> http://www.bbc.co.uk/worldservice/sci_tech/highlights/011025_ccr5.shtml
The main theme of that BBC story is: "New research suggests that Europeans have inherited a resistance to Aids because of the devastating effects of the bubonic plague", i.e "Stephen O'Brien from the US National Cancer Institute has discovered that a mutant form of one particular gene, called CCR5, confers protection against HIV."
However, another BBC story says that the Black Death may actually have been an Ebola/Marburg-type disease (i.e. a virus passed by human contact) rather than bubonic plague (i.e. bacteria spread by rats)
"Sue Scott, co-author of the book Biology Of Plagues, was studying records of the outbreak in Penrith, a small town in the north of England, when she began to wonder if the plague theory was mistaken. She explains why she thinks the rats and its bacterium might not have been the cause after all: 'In order to have bubonic plague you've got to have appropriate rats and at that time the only rats that were around were black rats . [they] tend to live in areas of human habitation, they tend to be around sea ports and temperate zones.' 'The only rat that could transmit it up to Penrith would be the brown rat and that didn't appear in this country until 50 years after the plagues disappeared.' Infectious Disease Since Scott and her co-author, Chris Duncan, believe that a bacterium was not responsible they looked for the real culprit using a combination of epidemiological, molecular biology and computer modeling. They took advantage of the fact that all deaths caused by the plagues had to be recorded in the parish register. Scott explains: 'We looked at the spread through families (because with parish registers they record the burials) and you can put them together as families and see how it spread from person to person, within each household. By doing that we were able to see that it was characteristically a disease spread person to person, it was an infectious disease.' 'You don't have to think in terms of rats and fleas, you think in terms of an infectious disease.' Old Disease, Modern Methods By placing the disease in geographical, historical and demographic frameworks, the authors present a new interpretation. Using modern methods to identify an old disease, they then tried to match The Black Death up with a modern equivalent. They conclude that the closest thing today would be the Ebola and Marburg viruses. These virulent strains are called filo viruses and are the most infectious and lethal viruses known today. The authors have also looked to the demise of the disease to find a solution to today's epidemics and in doing so have made comparisons to the HIV virus. Believing that The Black Death died out because people became resistant to it, Scott cites the partial or complete immunity to the HIV virus identified in people with a mutation of the virus called the CCR-5- Delta-32 mutation. In the authors view this same mutation may have been responsible for the protection of people against ancient viruses such as The Black Death.
http://www.bbc.co.uk/worldservice/sci_tech/highlights/010801_blackdeath.shtml