Emerging Filo and Paramyxoviruses

Question 1

What are similarities between Marburg and Ebola viruses

Answer 1

both viruses are members of the virus family Filoviridae

named based on where outbreaks occur

Question 2

What are differences between Marburg and Ebola viruses

Answer 2

genomes look similar but are antigentically distinct

Question 3

When and where was the largest outbreak of Marburg virus

Answer 3

largest outbreak was in Angola in 2004-2005

88% mortality rate, combined of all cases is 82%

most infections occur in people who have recently visited caves in Uganda

Question 4

When was the Marburg virus discovered

Answer 4

discovered in 1967 in Marburg germany

laboratory personnel contracted the virus while processing organs from African green monkeys imported from Uganda

Question 5

When did the Ebola virus first appear

Answer 5

first appeared in 1976 in the democratic republic of Congo that is in central africa

Question 6

When and where was the largest Ebola outbreak, what was the average morality rate for this virus

Answer 6

largest outbreak occurred in west africa during 2014-2016

average mortality rate is 42%

very lethal to the chimps and monkeys in the jungles of Africa

there is a current outbreak

Question 7

How is the Ebola virus transmitted

Answer 7

animal to humans and human to human

Question 8

How is Ebola transmitted from animal to human

Answer 8

eating of bushmeat: dead monkeys in the jungle

pteropodidae fruit bats are the reservoir host

transmitted by contacting fluids of wild animals or bats

Question 9

How is ebola transmitted from humans to humans

Answer 9

direct contact with bodily fluids

sharing of food, kissing, intercourse, sexual contact

virus can live in semen for up to 82 days

contaminated surfaces

breast feeding —- vertical transmission

ebola virus can
persist after symptoms are resolved

Question 10

Describe the pathogenesis of Ebola in general terms

Answer 10

Viral Hemorrhagic Fever
1 week incubation period
high level of viremia that is spread via the circulatory system
virus levels remain high throughout the infection
broken or ruptured blood vessels
loss of endothelial cells and breakdown of vascular structure
can be due to the direct infection or cytokine storm
destruction of lymphoid tissues, limited immune response
liver damage, kidney failure, gastrointestinal bleeding
severe infection leads to death in second week of illness, those that survive have a long recovery

day 7-9: headache, fatigue, fever, muscle soreness
day 10: sudden high fever, vomiting, blood, passive behavior
day 11: busing, brain damage, bleeding from mouth, nose, eyes, anus
day 12: loss of consciousness, seizures, massive internal bleeding, death

Question 11

What types of cells are targeted by Filoviruses

Answer 11

can infect a large number of cell types
endothelial cells: line the blood vessels
immune cells: tissue macrophages
epithelial cells: can get inside of the tissues

Question 12

Why are Filoviruses so deadly

Answer 12

can infect a large number of cell types

target tissue macrophages leading to tissue factor disregulation
induce prominent cytokine storm early in infection
very good at blocking the host antiviral defenses such as the interferon response
interferon makes interferon stimulated genes
VP35 blocks production in both Marburg and Ebola
VP40 blocks effects of interferon in Marburg
VP24 blocks effects of interferon in Ebola

Question 13

Why does Ebola viruses disproportionately affect healthcare workers

Answer 13

Ebola disproportionally affects healthcare workers
the number of healthcare workers in affected countries was desperately low so they had to see many patients increasing the risk of exposure

Question 14

What is ZMapp

Answer 14

convalescent plasma from a recovered patient
administration of neutralizing antibodies against Ebola Zaire glycoprotein: ZMapp
type of specific treatment for Ebola
is an experimental biopharmaceutical drug comprising of monoclonal antibodies as a treatment
viral polymerase inhibitor looks promising

Question 15

What type of vaccine is used for Ebola

Answer 15

live attenuated vaccine

Question 16

Describe the vaccine that has been developed for Ebola

Answer 16

Live- attenuated vaccine
only effective against Ebola Zaire virus
referred to as rVSV-ZEBOV

vaccine was developed by swapping the G envelope protein of vesicular stomatitis virus (VSV)
a Rhabdovirus with the Ebola GP envelope protein

shown to be effective in preventing infection by Zaire EBOV
5837 people vaccinated and no EBOV cases
23 cases in similar number of people in same locale and in same time frame that did not receive the vaccine
has been important tool in the outbreaks currently
the vaccine has to be specific for the strain circulating

Question 17

What are treatments for Ebola

Answer 17

supportive care

fluid replacement, anti-diarrheal therapy, electrolyte replenishment, respiratory support, analgesics for pain, anti-epileptic medications, renal replacement therapy (dialysis)

specific treatments: ZMapp

Question 18

What are emerging Paramyxovirues specifically the Henipaviruses

Answer 18

Hendra nad Nipah

Question 19

When and where did Hendra virus originate and why type of animal is most associated with this disease

Answer 19

Hendra virus is a type of Paramyxoviruses
causes severe disease in horses
humans in close contact have been infected
first cases were discovered in racehorses in Queensland Australia in 1994
high morality rate in both intermediate hosts (hosts) and dead end hosts (humans)
think the reservoir host is bats

Question 20

When and where did Nipah emerge

Answer 20

emerged in 1998 in Malaysia and Singapore
outbreak caused encephalitis in humans
link between pig workers and the disease so 1 million pigs were culled and this halted the spread of the virus
severe disease in pigs
resulted in huge economic loses due to the outbreak in 1998 there were more than 500 million dollars
think the reservoir host is bats

Question 21

What is the likely reservoir host for Hendra and Nipah viruses

Answer 21

bats
originate the same family of bats like eobla
there may be a specific species that is more likely to carry it than other bat species

Question 22

What is Henipavrius Pathogenesis

Answer 22

initial infection of lower respiratory tract followed by severe respiratory disease
damage leads to hemorrhage of the lung and release of virus into the circulatory system
once the virus is in the blood, it targets the organs including the brain
either compromises the blood brain barrier or travels along the olfactory bulb to gain entrance into the brain
causes severe encephalitis

Question 23

What are the intermediate hosts in Hendra virus

Answer 23

horses and dead end hosts are humans

Question 24

What are the intermediate hosts in the Nipah virus

Answer 24

pigs and dead end hosts are humans

Question 25

What virus is in horses and humans and originated in bats that causes severe disease and what viral family does it belong to

Answer 25

paramyxoviruses
Henipaviruses

Hendra

Question 26

What virus is in pigs and humans and causes encephalitis and originated in bats and what viral family does it belong to

Answer 26

paramyxoviruses
Henipaviruses

Nipah

Question 27

What virus causes viral hemorrhagic fever and was the biggest outbreak was in 2014-2015 in west Africa and what viral family does it belong to

Answer 27

ebola and belongs to the filoviruses family

Question 28

What virus had its largest outbreak in Angola from 2004-2005 and what viral family does it belong to

Answer 28

marburg and belongs to the filovirus family

Question 29

Are filoviruses + RNA or - RNA

Answer 29

• strand

viral hemorrhagic fevers

Ebola
Marburg

Question 30

Are paramyxoviruses + RNA or - RNA

Answer 30

• strand