A "defective virus" cannot replicate without a _______. Typically this is due to a mutation/deletion in their genetic material.
helper virus
True or false:
During the growth of most human viruses, many more defective than infectious virus particles are produced.
True
_________ viruses may aid in recovery from an infection by limiting infectious viral replication.
Defective viruses
A "pseudovirus" contains ______ instead of viral DNA within their capsid.
host-cell DNA
True or false:
Pseudovirions cannot infect cells or replicate.
False - they can infect cells, but not replicate
________ are formed during infections with certain viruses where the host-cell DNA is fragmented and incorporated within the viral capsid protein.
pseudovirions
________ consist solely of a single molecule of circular RNA without a protein coat or envelope
Viroids
True or False:
Viroids code for proteins but do not replicate.
False -- Viriods do NOT code for proteins, but DO replicate
Slow Viral infections refer to viruses whose viral growth is ____ and their incubation periods are _____.
1. viral growth is normal
2. incubation periods are long
Two slow virus examples:
Measles -->
JC Virus -->
Measles --> SSPE
JC Virus --> PML
Is immunosuppression a predisposing factor for development of SSPE?
No
SSPE is characterized by ________ in many areas of the brain.
inflammatory lesions
SSPE is caused by a persistant variant of a measles virus that cannot _________ so a large number of _____ are produced in neurons and glial cells.
1. replicate completely
2. nucleocapsids
True or false:
In SSPE, the measles virus survives persistently without evoking an immune response.
True
What is the rare, fatal, demyelinating disease of white matter caused by the JC virus?
PML - progressive multifocal leukoencephalitis
True or false:
The development of PML from JC virus is an inflammatory process.
False -- non-inflammatory
PML is almost exclusively seen in patients with ____ (disease) and/or compromised ______ immunity.
1. AIDS
2. cell-mediated immunity
In PML, JC virus infects and kills ______ causing ______.
1. oligodendroglia
2. demyelination
Prions are composed solely of ______.
proteins
These virus-like agents are thought to be implicated in the disease processes of Alzheimer's and Parkinson's disease.
Prions
Prions are composed of a _______ that encodes a protein; the amount of prion protein mRNA is the ____ in affected and unaffected host cells, suggesting that ______ of the prion protein is an important distinction in infectivity.
1. single glycoprotein
2. the same
3. post translational modifications
In prion proteins, would a post-translational modification changing the protein structure from alpha-helix to beta-sheet increase or decrease its infectivitiy?
Increase its infectious potential
Do prions induce an immune response or inflammation?
No
Which prion disease is associated with rare contraction from corneal transplants?
CJD
True or False:
Florid plaques is a characteristic finding seen in classic CJD.
False -- seen in variant CJD
What is the difference between the initial manifestations of classic versus variant CJD?
classic = dementia
variant = behavioral/psychiatric changes/dyesthesiasis
Which version of CJD (classic of variant) is characterized by sharp waves on EEG?
Classic CJD
Gerstmann-Staussler Sheinker Syndrome is a prion neurodegenerative disease that is exclusively ____ and only found in a few families all over the world.
exclusively heritable
Fatal familial insomnia is a rare genetic degenerative brain disorder caused by ____ that is characterized by _____.
1. prions
2. insomnia
Which prion disease is associated with cannibalism?
Kuru
Which prion disease is associated with New Guinea?
Kuru
Live, attenuated vaccines exist for which viruses:
(Mayday Small Children Really Yelling)
MMR
Smallpox
Chickenpox
Rotavirus
Yellow fever
Inactivated vaccines exist for which viruses:
(R.I.P. HAdrosaurus)
Rabies
Influenza
Polio
Hepatitis A
Recombinant vaccines exist for which viruses?
(Helping Hands Better Immunize)
HPV
Hepatitis B
Influenzae
Which type of vaccine requires boosters?
Inactivated vaccines
Which type of vaccine evokes more of a humoral immune response rather than cell-mediated?
inactivated
Viruses are being used as genetic vectors in two novel ways:
1. To deliver _____ to patients with genetic diseases
2. To produce _____ that contain ____ carrying the genes of several different viruses
1. To deliver functional genes to patients with genetic diseases
2. To produce new viral vaccines that contain recombinant viruses carrying the genes of several different viruses
How are retroviruses useful in gene therapy mechanisms?
Because they incorporate viral DNA into host cell DNA
West Nile Virus is a ____________ (viral family), that is ________ (enveloped or nah), __________ shaped, with a _______ genome.
1. Flaviviridae flavivirus
2. Enveloped
3. Icosahedral
4. +ssRNA
St. Louis Encephalitis Virus is a ____________ (viral family), that is ________ (enveloped or nah), __________ shaped, with a _______ genome.
1. Flaviviridae flavivirus
2. Enveloped
3. Icosahedral
4. +ssRNA
Powassan Virus is a ____________ (viral family), that is ________ (enveloped or nah), __________ shaped, with a _______ genome.
1. Flaviviridae flavivirus
2. Enveloped
3. Icosahedral
4. +ssRNA
Dengue Virus is a ____________ (viral family), that is ________ (enveloped or nah), __________ shaped, with a _______ genome.
