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Bubonic Plague
Andrea Cassa
Katie Gilmore
Jenni Laeger
Ivana Micanovic
Archaeological evidence now suggests that the Bubonic Plague may have
originated in ancient Egypt, not in Asia as originally thought. The disease,
termed "Black Death" also may have begun in North Africa. In a new study
reported in the Journal of Biogeography, Eva Panagiotakopulu, an archaeologist
and fossil-insect expert at the University of Sheffield reports that around the year
3500 B.C. the Nile River flooded, sending the rats that lived in the area into
human populated areas. A medical text known as the "Ebers Papyrus" identifies
a disease that "has produced a bubo, and the pus has petrified, the disease has
hit." Panagiotakopulu theorizes that the Nile rats arrived in Egypt with the sea
trade from India and spread across the Mediterranean to southern Europe.
The most famous plague outbreak that is known as fact swept across
Europe in the 1300's; during this epidemic the disease killed more than twenty
five million people equating to one fourth of the population. An Italian man
named Marchione di Coppo Stefani wrote a witnessed account of the plague's
wrath on the city of Florence, Italy in the year 1348. He writes of healthy families
and communities who became ill and were all dead within a matter of days.
Husbands abandoned wives and children; children left their parents, and mothers
left their children at the first sign of illness. Some who died simply starved to
death or died from lack of care because everyone had fled the city. All the
shops were closed except the churches. Many people became rich because of
the lack of resources like candles or coffins available at the time. The people
who fled to other areas to avoid the plague carried the disease with them thus
infecting new cities and countries. The plague at this time killed an estimated 96
thousand people in Florence between March and September. When the people
who had fled returned to their homes there were so many households without a
master that those who inherited the possessions became instantly wealthy. The
local government passed ordinances the following year limiting the prices that
could be charged by workers to try and stop the practice of a profit made by the
deaths of so many. Even weddings were regulated to try and curtail spending
by those who had suddenly found themselves in a position of wealth. The plague
not only killed entire communities in Europe but also changed the social status
instantly of those who managed to survive it. Because the Middle Ages were
also a time of strong religious convictions, anger towards the Roman Catholic
Church grew and the persecution of Jews intensified. People believed that the
plague was being caused by the wrath of God. As the numbers of infected
religious grew, people began to suspect that the church was somehow
responsible for the plague. Secular authorities began to cast blame on other
religious institutions and loyalties formed over centuries gave way to new
religious demographics. Many paintings made at the time reflect the fear brought
with the arrival of the plague. Ironically, because the clergy members attended to
the sick, almost half died as a result and this was cited as evidence of the wrath
of God. New religious sects were formed. An order of "flageliants" called the
Brethren of the Cross formed. These men traveled from town to town whipping
themselves with crops to try and appease the wrath of God. Unfortunately, they
imposed on themselves hardships including being forbidden to bathe which
helped spread the plague to additional areas. Incomprehensible horrors were
committed as all strangers were suspected of spreading the disease throughout
Europe. The Jews were especially persecuted and thousands were gathered,
murdered, and burned. Because the properties of the Jews reverted to the
Catholic Church upon the deaths of entire families, what the church lost in
followers and clergy members, it gained in tangible assets. By the end of 1351
Europe was left with a sizeable shortage of workers and a total redistribution of
wealth and assets.
What is the Bubonic Plague? The causative agent of the Bubonic Plague
is called Yersinia pestis, which are Gram-negative, bipolar-staining coccobacilli.
As we learned in class Coccobacilli are either rod or oval in shape and are short.
Like other Enterobacteriaceae, Y. pestis metabolism is fermentative. Y. pestis
produces a thick antiphagocytic capsule, which impedes or prevents white blood
cells from being able to ward off the infection of Y. pestis. There are three
diseases that are caused by Y. pestis, bubonic, septicemic, and pneumonic
plague.
Since the Yersinia pestis bacterium continues to be a problem in many
rural cities and countries world wide; it is predominately found in areas with large
numbers of rat infestation, where infection can be easily be transmitted.
