Good-to-have mutant gene

There I was believing all I was led to believe about the Black Death and the Bubonic Plague being one and the same thing, and it turns out that it may not have been the case at all. The spread of the Black Death was just too fast - and present in too many climates unfriendly to the black rat carrying those nasty fleas - for it to have been the plague.

Scientists now think that it was a combination of both the Bubonic Plague and something else - probably a viral haemorrhagic fever, something like today's ebola virus, quite possibly small pox in fact - that wiped out a staggering third (25 million people) of Europe's population in just four years (1348 to 1352).

The spread of the disease was about 2 miles a day - in other words, the distance a person could walk. Now, taking into consideration how far you can travel today in just 24 hours and you can understand why health ministries from Vietnam to Canada implemented such strict measures during the SARS alert.

But that is not the most interesting thing about the whole Black Death/Bubonic Plague story. A most extraordinary thing happened in a small town in England's Peak District, a mining community called Eyam. After it was virtually cut off from the rest of the region, most would have expected all the inhabitants to have been wiped out. However, a year later it was discovered that half had survived, and 700 years later scientists are beginning to understand why.

It seems that they had developed a mutant gene - CCR5 Delta 32. In fact of the surviving populations in Europe, about 14% had the gene. This compares to about 0-2% of African and Asian populations with the gene - because they had never had the Black Death in their communities.

And even more amazing is that those with the mutant gene are also almost always immune to the HIV virus. No wonder AIDS is so virulent among African and Asian populations.

The report here gives more of the story and so does this one .