BSS194
Life kills life
JAKUB DRMOLA
31. 3. 2020


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Historical cases
 - mostly flu, smallpox, cholera and plague
 - ancient pandemics
◦166 – smallpox, thousands of Romans dying daily
◦250 -  flu, half the population dead in some places, Roman Empire nearly collapsed
◦541 – “Justinian plague” across Mediterranean,                  up to 100 million dead and 50%
mortality
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 There were many more, but the ones in Mediterranean are best documented.

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Plague
 - bacteria Yersinia pestis
 - often spread by fleas, sometimes through air
 - 3 variants by progression:
◦1) bubonic plague (through lymphatic nodes, swelling)
◦2) septicemic plague (through blood, leads to surface necrosis)
◦3) pneumonic plague (lung infection, highest mortality)
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 - it still exists

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Black Death
 - plague
 - brought by Tartars through Crimea in 1347
 - 100-300 million dead
 - approx. half of Europe died out
 - corpses piled up in streets with no one to bury them
 - societal collapse, labor shortage


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America
 -  Aztec empire (pop. of 25 million)
◦Spaniards arrived 1517
◦1520 – smallpox and drought, 8 million dead
◦1521 – conquest complete
◦1545 – cocoliztli (typhoid fever), 14 million dead
 - Inca Empire (pop. of 17 million)
◦1520s – smallpox arrived (up to 50% died)
◦1526 – first contact with Spaniards
◦1532 – conquest mostly complete
 50-90% of Native Americans killed by infections…
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Spanish flu
•1918-1919
•global population 1.75 bil.
•WW1: 15-20 mil. dead
•WW2: 20-50 mil. dead
•Spanish Flu: 50-100 mil. dead
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•up to 20% mortality of deadly second wave
•(post)WW1 had perfect conditions
•


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Smallpox

 - vaccine in 1796
 - campaigns since 19th cent.
 - 2 million deaths per year in 20th century
 - eradicated in 1977
 - samples retained
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Intentional use?
 - during sieges
 - Native Americans
◦the infamous blankets…
 - 20th century
◦use against animals
◦use in China
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 - some terrorism attempts
 - quite ineffective and hard to control

Ongoing pandemics
 Malaria
◦0.5-1 million deaths per year
◦sickle red blood cells adaptation

 HIV
◦1 million deaths per year (via AIDS)
◦zoonosis from SIV

 - both are devastating for societies

Recent pandemic scares
 - SARS (2003) – 1000 dead, zoonis from bats
 - H1N1 “swine” flu (2009) – 100 000 dead
 - zika (2015-2016) - microcephaly
 - seasonal flus – 3-500 000 dead
 - Ebola – avg. 50% mortality, 12 000 dead during the 2013-2016 outbreak

Causes and complications

 - large concentrated populations
 - fast travel between populations
 - living in proximity with animals

Adaptation

 - Sewall Wright
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Antibiotic resistance
 https://www.youtube.com/watch?v=yybsSqcB7mE

 - antibiotic misuse and overuse
 - deaths probably already in millions, will get worse

 - bacteriophages as solution?

Zombies?
 - cordyceps
◦fungi spores
◦arthropod parasites (insects, arachnids, etc.)
 - horsehair worms
◦silent, thirsty crickets
 - rabies
◦change in behavior
 - toxoplasmosis
◦around 1/3 of humans
◦risky behavior?
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COVID-19
 - zoonotic coronavirus, possibly from pangolins
 - mortality very difficult to estimate
◦lack of testing
◦extremely sensitive to general healthiness

 - “flattening the curve”
 - prognosis unclear, too early to tell