https://padlet.com/rubybaldwin/m2u8ho9x8n5grc0 Evolution of infectious disease en-us 2023-03-16 16:27:06 UTC 2025-12-10 12:19:20 UTC hello@padlet.com https://padlet.net/icons/png/1f489.png rubybaldwin https://padlet.com/rubybaldwin/m2u8ho9x8n5grc0/wish/2519711078 I have chosen Rabies (caused by virus Rabies lyssavirus) as my disease of study.]]> 2023-03-16 16:44:05 UTC https://padlet.com/rubybaldwin/m2u8ho9x8n5grc0/wish/2519711078 rubybaldwin https://padlet.com/rubybaldwin/m2u8ho9x8n5grc0/wish/2526199554 The first written record of Rabies was in the Mesopotamian Codex of Eshnunna from 1930 BCE. The text dictates that the owner of a dog showing symptoms of rabies should take preventative measures against bites.

Because of the early discovery of the disease, the initial suspected infectious agent was just thought to be the dog/dog bite itself, the tongue of the infected, or in Ancient Greece, the spirit of mad rage, Lyssa.

The actual cause of Rabies, the rabies virus, was not determined until the 1800s, and the first successful rabies vaccine was created in 1885. 

Rabies is a viral zoonotic disease. Zoonotic diseases are those transferred between people and animals. ]]> 2023-03-21 23:43:27 UTC https://padlet.com/rubybaldwin/m2u8ho9x8n5grc0/wish/2526199554 rubybaldwin https://padlet.com/rubybaldwin/m2u8ho9x8n5grc0/wish/2535893235 Due to the ancient nature of the rabies disease, it is hard to determine the original path it took when spreading. Instead, I will be detailing the spread of rabies in the Western Hemisphere during the colonial era.

In the figure above, the proposed phylogeny suggests that the original population of rabies virus in North America was likely founded during the last ice age 15,000 years ago, when there was a land/ice bridge that joined the "Old World" with the "New World." That land bridge would have been the last contact that the Americas had with Eurasia until the next branch in the Americas in 1642-1782, during the colonial era.

Before the Americas were colonized, rabies was only found in skunks, raccoons and bats. When European invaders brought their domesticated dogs on their cross-ocean voyages, they brought canine-vectored rabies with them. 

Soon after the initial colonizing of the Americas, domesticated dogs transferred their rabies virus to foxes, coyotes, and mongoose in the Caribbean. 

This made efforts to quell the growing rabies problem exceedingly more difficult, as there were numerous points of possible infection.

There are no estimates (at least that I could find) for how many people died from Rabies during this time. But, using the current number of worldwide deaths (59,000) and the population of the world in 1700 (610,000,000), I was able to calculate a possible death count. Assuming the death rate for rabies today and in the 1700s was the same, over 4,500 people died from rabies each year. This number might of been even higher because there was no cure or preventative measures in the year 1700.]]> 2023-03-29 01:37:54 UTC https://padlet.com/rubybaldwin/m2u8ho9x8n5grc0/wish/2535893235 rubybaldwin https://padlet.com/rubybaldwin/m2u8ho9x8n5grc0/wish/2545630705 Virulence is the severity of a viral disease. It is measured by the disease's ability to survive and reproduce when inside of its host.

Rabies is a highly virulent disease. Without vaccination, it is virtually 100% fatal.

Rabies virulence has gone down since the invention of a rabies vaccine in 1885. Before then, a rabies diagnosis was a death sentence. Now, once exposed to rabies, it is important to seek medical attention immediately to receive a rabies post-exposure prophylaxis to prevent further spread of the disease in the body

The human rabies vaccine is unique in that it is mostly only given after possible exposure. Only those at frequent/high risk of infection are suggested to receive a preventative rabies vaccine (pre-exposure prophylaxis). 

Once rabies symptoms start to show, usually around 2-3 months after contraction, but as early as 1 week and as late as 1 year, it is too late for any vaccine treatment.


]]> 2023-04-06 01:17:52 UTC https://padlet.com/rubybaldwin/m2u8ho9x8n5grc0/wish/2545630705 rubybaldwin https://padlet.com/rubybaldwin/m2u8ho9x8n5grc0/wish/2552062373 Many attempts were made at curating home remedies before the invention of a rabies vaccine. one newspaper clipping from the 1700s presented a cure consisting of the plants rue and sage, flour, and yeast that you would add to your milk each morning. Rue in particular was a very common plant for rabies remedies, and has been used for different ailments since Ancient Greece. There is some merit to the use of rue, as recent studies suggest it may be effective in reducing some rabies symptoms.

