MayoClinic.com reprints
This single copy is for your personal, noncommercial use only. For permission to reprint multiple copies or to order presentation-ready copies for distribution, use the reprints link below.
· Order reprints of this article now.
Plague
By Mayo Clinic staffOriginal Article: http://www.mayoclinic.com/health/plague/DS00493
About our e-newsletters
- Free e-newsletters
- Mayo Clinic expertise
- We do not share your e-mail address
Housecall, our weekly general-interest e-newsletter, keeps you up to date on a wide variety of health topics with timely, reliable, practical information, recipes, blogs, questions and answers with Mayo Clinic experts and more. Our biweekly topic-specific e-newsletters also include blogs, questions and answers with Mayo Clinic experts, and other useful information that will help you manage your health.
Housecall Archives
Mayo Clinic Housecall
Stay up to date on the latest health information.
What you get
- Free weekly e-newsletter
- Mayo Clinic expertise
- Recipes, tools and other helpful information
- We do not share your e-mail address
Definition
Plague was known as the Black Death during medieval times, when it killed up to a third of the population of Europe. Currently, plague occurs in fewer than 3,000 people per year worldwide. It can be deadly if not treated promptly with antibiotics.
The organism that causes plague, Yersinia pestis, lives in a variety of small rodents on every continent except Australia. The organism is transmitted to humans when they are bitten by fleas that have previously fed on infected rodents.
The most common form of plague results in swollen and tender lymph nodes — called buboes — in the groin, armpits or neck. The rarest and deadliest form of plague affects the lungs, and it can be spread from person to person.
Symptoms
Plague is divided into three main types — bubonic, septicemic and pneumonic — depending on which part of your body is involved. Signs and symptoms vary depending on the type of plague.
Bubonic plague
Bubonic plague is the most common variety of the disease. It's named after the buboes — swollen lymph nodes — which typically develop within a week after an infected flea bites you. Buboes may be:
- Located in the groin, armpit or neck
- About the size of a chicken egg
- Tender and warm to the touch
Other signs and symptoms may 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. Signs and symptoms 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
Pneumonic plague
Pneumonic plague affects the lungs. It's the least common variety of plague but the most dangerous, because it can be spread from person to person via cough droplets. Signs and symptoms can begin within a few hours after infection, and may include:
- Cough, with bloody sputum
- Difficulty breathing
- High fever
- Nausea and vomiting
- Weakness
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.
When to see a doctor
Seek immediate medical attention if you begin to feel ill and have been in an area where plague has been known to occur. This includes parts of several states in the western portion of the United States — primarily New Mexico, Arizona and Colorado.
Causes
The plague bacteria, Yersinia pestis, is transmitted to humans when they are bitten by fleas that have previously fed on infected animals, such as:
- Rats
- Squirrels
- Rabbits
- Prairie dogs
- Chipmunks
The bacteria can also enter your body if you have a break in your skin that comes into contact with an infected animal's blood. Domestic cats can become infected with plague from flea bites or from eating infected rodents.
Pneumonic plague, which affects the lungs, is spread by inhaling infectious droplets coughed into the air by a sick animal or person.
Risk factors
The risk of developing plaque is very low. Worldwide, only a few thousand people develop plague each year. However, your risk of plague can be increased by where you live and travel, your occupation, and even by some of your hobbies.
Location
Plague outbreaks are most common in rural areas and in urban areas characterized by overcrowding, poor sanitation and a high rat population.
The greatest number of human plague infections occurs in Africa. But the largest concentration of infected animals is in the United States — particularly in New Mexico, Arizona and Colorado — and in the former Soviet Union.
Occupation
Veterinarians and their assistants have a higher risk of coming into contact with domestic cats that may have become infected with plague. Also at higher risk are people who work outdoors in areas where plague-infested animals are common.
Hobbies
Camping, hunting or hiking in areas where plague-infected animals reside can increase your risk of being bitten by an infected flea.
