A Bank Holiday visit to Eyam in Derbyshire started the thinking towards this post.
Eyam, in 1665, became a place afflicted by the plague, after some infected cloth arrived from London, which at the time was in the grip of what has been called the Great Plague.
The village went into quarantine, so that it would not spread. I was about to say I wondered how they knew this would help, but I imagine it is self evident - if no one comes into contact with you, and nothing from your village reaches anyone else, no one else will catch it, and you would not need to have modern knowledge of its causes to be confident about this.
Here are some things about the plague, either that of the 17th century, or the Black Death.
Harvard University Library Open Collections Program, about epidemics.
National Archives, for Key Stage 3 school students, including some primary sources.
A PubMed search found an article about possibly the last outbreak in the UK, in east Suffolk between 1906 and 1918.
And the title of this post? Well, it's the nursery rhyme, about the plague. Or is it? See this Library of Congress blogpost for a discussion.