Transcript Powerpoint for Lecture, 17 Nov.

‘Filth Diseases’
The term ‘Filth Diseases’
• We are used to thinking of infectious disease causing great human
suffering, but there are some diseases that actually seem to thrive in
conditions of filth and misery
• The term ‘filth diseases’ has its origins in the 19th century when some
physicians believed that filth itself was the cause of diseases
• Although the discovery of microbes in the late 19th century displaced
the ‘filth theory’ of diseases, it is still a useful term to identify some
infectious diseases that lead to epidemics and pandemic
• Seen in historical perspective, diseases like typhus and cholera thrive
in conditions where human suffering is already at high point
Typhus (Rickettsia prowazekii)
• Rickettsia prowazekii is a bacterium that
causes the epidemic typhus
• Its main vector is human body lice; they
become infected when they feed off an
infected person; they then pass on the
infection to other humans through their
excrement which makes its way into the
human body through their bite mark or
some other opening in the skin
• In most of the world humans are the
reservoir of the bacterium
• The pathogen probably originated in early
civilizations, making the jump from animals
to humans
• Although it has been around for a long
time, it is not really recoded much before
the 15th century, likely because its
symptoms (a high fever accompanied by a
rash) can be confused with other diseases
• Untreated, it can have a morbidity rate of
up to 60 per cent of adult victims
• Sufferers can be asymptomatic but still be
able to infect lice
Body louse with ingested blood meal
The name typus
• The term typhus was coined in the sixteenth century and was taken
from the Greek word τύφος – meaning smoky or hazy – which reflects
one of the main symptoms of the infection as it attacks the brain and
causes delirium
• The name reflects the humanist interest of sixteenth century
physicians who read Greek
• This also reflects the way in which diseases are socially constructed –
until they have a name and some sort of epidemiology, they do not
really get noticed, even though their existence on a biological level is
ancient
First recorded epidemic in 1489
• The first recorded epidemic of typhus
occurred as a Spanish Army of 25,000 was
laying siege to the Muslim stronghold of
Granada
• Sources cite the figure of 17,000 soldiers
succumbing to the disease
• Historians argue that the pathogen reached
Spain with Spanish soldiers returning from
the Crusades
• From Spain the pathogen was transmitted
to Italy with Spanish mercenary soldiers
Siege of Naples 1528
• In 1528 a French army of about 28,000 was
facing a much smaller Imperial army for
control of Italy
• Despite the greater strength of the French
army, and outbreak of typhus devastated
French forces, causing them to retreat
• This was a significant victory from Charles V
of Spain who was able to secure the title of
Holy Roman Empire
The Thirty Years War (1618-1648)
• The Thirty Years’ War originated as a conflict between Catholic and
Protestant states in Germany, but eventually grew through alliances
to encompass all the great powers of Europe
• The campaigns of this war are noted for their brutality, intensity, and
for the suffering that warfare wrought on the civilian population
• The greatest killer in these campaigns, especially before 1630, was
typhus, which took millions of victims, soldiers and civilians alike
• Many more people died as a result of disease than the actual battles,
which raised the intensity of the stuggle
Napoleon’s invasion of Russia 1812
• Although medical knowledge about typhus had increased by the 19th
century, it had a devastating effect on Napoleon’s 600,000 man
invasion force of Russia
• Despite being warned by his medical advisors that his soldiers could
not withstand the Russian winter, Napoleon went ahead
• It is estimated that nearly half of his invading army was killed by
typhus; starving through the Russian winter his soldiers descended
upon the peasants in the countryside … likely this is where they
encountered typhus which spread so quickly throughout his army
Typhus and warfare
• As these examples show, warfare created the perfect breeding ground
for typhus
• Because soldiers interact with the local civilians, and often seize their
dwellings and goods, it increases their contact with infected lice
• The cramped conditions, lack of food, sanitation, and generally dirty
conditions make it a good breeding ground for lice
• Because body lice were so common in the pre-modern period, people
would have seen them as a nuisance, but would not have identified
lice as a disease vector and would have seen them as relatively
harmless
Cholera
• Like typhoid fever, cholera also comes from
infected water supply contaminated by feces
containing the bacterium
• It originated in the Indian subcontinent
centuries ago, and only started to spread widely
into the rest of the world as a result of trade
and empire starting in the seventeenth century
• Since 1800 there have been seven cholera
pandemics across the world, and has been
responsible for millions of deaths across the
globe
Typhoid fever
• The infectious disease typhus must not be confused with the separate
infection typhoid fever
• Although they have similar names, they have little in common, except
for the fact that they both cause abdominal pain and fever
• The pathogen causing it, Salmonella typhi, comes from contaminated
food or water, and also can come from unwashed hands, thus a
completely different vector
• Another similarity is that a person can carry the the pathogen and
pass it on
The case of “Typhoid Mary”
• The case of so-called “Typhoid Mary” is an instructive one for our
study of disease because it shows the intersection of infectious
disease, medical knowledge, public health precautions and the
ramifications of enforcing public health measures
• As you watch the documentary, think about how the issues raised by
this case might have worked out in different parts of the world, with
different infectious diseases, at different times
• Also, the issues raised in the documentary will also set up the topic
for next week’s lecture on the advances that have been made by
modern science against infectious diseases