Viruses and Disease

Question 1

can a virus be both a DNA and RNA virus

Answer 1

nope- it’s either a DNA virus or an RNA virus

Question 2

do viruses have ribosomes

Answer 2

nope

Question 3

how might you describe a virus in terms of a parasite

Answer 3

they are obligate intracellular parasites

Question 4

what microscope is required to see a viral cell

Answer 4

electron microscope!

Question 5

explain simply the virus life cycle

Answer 5

virus binds via receptor binding to the host cell and enters the host. here, the host cell replicates the viral components. new viruses assemble and then these new viruses are released from host cell

Question 6

how are viruses spread

Answer 6

oral transmission, direct skin contact, sexual transmission, droplet transmission, direct inoculation

Question 7

what viruses may be spread from oral transmission

Answer 7

hep A, noroviruses, polio, rotaviruses

Question 8

what viruses may be spread from direct skin contacy

Answer 8

HPV, Herpes simple virus, Epstein Bar virus, Varicella- Zoster virus, Coxsackie (hand, foot and mouth)

Question 9

which viruses are transmitted sexually

Answer 9

HIV, HPV, HSV-2

Question 10

what viruses are transmitted via droplets

Answer 10

SARS-CoV-2, rhinovirus, influenza, RSV, measles

Question 11

which viruses are spread via direct inoculation

Answer 11

Hep B, HIV, yellow fever virus, west nile virus, rabies

Question 12

what is the CFR rate?

Answer 12

epidemiologic metric that measures the propotion of people who die from a certain disease among all positive cases.

Question 13

write a short note on smallpox

Answer 13

eradicated virus by varicolation (intentional infection) and vaccination. it is a DNA virus. similar to monkeypox which is transmitted via infected bushmeat

Question 14

write a short note on herpes virus

Answer 14

this virus is a lifelong infection. the virus infects nerve cells around the trigeminal nerve causing sores around mouth an lips. during its latent phase it may remain dormant in the neuronal cells, and then the infection can return in times of stress, illness and lack of sleep

Question 15

what type of virus are retroviruses usually

Answer 15

rna virus with reverse transcriptase

Question 16

write a note on HIV

Answer 16

targets CD4 lymphocytes specifically (type of T cell). is RNA virus initially but is transcribed to DNA via reverse transcriptase enzyme. incorporates itself into the host’s genome. replicates inside CD4 cell and then is released into the body to find more t cells

Question 17

how is HIV treated and transmitted

Answer 17

transmitted via unprotected sex, blood transfusion, needles, mother -> baby

treated by education around contraceptives and clean needles. also antivirals may be prescribed, combination anti-retroviral therapy (ART), nucleosides, protease inhibitors, RT inhibitors, HIV triple therapy (costly)

Question 18

what are the zoonotic viruses

Answer 18

influenza, HIV, ebola, SARS-Cov-2

Question 19

what are the key features of SARS-CoV-2

Answer 19

coronavirus with crown-like spikes (proteins). it binds to ACE2 receptors on host cells in the resp tract.

Question 20

Is SARS-CoV-2 a DNA or RNA virus

Answer 20

RNA

Question 21

draw diagram showing fusion of SARS-CoV-2 Binding + infection

Answer 21

8th slide from bottom in powerpoint

Question 22

how might you quantify SARS-CoV-2 in city wastewater for example

Answer 22

collect sample, centrifuge and purify RNA, reverse transcribe the RNA to DNA and quantify using PCR methods