Lecture 12--resp/emerging viral Flashcards
enveloped RNA virus with segmented genome
influenz
two types of spike proteins on envelope of flu virus:
hemagglutinin and neuraminidase
role of hemagglutinin?
recognize, attach to receptors on resp tract epithelial cells
role of neuraminidase?
degrade protective mucus coating resp tract allowing virus reach host cell surface, help release newly formed mature virus
most common type flu?
type A, most severe and broad host range
type A has __ diff H types, ___ diff N types
18; 11
what is shifting?
segmented genome allow H and N genes reassort if two diff flu subtypes infect same host cell at same time (progeny is mix, new subtype)
what is drifting?
during virus replication, random mutations occur in H or N genes, result in minor changes (progeny just slightly diff)
shifting facilitated in areas where ____
agricultural practices involve close human animal contact
type A has ___ day incubation, __ day symptoms, __ week recovery
1-3; 4-8; 1-2
type A is contagious __ day before symptoms, ___ day after symptoms
1; 5
characteristics of flu
high fever, headache, pains, fatigue, chest discomfort and coughing
how diagnose flu in lab?
nasopharyngeal swab (within 5 days of onset of symps)
main lab test for flu?
PCR
HOW DOES TAMIFLU AND RELENZA WORK?
block neuraminidase activity, work best in 1 or 2 days, reduce severity/duration, only given if hospitalized/severe complications
what’s in flu vaccine?
killed whole virus or purified H and N proteins
how effective is vaccine?
50-60%
why not so effective?
flu virus changes, diff patients respond diff (health factors)
why need get flu shot every year?
antibodies developed last year are gone, new flu strains not in last year
who should get vaccine
> 6mths, nursing homes, healthy >50, healthcare workers
enveloped RNA virus with pleomorphic morphology, hemorrhagic fever virus
ebola
mechanism of ebola?
replicate in WBC, spread via lymph, secondary infections throughout body, transmit with blood/body fluids
how care for ebola?
fluid replacement, maintain electrolyte balance
traits of emerging diseases?
usually start zoonotic, sustained by human to human transmission, international outbreak possible, combatting is challenging
