The pair found exactly the same pattern in 17th-century outbreaks in Florence, Milan and a dozen towns across England, including London, Colchester, Newcastle, Manchester and Eyam in Derbyshire. In , the inhabitants of Eyam selflessly confined themselves to the village. A third of them died, but they kept the disease from reaching other towns. This would not have worked if the carriers were rats.
Despite the force of their argument, Scott and Duncan have yet to convince their colleagues. None of the experts that New Scientist spoke to had read their book, and a summary of its ideas provoked reactions that range from polite interest to outright dismissal. Human fleas can keep it in their guts for a few weeks, leading to a delay in spread.
But this would be unlikely to have happened the same way every time. Moreover, people with enough Yersinia in their blood for a flea to pick it up are already very sick. They would only be able to pass their infection on in this way for a very short time-and whoever the flea bit would also sicken within a week, the incubation time of Yersinia. This does not fit the pattern documented by Scott and Duncan.
Neither would an extra-virulent Yersinia, which would still depend on rats. There have been several other ingenious attempts to save the Yersinia theory as inconsistencies have emerged. Many fall back on pneumonic plague, a variant form of Yersinia infection. This can occur in the later stages of bubonic plague, when the bacteria sometimes proliferate in the lungs and can be coughed out, and inhaled by people nearby. Untreated pneumonic plague is invariably fatal and can spread directly from person to person.
Yet the Black Death typically jumped between towns in the time a healthy human took to travel. Also, pneumonic plague kills quickly-within six days, usually less. With such a short infectious period, local outbreaks of pneumonic plague end much sooner than 8 or 9 months, notes Scott.
Rats and fleas can restart them, but then the disease is back to spreading slowly and sporadically like flea-borne diseases. Possibly-and ominously-it may have been a virus. The evidence comes from a mutant protein on the surface of certain white blood cells. The protein, CCR5, normally acts as a receptor for the immune signalling molecules called chemokines, which help control inflammation. From its pattern of occurrence in the population, they think it arose in north-eastern Europe some years ago-and around years ago, something happened to boost its incidence from 1 in 40, Europeans to 1 in 5.
The only plausible explanation, he thinks, is that the mutation helped its carriers survive the Black Death. Someone exposed to Yersinia pestis through the air—either from an intentional aerosol release or from close and direct exposure to someone with plague pneumonia—would become ill within 1 to 6 days. Can pneumonic plague be treated? To prevent a high risk of death, antibiotics should be given within 24 hours of the first symptoms.
Several types of antibiotics are effective for curing the disease and for preventing it. Available oral medications are a tetracycline such as doxycycline or a fluoroquinolone such as ciprofloxacin. For injection or intravenous use, streptomycin or gentamicin antibiotics are used. Early in the response to a bioterrorism attack, these drugs would be tested to determine which is most effective against the particular weapon that was used. Would enough medication be available in the event of a bioterrorism attack involving pneumonic plague?
National and state public health officials have large supplies of drugs needed in the event of a bioterrorism attack. These supplies can be sent anywhere in the United States within 12 hours. What should someone do if they suspect they or others have been exposed to plague?
Get immediate medical attention: To prevent illness, a person who has been exposed to pneumonic plague must receive antibiotic treatment without delay. If an exposed person becomes ill, antibiotics must be administered within 24 hours of their first symptoms to reduce the risk of death.
Notify authorities: Immediately notify local or state health departments so they can begin to investigate and control the problem right away.
How can the general public reduce the risk of getting pneumonic plague from another person or giving it to someone else?
If possible, avoid close contact with other people. People having direct and close contact with someone with pneumonic plague should wear tightly fitting disposable surgical masks. If surgical masks are not available, even makeshift face coverings made of layers of cloth may be helpful in an emergency.
People who have been exposed to a contagious person can be protected from developing plague by receiving prompt antibiotic treatment. How is plague diagnosed? Difference Between Similar Terms and Objects. MLA 8 Mukarjee, Sagarika. Name required. Email required. Please note: comment moderation is enabled and may delay your comment. There is no need to resubmit your comment. Notify me of followup comments via e-mail. Written by : Sagarika Mukarjee. Duncan Biology of Plagues: Evidence from Historical Populations.
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Shigellosis is a bacterial infection that affects the digestive system. The Shigella bacterium is spread through contact with contaminated feces. Health Conditions Discover Plan Connect. The Plague. Medically reviewed by Daniel Murrell, M. In medieval times, the plague was responsible for the deaths of millions of people in Europe.
Types of plague. How plague spreads. Signs and symptoms of the plague. What to do if you think you might have the plague. How the plague is diagnosed.
Treatment for the plague. Outlook for plague patients. How to prevent plague. Plague around the world.
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