Exotic viruses Flashcards
what are the effects of viral hemorrhagic fevers (VHF)? What are the symptoms?
multisystemic syndrome: damages within the vascular system, hemorragies
–> bleedings in
-conjuctivitis
-petechia
-ecchymosis
-internal organs
initial symptoms
-fever
-tiredness
-dizziness
-muscle pain
-fatigue
which 4 virus families are responsible for VHF? Name for each family example diseases
-Bunyaviridae (Rift valley fever)
-arenaviridae (Lassa)
-filoviridae (Ebola)
-flaviviridae (Dengue, Yellow fever)
What are common features of hemorrhagic fever viruses?
-RNA viruses
-coated
-animals as natural reservoir but not humans
-communication from human to human is rare
-outbreaks are sporadic and irregular
-most often no therapy available
-people get infected by contact to infected host animals
Which Hemorrhagic fever viruses have a high and which a low communication from human to human?
no: Yellow fever, Dengue, Hanta
low: Lassa
high: Ebola, Marburg, Krim-Kongo
How do hemorrhagif fevers lead to shock?
-increased vessel permeability
-decrease of blood pressure
-coagulopathy
-cytokine storm
lead to shock
How can HFV be diagnosed?
-Serology
-PCR (only in acute phase)
-immunoflourescence
-virus isolation, virus culture
–> BSL-4 safety level
What are the symptoms of Marburg virus?
-rash
-hemorrhages
How was Marburg virus isolated?
Blood of patients –> inocculation in guinea pigs –> multiple passages –> hemorrhagic fever –> EM of blood and organs
What are the Symptoms of Ebola?
-high fever
-headache
-sickness
-diarrhea, vomiting
.myalgia
-rashes
-severe hemorrhages
-shock by hypotension
-disturbance of coaggulation
–> systemic infection
What is the mortality rate of Ebola? What is the cause of death?
53 - 88 % due to overreaction of the body –> cytokine storm
what is the progression of infection of ebola?
monocytes/macrophages –> liver, spleen, lymph nodes –> blood vessels –> viremia (virus in blood)–> systemic infection
What is a reservoir?
high viurs titers but no symptoms and not lethal
How does ebola infect humans?
bat infects bush meat or is directly eaten –< Gorilla and duiker killed/eaten –> human infected by bush meat –> human to human communication via body fluids of infected patients, ritual washing of dead people, treatment of infected persons
How do bats react to ebola?
can be infected experimentally and develop high virus titers but show mo sign of illness
What are mononegavirales? Which virus families?
single stranded, non segmented, negative Sense RNA genome, enveloped
-Filoviridae (Marburg, Ebola)
-Parammyxoviridae (measles)
-Rhabdoviridae (rabies, VSV)
-Bornaviridae
Which additional transcription factor is essential for transcription initiation in ebola virus?
VP30
Describe the infection cycle of Ebola
1.entry
2.uncoating
3.transcription, Translation and replication
4.assembly
5.budding
How is ebola replicated?
-strand to plus strand to many -strands
How can ebola be treated?
-antivirals: must be applied before onset of symptoms
-vaccines: 2 licensed
How do ebolavirus infected cells look under the microscope?
liquid-liquid phase separation in virus factories –> high local concentrations
Why was the ebola outbreak in 2013/2014 so fatal?
-recognized too late
-isolation measures taken too late and too inefficient
-population uneductaed
-health care system overwhelmed
-no confidence in government and foreign medical doctors
why is there a higher likelihood for a vaccine in zika virus?
only 3-5 % amino acid variability in E-Protein but it needs to protect the fetus from infection