1. Flaviviridae flavivirus
2. Enveloped
3. Icosahedral
4. +ssRNA
Zika Virus is a ____________ (viral family), that is ________ (enveloped or nah), __________ shaped, with a _______ genome.
1. Flaviviridae flavivirus
2. Enveloped
3. Icosahedral
4. +ssRNA
Yellow Fever Virus is a ____________ (viral family), that is ________ (enveloped or nah), __________ shaped, with a _______ genome.
1. Flaviviridae flavivirus
2. Enveloped
3. Icosahedral
4. +ssRNA
Equine Encephalitis Viruses are a ____________ (viral family), that is ________ (enveloped or nah), __________ shaped, with a _______ genome.
1. Togaviridae Alphavirus
2. Enveloped
3. Icosahedral
4. +ssRNA
Chikungunya Virus is a ____________ (viral family), that is ________ (enveloped or nah), __________ shaped, with a _______ genome.
1. Togaviridae Alphavirus
2. Enveloped
3. Icosahedral
4. +ssRNA
LaCrosse Virus is a ____________ (viral family), that is ________ (enveloped or nah), __________ shaped, with a _______ genome.
1. Bunyaviridae Bunyavirus
2. Enveloped
3. Helical
4. -ssRNA
Colorado Tick Fever Virus is a ____________ (viral family), that is ________ (enveloped or nah), __________ shaped, with a _______ genome.
1. Reoviridae Coltivirus
2. Non-Enveloped
3. Linear, segmented
4. dsRNA
Arthropod-borne Viral Zoonoses must reach the ______ or an insect in order to be transmitted to another host.
salivary glands
In arboviral diseases, _____ and _____ immunity are important for recovery.
antibody and cell-mediated
Diagnosis of Arboviral diseases is usually through testing of serum or CSF for ______, usually in the form of virus-specific _____, or with _____ for viral RNA.
1. antibodies
2. IgM
3. qRT-PCR
Mosquitos are the vectors for all encephalitic arboviruses except for ______
Powassan virus (POWV)
Mosquitos are the vectors for all systemic arboviruses except for _____.
Colorado Tick fever
West Nile Virus causes ________ (encephalitic or systemic) disease that is transmitted via a cycle of ____ and ____.
1. encephalitic
2. birds and culex mosquitos
St. Louis Encephalitis Virus causes ________ (encephalitic or systemic) disease that is transmitted via a cycle of ____ and ____.
1. encephalitic
2. wild birds and culex mosquitos
Japanese Encephalitis Virus causes ________ (encephalitic or systemic) disease that is transmitted via a cycle of ____ and ____; ____ are an amplifying host
1. encephalitic
2. water birds and culex mosquitos
3. pigs
________ is the leading cause of neurologic disease in China; 90% of cases are in ______.
1. Japanese Encephalitis Virus
2. children
Japanese Encephalitis Virus causes diffuse _______ in its victims and up to 70% of affected individuals have _______.
1. diffuse brain damage
2. residual symptoms
What encephalitic viruses have vaccines?
Japanese Encephalitis Virus (available in asia)
True or False:
Infection with one serotype of Dengue virus provides protection against infection with another serotype.
False
True or false:
Secondary infections with Dengue virus generally lessens the risk of serious disease.
False - greater risk for serious disease
True or False:
Dengue Virus vaccines are available for individuals who have never been infected with the virus.
False -- If not previously infected, the vaccine may increase the risk for developing sever dengue
Zika Virus causes ________ (encephalitic or systemic) disease that is transmitted via ____ and ____.
1. systemic
2. sexually transmitted and aedes mosquitos
Recent outbreaks of Zika virus are associated with neuro-complications such as ____.
Guillan-barre's Syndrome (GBS)
Microcephaly in a neonate is associated with infection with ____ virus in the first trimester of pregnancy.
Zika virus
Yellow Fever Virus causes ________ (encephalitic or systemic) disease that is transmitted via ____.
1. systemic
2. aedes mosquito
Which systemic virus is associated with flu-like symptoms, nausea, and "black" vomit with jaundice?
Yellow Fever Virus
Which systemic viruses have vaccines available?
Yellow Fever Virus, Dengue Virus,
Powassan Virus causes ________ (encephalitic or systemic) disease that is transmitted via ____ with a _____ reservour.
1. encephalitic
2. ixodes ticks
3. small rodent reservoir
Powassan Virus infections are seen mostly in the ____ and _____ regions.
NE and Great Lakes regions
True or False:
Wester Equine Encephalitis virus is the most virulent of the equine viruses.
False -- EEEV is the most virulent.
What is the order of case fatality and neurological sequelae, from greatest to least, of the equine encephalitis viruses?
EEEV > WEEV > VEEV
Chikungunya Virus causes ________ (encephalitic or systemic) disease that is transmitted via ____ and ____.
1. Systemic
2. primates and aedes mosquitos
Large urban outbreaks of Chikungunya are associated with the _____ season and causes immediate ____ symptoms.
