The Mid-Fourteenth century was a dark time as the 1348 Black Death struck England. It would claim a third of the entire population within a few months.
Carried by the fleas living on black rats the disease induced a painful and unpleasant death. The fleas bit the rats to live of their blood, they then bit humans and carried the disease.
The Government did react, the King ordered the Mayor of London to clear the streets of waste and dung. This was only a reactive, temporary measure. The problem resurfaced once the plague had gone. The country was hit many times by epidemics of plague, but none more serious that the Black Death of 1348.