John Snow
Who was John Snow?
John Snow was born on the 15th of March
in 1813. He was an English physician, and
one of the first to adopt the anaesthesia
and medical hygiene. (We will come to this
later on) He was born in York, and the first
of nine children. John lived in one of the
poorest neighbourhoods in the city, and
which was always in danger of flooding.
This was because they lived nearby the
river Ouse.
His career
John studied also in York, until his 14th. At
this age he was allowed to learn with, and
learn from William Hardcastle. William
was a surgeon, and a physician. He also
was a family friend of the Snow’s. Later
on, Snow became an assistant in practice,
at different locations.
He began working at the Westminster
Hospital, and in December 1844,
he graduated from the University of
London. In 1857 he made a contribution to
epidemiology in a little-known pamphlet
“On the adulteration of bread as a cause
of rickets.”
Anaesthesia
John Snow was one of the first physicians
(he graduated and became member of the
Royal College of Physicians in 1850) to
study on, and calculate dosages for the
use of ether and chloroform. This could be
used as anaesthetics, which would make
surgery easier because the patients are in
less pain. Without this they would
experience a massive pain.
John Snow personally gave
this medicine to Queen
Victoria when she gave birth
to the last two of her nine
children.
This also lead to a wider acceptance of the
public about this medicine. And of course
he also published an article about this
explorations.
Cholera
John didn’t believe that cholera was
caused through means of “bad air”.
Because the germ theory of disease didn’t
exist yet, Snow couldn’t understand the
mechanism by which diseases were
transmitted. But by his observations he
discovered that all people, who used the
water pump on Broad Street (now
Broadwick Street) became ill.
At first he couldn’t convince anybody of
his findings, but as soon as he came with
evidence to show how the disease was
caused, he was convincing enough to
persuade the local council. They
immediately disabled the pump by
removing its handle.
Cholera
What is Cholera?
Cholera is an infection. An infection in the
small intestine caused by bacteria. In some
cases the illness could be deadly, in the
16th century it was in the most cases
deadly. John Snow was one of the first to
discover how cholera actually spread itself,
through water.
Signs/symptoms
 Diarrhoea
 Vomiting
These symptoms occur usually after one to
five days. Of course after ingestion of the
actual bacteria. Cholera is also called the
“blue death” this because the skin turning
blue/grey due to the extreme loss of fluids
(trough diarrhoea and vomiting)
If the diarrhoea is not severe treated, it
can result in life-threatening dehydration.
Symptoms for dehydration are:
 Low blood pressure
 Wrinkled skin
 Sunken eyes
 A rapid pulse
Cause
Well, transmission is through eating
infected food, or drinking infected water.
Due to poor sanitation, the water will be
infected soon. But the bacteria itself can
live in any natural environment.
In our developed world, seafood is the
most common cause. Well in the
developing worlds the most common
cause is water.
Prevention
If strict sanitation practices are followed
there won’t be such a big chance of the
water/food getting infected with the
cholera bacteria. But luckily cholera is no
longer a major health threat. Effective
sanitation practices are often enough to
stop an epidemic.
Vaccine
There are a number of safe vaccines
available, however it is not recommended
by the CDC (Center for Disease Control and
Prevention). Because the protective
efficiency became lower over the years,
but they are still working on a better
vaccine to prevent cholera.
Treatment
Continuously eating speeds up the
recovery. This is actually a generally
recommendation for any cases of
diarrhoea .