1. the rainy season
2. flu-like symptoms
With Chikungunya Virus, neurological infections are common in _____ and chronic sequelae may continue up to ______ following initial infection.
1. children
2. up to 10 years
La Crosse Virus causes ________ (encephalitic or systemic) disease that is transmitted via ____ and ____.
___________ are at highest risk fo severe disease.
1. Encephalitic
2. small mammals and aedes mosquito
3. Children
Colorado Tick Fever Virus causes ________ (encephalitic or systemic) disease that is transmitted via ____ and ____. Most cases occur in the _____ and 50% present with a _______ fever.
1. Systemic
2. small rodent and wood tick
3. spring and summer
4. biphasic
Hantavirus belongs to the family _______ with a _____ host. Outbreaks are associated with _______.
1. Bunyaviridae hantavirus
2. Rodent host
3. increased precipitation (affecting rodent population)
Severe manifestations of Hantvirus include ________ and __________.
Hantavirus pulmonary syndrome and hemorrhagic fever with renal syndrome
The two important serotypic groups of Hantaviruses are _____ and _____.
Sin Nombre (new world) and Seoul (old world)
Sin nombre hantavirus is usually found in the _______ (region) and its host is a ________
1. Central and western US, canada
2. deer mouse
Seoul hantavirus is usually found ______ (region) and its host is a ______.
1. worldwide
2. norway brown rat or roof rat
Most cases of Hantavirus pulmonary syndrome in the US are caused by which serotype of hantavirus?
Sin Nombre (new world)
The initial phase of hemorrhagic fever with renal syndrome caused by hantavirus is characteristics by acute onset headaches, back and abdominal pain, ____ vision, _____ of the face, and inflammation or redness of the _____.
1. blurred
2. flushing
3. eyes
Crimean-Congo Hemorrhagic Fever is caused by the viral family _______ with a _____ vector and ____ host.
1. Bunyaviridae Nairovirus
2. tick vector
3. animals = amplifying hosts
Animal herders, livestock workers, and slaughterhouse workers in endemic areas are at an increased risk for which hemorrhagic-fever associated viral disease?
Crimean-Congo hemorrhagic fever
Crimean-congo hemorrhagic fever has a sudden onset flu-like syndrome with _____ on the ______.
petechiae on the palate
_______ is used in the management of Crimean-Congo hemorrhagic fever with some efficacy reported.
Ribavirin
Ribavirin is used in the management of which viral hemorrhagic fevers?
Crimean-congo hemorrhagic fever and Lassa Fever
Rift Valley Fever is caused by the viral family _______ and is transmitted through _______.
1. Bunyaviridae Phlebovirus
2. Domesticated farm animals
Severe manifestations of Rift Valley fever may cause ____ disease with permanent ______.
1. Ocular
2. permanent vision loss
Which viral zoonoses is associated with ocular disease with permanent vision loss in the 10% of patients that develop severe manifestations?
Rift Valley Fever
Arenavirus hemorrhagic fever is transmitted through ___ vectors and includes _____ and ______ (diseases/viruses).
1. rodent
2. Lassa Fever and Lymphocytic choriomeningitis virus
Lassa Fever is caused by the viral family _______ and is transmitted via ______.
1. Arenaviridae arenavirus
2. multimammarate rat
Lassa Fever is endemic in _____.
____ is used in its treatment and can be effective early in the disease course.
1. West Africa
2. Ribavirin
Lymphocytic Choriomeningitis Virus is caused by the viral family _______ and is transmitted via ______.
1. Arenaviridae mammarenavirus
2. common house mouse; guinea pigs/hamsters may be carriers
_______ patients are at higher risk of contracting Lymphocytic choriomeningitis virus.
organ transplant patients
Patients with LCMV (lymphocytic choriomeningitis virus) will characteristically present with the following lab values:
______penia
______penia
CSF with _______
1. leukopenia
2.thrombocytopenia
3. CSF with low glucose
Infection with ________ (which arenavirus) during pregnancy can lead to congenital hydrocephalus, chorioretinitis, and intellectual disability?
Lymphocytic choriomeningitis virus
Ebola is caused by the viral family _______ and its vector is _____.
1. Filoviridae ebolavirus
2. Vector is unknown
True or False:
There is a vaccine for Ebola.
True
Marburg is caused by the viral family _______ and its reservoir is _____ and it is endemic in _____.
1. Filoviridae Marburgvirus
2. the African fruit bat
3. Central africa
Rabies is caused by the viral family _______ and it is transmitted via _______.
1. Rhabdoviridae lyssavirus
2. bite from infected animal
_____ and ____ have the highest incidence of rabies.
Africa and Asia
Rabies has a ~ ______ incubation period; once symptoms due manifest , most infected animals die within _____.
1. ~2 month incubation
2. within 7 days of symptoms
Post-mortem, brains of those infected by rabies exhibit ____ in brain tissue.
Negri bodies
True or False:
If someone has been vaccinated for rabies and gets bitten by an animal suspected to have rabies, they do not need post-exposure prophylaxis.
False -- even if vaccinated will need post-expo prophylaxis treatment