Virology 1.3 Flashcards
non-enveloped RNA viruses
lack lipid envelope, stable in environment, enteric pathogens are acid stable, cause GI lines, RHINOVIRUSES are part of this family, as well as picornaviruses, calciviruses and reoviruses.
Poliovirus
picornavirus (very small)
fecal oral route
replicated in oropharynx and gut
viremia to CNS- why it leads to paralysis
replicates in motor cells of anterior horn
excreted in feces for MONTHS!!
other non enveloped RNA viruses
Hep-A rhinoviruses- common cold enteroviruses norwalk rotavirus
Influenza
orthomyxovirus-ssRNA, SEGMENTED, enveloped. Myxo=mucin adhering
two groups, a&b a causes pandemics.
spread by aerosols
cause approx 30K excess deaths per year in the US
influenza A
affects variety of hosts
pigs are the mixing bowl for genetic reassortment
basis of antigenic shift**
> exchange of *segments so that the immunity doesn’t work
DRIFT DUE TO MUTATION
we now have a live attenuated vaccine as well as inactivated.
Hemagglutinin
a glycoprotein found on the surface of the influenza viruses. It is responsible for binding the virus to cells with sialic acid on the membranes, such as cells in the upper respiratory tract or erythrocytes.[1] It is also responsible for the fusion of the viral envelope with the endosome membrane, after the pH has been reduced. The name “hemagglutinin” comes from the protein’s ability to cause red blood cells (erythrocytes) to clump together (“agglutinate”) in vitro.
Measles
most likely to kill or give brain damage, of all childhood diseases.
paramyoviruses
measles, mumps, respiratory syncytial virus, parainfluenza, ssLinear RNA viruses
fusogenic, giant cell formation
respiratory transmission, viremia, spread to target organs.
Rubella
German measles
only pathogenic TOGAVIRUS
rash usually flushed appearance
family includes EEC(high rate of brain damage) and WEC and alphaviridae
ALL MOSQUITO BORNE PATHOGENS
chikungunya virus
can lead to arthritis
arboviruses
not a real taxonomic term
flaviviruses
bunyaviruses
reoviruses: colorado tick fever
flaviviruses
yellow fever
dengue (breakbone fever)
st louis encephalitis
west nile
Rabies
rhabdovirus
bullet shaped enveloped virus
infects all mammals
bat exposure could be enough
site of bite is important, it takes time to spread!
Non-enveloped DNA viruses
adenovirus- conjunctivitis, pharyngitis, pneumonia gastroenteritis, disseminated disease in immunocompromised
*has a polymerase that is a target of choice for drugs
HPV- can lead to cervical cancer.
Parvovirus (B19)- can wipe out RBCs in HIV patients
Polyomaviruses- JC- neuro syndrome, BK-renal failure
Enveloped DNA viruses
Hep B
herpes
poxviruses
