Definition:
The typical sign of the most common form of human plague is a swollen and very tender lymph gland in the neck.This is known as a bubo – hence the alternative name for the disease of bubonic plague.
Plague is an infectious disease caused by a bacterium named Yersinia pestis.People usually become infected after being bitten by a flea which lives on rats and carries the bug.
Bubonic plague is often used synonymously for plague, but it does in fact refer specifically to an infection that enters through the skin and travels through the lymphatics, as is often seen in flea-borne infections. Bubonic Plague kills about 70% of patients in 4-7 days.
Today plague is uncommon. This is largely due to better living conditions and antibiotics.
There are three forms of plague:
* Bubonic, which causes the tonsils, adenoids, spleen and thymus to become inflamed. Symptoms include fever, aches, chills and tender lymph glands
* Septicemic, in which bacteria multiply in the blood. It causes fever, chills, shock and bleeding under the skin or other organs
* Pneumonic, in which the bacteria enter the lungs and cause pneumonia. People with the infection can spread this form to others. This type could be a bioterror agent
Treatment for plague is a strong antibiotic. There is no vaccine for plague.
Plague was once deadly, but the disease is now curable provided it is caught in its early stages.
Pathology and transmission:
The Bubonic plague is an infection of the lymphatic system, usually resulting from the bite of an infected flea. The bacteria rapidly spreads to the lymph nodes and multiplies. Yersinia pestis can resist phagocytosis and even reproduce inside phagocytes and kill them. As the disease progresses, the lymph nodes can hemorrhage and become necrotic. Bubonic plague can progress to lethal septicemic plague in some cases.
Symptoms:
There are three types of plague: bubonic, septicemic and pneumonic. Signs and symptoms of plague vary depending on the type and on how you contract it. It’s possible to develop more than one type of plague.
Bubonic plague
This is the most common type of plague in humans, accounting for the majority of naturally occurring cases. Bubonic plague is caused by a bite from an infected flea and is characterized by an enlarged, infected lymph node called a bubo.
Signs and symptoms of bubonic plague generally appear within two to eight days after a plague-infected flea bites you. After you’re bitten, the bacteria travel through your lymphatic system, infecting the first lymph node they reach. The resulting bubo is usually 1 to 10 centimeters in diameter, swollen, painful and warm to the touch. It can cause so much pain that you can’t move the affected part of your body. The bubo usually develops in your groin, but may also appear in your armpit or neck, depending on where the flea bit you. More than one bubo can develop, but typically buboes affect only one area of your body.
Buboes may not be noticeable until a day or more after other symptoms appear. Other signs and symptoms of bubonic plague include:
* Sudden onset of fever and chills
* Headache
* Fatigue or malaise
* Muscle aches
Septicemic plague
Septicemic plague occurs when plague bacteria multiply in your bloodstream. You can contract this form of plague when bacteria transmitted by a fleabite enter directly into your bloodstream, or as a complication of bubonic or pneumonic plague. If septicemic plague occurs as a complication of bubonic plague, buboes may be present.
Signs and symptoms of septicemic plague include:
* Fever and chills
* Abdominal pain, diarrhea and vomiting
* Bleeding from your mouth, nose or rectum, or under your skin
* Shock
* Blackening and death of tissue (gangrene) in your extremities, most commonly your fingers, toes and nose
The gangrene associated with septicemic plague inspired the nickname Black Death for the 14th-century pandemic.
Pneumonic plague
Pneumonic plague is the least common form of plague — accounting for 12 percent of U.S. cases in the last 50 years — but the most rapidly fatal. Primary pneumonic plague can occur when you inhale infectious droplets coughed into the air by a person or animal with pneumonic plague. Early signs and symptoms, which generally occur about two days after inhaling contaminated droplets, include:
* High fever
* Weakness
* Signs of pneumonia, including chest pain, difficulty breathing and a cough with bloody sputum
* Nausea and vomiting
You can also develop pneumonic plague as a complication of bubonic or septicemic plague if the bacteria spread to your lungs. This is called secondary pneumonic plague.
Pneumonic plague progresses rapidly and may cause respiratory failure and shock within two days of infection. If antibiotic treatment isn’t initiated within a day after signs and symptoms first appear, the infection is likely to be fatal.
Plague resulting from a bioterrorist attack
It’s possible that plague bacteria could be turned into an aerosol and then might be spread over large populations as a bioterrorist weapon. An attack of this kind would cause pneumonic plague — the most deadly and most contagious type. In 1970, the World Health Organization estimated that if plague bacteria were sprayed over a city of 5 million people, up to 150,000 people could be infected and 36,000 might die.
According to a consensus statement by a group of scientists published in the Journal of the American Medical Association, the incubation period for pneumonic plague following a bioterrorist attack might last from one to six days, but more often from two to four days. Signs and symptoms would mirror those of naturally occurring pneumonic plague, but might also include nausea, vomiting, abdominal pain and diarrhea.
Other indications that a bioterrorist event or germ warfare is behind a pneumonic plague outbreak include a high incidence of pneumonic plague in humans in regions of the country that haven’t had outbreaks among animals or rodents, or when plague occurs in people without any known risk factors.
The most famous symptom of bubonic plague is swollen lymph nodes, called buboes. These are commonly found in the armpits, groin or neck. The bubonic plague was the first step of the ongoing plague. The two other forms of the plague, pneumonic and septicemic, resulted after a patient with the bubonic plague developed pneumonia or blood poisoning.
