Horrifying simulation shows how doctor let mosquito kill him to eventually prove they carried disease

A simulation has highlighted the effective but extreme work of a physician who died back in 1900.

We know quite a lot about the dangers of diseases and infections today, but if you rolled the clock back by a century or more, you'd likely find that humanity was in much more of a pickle when it comes to understanding health.

Unfortunately, millions of people have had to suffer and perish as we figured out the cause of certain sicknesses - take the plague as an example, with millions dying over the course of centuries, though it still lingers today.

But a more recent issue faced humanity in the early 20th century.

For hundreds of years, yellow fever affected travellers and caused tens of thousands of deaths across the world.

Jesse William Lazear was one of the most influential figures in finding a vaccine for yellow fever (The Print Collector/Print Collector/Getty Images)

A number of medical experts fought and suffered to formulate cures and vaccinations for our species to go on, and one of these brave doctors was named Jesse William Lazear.

The American was determined to find a cure for yellow fever, having studied the disease as part of the Yellow Fever Board for the army with a number of other physicians in Walter Reed, James Carroll and Aristides Agramonte.

A resident at John Hopkins Hospital, he focused on malaria and yellow fever in particular and moved to Columbia Barracks as an assistant surgeon at Columbia Barracks in Cuba for the US Army back in 1900.

After months at the camp, he scientifically confirmed the 1881 hypothesis first brought up by Cuban researcher Carlos Finlay, which stated that mosquitoes transmitted the horrid disease.

Yellow fever would result in symptoms such as chills, headache, a fever, nausea and vomiting, before a 'toxic' phase, which is less common nowadays.

This could be identified through jaundice, dark urine, and liver and kidney problems - people could die as a result.

Lazear, the only member of the commission who had worked with mosquitoes before, used the insect's larvae to come to his conclusion, even writing to his wife in September 1900 that he thought he was 'on the track of the real germ'.

While his claims were true, it turned out that the doctor had actually purposely allowed an infected mosquito to bite him so he could study the disease, first-hand.

He contracted the disease and would pass away at 34 on 25 September, 1900, just over two weeks after penning the letter to his wife.

A simulation from none other than Zack D. Films has now depicted the doctor's experience after being bit, as he started to experience a fever and yellow eyes within a week of being bitten.

It's even claimed that the medical professional started to vomit black sludge as a result of being bitten by the mosquito.

But as one of the symptoms known in the 'toxic phase' of yellow fever, his organs started to shut down and Lazear would be dead just weeks after choosing himself as the test subject of the mosquito bite, proving the hypothesis right.

The visualisation of the doctor's symptoms are chilling (YouTube/Zack D. Films)

However, people wouldn't know that this was a deliberate act at the time, as he covered it up for unknown reasons.

It was said at the time that Lazear thought the mosquito was uninfected, but physician Phillip S. Hench would discover via Lazear's notebook in 1947 that the move was intentional in a move to better understand the condition.

Luckily, his death wasn't in vein as the modern Yellow Fever 17D vaccine was developed in 1937 by Max Theiler.

It used a weakened virus strain which was highly effective, providing lifelong protention and preventing the disease in individuals.