Resp. Tract Infections I & II Flashcards
contrast the upper and lower respiratory tracts
name the 3 enzymes that play a role in non-specific defenses of the URT
- S-IgA
- lysozyme
- lactoferrin
describe situations where defenses of the respiratory system are defeated/surpassed
- smoking
- endotracheal intubation
- pollution
- suppression of cough reflex
- predisposing infxn
- disruption of homeostasis
- age, malnutrition, immunosuppression, underlying disease, etc.
describe the types of pathogens
name an example of professional and secondary pathogen
- primary/professional/frank = influenza
- secondary/opportunistic = pneumococcal pneumonia
____ are the most common cause of resp. tract infections
viruses are the most common cause of resp. tract infections
name the 6 major families of viruses that cause RT infxns
- adenovirus
- rhinoviarus
- corona virus
- HPIV
- RSV
- influenza virus
describe rhinovirus
- small, icosahedral, non-enveloped virus
- contain one positive-strand RNA
- labile at acidic pH
___ infections cause up to 50% of all common cold
name the seasons it is prevalent in
human rhinovirus (HRV) infections cause up to 50% of all common colds
seasonality: spring, summer, fall
the normal flora of the URT varies with ____ & _____
the normal flora of the URT varies with age & location
describe other complications of rhinovirus
- can lead to:
- secondary infxns of sinuses and middle ear
- LRT infections such as pneumonia, bronchiolitis in young children and immuno-compromised adults
viral pneumonia
describe the pathogenesis of rhinovirus
name features of rhinovirus and how it helps its pathogenesis
describe the Sketchy
describe the claslsification of adenoviruses
- linear, ds DNA
- medium-sized (90-100 nm)
- non-enveloped, icosahedral
describe characteristics of adenovirus
- virus encodes proteins to promote mRNA and DNA synthesis, including its own DNA polymerase
- human adenovirus are grouped from A through G by DNA homolgies and by serotypes (>55 human types)
- serotype is mainly a result of differences in the penton base and fiber protein which determine the nature of tissue tropism and disease
describe the outcomes of adenoviruses
- outcomes of adenoviral infxns:
- lytic, e.g. mucoepithelial cells (killing cells)
- latent, e.g. adenoid cells
describe the epidemiology of adenovirus
- endemic throughout the year
- typically affects children from infancy to school age
- young adults in a setting of close quarters and stress may be affected
describe respiratory diseases associated with adenoviruses and the patient population it affects
describe other diseases associated with adenoviruses
describe the pathogenesis of adenovirus
____ enables attachment of adenovirus to the host cell receptor
fiber protein enables attachment of adenovirus to the host cell receptor
___ of the adenovirus has toxic activity, and the viral genes ____ inhibit cellular _____
penton base of the adenovirus has toxic activity, and the viral genes E1A, E1B, E3, E4 inhibit cellular mRNA synthesis
the survival time for adenovirus is ____
the survival time for adenovirus is 7 days - 3 months
describe the Sketchy
describe the biology of coronavirus
- single molecule of linear positive-sense, ssRNA
- largest positive-strand RNA virus
- helical nucleocapsid, enveloped
describe the epidemiology of coronavirus
- incidence peaks in winters
- transmission usually via airborne droplets
- antibodies appear after initial infxn and wanes
describe major human coronavirus proteins
describe the pathogenesis of coronavirus
a unique aspect of the coronavirus replicative cycle is that replication occurs in the ____
a unique aspect of the coronavirus replicative cycle is that replication occurs in the cytoplasm
a unique aspect in the replicative cycle of coronavirus is that the virus obtains its envelope from the ____, not from the _____
a unique aspect in the replicative cycle of coronavirus is that the virus obtains its envelope from the endoplasmic reticulum, not from the plasma membrane
the ___ protein of the coronavirus allows binding to host cell and fusion activity
the E2 (peplomeric glycoprotein; aka spike protein) protein of the coronavirus allows binding to host cell and fusion activity
describe the prognosis of coronavirus
- prognosis:
- excellent prognosis
- usually mild and self-limiting illness
- complete recovery is usually within 7 days for adolescents & adults; within 10-14 days for children
- complications not common; very rarely causes fatal disease
describe severe acute respiratory syndrome (SARS) (case definition and lab diagnosis)
- case definition
- history of fever or documented fever AND
- one or more symptoms of LRTI (cough, dyspnea/SOB) AND
- radiologic evidence of pneumonia/ARDS or autopsy confirmation without identifiable cause
- lab diagnostics:
- antibodies by ELISA or IFA
- viral DNA by RT-PCR
describe the etiology of SARS
describe the clinical features of SARS
describe a probable clinical case of MERS
- febrile acute respiratory illness with clinical, radiographic, or histopathologic evidence of pulmonary parenchymal disease AND
- direct epidemiological link with a confirmed MERS-CoV case
describe the clinical features and lab diagnosis of MERS
describe clinical features of MERS
describe the Sketchy
describe enterovirus EV-D68
