I have always felt that the Black Death in Europe was from something significantly different from the Bubonic Plague as we know it now, if just because the speed of the spread was astonishingly fast (something more than 20 miles a day in Britain).

Well, a study now indicates that it was likely a variant of Yersinia pestis that was genetically predisposed to go pneumonic, meaning that the transmission would have been far faster than the flea borne variants that we see today:

It was already known as perhaps the bleakest episode in British history.

Now, new research suggests the Black Death was even more lethal than was previously thought.

The findings go further to exonerate rats as being responsible for the outbreak, which swept the country in the middle of the fourteenth century, killing vast swathes of the population.

Instead, the study claims the disease was passed directly from human to human and was, in fact, pneumonic plague – a more virulent and infectious form than bubonic plague, which has historically been blamed.

………

The same bacteria – which is almost identical to the strain still found on four continents – is responsible for both bubonic and pneumonic plague, but the experts taking part in the show concluded that the latter, which is spread by the fleas of infected rats, would not have been able to have the devastating impact caused by the Black Death.

Dr Tim Brooks, an expert in infectious diseases from Public Health England who is based at Porton Down – the Wiltshire site used by the government for dealing with biological threats – said: “As an explanation, for the Black Death in its own right, it is simply not good enough. It cannot spread fast enough from one household to the next, to cause the huge number of cases that we saw during the Black Death epidemics.”

Instead, he identified what he considers was a mutation from the bubonic plague, borne on rats, to the pneumonic variant, whereby it spread to the lungs of sufferers, who then passed it on to others, by coughing.

This makes sense, though there are alternate ways for it to spread so quickly, such as it being carried by bird borne parasites.

It is almost certain that it was Y. pestis though.