Lecture 15 (Exam 2)

Question 1

Who was misquoted saying “the war against epidemics due to pathogens is over”?

Answer 1

William H Stewart

Question 2

What year did doctors in the US find a mysterious new disease that was mostly affecting homosexual men?

Answer 2

1981

Question 3

What was hypothesized about the mysterious new disease?

Answer 3

That it was a sexually transmitted disease

Question 4

Doctors and other medical professionals made what to track the disease?

Answer 4

Patient maps
patients who were infected would detail who they slept with and those people would detail who they slept with

Question 5

Who was wrongly identified as patient zero? What year?

Answer 5

Gaetan Dugas, a french Canadian airline steward
1988

Question 6

How was it estimated that HIV arrived to the US?

Answer 6

used measurements of virus diversity

Question 7

what is virus diversity?

Answer 7

number of mutations that have accumulated

Question 8

When and where did HIV come to the US from?

Answer 8

1966 via Haiti, from Africa

Question 9

When and where were the earliest known HIV positive human samples from men found?

Answer 9

1959 in Kinshasa, DRC

Question 10

How were theses samples (1959 ones) used?

Answer 10

to date the spillover event to about 1908

Question 11

what is a spillover event?

Answer 11

when a virus in one species passes into another species

Question 12

Around the same time (1959) what similar virus was found in several primate species?

Answer 12

SIV: simian immunodeficiency virus

Question 13

Where was it discovered that human AIDS comes from chimps?

Answer 13

A small part of Cameroon

Question 14

What is the most plausible hypothesis of transmission?

Answer 14

cut hunter theory

Question 15

What does the cut hunter theory propose?

Answer 15

that HIV-1 crossed from a chimpanzee to human in the course of hunting, butchery, and eating of chimpanzees as bushmeat

Question 16

By what year and where did HIV arrive and begin its spread>

Answer 16

1920 and Kinshasa

Question 17

What is Chimp SIV?

Answer 17

a hybrid composed of virus from red capped mangabey and spot nosed guenon

Question 18

When is Chimp SIV spillover thought to have occured?

Answer 18

less than 1 mya

Question 19

How many spillover events have been documented so far?

Answer 19

13

Question 20

When did the US SHHS predict that an AIDS vaccine would be ready for test?

Answer 20

1986
*did not happen, still do not have vaccine

Question 21

How is HIV transmitted?

Answer 21

When a bodily fluid carries the virus from an infected person directly onto a mucus membrane or bloodstream of an uninfected person

Question 22

HIV is spread via ______ _____ in different parts of the world.

Answer 22

different routes

Question 23

What is HIV?

Answer 23

• it is an intracellular parasite incapable of reproducing on its own
• it uses the host cell’s machinery to replicate

Question 24

Why are viral diseases challenging?

Answer 24

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

Question 25

How does HIV invade host cells?

Answer 25

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)

Question 26

When does AIDS begin?

Answer 26

when the T cell count (CD4) is low and the immune system begins to collapse

Question 27

How do you prevent AIDS?

Answer 27

Prevented HIV from replicating

Question 28

Why is HIV lethal?

Answer 28

For higher transmissibility
- trade off, high viral load = host death but also = higher transmission