posted on Jun, 25 2013 @ 03:05 PM
A little about the plague, yersinia pestis was originally native tropical east Africa, where it is much less a problem.
In hot climates the infection affects the vector, fleas, differently. The bacteria lives in the gut of the flea, when the flea feeds, there is not
exchange of bacteria to the host, and the flea only feeds once and lays eggs then dies.
In cooler climes , ave. temps less than 80 deg. F., there is a change in the flea. This change is described here,
The Hms system plays an important role in the transmission of Y. pestis back to a mammalian host. While in the insect vector, proteins encoded
by Hms genetic loci induce biofilm formation in the proventriculus, a valve connecting the midgut to the esophagus. Aggregation in the biofilm
inhibits feeding, as a mass of clotted blood and bacteria forms (referred to as "Bacot's block" ). Transmission of Y. pestis occurs during the
futile attempts of the flea to feed. Ingested blood is pumped into the esophagus, where it dislodges bacteria lodged in the proventriculus and is
regurgitated back into the host circulatory system.
So the biofilm and bloodclot block the gut of the flea, when it attempts to feed, it gets no nutrition, and transmits the bacteria to the new host,
then the flea jumps to new host and repeats this process, thus infecting multiple hosts.
The Byzantine empire had just started trading heavily with tropical east African in the early 6th century, but it wasn't till the global cool down of
536-538 that the plague shows up. It spread all through the med and into Britain via Roman shipping. In Britain the effects were pretty serious, the
British who traded heavily with Rome were decimatedd by the disease and whole districts were depopulated. On the other hand the angles, saxons and the
jute, who did not trade with Romans had plagues, and found large swaths of Britain unpopulated, and just moved in
edit on 25-6-2013 by
punkinworks10 because: (no reason given)
edit on 25-6-2013 by punkinworks10 because: (no reason given)