As mentioned briefly in previous posts, the rabies vaccine wasn't invented until 1885. Louis Pasteur spent 4 years researching and perfecting the vaccine. Up until that point, rabies was a death sentence.

Pasteur's first use of the vaccine on a human was on a 9 year old Joseph Meister. With the assumption that Meister would certainly die without the vaccine, Pasteur decided it was worth a try. Over the next 14 days, Pasteur administered increasingly potent daily doses of his rabies vaccine. At the end of the two weeks, Meister did not develop rabies. 

The rabies vaccine works like many other vaccines we receive today. In fact, the magic recipe for the vaccine has remained largely unchanged since its inception. In a lab, scientists grow live rabies viruses in different cell-grown tissues (Pasteur actually took rabies cells from live infected rabbits). These viruses are then separated from the host tissue and subsequently killed/weakened via exposure or drying out. The dead rabies virus is the first vaccine of many that an infected patient will receive. Each following vaccine will be slightly more virulent and alive, building up the human body's ability to fight against the virus. 

This experimental vaccine was groundbreaking, the first of its kind. Although the very first "vaccine" came 100 years before, Louis Pasteur is credited with the widespread adoption and further creation of other vaccines, as well as the germ theory of diseases. He also discovered pasteurization, the process of mildly heating food to kill off pathogens, which was named after him.]]> 2023-04-12 19:20:44 UTC https://padlet.com/rubybaldwin/m2u8ho9x8n5grc0/wish/2552062373 rubybaldwin https://padlet.com/rubybaldwin/m2u8ho9x8n5grc0/wish/2560754105 In the first written record of rabies, the Mesopotamian Codex of Eshnunna from 1930 BCE, the text says that if a dog exhibits rabies symptoms the owner must take action to prevent bites. If someone was bitten by a rabid dog, the owner of the dog was fined.

Until the invention of the rabies vaccine in 1885, warning others about the dangers of dog bites was the best any leadership could do. Because of the virulence of rabies, just knowing the consequences and avoiding bites was protection enough for most people.

In France and Belgium during the 19th century, the "St Hubert's Key," named after the patron saint of hunting and metalworkers, was heated and applied to open bite wounds assumed to harbor rabies. Dogs were also branded with the key as an attempt at a protection measure.

It is currently required for domestic dogs and cats to receive the rabies vaccine in 41 states. In the U.S., about 5,000 animal rabies cases are reported each year, with about 90% of those cases being in wildlife. Only 1-3 cases are reported every year in the U.S., but between 30,000 and 60,000 people receive the post-exposure vaccine each year. 

Because this disease is so ancient and people had to go without vaccines for thousands, if not tens of thousands of years, I cant imagine a better response than just actively avoiding dog bites. Rabies is transferred through bodily fluids, so no quarantine is required so long as you are avoiding contact with blood and saliva. Because dogs were the major vector with their constant proximity to humans, a outright abandonment of the keeping of dogs as pets might've improved infection/death rates slightly, but personally, I wouldn't want to live in that reality.]]> 2023-04-19 22:01:41 UTC https://padlet.com/rubybaldwin/m2u8ho9x8n5grc0/wish/2560754105 rubybaldwin https://padlet.com/rubybaldwin/m2u8ho9x8n5grc0/wish/2569352383 Rabies has left a lasting effect on how we view wild animals and dog bites. Because most domesticated dogs receive a rabies vaccine during puppyhood, it has become increasingly more likely that someone gets rabies from a wild animal over a family dog. Raccoons, opossums, foxes and rodents are commonly avoided specifically because of their ability to carry and infect people with rabies. Even though the US has only had 25 rabies cases in the last 10-15 years, Rabies has still managed to be brought up in media and day-to-day conversations.

Society has the understanding that rabies is scary but can be avoided pretty easily. Some countries still struggle with rabies infections, especially ones with large populations but a low GDP per capita, and a large stray dog population. Homeless street dogs in India, China and some parts of Africa live and reproduce in semi-urban areas, increasing the chances that someone gets bit by a rabid dog. Poorer areas might not have the money or infrastructure to vaccinate this constantly growing population, let alone effectively treat the people who are bitten. Volunteer efforts in these vulnerable areas have made great advancements in widespread rabies vaccination.]]> 2023-04-26 20:49:44 UTC https://padlet.com/rubybaldwin/m2u8ho9x8n5grc0/wish/2569352383