L15- RTI V Flashcards
Acute Bronchitis:
- (1) definition
- (2) defining Sxs
- (3) is the most common cause, (4) is second most
- (5) is the way to distinguish from pneumonia
1- inflammation of bronchi due to upper airway infection
2- cough > 5 days lasting 1-3 weeks
3- viruses
4- bacteria
5- pneumonia has systemic symptoms like fever
Croup = (1):
- (2) typical age of infection
- (3) list the characteristic Sxs
- (4) is the most common cause, (5) are other frequent causes
- (6) is a common complication
1- laryngotracheitis, laryngotracheobronchitis (inflammation of larynx, sub-glottic area)
2- 6 mos - 3 yrs
3- inspiratory stridor, ‘barking cough’ in children (hoarseness in older people)
4- HPIV-1
5- RSV, adenovirus
6- secondary bacterial infections
Croup:
- (1) are the initial typical Sxs
- (2) is a key associated Sx
- (3) is the most severe complication
- (4) is the radiological feature
1- non-specific URI sxs
2- mild fever, <40C
3- severe respiratory distress
4- subglottic narrowing of trachea = ‘steeple sign’
list the important Paramyoxviridae by subfamiles
1) paramyxovirinae: HPIV-1/3 (respirovirus), HPIV-2/4 (rubulavirus)
2) pneumovirinae: RSV
Paramyxoviridae:
- (non-/enveloped) (+/-) sense (ss/ds)(DNA/RNA) with (5) nucleocapsid shape
- replication occurs in (cytoplasm/nucleus)
- transmitted via (7)
(HPIV, RSV)
1-5- enveloped (-) sense ssRNA, helical nucleoocapsid
6- cytoplasmic replication
7- respiratory droplets
List the important VAPs seen in paramyxoviruses, include function
F, fusion protein: forms syncytia between cells, allows for travel/spread from cell to cell (HPIV and RSV)
- HN, hemagglutinin-neuramidase (HPIV only): H for attachement, N for lysis/release
- G, glycoprotein (RSV only): attachment and cell entry
HPIV infections, list the predisposing factors (hint- 2 main ones, 3 other ones)
- vitA deficiency
- lack of breast feeding
- malnutrition
- overcrowding
- environmental smoke (infantile exposure) or toxins
HPIV infections:
- (1) is form of transmission
- requires a (large/small) inoculating dose
- (3) incubation period
1- respiratory droplets or direct contact with secretions / fomites
2- small dose needed
3- 1-7 days
Croup is mainly caused by…..
(laryngotracheitis)
HPIV-1, 2, 3
list the membrane proteins for HPIV, include function (include shape)
(spherical shape)
1) F, fusion protein: forms syncytia between cells
2) HN, hemagglutinin-neuramidase: H for attachement, N for lysis/release
3) M, matrix protein: assembly
4) P, phosphoprotein: along with F, induces cell-mediated immune response
5) N, nucleoprotein
6) L, RNA dep. RNA polymerase
HPIC, name the viral protein:
- (1) syncytium formation
- (2) immune evasion
- (3) attachment, entry, and release of virus
- (4) matrix structural protein, assembly
- (5) polymerase
1- F, fusion proteins 2- P/F proteins (disrupts IFN production) 3- HN protein 4- M, matrix protein 5- L protein
describe how P/F proteins on HPIV work to evade immune response
blocks IFN-α/β production and signaling pathways
Bronchiolitis:
- (1) definition
- (2) most affected age group
- (3) season with highest incidence
- (4) Sxs followed by (5)
1- inflammation of bronchioles and small bronchi 2- <2y/o 3- fall, winter 4- URI sxs 5- LRT infection w/ inflammation
Bronchiolitis:
- (1) most common cause
- (2) other causes
- (3) list the numerous risk factors
1- RSV (respiratory syncytial virus)
2- rhinovirus, HPIV, adenovirus, coronavirus
3- prematurity (<35 wks), low birth weight (<2.5 kg), congenital/cyanotic heart disease, chronic pulmonary disease, passive smoking, overcrowding, daycare
In bronchiolitis, (1) will infect (2) cells causing direct (3). (4) will accumulate as a result of (3), and can lead to (5) complication.
