause of epidemics in humans. Diseases like smallpox, influenza, TB, malaria, plague, measles, and cholera adapted to humans, then allowed for human to human transmission.

As humans began to create advancements in farming, they also created avenues of transmission. For example, ditches and irrigation systems allowed for better farming by drowning weds that may compete with crops, but it also acted as a breeding pool for vectors. This is how Schistosoma (blood fluke) first appeared in humans. Aquatic snails acted as a vector and penetrated the skin of humans as they swam or waded in the water.

What do plagues look like now? They are much more controlled. We now have vaccinations and ways to treat these illnesses so they do not spread as quickly or as much. We supposedly eliminated measles—a highly contagious illness that can lead to death—in 2004. However, there were over two-hundred and fifty cases of measles in 2014, ten years after we supposedly eliminated the illness. The two-hundred and eighty-eight cases can be attributed to fifteen outbreaks that caused about five cases each. Even though we still have outbreaks for an illness that we supposedly eliminated, we have significantly cut down the number of cases in the last decade or so. We are still doing research and finding new ways to prevent outbreaks, and I have no doubt that we will have even less outbreaks in the years to come.

Help Received: PowerPoint (The Price of Being Sedentary)

References

Measles — United States, January 1–May 23, 2014. (2014, June 06). Retrieved February 09, 2017, from https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6322a4.htm

Sherman, I. W. (2006). The power of plagues. Washington, D.C.: ASM Press.