The plague causes fever and a painful swelling of the lymph glands called buboes, which is how it gets its name. The disease also causes symptoms like spots on the skin that are red at first and then turn black, heavy breathing, continuous blood vomiting, aching limbs and terrible pain. The person would not live 24 hours.
.Infection of the lungs with the plague bacterium causes the pneumonic form of plague, a severe respiratory illness.Symptoms include high fever, chills, coughing up blood, and breathing difficulty.
Causes:
Plague has afflicted humans throughout history. The first recorded plague outbreak began in Egypt in A.D. 541.The Black Death pandemic in the 14th century killed one-third of Europe’s population. Europeans living during early pandemics believed the disease was a punishment from the gods or an unlucky confluence of astrological or supernatural elements.
The most recent plague pandemic began in China in the late 1800s and, due to booming international trade and ships with high rat populations, spread quickly throughout Asia and other parts of the world. That outbreak caused more than 12 million deaths in India and China alone.
The cause of plague, the Yersinia pestis bacterium, was discovered in 1894 by Alexandre Yersin. Soon after, scientists realized that fleas transmitted the bacteria.
In World War II, the Japanese army released plague-carrying fleas over a part of China, causing outbreaks of the disease. After World War II, both the United States and the former Soviet Union pursued biological weapons programs that developed means of exposing large populations to plague bacteria. Today, plague is one of a number of feared potential agents of bioterrorism, along with anthrax, smallpox, botulism, tularemia and nerve gases.
Diagnosis:
Your doctor may suspect plague if you live in a high-risk region. With the exception of a visible bubo, signs and symptoms often mimic other, more common infectious diseases.
You’ll likely be asked to describe the type and severity of your symptoms and tell your doctor about your recent history, including whether you’ve been exposed to sick animals or traveled to areas with plague outbreak.
If your doctor suspects plague, he or she may confirm the diagnosis through microscopic examination of fluid extracted from your bubo, bronchi or trachea. Needle aspiration is used to obtain fluid from your bubo. Fluid is extracted from your airways using endoscopy. In this procedure, a thin, flexible tube is inserted through your nose or mouth and down your throat. A suction device is sent down the tube to extract a fluid sample from your airways.
Your doctor may also test blood drawn from your veins to diagnose plague. Y. pestis bacteria generally are present in your bloodstream only if you have septicemic plague.
Treatment:
In the modern era, several classes of antibiotics are effective in treating bubonic plague. These include the aminoglycosides streptomycin and gentamicin, the tetracyclines tetracycline and doxycycline and the fluoroquinolone ciprofloxacin. Patients with plague in the modern era usually recover completely with prompt treatment, although the disease is rarely seen in the industrialized world.
However, there is concern about growing levels of resistance to the drugs.People suspected of having the plague should be hospitalised and medically isolated.
It is also important to test people who have been in close contact with sufferers.
Risk Factors:
The World Health Organization reports 1,000 to 3,000 cases of plague world-wide every year.It is found across south Asia, southern Africa and Central America.
Naturally occurring plague outbreaks are most common in rural areas and in urban areas characterized by overcrowding, poor sanitation and a high rat population. Outbreaks can happen at any time of year.
In the United States, plague outbreaks occur most often between April and November. Most U.S. cases occur in Western states, including New Mexico, Arizona, Colorado and California.
Rock squirrels and ground squirrels are the most common sources of infection in the United States. Other rodents, including chipmunks and prairie dogs, may host plague-carrying fleas. Animals that may be infected and pose a transmission risk to humans include wild rabbits and domestic cats that have contact with wild rodents.
The disease usually spreads through fleabites, but you can also contract plague after being exposed to an infected animal that may have coughed infectious droplets into the air or through a break in your skin after handling an animal with plague. Groups at increased risk include veterinarians, cat owners, hunters, campers and hikers in areas with recent plague outbreaks among animals.
Prevention:
Previously, a vaccine was available for bubonic plague, but its efficacy was never well studied and the manufacturer stopped producing it in 1999. Clinical trials on a new plague vaccine are in the earliest stages.
Although no effective vaccine is available, antibiotics offer effective preventive therapy if you’re at risk or have been exposed to plague. Ask your doctor immediately about preventive antibiotics if you:
* Have had close contact with a person or animal with known or suspected pneumonic plague
* Have been bitten by a flea or unknown insect in an area known to have recent plague cases
* Are planning to spend time in a region with recent plague outbreak
Take the following precautions if you live or spend time in regions where plague outbreaks occur:
* Avoid contact with sick or dead animals. If you hunt, wear gloves when handling dead animals.
* Rodent-proof your home. Remove potential nesting areas, such as piles of brush, rock, firewood and junk. Don’t leave pet food or any other foods in areas that rodents can easily access.
* Prevent your pets from contracting fleas. Use flea-control products and don’t allow pets to wander unsupervised. Ask your veterinarian for recommended flea-control brands and guidelines.
* Take precautions when outdoors. Closely supervise your children and pets when spending time outside in areas with large rodent populations. Use insect repellent on your skin and clothing.
Know the risk factors and the symptoms of plague so that you can identify it early and contact your doctor immediately. If you know of recent plague cases in your area, report sick or dead animals to your local health department or to police.
Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose
Resources:
http://news.bbc.co.uk/2/hi/health/medical_notes/n-p/1834332.stm
http://en.wikipedia.org/wiki/Bubonic_plague
http://www.mayoclinic.com/print/plague/DS00493/DSECTION=all&METHOD=print
