The actual term Expiration Date refers to the last date a food should be eaten or used. Last means last -- proceed at your own risk. Other, more commonly spotted terms are:  1 Sell by date. 2  The labeling sell by tells the store how long to display the product for sale. 3  You should buy the product before the date expires. 4  This is basically a guide for the retailer, so the store knows when to pull the item.
When an animal or person is infected with Yersinia pestis, the bacteria affect the lymph system, causing the characteristic symptoms. If bubonic plague is left untreated, plague bacteria can quickly multiply in the bloodstream, causing septicemic plague. The bacteria could also progress to the lungs, causing pneumonic plague.
Bubonic plague: Patients develop sudden onset of fever, headache, chills, and weakness and one or more swollen, tender and painful lymph nodes (called buboes).This form usually results from the bite of an infected flea. The bacteria multiply in the lymph node closest to where the bacteria entered the human body.neumonic plague is the most serious form of the disease and is the only form of plague that can be spread from person to person (by infectious droplets). Plague is a serious illness. If you are experiencing symptoms like those listed here, seek immediate medical attention.