Micro Viral infections Flashcards
what are the MCC of the common cold
rhinovirus, coronavirus, influenza
what are the features of viral respiratory infections?
- virions reach respiratory tract by fomites or aerosol transmission
- epithelial cells first site
- infected cells release cytokines that cause typical symptoms
which viruses manifest clinically as rhinitis, pharyngitis, laryngitis?
rhinovirus, coronavirus, parainfluenza, RSV, influenza, adenovirus, herpes simplex, EBV
which viruses manifest clinically as tracheitis, bronchitis, bronchiolitis, bronchopneumonia?
parainfluenza, RSV, influenza, adenovirus
acute pattern of virus replication
infection with replication confined to respiratory mucosal surface
persistent pattern of virus replication
replication on respiratory mucosal surface
systemic pattern of virus replication
replication (dissemination) after primary replication in respiratory tract
corona virus bacteriology
“crown” of spikes, +ssRNA virus, causes cold like symptoms
myxoviruses
“mucus”, bind to mucin protein on RBCs
orthoviruses
straight, right proper, influenza is the “right” one
paravirus
beside, resembling - measles virus, parainfluenza, measles, RSV) (a bit like orthomyxoviruses but no the same)
differences between orthoviruses and paraviruses
ortho: nuclear replication, segmented -ssRNA, enveloped
para: cytoplasmic replication, non-segmented -ssRNA, enveloped
what are the major contributors to pathogenesis of influenza syndrome?
replication of flu in respiratory tract causing desquamation of mucus-secreting and ciliated cells, T-cell responses, and interferon induction
what are the less frequent outcomes of influenza disease?
secondary bacterial infection causing pneumonia, primary viral pneumonia, and CNS/muscle involvemnt
what are the treatments and prevention for the flu?
antivirals (tamiflu and relenza)
vaccines (fluzone and flumist)
fluzone vs flumist vaccine
fluzone: trivalent inactivated
flumist: live attenuated
croup
parainfluenza virus and respiratory synctial virus:
laryngotracheobronchitis
what are symptoms of croup and what are the complications?
symptoms: distinctive barking cough with a peak incidence in winter
complications: pneumonia and respiratory distress
adenovirus bacteriology
icosahedral, naked, DNA virus that is widespread in nature
most people have been infected with at least 1 by age 15
very common, most asymptomatic
what do most adenovirus infections involve
respiratory, GI, or eye
disease mechanism for adenoviruses
- transmitted by aerosol, close contact, fecal-oral, finger, ophthalmologic instruments
- infect mucoepithelial cells
- persists in lymphoid tissue
adenovirus recovery
antibody is esstential