According to Responsible Wildlife Management, we have seen our fair share of
the plague epidemic here in the United States, with the most recent large
reported occurrence in Los Angeles between 1924 and 1925. More documented
cases have been found within the United States; however, only 10 to 15 people
are affected annually and they are scattered amongst rural cities. In the U.S.
infection is usually spread through few specific animals, whose bodies provide
the perfect atmosphere for the bacterial containing fleas. Most documented
cases of Y. pestis infection occur in California, Southern Colorado, parts of
Mexico, Western Nevada, and Southern Oregon. According to the World Health
Organization (WHO) approximately 1,000 to 3,000 cases of the plague are
reported annually, mostly localized in or surrounding Africa, Asia, South America,
and the United States.
Sadly unlike the eradication of the small pox epidemic, the Y. pestis
bacterium will never be totally gone, since it's found in fleas, and of course the
fleas are living upon millions of animals. At this time the chances of permanently
warding off the plague are unfeasible, and to make matters worse there has been
much speculation as to Y. pestis becoming a new weapon in bio-terrorism. Due
to the tremendous amount of research, study, and investigation into the Bubonic
Plague, along with increased efforts into the study of this bacterium such
speculation could feasibly become reality, without an inoculation
At the present time, rate of infection is difficult to calculate since the
plague can suddenly reappear after a few or even a couple hundred years of a
silent period. In centuries past, scientist believed they had eradicated the
plague since it suddenly would disappear after the population of infected rodents
dissipated to almost non-existence. Outbreaks usually occur in areas of poor
sanitation and housing conditions, or areas known to have an abundance of
rodents, primarily rats.
To better understand the transmission of the bubonic plague, looking back
several centuries is a good place to start. The Bubonic Plague is an etiologic
agent known as Yesinia pestis; which is a facultative anaerobic, intracellular,
gram-negative bacillus. Human infection of the Y. pestis bacteria most often
occurs when a person is bitten by an infected rodent such as a rat or squirrel.
Origination of this bacterium is only traced back to a specific flea (Xenopsylla
cheopis) at this point in time. While the bacteria is growing within the flea,
Yersinia Pestis loses its protective capsule layer and because of this, when it is
later transferred to an animal host, most of the organisms are destroyed by
leukocytes. However some are captured by certain macrophages (histiocytes),
unfortunately unable to kill Y. pestis. Inadvertently the macrophages provide a
protected environment for the organisms to reform the capsule and its extremely
infectious antigens. The newly re-capsulated organisms kill the macrophage
and are released into the extra-cellular environment where they resist being
phagocytosized by leukocytes. Since the flea is the main carrier of the Y. pestis
bacterium, as it feeds upon rats for blood, some of the Y. pestis pathogens are
rushed out and into the rat it is feeding upon, thus another host has been
created. As the new host "rat" continued its life, it also transferred its infected
saliva into the carcasses of dead animals being preyed on, so anything that
touches or eats off it later would become infected as well. Several hundred bites
easily can occur before the host "rat" dies, thus a small start to what would later
be known as an epidemic was in the making. Later the host animal either bits a
human, or a human comes into contact with a dead animal carrying the bacteria;
which explains why there can be several years before another episode arises
amongst human civilization. Typically, humans can not be affected by the
bacteria if a host "rat" has died, and has been dead for more than 24 hours.
After infection has begun, starting with the initial bite Y. pestis quickly
spreads throughout a person's blood stream invading the entire body starting
with drainage of the lymph nodes, which later become inflamed and hot and
swollen to the touch, while constantly multiplying during its cycling throughout the
blood. Initial signs and symptoms of bubonic plague can include fever, chills,
malaise, muscle pain or tenderness, nausea, extreme weakness, sore throat,
and headache. In some cases there may be a lesion found at the bite spot,
whereas in severe cases gangrenous like lesions appear usually on the
extremities of the infected person’s body. First signs of bubonic plague are
usually seen within 2-6 days of being bitten by an infected flea or rodent.
