Manuel,have you ever heard of the bubonic plague? It was very popular around here are one time...
Posted on 01/15/2018 6:21:35 PM PST by nickcarraway
A provocative new study suggests that medieval plagues spread via fleas and lice on people.
Rats have long been blamed for spreading the parasites that transmitted plague throughout medieval Europe and Asia, killing millions of people. Now, a provocative new study has modeled these long-ago outbreaks and suggests that the maligned rodents may not be the culprits after all.
The study, published on Monday in the journal PNAS, instead points the finger at human parasites—such as fleas and body lice—for primarily spreading plague bacteria during the Second Pandemic, a series of devastating outbreaks that spanned from the 1300s to the early 1800s.
These outbreaks include the infamous Black Death, which wiped out a third of Europe’s population in the mid-1300s, amassing a body count in the tens of millions.
“The plague really transformed human history, so it’s really important to understand how it was spreading and why it was spreading so fast,” says lead study author Katharine Dean, a doctoral research fellow at the University of Oslo’s Centre for Ecological and Evolutionary Synthesis.
DEADLY BITE
When fleas infected with the bacterium Yersinia pestis bite humans, the bacteria can jump into the bloodstream and congregate in humans’ lymph nodes, which are found throughout the body. The infection causes lymph nodes to swell into ghastly “buboes,” the namesakes for bubonic plague. (Find out how plague bacteria evolved.)
In cases of plague since the late 1800s—including an outbreak in Madagascar in 2017—rats and other rodents helped spread the disease. If Y. pestis infects rats, the bacterium can pass to fleas that drink the rodents’ blood. When a plague-stricken rat dies, its parasites abandon the corpse and may go on to bite humans.
Because of rats’ role in modern plagues, as well as genetic evidence that medieval plague victims died of Y. pestis, many experts think that rats also spread plague during the Second Pandemic.
In 1986, archaeologists uncovered a mass grave in East Smithfield, London, used to bury victims of the Black Death in the 1340s. At the time, one observer said that 200 victims of the plague were being buried each day. PHOTOGRAPH BY MOLA/GETTY But some historians argue that the Black Death may have spread differently. For one, the Black Death tore through Europe far faster than any modern plague outbreaks. In addition, “rat falls” precede some modern outbreaks, but medieval plague records don’t mention rats dying en masse.
“Geneticists and modern historians were putting the rat into the position [of spreading the plague] and were straining bits of evidence,” says Samuel Cohn, a University of Glasgow medieval historian who has criticized the rat-flea theory.
As an alternative, some scholars have long toyed with the idea that fleas on humans spread the Black Death. If fleas and lice picked up the plague by biting an infected human, they could potentially hop onto a person in close quarters and transmit the disease.
Mathematically, the patterns in how disease moves through a population are different for the rat-flea and human-parasite modes of transmission. To put them to the test, Dean’s team modeled each with equations that simulated the rise and fall of an outbreak, based on how rats, fleas, and body lice would behave and spread plague.
“It’s basically bookkeeping—you see how people move [in the simulation],” says coauthor Boris Valentijn Schmid, a University of Oslo computational biologist and Dean’s Ph.D. adviser.
After running their models many times, Dean and Schmid statistically evaluated which models best matched mortality patterns from nine different European plague outbreaks from the Second Pandemic. To their surprise, they found that in seven of the nine cities they examined, the human-parasite model more closely fit mortality records than the rat-flea model.
“It’s a really cool piece of work,” says Charles “Chick” Macal, a systems scientist at Argonne National Laboratory who models the spread of diseases but wasn’t involved with this study. “It gets at the underlying question of why these outbreaks occur at all.”
Dean and Schmid say that there’s room to improve their models with more experimental data. They also acknowledge that their study is likely going to stir controversy among plague scholars, some of whom passionately argue that rats caused the medieval outbreaks.
“In plague, there’s a lot of hot debate,” says Dean, who sees herself and Schmid as more objective observers in this case. “We have no dogs in this fight.”
I blame the ‘Rats for imposing a substandard health care system on Medieval Europe.
I thought it has long been known that fleas were the cause...
I just blame the rats
I just blame the rats
Me, too.
No loyalty in fleas.
The rat dies and the fleas just jump ship....or jump rat in this case.
Manuel,have you ever heard of the bubonic plague? It was very popular around here are one time...
I never heard that anyone blamed rats
It was the fleas on the rats
This is new?
BTW just posted about how the Japanese during WW2 perfectec a bio warfare bomb capable of delivering millions of plague infected fleas- and planned to use it against California as soon as they got a long range delivery system- which was only months from happening before we put an end to the madness at Hiroshima and Nagasaki
The Japanese had tested their bio weapons on our POWs and Chinese to find the most lethal weapon ( plague) and delivery of plague by fleas -
The Japanese field tested their biowarfare- by seeding Chinese cities when they withdrew
The Chinese death toll from Japanese bio warfare was estimated at 250,000
So this research has been around for decades
Thanks History Channel “ Secrets of the Axis”
"The epidemic of cocoliztli from1545 to 1548 killed an estimated 5 million to 15 million people, or up to 80% of the native population of Mexico (Figure 1). In absolute and relative terms the 1545 epidemic was one of the worst demographic catastrophes in human history, approaching even the Black Death of bubonic plague, which killed approximately 25 million in western Europe from 1347 to 1351 or about 50% of the regional population. "
"The cocoliztli epidemic from 1576 to 1578 cocoliztli epidemic killed an additional 2 to 2.5 million people, or about 50% of the remaining native population."
I blame the demonRATS for about everything bad...I guess that includes the plague, no?
That was my understanding, too. Seems that this article says the fleas jumped person to person (or via crappy “bedding” and infested clothes) rather than traveling on rats. The fleas probably weren’t fussy about how they got around as long as a meal was waiting.
The bigger question is how or why the bacterium Yersinia pestis carried by the fleas turned so nasty.
Post to me or FReep mail to be on/off the Bring Out Your Dead ping list.
The purpose of the “Bring Out Your Dead” ping list (formerly the “Ebola” ping list) is very early warning of emerging pandemics, as such it has a high false positive rate.
So far the false positive rate is 100%.
At some point we may well have a high mortality pandemic, and likely as not the “Bring Out Your Dead” threads will miss the beginning entirely.
*sigh* Such is life, and death...
It was basically all manner of filth that people lived in back then. Both the rats and the fleas were a part of it, but it IS significant that large numbers of villagers stopped dying when merchant ships that traveled from coastal town to coastal town doing business started carrying cats that then killed the rats and halted the spread of the plague.
In September 1970, in Vietnam, I was scheduled to go on R&R. One of the items that you had to do for R&R was to get your immunizations updated. So I went with 2 of my buddies to the Vungtau Air Base and we reported to the medical facility there.
A few days later all 3 of us had bubonic plague and were hospitalized. I spent 24 days in the hospital on antibiotics (streptomycin) and went from 185 pounds to 115 pounds. They eventually figured out that the plague vaccine was defective and virulent.
So, on matters of bubonic plague, I have first hand knowledge.
Ping!
The interesting thing is that back in the 1300s, there were many areas of Europe hit hard by the plague where there were no rats. They hadn’t extended their range that far at the time.
So you are saying Pelosi was somewhere nearby?
Rats are to blame for a lot of black deaths.
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