As the deadly ebola epidemic seems to be gradually getting under control, there is an emerging fast killer called bubonic plague that has started claiming the lives of many in some African countries. It is reported that the plague has killed about 20 people in Madagascar.
Bubonic plague is a zoonotic disease, circulating mainly in fleas on small rodents, and is one of three types of bacterial infections caused by Yersinia pestis (formerly known as Pasteurella pestis), that belongs to the family Enterobacteriaceae. Without treatment, the bubonic plague kills about two thirds of infected humans within four days.
The term bubonic plague is derived from the Greek word βουβών, meaning “groin”. Swollen lymph nodes (buboes) especially occur in the armpit and groin in persons suffering from bubonic plague. Bubonic plague was often used synonymously for plague, but it refers specifically to an infection that enters through the skin and travels through the lymphatics, as is often seen in flea-borne infections.
Bubonic plague—along with the septicemic plague and the pneumonic plague, which are the two other manifestations of Y. pestis—is commonly believed to be the cause of the Black Death that swept through Europe in the 14th century and killed an estimated 25 million people, or 30–60% of the European population. Around the Mediterranean Region, summers seemed to be the season when the disease took place. In northern Europe, the disease had its most frequent outbreaks in the autumn. Because the plague killed so many of the working population, wages rose with the demand for labor. Some historians have seen this as a turning point in European economic development.
- Gangrene of the extremities such as toes, fingers, lips and tip of the nose.
- General ill feeling (malaise)
- High fever (39 °C; 102 °F)
- Muscle cramps
- Smooth, painful lymph gland swelling called a bubo, commonly found in the groin, but may occur in the armpits or neck, most often at the site of the initial infection (bite or scratch)
- Pain may occur in the area before the swelling appears
- Skin color changes to a pink hue in some very extreme cases
Bubonic plague is an infection of the lymphatic system, usually resulting from the bite of an infected flea, Xenopsylla cheopis (the rat flea). In very rare circumstances, the disease can be transmitted by direct contact with infected tissue or exposure to the cough of another human. The fleas are often found on rodents such as rats and mice, and seek out other prey when their rodent hosts die. The bacteria began its life harmlessly living in the digestive tracts of mammals. The ability to propagate was dependent only upon its ability to travel from mammal host to mammal host. The bacteria remained harmless to the flea, allowing the new host to spread the bacteria. The bacteria form aggregates in the gut of infected fleas and this results in the flea regurgitating ingested blood, which is now infected, into the bite site of a rodent or human host. Once established, bacteria rapidly spread to the lymph nodes and multiply. As the disease progresses, the lymph nodes can haemorrhage and become swollen and necrotic.
- Caused by the bacterium Yersinia pestis
- Essentially a disease of wild rodents, spread by flea
- Plague spreads to humans either by the bite of infected fleas or rats
- Does not spread from person to person
- Patients develop swollen, tender lymph glands (called buboes) and fever, headache, chills and weakness
- It is treatable if caught early, but can be lethal
Prevention and control
The requirement to reduce outbreaks are: treating pets for fleas, using insecticide to reduce the number of fleas, control of rat population and watch watch for plague cases in rats and humans in the area.