Mosquitoes, etc. as infection vectors?

[Tom Valesky CS 555]

Question from a layman:

Malaria spreads through mosquitos. Sleeping sickness spreads through
tsetse fly bites. Why haven't mosquitoes, biting flies, etc., become
infection vectors for viral diseases like Ebola and AIDS?


--
===========================================================================
Tom Valesky   -- tvalesky at osf1.gmu.edu -- tvalesky at site.gmu.edu
Programmer/Analyst C/C++/SQL/Visual Basic 
(I don't work for GMU; I'm a part-time grad student)