What is a re-emerging virus? Epidemic outbreaks- new areas or new hosts *difference due to incubation & Sx- hot viruses
are easier to contain than latent ones E.g.: canine parvo- sudden appearance in 1978 view of recent human outbreaks- emerging &
re-emerging A good way to learn how to look forward is to look
back: E.g.: Rift Valley fever in Africa Dengue fever in Central America, Caribbean, SE
Asia Emergence isn't just for humans & pets: plant virus
outbreaks have also occurred rabbits in Australia So how can you tell if a virus is really new or just
newly discovered? E.g.: HHV-8 & Kaposi's sarcoma vs. HHV-6 &
HHV-7
What is a new or emerging virus?previously unknown virus; "benign" virus becomes
"hot"; known virus appears in new host or in new areas;
recombination/mutation leads to a truly new virus
known virus increasing rate after period of
control or natural decrease
may be sudden onset- Ebola: stays in limited
area
slow onset- HIV: distributed
influenza- ongoing emergence of new strains
due to recombination
what factors play a role? of those factors,
which are as a result of human activity?
E.g.: cocoa trees; tomato & corn dz; lettuce
wilt dz
use epidemiological techniques: look for
distribution, variant strains; look for Ab titers in
population
Updated 1/25/04 by thatcher@sonoma.edu