The real good
news is that we are disposing of the mystery.
We know exactly what to be on guard for and that makes defense possible
and quite practical. I suspect that
global pandemics of any kind are becoming progressively more difficult because
our huge interconnectivity has shared disease resistance globally. Even then we have the tools to hit them
immediately and we have stopped nasties a number of times already.
If we have a
problem it is minority problems popping up and causing issues until it is
controlled. AIDs is a pretty good
example of a disease that prospered only because of air travel. A century ago it would have simply died out
locally
Our explosion in
medical knowledge also assures us that we have many tools to stop such a
disease factor.
Scientists
decode 1,500-year-old plague and warn it could strike again
Scientists have, for the first time, achieved a
complete reconstruction of the genome responsible for the bubonic plague, which
struck the Eastern Roman Empire 1,500 years ago, and is said to have been
responsible for between 25-50 million deaths worldwide. The new study published in the journal Lancet Infectious
Diseases, revealed that the pathogen is linked with the ‘Black Death’ pandemic
that killed 50 million people in medieval Europe 800 years later, and warned
that it could strike again.
Scientists have previously analysed DNA samples
taken from plague victims to determine that the bubonic plague, otherwise known
as the ‘Plague of Justinian’, was likely caused by the bacterium Yersinia
pestis. In the new study, researchers built on this previous work and
sampled DNA from the teeth of two 1,500-year-old plague victims in Bavaria.
With those fragments, they reconstructed the genome of the oldest bacteria
known. They confirmed that the Justinian plague was indeed caused by a strain
of Yersinia pestis, and that this is the same pathogen responsible for the
Black Death that struck medieval Europe.
"This is the first complete genome from one of
the most significant disease events in human history," said Professor
Edward Holmes, from the University of Sydney.
The Justinian Plague, which occurred in the sixth
century AD, was one of the first recorded plague pandemics in the world. Named
after the Byzantine emperor Justinian I, the outbreak was nearly worldwide in
its scope, striking central and south Asia; north Africa and Arabia, and Europe
all the way to Denmark and Ireland. It is believed that the pandemic originated
from Asia and then spread to Europe along trade routes such as the Silk Road.
Holmes said one of their objectives of the study was
to determine why the Justinian plague was so severe. "Was there something
about the genome of these ancient pathogens that made them especially virulent,
or was it the way that people lived in the past, conditions were not so good,
general health wasn't as good, that made them die in higher numbers?" He
added that there were some hints of gene mutations affecting virulence in the
Justinian plague but said more research was required to confirm any specific
mechanisms.
However, the results of the study did show that the
strains of Yersinia pestis from the plague victims were distinct from those
involved in the Black Death, the later pandemic which killed an estimated 60%
of the European population. According to Associate professor Jeremy Austin,
from the Australian Centre for Ancient DNA, this suggests that “catastrophic
diseases aren't things that evolve once, and then lurk around waiting for an
opportunity to reappear – they actually evolve multiple times from different
ancestors,"
"What this shows is that the plague jumped into
humans on several different occasions and has gone on a rampage," said Tom
Gilbert, a professor at the Natural History Museum of Denmark who wrote an
accompanying commentary. "That shows the jump is not that difficult to
make and wasn't a wild fluke."
Researchers have warned that this means another
outbreak could occur. “If the Justinian plague could erupt in the human
population, cause a massive pandemic, and then die out, it suggest it could
happen again,” said Dave Wagner, professor in the Centre for Microbial Genetics
and Genomics at Northern Arizona University.
However, Hendrik Poinar, director of the Ancient DNA
Centre at McMaster University in Canada, who led the new research, believes
that it is unlikely a modern plague epidemic would be so devastating. “Plague
is something that will continue to happen but modern-day antibiotics should be
able to stop it," he said. The real danger would be if the plague
manages to transform into an airborne version. According to Poinar, this would
be much harder to snuff out.
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