Arboviral Diseases

Arboviral diseases are infections, which are transmitted via invertebrate insects such as mosquitos and ticks. Lyme disease is the one I am most familiar with as I had a close family friend who lost his dog to the disease. It was thought that the dog was bitten by a wood tick in northern Minnesota, which infected him with the disease. Apart from Lyme disease there are many other arboviral diseases. These include dengue fever, yellow fever, encephalitis virus and West Nile virus. West Nile virus made major headlines when it was discovered to have spread to the western hemisphere for the first time in 1991. It is believed that arboviral diseases have been around for thousands of years, but we did not know their existence until the late 1800s.

Cuban doctor, Carlos Finlay was the first to propose that Yellow fever may be transmitted by mosquitos rather than by human contact in 1881. This was later verified by U.S. Army doctor Walter Reed in 1901.Arboviral diseases survive by a cycle between hosts, such as humans and vectors, such as mosquitos and ticks. The vectors are able to transport these diseases from one infected host to a new host by way of consuming the infected hosts blood and injecting their saliva into the new host. Once the virus reaches a new host, it amplifies itself by killing blood cells and multiplying.

Transmission of arboviral diseases from human to human is rare but can occur. If it is not known that a donor is infected with the virus, blood transfusions and organ transplants can lead to the infection spreading from one human to another.  In order to try and prevent this form of transmission, blood and organs are screened for the viruses prior to their use in for treatment. Infected mothers also run the risk of possibly infecting their newborn child. Also, those who use needles are at an increased risk for the contraction of arboviral disease just as they are with many other kinds of infections.

The Poison Squad

            The poison squad was a group of people who’s main objective was to test the effects of common food additives on the human body. They would all eat foods with progressively higher levels of these food additives until someone would start to get sick. During these series of experiments, the participants would eat only the food prepared in the Poison Squad’s kitchen. They were also required to sign a waiver that would prevent them from suing the government for damages including death. Each of the participants selected had to be men. The leading doctor, Dr. Riley reportedly referred to women as savages.

            During his time at Purdue University, Riley experimented with food additives by testing their effects on dogs. After being hired by the Agriculture department, Riley pushed for having tougher regulations on food additives. Unfortunately high paid lobbyists of the packing and canning industries shot down most of these proposed bills. Riley decided it was necessary to have physical test results to show the effects of the additives on the human body and he convinced congress to fund his “table trials” with $5,000. The first additive tested was a common food preservative called borax. It did not take long for the effects of the additive to be noticed among those in the group. They began to show signs of headaches and digestive problems after consuming them with every meal. The group continued and test many other additives including copper sulfate which is used today more commonly as a pesticide.

            Once the group finally had its test results showing the negative effects of many of these food additives, they had to find a way to beat the lobbyists of the food industry. The secretary of agriculture reportedly even shot down some of the reports from the poison squad himself. Wiley’s efforts eventually started to pay off when the Meat Inspection Act and the Pure Food and Drug Act were passed in 1906.

Who Was John Snow?

John has been called the father of modern epidemiology for his efforts in finding the source of the cholera out break in London during the 1850’s. From an early age, Snow was interested in medicine and spent much of his time studying and working as an apprentice to different surgeons. He first encountered cholera at a young age. He was sent to treat some of the sick when one of the physicians, he was working for, could not make it around to every patient. Along with attending different colleges to increase his medical knowledge, Snow contributed to the founding of the Epidemiological Society of London following the cholera outbreak of 1849. He spent a lot of his early efforts as a M.D. developing anesthetics.

            The common theory of disease causes around this time in history was that pollution in the air was spread, and then infected those who contracted diseases such as cholera and the bubonic plague. Snow thought that many of these diseases were actually caused by tiny invisible parasites. His research of diseased miners led to this discovery. He realized that many of these miners were working in close proximity underground, and that the parasites were likely spread on the miner’s hands. This happened because they had no means for washing their hands in the mines.

            When cholera struck London in 1849, Snow wanted to do anything he could to trace the source of the outbreak. Due to the digestive symptoms of the disease, Snow looked into possible ways for the water and food sources to become contaminated. He used his own funding to publish a pamphlet including all information that supported his theory. After using this theory, that a contaminated water source is to blame for the spread of cholera, Snow was able trace the water supply to discover the source.