The graph, not shown during the lecture, shows that the port city of Liverpool experienced a death rate much higher than usual from 1846 to 1849 during the Irish potato famine. In 1849 5,308 deaths were attributed to cholera.
Lack of familiarity with the disease engendered dread, especially because of its rapid and painful development.
The progress of the illness in a cholera victim was a frightening spectacle: two or three died of diarrhoea which increased in intensity and became accompanied by painful retching; thirst and dehydration; sever pain in the limbs, stomach, and abdominal muscles; a change skin hue to a sort of bluish-grey. http://www.victorianweb.org/science/health/health10.html
Liverpool's economy depended on trade and so was vulnerable to health threats from outside brought in by travelers.
Sarah Hutton presented two case studies of how local communities reacted to such external health threats, often in a manner disproportionate to the nature of the threat.
The presentation should eventually be available as a podcast, if the persistent coughing of one audience member isn't too distracting.