Multiplication of the bacteria causes the characteristic "bubo" (meaning swollen),
painful lymph nodes. The case fatality rate for infected persons who are not
treated is 50%-60%.
If bubonic plague is left untreated Septicemic plague can occur as a
complication. When the Y. pestis bacteria spreads into the bloodstream it can
cause a blood infection called septicemia, it can develop without detectable
lymph node swelling and pain. Occasionally direct infection of Septicemic plague
has occurred when the bacteria gets into the bloodstream through direct contact
with the tissue or blood of an infected animal. Signs of this type of infection
initially can mimic gastroenteritis- nausea, vomiting, diarrhea, and sharpe
abdominal pain. As the infection persists, the person develops severe bleeding
problems; spontaneous bleeding under the skin, scattered bruises, noticeable
blood in their urine, and abnormal bleeding from the mouth, nose and rectum.
The bleeding problems usually are followed by signs of shock, severe drop in
blood pressure, rapid pulse, unconsciousness, kidney failure and severe
breathing difficulties. Patients who do not receive adequate treatment within 18
hours after onset of respiratory symptoms are unlikely to survive. Complications
of this form of plague include septic shock, meningitis, and coma.
Pneumonic plague the least common but most dangerous form of Y.
pestis, which can develop as a secondary complication of septicemic plague or
result from inhalation of infectious respiratory droplets expelled from a human or
animal that has plague pneumonia. Signs of pneumonic plague include severe
pneumonia accompanied by high fever, difficulty breathing and shortness of
breath, and often coughing up blood. This form is characterized by a shorter
incubation period between 1 and 3 days, with a 90% mortality rate.
Our immune system is unable to fight off the bacterium by producing an
antibody for containment and lysis of Y. pestis. Thankfully after years of
research scientist have been able to make antibiotics available to people infected
with the plague, as long as it is administered in a timely manner.
When someone has positively being diagnosed with bubonic plague a
series of treatment antibiotics and injections begin, all of which present the
possibility of permanent damage to major organs and special senses. Since the
Y. pestis bacterium is gram negative special antibiotics have been created
especially for the Y. pestis bacteria.
After much research into treatment of the Bubonic Plague the Center for
Disease Control best explained the types of treatment for helping victims of the
plague. The Primary antibiotic injection is Aminoglycoside, which must be used
in conjunction with one or several other injections for effective treatment of
ridding ones bodies of the bacterium. Streptomycin sulfate is used as a
secondary injection of treatment; however kidney toxicity can occur resulting from
treatment of this drug, so patients on dialysis can not receive this drug.
Chloramphenicol can also be used as a secondary agent of plague infection; its
job is to bind to 50S ribosomal subunits there for inhibiting bacterial growth. This
drug has been proved to work against both gram-negative and gram-positive
bacteria. Those three drugs are not very easy to attain, therefore it is impairative
that multiple antibiotics be used in order to ward off the Y. pestis bacterium.
Doxycycline is a pretty common antibiotic that is readily available; it inhibits
protein synthesis/ bacterial growth on 30S and 50S ribosomal subunits of
bacteria. This is a secondary treatment, used in postexposure prophylaxis.
Ciprofloxacin also is a very common antibiotic easily accessible which inhibits
bacterial DNA synthesis and studies have shown that it is effective against the
plague, this too a postexposure prophylaxis.
People are urged to be aware of their surroundings and environment in
order to prevent further chance of plague outbreak. Try to keep living space
rodent free, and don't allow mess piles to accumulate in yards or field near
housing areas.
Works Cited
(not quite complete in correct form; rough draft )
Marchione di Coppo Stefani, Chronicles Scriptores, Vol 30, Late 1370's
National Geographic, Cameron Walker, March 10, 2004.
Center for Disease Control, www.cdc.gov/ncidod/divid/plague/bacterium.htm
Global Invasive Species Database.
http://www.issg.org/database/species/ecology.asp?si=450&fr=1&sts=
Responsible Wildlife Management
www.responsiblewildlifemanagement.org/plague_q_&_a.htm