7 wonders of the microbe world - black death (2/7)

1683 invention of microscope allowed discovery of microbes by a dutchman

in 14th century black death microbe became deadly

thrives at a person's healthy temperature

the microbe invades fleas, rats, cats, dogs, farm animals and humans

fleas spread it (microbe blocks flea's stomach so the flea needs to feed) so when it does feed on a hosts blood it regurgitates the microbes into the hosts bloodstream

immune systems launches white blood cells to defend the host but the microbe multiplies within them and kills the white blood cells

microbe then floods out stronger than before so it can overcome white blood cells

symptoms start as a sneeze or like flu

but then painful black lesions on skin in joints - exude pus - and the host dies a slow excruciating death over several days

14th century outbreak started in mongolia 1330 and spread along trade routes

in 4 years - 1347 to 1351 microbe killed around 75m people worldwide (including 1/3rd of the entire population of europe)

reached england summer 1348 - between then and 1350 around 40% of the english population died from the black death

some say english reformation was caused by black death because at the time of the plague the religious leaders couldn't explain how or why the disease spread

and of course the nursery song "ring oh ring of roses" has its background in the symptoms of black death and the practice of carrying pouches of sweet smelling  herbs to ward it off