Lecture 28 - Emerging Viruses

Question 1

What is an emerging virus (definition)?

Answer 1

new/recently identified virus to humans

Question 2

What is a reemerging virus (definition)?

Answer 2

virus under control from public health perspective; making a comeback/reappearance and increasing in incidence/geographical range of exposed human populations

Question 3

What are the 3 characteristics of emerging viruses?

Answer 3

expanded host-range w/ increase in disease | virus transmission from animals to humans | cross-species infection = can establish new virus in population

Question 4

What are the 5 forces that drive viral emergence?

Answer 4

human population/social behavior (ie: travel) | climate/environmental changes | ecological factors | genetic/biological factors | microbial evolution/adaptation

Question 5

What are the 4 host-virus interactions?

Answer 5

stable, evolving, dead-end, resistant

Question 6

What is the stable host-virus interaction?

Answer 6

virus is maintained in the ecosystem

Question 7

What is the evolving host-virus interaction?

Answer 7

passage of virus to naive population (same or different host)

Question 8

What is the dead-end host-virus interaction?

Answer 8

one-way passage of virus to a different species

Question 9

What is the resistant host-virus interaction?

Answer 9

viral infection is blocked

Question 10

What are the 3 characteristics of a stable host-virus interaction?

Answer 10

both participants (host and virus) survive and multiply | some interactions are effectively permanent | may include infection +1 species

Question 11

What are the 2 characteristics of an evolving host-virus interaction?

Answer 11

hallmarks = instability an unpredictability | infection outcome ranges from benign to death

Question 12

What are 3 characteristics of a dead-end host-virus interaction?

Answer 12

frequent outcome of cross-species infection | new infected host may not transmit virus to others of same species | contributes little to spread of a natural infection

Question 13

What type of host-virus interaction do West Nile Viruses have?

Answer 13

stable (generally) | large mammals = dead-end hosts

Question 14

What are 5 characteristics of West Nile Virus?

Answer 14

brain-related severe illness | neurological symptoms = 10% = severe brain damage/die | RNA, flavivirus

Question 15

What mosquito can help spread West Nile Virus and what are its biting habits?

Answer 15

Culex | dusk to dawn

Question 16

What are characteristics of Zika virus?

Answer 16

1st outbreak in Yap = infected 78% population, 18% = symptoms | strong preference for maternofetal transmission and adverse fetal outcomes

Question 17

What mosquito spreads Zika virus and what are its biting habits?

Answer 17

Aedes | daytime

Question 18

What are 2 diseases/conditions as a result of Zika virus infection?

Answer 18

microcephaly | neuological disorders (motor weakness)

Question 19

How is Zika virus spread person-to-person?

Answer 19

congenitally | sexually

Question 20

What are the hosts for Yellow Fever virus?

Answer 20

humans and primates

Question 21

What mosquito spreads Yellow Fever virus?

Answer 21

Aedes

Question 22

What is the transmission of Poliovirus?

Answer 22

fecal-oral | via contaminated water

Question 23

What is the H7N9 influenza virus?

Answer 23

lasted only 2013 | 8 of viral genes = closely related to viruses found in domestic ducks and poultry and wild birds in Asia

Question 24

What disease does Nipah virus cause to humans?

Answer 24

respiratory and neurological disease due to pig farms

Question 25

What animal spreads Nipah virus but is unaffected?

Answer 25

fruit bats = excrete virus in urine

Question 26

Which animals spread Nipah virus to humans?

Answer 26

pigs and bats

Question 27

What are 3 characteristics of Hantavirus?

Answer 27

virus excreted in mouse feces | humans not natural host | hantavirus pulmonary syndrome

Question 28

What are the symptoms of SARS?

Answer 28

fever, chills, malaise, myalgia, dyspnea, dry cough

Question 29

What disease does SARS cause?

Answer 29

severe atypical pneumonia

Question 30

What method of treatment could be used against SARS?

Answer 30

mechanical ventilation

Question 31

What type of virus is MERS-CoV?

Answer 31

emerging

Question 32

What happened within 6 months of discovery of MERS-CoV?

Answer 32

isolated and studied via 1-step growth analysis | genome cloned and sequence determined | infectious DNA clone used to make viral mutants | identified receptor | immunofluorescence to study infection of various cell types | serological assays used to determine origin of virus

Question 33

What is the Mayaro virus characterized by?

Answer 33

fever, rash, aches, pains (FRAP)

Question 34

What spreads Mayaro virus?

Answer 34

Aedes mosquito

Question 35

What can Mayaro virus cause in humans?

Answer 35

arthralgia; can persist for months, can be incapacitating

Question 36

What animal host does MERS-CoV infect?

Answer 36

camels, may have been infected by bats

Question 37

What cells does Ebola infect?

Answer 37

mucosal

Question 38

What does Ebola induce in the body?

Answer 38

inflammatory cytokines

Question 39

How does Ebola cause internal bleeding/hemorrhaging?

Answer 39

all coagulation proteins and platelets get consumed | small blood clots in vessels

Question 40

What does liver dysfunction due to Ebola infection cause?

Answer 40

increase liver enzymes

Question 41

What is AFM?

Answer 41

Acute Flaccid Myelitis

Question 42

What does AFM affect?

Answer 42

nervous system, esp. spinal cord

Question 43

What does AFM cause?

Answer 43

weakens muscles and reflexes, may cause paralysis

Question 44

Which individuals are mostly affected by AFM?

Answer 44

children

Question 45

What virus or type of virus causes AFM (assumed)?

Answer 45

enterovirus

Question 46

What virus/disease is similar to what causes AFM?

Answer 46

polio