Complications
Complications of plague may include:
- Death. Most people who receive prompt antibiotic treatment survive plague. Untreated plague has a fatality rate over 50 percent.
- Gangrene. Blood clots in the tiny blood vessels of your fingers and toes can disrupt the flow of blood and cause that tissue to die. The portions of your fingers and toes that have died may need to be amputated.
- Meningitis. Rarely, plague may cause meningitis, an inflammation of the membranes surrounding your brain and spinal cord.
Preparing for your appointment
You're likely to start by going to an emergency room. You may eventually need to see a doctor specializing in infectious disease.
What you can do
If you have respiratory symptoms, you may need to wear a surgical mask to your appointment to help prevent spreading the disease to others. You also might want to write a list answering the following questions:
- What symptoms do you have and when did they begin?
- Does any activity make your symptoms better or worse?
- Have you traveled recently to a locale where plague is common?
- What drugs and supplements do you take?
Tests and diagnosis
If your doctor suspects plague, he or she may look for the Yersinia pestis bacteria in samples taken from your:
- Buboes. If you have the swollen lymph nodes (buboes) characteristic of bubonic plague, a fluid sample can be taken from them with a needle.
- Blood. Yersinia pestis bacteria generally are present in your bloodstream only if you have septicemic plague.
- Lungs. To check for pneumonic plague, fluid is extracted from your airways using endoscopy — a thin, flexible tube inserted through your nose or mouth and down your throat.
Treatments and drugs
Medications
As soon as your doctor suspects that you have plague, you'll need to be admitted to an isolation room in a hospital. There, you'll receive powerful antibiotics, such as:
- Streptomycin
- Gentamicin
- Doxycycline (Vibramycin)
- Ciprofloxacin (Cipro)
- Chloramphenicol
Prevention
Although no effective vaccine is available, antibiotics can help prevent infection if you're at risk of or have been exposed to plague. Take the following precautions if you live or spend time in regions where plague outbreaks occur:
- Rodent-proof your home. Remove potential nesting areas, such as piles of brush, rock, firewood and junk. Don't leave pet food in areas that rodents can easily access.
- Keep your pets free of fleas. Ask your veterinarian which flea-control products will work best.
- Use insect repellent. Closely supervise your children and pets when spending time outside in areas with large rodent populations. Use insect repellent.
- Everett ED. Microbiology, pathogenesis and epidemiology of plague (Yersinia pestis infection). http://www.uptodate.com/home/index.html. Accessed June 17, 2010.
- Gage KL. Plague and other Yersinia infections. In: Goldman L, et al. Cecil Medicine. 23rd ed. Philadelphia, Pa.: Saunders Elsevier; 2007. http://www.mdconsult.com/das/book/body/206594927-5/1015859897/1492/1167.html#4-u1.0-B978-1-4160-2805-5..50338-4_14426. Accessed June 17, 2010.
- Everett ED. Clinical manifestations, diagnosis and treatment of plague (Yersinia pestis infection). http://www.uptodate.com/home/index.html. Accessed June 17, 2010.
- Plague fact sheet. National Park Service. http://www.nps.gov/public_health/info/factsheets/fs_plague.htm. Accessed June 18, 2010.
- Frequently asked questions (FAQ) about plague. Centers for Disease Control and Prevention. http://www.bt.cdc.gov/agent/plague/faq.asp. Accessed June 18, 2010.
- Information on plague. Center for Disease Control and Prevention. http://www.cdc.gov/ncidod/dvbid/plague.info.htm. Accessed June 18, 2010.
- Interregional meeting on prevention and control of plague. World Health Organization. http://www.who.int/csr/resources/publications/WHO_HSE_EPR_2008_3w.pdf. Accessed June 21, 2010.
- Plague fact sheet. Centers for Disease Control and Prevention. http://www.cdc.gov/ncidod/dvbid/plague/qa.htm. Accessed June 21, 2010.
Find Mayo Clinic on