By Gorbachev's time, the farm population had shrunk to a quarter of its former size; only older workers remained, working perfunctorily on state land or tending their private plots.

As the population soared, more and more forest was cut down to increase farm and grazing land.

And Britain's population of wild deer—bigger now than it has been for hundreds of years—would provide a reservoir of infected blood even if all the diseased farm animals were killed off.