Plague is caused by the bacteria, Yersinia pestis. The bacteria lives in the stomach of fleas
Plague has three main forms: bubonic, pneumonic and septicemic.Bubonic plague is transmitted to humans by the bite of fleas which lived mainly on rats, squirrels and wild animals. When the bacteria enters the lungs , pneumonic plague will result.This form spreads very easily, through air when an infected person coughs or sneezes.Septicemic plague may result from either bubonic or pneumonic plague.
The symptoms of plague vary with the forms of plague(as above).A person may have some or all forms of the plague.
Bubonic plague-Bacteria sperads throughout body from site of flea bite.They enter lymph nodes, causing swelling.These are called buboes, hence the name bubonic plague.Fever,chills,nausea,pain may be experienced.
Septicemic plague-Purple colouration appears on the skin due to the breaking of blood vessels.The bacteria are now present in blood, a condition known as septicemia.If the bacteria enters the lungs,pnemonic plague will result.
Pneumonic plague- Headaches,fever,coughs with bloody sputum occur.The bacteria can now spread easily via the droplets discharged by sneezing or coughing. Pneumonic plague is almost fatal.
The treatment of plague includes antibiotics like chloramphenicol,tetracyclines,streptomycin to kill the bacteria.Treatment must start early as plague is fatal and kills its victims fast.
When travelling to plrevalent areas, tourists should avoid rodents(rats) and the fleas.Patients' clothing and belongings should be treated to kill all fleas. Rodents and fleas should be controlled where the disease has occurred. The patients should also be qurantined to prevent pneumonic plague.
Plague is also known as the"Black Death". The saying of "God Bless You" when people sneeze is to bless people when they sneeze so that they hopefully would not get plague.