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Wednesday, July 31, 2013

Time Warps: Bubonic Plague


Image Source: Stan Honda / AFP / Getty Images via The National Post.

Last week, Californian campgrounds were closed when a squirrel tested positive for bubonic plague:
Campgrounds at a California national park have been closed after officials found a plague-infested squirrel. The squirrel was trapped earlier this month and found to be infected with the bacteria that causes plague — also known as the Black Death that is estimated to have wiped out up to 50% of the European population in the 14th and 15th centuries. The plague is caused by the bacterium Yersinia pestis, mostly found in rats and fleas that feed off them.
“Plague is a very serious illness, but is treatable with commonly available antibiotics. The earlier a patient seeks medical care and receives treatment that is appropriate for plague, the better their chances are of a full recovery, says the Center for Disease Control and Prevention on its website.
“It is important for the public to know that there have only been four cases of human plague in Los Angeles County residents since 1984, none of which were fatal,” said L.A. County health officer Dr. Jonathan Fielding in a statement.
The last urban plague epidemic in the United States occurred in Los Angeles in 1924-1925. In 2012, a Portland Oregon man contracted bubonic plague when he took a mouse out of his cat's mouth. HuffPo included photos of his afflicted limbs (caution - graphic images below the jump):
The welder's once-strong hands have been withered by the cell-killing infection and darkened to the color of charcoal. Doctors are waiting to see if they can save a portion of his fingers, but the outlook is grim for the man who needs them for his livelihood.
"I don't think I can do my job," Gaylord said in a phone interview from a Bend, Ore., hospital. "I'm going to lose all my fingers on both hands. I don't know about my thumbs. The toes – I might lose all them, too."
Gaylord, who turns 60 next month, contracted a rare case of the plague trying to take a mouse from the jaws of a choking cat at his home in Prineville, in rural Oregon.
He faces a difficult recovery now that he's out of intensive care. His family is trying to raise money to get him into a new house, because the manufactured home he was living in has a leaky roof, a moldy bathroom and mice – dangerous living conditions for a man with a weakened immune system.
"We didn't even know the plague was around anymore," said his sister, Diana Gaylord. "We thought that was an ancient, ancient disease."
The bacterium that causes the plague is carried by fleas, which can infect people and animals. The disease that killed millions in the Middle Ages is extremely rare in current times – an average of seven cases occur in the U.S. each year.
Gaylord's illness began after he saw a stray cat – who he'd named Charlie – with a dead mouse jammed in the back of his throat. The cat appeared to be choking, so Gaylord and a friend attempted to dislodge the mouse.
The friend also contracted the disease, but she was treated successfully before it progressed. In another 2012 case, a 7-year-old Colorado girl contracted the plague after burying a dead squirrel. Also in 2012, the FDA approved a new 2012 antibiotic, Levaquin, known generically as levofloxacin, and made by Johnson & Johnson, to treat the plague.

Modern recovery from bubonic plague can be rather more involved than Californian authorities suggested last week. Paul Gaylord contracted the disease in Oregon in 2012 and spent one month on life support. Gaylord later underwent extensive amputations. Image Source: HuffPo.

"This photo supplied by the Gaylord family taken July 11, 2012, at a hospital in Bend, Ore., shows the blackened hand of Paul Gaylord as he recovers from the plague." Image Source: HuffPo.

"This photo supplied by the Gaylord family taken July 6, 2012, at a hospital in Bend, Ore., shows Paul Gaylord as he recovers from the plague. ... The disease, a version of the medieval scourge that wiped out at least a third of Europe, took away the 59-year-old welder's fingertips, his toes and his ability to make a living. He faces an arduous recovery surrounded by constant reminders of his misery, the infected cat died, and the trailer he's living in has a mouse problem. Image Source: AP Photo / The Gaylord Family via HuffPo.

Also last year, researchers at McMaster University in Canada genetically mapped the bacterium Yersinia pestis in order to understand its evolution from medieval times to the present; their work presented results from a fascinating combination of genetics and archaeology:
When put up against modern medicine, the Black Death is really not all that dangerous.
“Based on what we know from this (genetic) sequence, would modern antibiotics work on this? Yes,” Poinar said.
The reason the Black Death was such an efficient killer was a combination of issues, including the environment and the health of those who contracted the pathogen, Poinar said.
The new findings build on earlier research the team conducted that identified Yersinia pestis as the bacterium responsible for the Black Death and for the deaths of approximately 2,000 people annually from the bubonic plague.
The researchers studied DNA from the remains of 109 skeletons, now more than 650 years old, that were buried beneath the Royal Mint in London, England, just outside the walls of the Tower of London.
Poinar and his team took bone and teeth samples to get ahold of whatever small bits of DNA they could find.
They then used what can be described as a magnetic fishing line to hook Yersinia pestis from the morass of viruses, bacteria and human genes.
The bits of DNA the team captured was then used to reconstruct the entire genetic string of the Black Death that stretches more than 4.6 million units.
That unique piece of technology — to fish for DNA — can now be used to study and reconstruct other ancient pathogens that turned into deadly killers, Poinar said.
“This technology will allow us to time travel and capture pathogens in the past, which was really (once) a pipe dream. We never thought this was possible,” Poinar said.
Poinar said the team was able to confirm that every modern version of the plague is a descendant of the original Black Death, meaning the pathogen has barely evolved in 660 years.

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