Around 1900, historians spread the idea that the plagues of Europe were not a directly infectious disease but were outbreaks of bubonic plague, overturning an accepted belief that had stood for 550 years. Professor Duncan and Dr Scott illustrated in their book, Return of the Black Death (2004, Wiley), that this idea was incorrect and the plagues of Europe (1347-1660) were in fact a continuing series of epidemics of a lethal, viral, haemorrhagic fever that used the CCR5 as an entry port into the immune system. Using computer modeling, they demonstrated how this disease provided the selection pressure that forced up the frequency of the mutation from 1 in 20,000 at the time of the Black Death to values today of 1 in 10.
Lethal, viral haemorrhagic fevers were recorded in the Nile valley from 1500 BC and were followed by the plagues of Mesopotamia (700-450BC), the plague of Athens (430BC), the plague of Justinian (AD541-700) and the plagues of the early Islamic empire (AD627-744). These continuing epidemics slowly raised the frequency from the original single mutation to about 1 in 20,000 in the 14th century simply by conferring protection from an otherwise certain death.
Professor Duncan added: “Haemorrhagic plague did not disappear after the Great Plague of London in 1665-66 but continued in Sweden, Copenhagen, Russia, Poland and Hungary until 1800. This maintenance of haemorrhagic plague provided continuing selection pressure on the CCR5-Ä32 mutation and explains why it occurs today at its highest frequency in Scandinavia and Russia.”
From a UL press release.