Plague is a term applied to an infectious disease that spreads easily and, without antibiotics treatment, can be fatal. The plague has caused more fear and terror than perhaps any other infectious disease in history. It has killed nearly 200 million people and has produced monumental changes, such as marking the end of the Dark Ages and causing the advancement of clinical research in medicine.
Causes of plague:
Plague is caused by the gram-negative, nonmotile, nonspomlating bacillus Yersinia pest. It's usually transmitted to humans through the bite of a flea from an infected rodent host, such as a rat, squirrel, prairie dog, or hare. Occasionally, transmission occurs from handling infected animals or their tissues.
More than 200 different rodents and species can serve as hosts. These include domestic cats and dogs, squirrels, chipmunks, marmots, deer mice, rabbits, hares, rock squirrels, camels, and sheep.
Plague is carried by rodents like rats and squirrels, but it is transmitted to humans by the fleas who live on them. A flea, having ingested plague-infected blood from its host, can live for as much as a month away from that host before he needs to find another warm body to live on.
The cause of plague, the Yersinia pestis bacterium, was discovered in 1894 by Alexandre Yersin. Soon after, scientists realized that fleas transmitted the bacteria.
The bacteria responsible for the plague and some forms of food poisoning "paralyze" the immune system of their hosts in an unexpected way, according to a new study in the September 8, 2006 issue of the journal Cell, published by Cell Press.
The Black Death pandemic in the 14th century killed one-third of Europe's population. Europeans living during early pandemics believed the disease was a punishment from the gods or an unlucky confluence of astrological or supernatural elements.
The most recent plague pandemic began in China in the late 1800s and, due to booming international trade and ships with high rat populations, spread quickly throughout Asia and other parts of the world. That outbreak caused more than 12 million deaths in India and China alone.
Transmission of plague:
Plague is usually transmitted to humans through the bite of a flea from an infected rodent host, such as a rat, squirrel, prairie dog, or hare. (See Carrier of bubonic plague.) Occasionally, transmission occurs from handling infected animals or their tissues. Bubonic plague is notorious for the historic pandemics in Europe and Asia during the Middle Ages, which in some areas killed up to two-thirds of the population. This form is rarely transmitted from person to person.
Symptoms of plague:
It started with a headache.
Then chills and fever, which left exhausted and prostrate.
experienced nausea, vomiting, back pain, soreness in arms and legs.
bright light too bright to stand.
Within a day or two, the swellings appeared. They were hard, painful, burning lumps on neck, under arms, on inner thighs.
Preventive measures:
Limit contact with rodents.
Treat domesticated animals for fleas.
Consider use of insect repellants, insecticides, and/or rodenticides, especially if in an endemic area.
Improve environmental sanitation, such as proper disposal of trash, which may serve to attract rodents.
