lect 11 Flashcards
syndrome of fever, hoarseness and barking cough in children 6-18 months of age
croup
croup
laryngotracheobronchitis is a complication of an upper respiratory tract infection inflammatory response that constricts the trachea below the vocal cords due to laryngeal edema.
Causative agents of croup:
PIV type 1 > PIV type 2 >> RSV
Parainfluenza Viruses (PIV) genome
- Nonsegmented, negative sense ssRNA genome
- enveloped
The Parainfluenza Viruses (PIV) replicates where
- Respiratory tract entry via droplets from infected individuals
- Replication in upper respiratory tract epithelial cells.
- Especially the nasal turbinates and ciliated epithelium of the respiratory tract
The signal illness for PIV is
croup
PIV illness in adults typically presents as
nonspecific upper respiratory tract infection
PIV complications
- croup
- otitis media
- parotitis
PIV has season upsurge. what season
fall-winter
- types 1 and 2 exhibit epidemic periodicity
- type 3 show no seasonality
is there lifelong immunity after PIV infection
NOT observed, virus somehow interferes with full immune memory establishment.
PIV diagnosis
- Direct viral isolation from nasal washings (preferred) or throat swabs
- Direct fluorescent antibody (FA)
treatment of PIV
- supportive
- no vaccines
respiratory syncytical virus (RSV) commonly has outbreaks during what season
winter
PIV and RSV are both what type of virus
Paramyxovirus
RSV infects what parts of body
- Viral infection in the epithelium of the nose, throat, and bronchi
- The symptoms are actually due to the inflammatory response to infection
symptoms of RSV
- cough
- dyspnea
- cyanosis
- sometimes croup (PIV are most common cause)
symptoms of RSV are due to
The symptoms are actually due to the inflammatory response to infection
- IgE
- T cells
RSV diagnosis
- Rapid antigen tests are available to screen infants with clinical RSV symptoms
- Nucleic acid tests
treatment of RSV (include preventative)
- Monoclonal Immune globulin (Palivizumab) is available for high-risk patients as a preventative measure
- Ribavirin (controversial, but effective if symptomatic treatments fail)
what is the most common etiology of lower respiratory tract infection in children < 4 yo
RSV
- peak incidence is infeants < 1 yo
what increases risk associated with RSV
- Children with underlying diseases are by far at the greatest risk for severe disease and complications
- birth a few months before RSV season
- Maternal antibodies decline over time, leave infant vulnerable
what does SARS stand for
Severe, acute respiratory syndrome
what agent caused SARS
coronavirus
- SARS now presumed to be extinct
how was coronavirus spread
- respiratory
- fecal-oral spread
- *Zoonotic reservoirs
what is MERS
Middle East Respiratory Syndrome
- caused by novel coronavirus
