Bubonic Plague
Bubonic plague is a severe infection in humans and many species of rodents. It is caused by a bacterium called Yersinia pestis (formerly known as Pasteurella pestis). Plague pneumonia, or pneumonic plague, is caused by the same bacteria as bubonic plague but the victim becomes infected by inhaling infected droplets from the lungs of someone whose plague infection has spread to the respiratory system. This is the most contagious form of the disease and the form that progresses most rapidly, with death usually occurring in less than three days in virtually all untreated cases.
For hundreds of years, children have chanted this rhyme, without ever realizing its meaning.
Ring around the rosies,
A pocket full of posies,
Ashes, ashes!
We all fall down.
The rosies referred rosary beads, used for praying for help. The boboes released an offensive odour, the posies, flowers, were carried to mask the stench. Ashes derived from the burning of corpses. Fall down symbolizes dying people.
Ring around the rosies,
A pocket full of posies,
Ashes, ashes!
We all fall down.
The rosies referred rosary beads, used for praying for help. The boboes released an offensive odour, the posies, flowers, were carried to mask the stench. Ashes derived from the burning of corpses. Fall down symbolizes dying people.
History
There were three major epidemics of the bubonic plague in history. In 542, there was the Plague of Justinian. It killed 70,000 people in the city of Constantinople, in two years. Once it killed 1,000 people in a single week. Fifty-two years following the Plague of Justinian, smaller outbreaks continued to arise, until 1340. In 1346-50, in Europe, the most devastating outbreak of bubonic plague occurred, the ‘Black Death.’ By the end of 1348, all of Italy and most of France was infested with the plague. From England, it spread to Scotland, Ireland, Denmark, and most of Germany. In 1351, it reached Russia. About 25 million people, 1/3 of the population of Europe was killed by the ‘Black Death.’ In 1563, the bubonic plague hit England. About 20,000 Londoners were killed. Later, in 1603, it reappeared and killed 30,500 Londoners. The third major epidemic occurred in 1890, in Manchuria, it reached San Francisco in 1900. In the end, 12,597,789 people, mainly in India and Asia, were killed. Overall, the bubonic plague killed 137 million people, and outbreaks, though small, are still occurring.
Transmission
Bubonic plague is transmitted by the bite of any of numerous insects that are normally parasitic on rodents, and that seek new hosts when the original host dies. The most important of these insects is the rat flea Xenopsylla cheopis, which is parasitic on the brown rat. This bacterium is transmitted by fleas that have fed on the blood of infected rodents, usually rats. The plague bacteria multiply in the flea's upper digestive tract and eventually block it. When the flea feeds again, the block causes the freshly ingested blood to be regurgitated back into the bite, along with plague bacteria. The circulatory system of the bitten individual then carries the bacteria throughout the body.
In the pneumonic form the plague spread from person to person by coughing, sneezing, or simply talking.
Steps for Spread of the Bacteria:
- The rat is infected with the bacteria.
- The flea gets on the rat and bites the rat, and through the rats blood contracts the bacteria.
- The bacteria multiplies in the flea's digestive tract
- The flea's digestive tract gets blocked with the bacteria.
- The flea bites a human, regurgitates blood into open wound.
- Human becomes infected
Symtoms
Once the bacterium, Yersinia pestis, enters the bloodstream, it travels to the liver, spleen, kidneys, lungs, and brain. The first signs of infection, in humans, appear abruptly, within about a week of exposure. The body temperature quickly rises to between 38.3E and 40.5E C (101E and 105E F). This is accompanied by shivering. The pulse rate and respiration rate are increased, and the victim becomes exhausted and unenthusiastic. Victims become extremely ill, they experience nausea, vomiting, aching joints, chills, diarrhea muscular pain in the back and limbs, headaches, mental disorganization, giddiness, intolerance to light, white coating on their tongue, and delirium (madness). The lymph nodes (part of the immune system) throughout the body, especially those in the groin and the thighs or, less commonly, in the armpit or neck, become enlarged and extremely painful. The inflamed lymph nodes, that become filled with pus, are called buboes. (Boubon is Greek for groin. This is how the disease gets its name.) The buboes swell until they are approximately the size of a chicken egg. Blood vessels then break, causing internal bleeding. The blood then dries under the skin and gives the buboes the characteristic black colour. (The disease is also known as the black death.) The disease then spreads throughout the body through the infected bloodstream and the lymphatic system (system connecting lymph nodes). In autopsies, the bacterium has been found in the pericardial sac (sac that surrounds the heart), spleen, liver, lymph nodes, and bone marrow.
In nonfatal cases, the temperature begins to fall in about five days, and approaches normal in about two weeks. The person then becomes immune to the bubonic plague. Death occurs, in most cases, two or four days after the first appearance of symptoms. Untreated bubonic plague is fatal in 30 to 75 percent of all cases, pneumonic plague 95 percent of the time, and septicemic plague is almost always fatal. Mortality in treated cases is 5 to 15 percent. In 60-90 percent of untreated cases, death occurs within a few days.
Early symptoms:
- fever 38.3-40.5EC
- shivering
- lack of interest
- fatigue
- nausea
- chills
- diarrhea
- vomiting
- aching joints
- muscular pain (back and limbs)
- headaches
- mental disorganization
- giddiness
- intolerance to light
- white coating on tongue
- delirium (madness)
Later Symptoms:
- appearance of buboes (lymph nodes full of pus) (boubon is Greek for groin)
- blood vessels break, internal bleeding, turn black (giving name, ‘Black Death’)
- bacterium spreads throughout the body
Early Treatments
Some of these early treatment included:
- bathing in human urine
- wearing of human excrement
- placing of dead animals in homes
- use of leeches
- drinking molten gold/powdered emeralds
- incising (cutting) and draining of abscesses (bubo)
- placing patients in pest houses and isolate them from the general public
- eating figs before six in the morning
- chopping a snake up everyday
- trying to fall asleep on the left side of the bed
- not to sleep during the day
- not exercising
- not eating any desserts
It was only in the 1890's that they knew what caused and spread the plague. Fourteenth century physicians did not know what caused the plague, yet they knew that it was contagious. As a result they wore a type of bio-protective suit which included a large bird-like beaked head piece. The beak of the head piece was meant to be filled with vinegar, sweet oils and other strong smelling compounds to counteract the stench of the dead and dying plague victims. They believed that the smell could spread the disease.
Current Treatments
Bubonic plague can be easily treated if it caught early. Treatment that is started early can reduce overall plague mortality from 60-100 percent to 5-15 percent. The plague organism is vulnerable to antibiotics, if treatment is started within about 15 hours of the first appearance of symptoms. (Streptomycin in the preferred drug, but gentamicin, tetracyclines, and chloramphenicol are also effective.) Even penicillin is useless against the plague.
To prevent plague, the most effective ways are to:
- control the rat population with rodenticides
- control the flea population with insecticides
- improve conditions around human dwellings to diminish the food and shelter for rodents
- use separate facilities for livestock
- quarantine bubonic plague patients as soon as they are diagnosed
Life Cycle:
