Module 8 Flashcards
describe the influenza virus
ssRNA virus with a nucleocapsid and outer lipoprotein evelope
what are the antigenic differences of the internal structure proteins in the influenza virus
nucleocapsid (NP)
matrix (M) protein
how are Influenza A viruses subtyped
hemagglutinin
Neuraminidase
describe hemagglutinin
binds to target cell surface to initiate infection
Ab against the hemagglutinin neutralizes the infectivity of the virus and prevents disease –> useful in vax
describe neuraminidase
cleaves neuraminic acid to release progeny virus from infected cell
degrades protective layer of mucus in resp tract
enhances ability of virus to infect the respiratory epithelium
Ab against neuraminidase does not neutralize infectivity but does reduce disease
what are antigenic shifts
major changes based on the reassortment of segments of the genome RNA between virus subtypes
what are antigenic drifts
minor changes based on mutations in the genome RNA
describe the reassortment of H1N1
hemagglutinin, nucleoprotein and nonstructural protein genes from NA swine origin
neuraminidase and matrix protein genes from Eurasian swine origin
two polymerase subunits from NA avian origin
3rd polymerase subunit from human H3N2 origin
treatment options for influenza
antivirals –> zamanivir, aseltamivir
in young population better to treat symptoms
describe influenza vaccines
inactivated preparations derived from influenza A/B that circulated late in previous season –> safe in pregnancy
live preparations not safe in pregnancy
describe herpes dsDNA enveloped viruses
HSV 1
HSV 2
VZV
EBV
CMV
cause latent infections
what is hepetitis
inflammation of liver
what causes hepatitis
viruses and alcohol abuse
2 forms of hepatitis
acute and chronic
describe parvovirus
ssDNA virus
respiratory or in utero transmission
in pregnancy only mild illness will occur
<5% of infections will cause miscarriage, fetal anemia or hydrops fetalis
describe rubella in pregnancy
crosses placenta
can cause congenital rubella –> teratogen
HTLV-1
retrovirus
transmitted through intercourse, blood, milk
infected asymptomatically for life
5% risk of T cell leukemia 30 years post infection
rare for in utero transmission
infants develop dermatitis, myelopathy, high risk for adult type leukemia
describe HIV
ssRNA retrovirus
transplacental, perinatal or postatal transmission
25% of infants with HIV+ mothers not on retrovirals will be infected
newborn symptoms include low birth weight, sepsis, pneumonia, encephalopathy
describe zika virus
ssRNA enveloped virus
vector or sexual transmission
can cause congenital zika sydrome
congenital zika syndrome
microcephaly
incomplete brain development
increased muscle tone impacting development
club foot and contracted limns
abnormal eye movement
describe covid-19
enveloped positive sense RNA virus
large portion of infections are asymptomatic
