Arbovirus danger?

[ajmst37 at vms.cis.pitt.edu]

hello,
just doing some reading on arboviruses, and I was wondering just how 
worried people in the U.S. should be.  Is it true that the Aedes Aegyptes
(sp?) mosquito is in the U.S.?  Is this not the same mosquito that carries
yellow fever and Dengue fever?  Since the attempted malaria eradication,
are all mosquitos immune to most pesticides, or is that still the best way
to prevent arbovirus outbreaks?

By the way, how long has Dengue been around, and could it really become
a serious problem in the U.S.?

Very curious,

Andrew=AJMST37 at vms.cis.pitt.edu