PLAGUE

About:

• Cause: Plague is an infectious disease caused by the bacteria Yersinia pestis, a zoonotic bacteria, usually found in small mammals and their fleas.
  
  
• Transmission: It is transmitted between animals through fleas. Humans can be infected through:
  • the bite of infected vector fleas
    
    
  • unprotected contact with infectious bodily fluids or contaminated materials
    
    
  • the inhalation of respiratory droplets/small particles from a patient with pneumonic plague.
    
    
  
  
  
• Two main forms of plague infection, depending on the route of infection are:
  • Bubonic plague is caused by the bite of an infected flea. Plague bacillus, Y. pestis, enters at the bite and travels to the nearest lymph node where it replicates itself. The lymph node then becomes inflamed, tense and painful, and is called a ‘bubo’. Human to human transmission of bubonic plague is rare.
    
    
  • Pneumonic plague, or lung-based plague, is the most virulent form of plague. Any person with pneumonic plague may transmit the disease via droplets to other humans.
    
    
  
  
  
• Where is plague found? As an animal disease, plague is found in all continents, except Oceania. Since the 1990s, most human cases have occurred in Africa. The three most endemic countries are the Democratic Republic of Congo, Madagascar, and Peru.
  
  
• Treatment: Nowadays, plague is easily treated with antibiotics and the use of standard precautions to prevent acquiring infection.
  
  
• Timeline:
  • Historically, plague was responsible for widespread pandemics with high mortality. It was known as the "Black Death" during the fourteenth century, causing more than 50 million deaths in Europe.
    
    
  • Between 2010 and 2015 there were 3,248 cases worldwide, leading to 584 deaths – a fatality rate of 18%, according to the World Health Organization.