Within a year of his arrival, in 1873, sheep in the area began to die.
Worse, local farmers and sheep shearers began to sicken. The malady was
all too familiar to the denizens of the area: woolsorters disease (also
known as anthrax). Herbivores (e.g., cattle, sheep, horses, goats, antelopes)
are most commonly affected, but humans are at risk if exposed to the
tissues of affected animals. When sheep and cattle are infected, the
clinical course is characterized by sudden onset and a rapidly fatal course,
with staggering, dyspnea (labored breathing), trembling, collapse, and
even convulsions.^33 Occasionally, bloody discharges from body openings
(mouth, nose, anus) occur; in humans, skin lesions with ghastly
ulcerations and necrotic, blackened skin lesions often develop. Since
ancient times, anthrax had been interpreted as a type of celestial judgment
or biblical plague, so great and unexplainable was the terror.
As the outbreak spread to humans that summer of 1874, Koch started to
see an influx of patients in his Wöllstein house, likely using folk remedies
to care for the scabbed, swollen, and carbuncled victims. Ever the
scientist, Koch would collect blood and fluid from his affected patients. In
his makeshift lab on the first floor, he would examine his test subjects’
samples under his microscope and record his findings in his personal
research notebooks. On April 12, 1874, he used the term “bacteria,”
(following the lead of German zoologist Christian Gottfried Ehrenberg),
when he recorded in his notebook, “The bacteria swell up, become shinier,
thicker, and much longer.”^34 Koch’s observations mirrored what a few
researchers had seen in the years before, but no scientist had ever taken the
next step to evaluate if those bacteria, resembling grains of rice lined up
end-to-end, were the cause of anthrax.
Eighteen months later, a few days before Christmas 1875, a local
constable in Wöllstein appeared one evening at Koch’s home, likely
mounted on horse-drawn wagon, with a carcass of a dead animal whose
blood was dark and thick. Terrified that the lifeless beast would resurrect
the anthrax plague, the police officer brought the remains to the one
person in town who might know what to do next.
Robert Koch surveyed the animal, and immediately knew that his
microscope was his best analytical tool. Koch had a hunch the beast was
suffering from anthrax, and eagerly extracted blood from the dead animal
and inspected it under his microscope. The bearded and bespectacled
thirty-two-year-old was delighted to see his slide suffused with the same