1- virus (causal agent)
2- terminal bronchiolar epithelium
3- cell damage and inflammation
4- edema, excess mucus, sloughed epithelial cells
5- small airway obstruction and atelectasis
Bronchiolitis:
- starts with (1) type Sxs
- (2) sxs start next, include specifics
- illness duration depends on (3)
- (4) is the end result of most infections
1- URI sxs (nasal congestion and discharge)
2- LRT infections sxs: fever <101F, cough, respiratory distress (inc RR, retractions, wheezing, crackles), preceding h/o URI
3- age, severity, associated conditions, causative agent
4- self-limiting
(1) is the leading cause of LRTIs in infants/young children, mainly causing (2) and (3). Infections by (1) are usually limited by (4). (1) LRTIs are also linked to (5) in infancy, although association remains controversial.
1- RSV 2- bronchiolitis 3- viral pneumonia 4- to respiratory tract 5- subsequent reactive airway disease
list the risk factors for RSV infections
- infants < 6 mos
- immuno-compromised
- asthma
Infants with: *Down syndrome, underlying lung disease, premature birth (<35 wks), congenital heart disease, passive smoking
RSV:
- (1) family, subfamily, genus
- (non-/enveloped), (3) capsid shape
- list important VAPs, (4)
1- paramyxoviridiae, pneumovirinae, pneumovirus
2- enveloped, helical nucleocapsid (neg. sense ssRNA, cytoplasm replication)
3:
-F, fusion factor: main viral Ag, forms syncytia between cells
-G glycoprotein: attachment
(NOTE- no HN glycoprotein)
RSV enters body via (1) process. (2) are responsible for attachment and fusion to target cells. (3) is the primary site of replication and has a (4) direct effect on (3). It will spread to (5) after (6) days via various mechanism.
1- large droplets on hands –> self inoculation to epithelia of nose, eye
2- F/fusion protein, G glycoprotein
3- nasopharyngeal epithelium
4- cytopathic effect => loss of function for (3)
5- LRT
6- 2-5 days
It is suggested that ____ is responsible for the immune response to RSV.
Tc cells (CD8+)
It is thought that (1), (2), (3) are directly responsible for the clinical outcome of RSV infections..
1- immunological response
2- anatomy of airway (worse in younger people with already narrow airways)
3- tropism for respiratory epithelium
Whooping cough is caused by (1), and is also called (2) cough. It typically occurs in (3) people, where (4) are the normal reservoirs.
1- bordetella pertussis 2- 100 day cough 3- unvaccinated children <10y/o 4- adults (Note- highly communicable)
Bordetella pertussis: (large/small) (thin/thick) Gram(+/-) (cocci/bacillus)
small, thin, Gram-, coccobacillus
Whooping cough (B. pertussis):
- (1) incubation period
- (2) initial stage
- (3) middle stage
- (4) last stage
- (5) communicable period
1- 5-10 days (max 21 days) 2- Catarrhal stage, 1-2 wks (URI Sxs) 3- Paroxysmal stage, 1-6 wks 4- Convalescent stage, wks-mos 5- onset to 3 wks (bacteria is gone, but exotoxin keeps persistent Sxs)
Bordetella pertussis virulence factors:
- (1) responsible for bacterial attachment
- (2) causes local tissue damage + bacterial proliferation
- (3) is responsible for systemic toxicity
1- Protein Adhesins: pertactin, FHA (filimentous hemagglutinin), fimbria
2- dermonecrotic toxin, tracheal cytotoxin
3- pertussis toxin
describe MOA of tracheal cytotoxin and pertussis toxin, how do they relate (B. pertussis)
Pertussis: inactivates adenylate cyclase –> inc cAMP –> inc respiratory secretions (mucus)
Tracheal: prevents release of mucus secretions –> trapping it and causing whooping cough
Bordetella pertussis must be sampled through (1) because of (2) property. (3) is the required agar because it is a fastidious organism. (4) can also be complete for evaluation of B. pertussis.
1- nasopharyngeal swab, or secretions
2- very susceptible to drying
3- charcoal blood agar + cephalosporin (aka Bordet-Gengou)
4- PCR
describe the vaccines for bordetella pertussis
(DTaP, aP = acellular pertussis)
1) (rarely used) whole cell, formalin inactivated
2) *Acellular components (many): Fha, PT, pertactin, fimbriae-2/3 [lower rates of side effects]
Note- immunity can dec over time
