Bubonic plague is the most common type of plague — an infectious disease caused by bacteria known as Yersinia pestis. The disease, which affects the lymphatic system (lymph nodes, ducts, and vessels), makes its way to people through bites from fleas, which acquire the bacteria by biting rodents that carry it (such as squirrels, prairie dogs, and rats). There have been several bubonic plague pandemics throughout history, most famously the “Black Death” of the 1300s. That medieval outbreak killed up to 60 percent of the European population, according to the Centers for Disease Control and Prevention.
Bubonic Plague Symptoms
When Y. pestis bacteria enter the body, they infect the nearest lymph node, causing it to become swollen, tender, and painful. The bacteria can then travel through the lymphatic system, resulting in more inflamed lymph nodes (or buboes, from which bubonic plague gets its name) — particularly in the groin, armpits, and neck. Other symptoms, which tend to develop within three to seven days of the initial infection, include:
Fever and chillsHeadacheMalaise (general ill feeling)WeaknessMuscle painSeizures
Bubonic Plague Complications
Left untreated, bubonic plague can spread from the lymphatic system to the bloodstream or the lungs, causing septicemic (blood) or pneumonic (lung) plague. In addition to the symptoms of bubonic plague, septicemic plague can cause:
Abdominal painCirculatory shock (a life-threatening condition in which the vital organs of the body stop working)Nausea and vomitingBleeding into the skin and other organs
It can eventually lead to gangrene, in which the skin and other tissues — particularly the fingers, toes, and nose — turn black and die. Pneumonic plague causes severe pneumonia (lung infection) symptoms, such as:
CoughBreathing problemsChest painBloody sputum (a mixture of saliva and mucus produced when you cough)
As it progresses, pneumonia from plague can cause respiratory failure and shock. In rare cases, plague can spread to the central nervous system and cause meningitis, which is an inflammation of the membranes around the brain and spinal cord. Ultimately, plague can cause death. In all, 30 to 60 percent of plague cases result in death if left untreated, according to the World Health Organization.
Diagnosing Bubonic Plague
To find out if you have bubonic plague, your doctor will begin by inspecting your buboes and determining whether you have any other symptoms of the disease. Your doctor will also most likely ask you about the specific timing of your symptoms, any recent insect bites, and places you’ve recently traveled. If plague is still suspected at this point, a fluid sample will be taken from one of your swollen lymph nodes. It will be inspected for Y. pestis using either a microscope or culture tests that allow the bacteria to grow. Your doctor may also conduct similar tests on your blood. In the early stages of bubonic plague, the bacteria usually can’t be detected in the blood using a microscope, but culture tests may still effectively show the bacteria. Blood tests are also used to diagnose septicemic plague, while pneumonic plague is diagnosed by performing culture tests on your sputum and saliva or mucus in your throat.
Bubonic Plague Treatment
If you have plague, it can rapidly get worse and become life-threatening, so your doctor will begin treatment immediately after your diagnosis. Plague can usually be successfully treated with various antibiotics, including:
StreptomycinGentamicinLevofloxacinCiprofloxacinDoxycyclineMoxifloxacinChloramphenicol
If you don’t have plague but have recently been exposed to someone with the disease (within the past week), your doctor may give you a “post-exposure prophylaxis” dose of doxycycline or ciprofloxacin to prevent you from getting it.
