Brown rats, black rats, spotted fever

K. Weber kweber at efn.org
Tue Dec 10 13:34:57 EST 1996



        One explanation for the dwindling of the Bubonic Plague in Britain
has been that the native black rats were replaced by the European brown
rat.  A friend of mine and I have been batting this around.  Does anyone
know whether we have native black rats or brown rats in America?  I assume
that our domesticated rats are bred from the brown ones.  From my
observations of these, at least some of them eat fleas during grooming.
It has occured to me that if the brown rat learned to destroy fleas as
part of grooming and the black rats had never picked up this habit, that
this might be one reason that these rats were assumed to not transmit the
plague.  Did they get it?  When there are outbreaks of plague as happened
in a high sierra campground in the late sixties (thirty cases), how do the
host animals (assumed to be squirrels) get the organism.  Can it be
carried in a benign form?
        My sister-in-law got a very virulent infection in southern Utah
about twelve years ago.  In relating the story at church, my mother
learned that one of her friends had a daughter who was diagnosed with
spotted fever at the University of Utah.  My sister-in-law was treated at
the federally funded Santa Clara Health Center in St. George, Utah by a
retired hematologist who was able to respond quickly.  He removed her
spleen.  
        We have also been wondering whether it was actually the plague
which caused the massive die off of rats at the very beginning of the
plague.  Might something else have set up the conditions necessary for the
development of virulence in the spotted fever organism.  Are spotted fever
and bubonic plague the same thing?  Defoe mentions both names in his
Journal of the Plague Year.  The friend at church did not have rocky
mountain spotted fever unless there is something important I don't know
about it.  Her baby was in a coma six hours after contracting it.
        If you answer this please send me a copy e-mail.  I may not be
able to pick up all my mail from the groups.


                                        Kathleen







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