Lecture 15 (Exam 2) Flashcards
Who was misquoted saying “the war against epidemics due to pathogens is over”?
William H Stewart
What year did doctors in the US find a mysterious new disease that was mostly affecting homosexual men?
1981
What was hypothesized about the mysterious new disease?
That it was a sexually transmitted disease
Doctors and other medical professionals made what to track the disease?
Patient maps
patients who were infected would detail who they slept with and those people would detail who they slept with
Who was wrongly identified as patient zero? What year?
Gaetan Dugas, a french Canadian airline steward
1988
How was it estimated that HIV arrived to the US?
used measurements of virus diversity
what is virus diversity?
number of mutations that have accumulated
When and where did HIV come to the US from?
1966 via Haiti, from Africa
When and where were the earliest known HIV positive human samples from men found?
1959 in Kinshasa, DRC
How were theses samples (1959 ones) used?
to date the spillover event to about 1908
what is a spillover event?
when a virus in one species passes into another species
Around the same time (1959) what similar virus was found in several primate species?
SIV: simian immunodeficiency virus
Where was it discovered that human AIDS comes from chimps?
A small part of Cameroon
What is the most plausible hypothesis of transmission?
cut hunter theory
What does the cut hunter theory propose?
that HIV-1 crossed from a chimpanzee to human in the course of hunting, butchery, and eating of chimpanzees as bushmeat
By what year and where did HIV arrive and begin its spread>
1920 and Kinshasa
What is Chimp SIV?
a hybrid composed of virus from red capped mangabey and spot nosed guenon
When is Chimp SIV spillover thought to have occured?
less than 1 mya
How many spillover events have been documented so far?
13
When did the US SHHS predict that an AIDS vaccine would be ready for test?
1986
*did not happen, still do not have vaccine
How is HIV transmitted?
When a bodily fluid carries the virus from an infected person directly onto a mucus membrane or bloodstream of an uninfected person
HIV is spread via ______ _____ in different parts of the world.
different routes
What is HIV?
- it is an intracellular parasite incapable of reproducing on its own
- it uses the host cell’s machinery to replicate
Why are viral diseases challenging?
It is hard to find drugs that disrupt viral life cycle without disrupting the host cell’s functioning
- effective antiviral therapies usually target enzymes specific to the virus
How does HIV invade host cells?
By latching on to two proteins CD4 and CD5
- cells that contain these proteins are especially vulnerable (includes macrophages and T cells~immune system cells)
When does AIDS begin?
when the T cell count (CD4) is low and the immune system begins to collapse
How do you prevent AIDS?
Prevented HIV from replicating
Why is HIV lethal?
For higher transmissibility
- trade off, high viral load = host death but also = higher transmission
