The bubonic plague is the most common form of plague and is spread through the bite of an infected flea. The infection spreads to immune glands called lymph nodes, causing them to become swollen and painful and can develop into open sores. Human-to-human transmission of bubonic plague is rare and is usually caught by animals.
If the plague infects the lungs – either through the progression of the bubonic form through the body or by catching the infection from an infected patient or the breath of an animal – it is called pneumonic plague.
Historically, the plague was responsible for widespread pandemics with a high mortality.
People infected with the plague usually develop acute febrile illness with other nonspecific systemic symptoms after an incubation period of one to seven days, such as sudden onset of fever, chills, head and body aches, weakness, vomiting, and nausea.
It was known as the ‘Black Death’ in the fourteenth century and caused more than 50 million deaths in Europe.
Today, the plague is easily treated with antibiotics and the use of standard precautions to prevent infection.
As an animal disease, the plague occurs on all continents except Oceania. There is a risk of human plague where the presence of natural foci of the plague and human population coexist.
Plague epidemics have occurred in Africa, Asia and South America; but since the 1990s, most human cases have occurred in Africa.
The three most endemic countries are the Democratic Republic of the Congo, Madagascar and Peru. Cases of bubonic plague are reported in Madagascar almost every year, between September and April.
The WHO does not recommend vaccination, except for high-risk groups (such as laboratory personnel who are constantly exposed to the risk of infection, and health professionals).
Source: World Health Organisation