Micro- Upper respiratory Flashcards
What are 3 ways of which bacteria can cause dz?
- Toxin production
- Host immune response
- bacterial proliferation and invasion
What are 3 ways which viruses can cause dz?
- Cytopathic effect
- Host immune response
- Tumorgenesis
What are some common pathogens that cause otitis media?
- Step pneumoniae
- Haemophilus influenzae
- other bacteria
What are some common pathogens that cause sinusitis?
Various bacteria and fungi
- S pneumonia and H influenzae
- 2’ bacterial infection
What are some common pathogens that cause Rhinitis?
over 200 viruses
AKA common cold
- mostly viruses
What are some common pathogens that cause pharyngitis?
- Strep pneumoniae
- fusobacterium necrophorum
- viruses
What are some common pathogens that cause Pneumonia?
- Strep pneumoniae
- Legionella
- Mycoplasma pneumoniae
- Hantavirus
- Histoplasma capsulatum
- Pneumocytis jiroveci
What are some common pathogens that cause whooping cough?
Bordetella pertussis
What are some common pathogens that cause TB?
Mycobacterium tuberculosis
- mycobacterium avium complex
What are the Upper respiratory infections? URT?
Otitis externa/media
- rhinitis
- pharyngitis
- epiglottitis
- laryngitis/croup
- Sinusitis
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What are some lower respiratory tract infections? LRT?
Bronchitis
- bronchiolitis
- influenza
- pneumonia
- TB
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What are some normal biota of the respiratory system?
Moraxella, nonhemolytic and alpha hemolytic steptococci
- Corynebacterium and other diphtheroids
- Candida albicans
What could show up on respiratory culture as normal biota?
- Strep pyogenes/ pneumoniae
- H. influenza
- N meningiditis
- S. aureus
What are the respiratory systems defenses?
- Mucociliary lining
- Change direction of airway from sinuses to pharynx
- Alveolar macs
- Ciliary elevator
- Normal flora competition
What virulence factors doe the mucociliary lining have?
Lysozyme
Lactoferrin
IgA
Exact same as urogenital mucosa
What are the 2 obstacles microbes must overcome to initiate infection?
- Avoid being swallowed
- avoid phagocytosis
What are the purpose of the nasal chonchae?
Cause air to become turbulent and swirl.
- causes air to touch mucous membranes and this traps microbes
- anything not filtered by nasal hairs
What is the mucociliary escalator?
- Mucus producing goblets
2. Ciliated epithelium
What does smoking do to the mucociliary escalator?
Paralyzes it
- infect these cells and you can cause dz
How do microbes start colonization?
adherence factos and immune evasion factors
What percent of vires cause pharyngitis?
90%
What is the common cause of the common cold?
Rhinitis
- 100-200 rhinoviruses
- 50 adenoviruses
- several Coronoaviruses
When is adenovirus more common?
Summer
- otherwise common cold is more common in winter
What are the initial progression of sx’s of the common cold?
Nasal stuffiness, sneezing and HA
What are the initial progression of sx’s of the common cold?
Nasal Cavity with fluid
- Tiredness
- watery eyes
- sore and scratchy throat
- slight F
- Anorexia
Where must the common cold settle in order to causes cough?
Lower respiratory tract
What are some possible complications with the common cold?
2’ bacterial infections by normal flora–> purulent nasal secretions
- Sinus blockages–> sinusitis or otitis media
- access to LRT–> bronchitis
What is the tree for Rhino virus?
RNA virus–> Isoahedral nucleocapsid–> Nonenveloped –> SS + (4)–> Non-segmented–> picornaviridae
What is the tree for coronavirus?
RNA virus–> helical nucleocapsid–> envelope–> SS + (4)–> nonsegemented–> coronaviridae
What is a common adherence factor for rhinovirus?
ICAM-1
- 2-5 days sx peak
- 14 days post cells are completely regenerated
- cause ciliated epithelial cells get destroyed
What is the most common cause of conjunctivitis?
Adenoviruses
- summer time and cold symptoms with conjunctivitis think this virus
What is the tree for influenza A and B?
RNA virus–> Helical nucleocapsid–> enveloped–> SS - (5)–> Segmented
–> orthomyxoviridae
What is the tree for coxsackievirus A and B?
RNA virus–> icosahedral nuclocapsid–> Non-enveloped–> SS + (4)–> Picornaviridae–> enterovirus
What is the tree for Parainfluenza virus (paramyoxvirus)?
All same but paramyxoviridae
What is the tree for Adenovirus (Mastadenovirus)?
DNA virus–> Icosahedral nucleocapsid–> enveloped–> DS linear (1)–> adenoviridae
What is another term for sinusitis?
Rhinosinusitis
What is the definition of acute rhinosinusitis?
Inflammation and infection of mucosa of nasal passages and at least one of the paranasal sinuses
- NO- longer than 4 weeks
- URI predisposes
What are sx’s of rhinosinusitis?
Sneezing
- rhinorrhea, nasal congestion,
- post nasal drip
- aural fullness
- facial pressure
- Ha
- ST
- Cough
- Fever
- Muscle aches
What do bacterial sinus infections follow?
Common cold
Dental extractions
Allergic rhinitis
- 2% of adults and 10% of children
When is sinusitis most common?
winter
How long do sx’s usually last with sinusitis?
5-7 days
- mostly viral
What is the dx for acute bacterial sinusitis?
- beyond 7 days
- facial swelling or tooth pain
- longer in kids like 10-14 days
- kids get fever
are antibiotics recommended for bacterial sinusitis?
Yes
What the 2 most common cause of bacterial sinusitis?
Strep Pneumonia
H Influenzae
What re some other causes of bacterial sinusitis?
Step pyogenes
S aureus
Morexella catarrhalis
can you get a fungal sinusitis? How often what causes it?
Yes but rare
- Aspergillus fumigatus
- usually dx after antibiotics fail.
- immunocompetent is to physically remove the fungus
What do you treat acute bacterial sinusitis with?
Augmentin
Azithromycin
What is the only thing to shorten the severity of the sinusitis?
Nasal saline washes and steam
- can also try NSAIDS, decongestants and mucolytics
What are some facts about pharyngitis?
Common worldwide
- winter and spring
- self limiting
- viruses most common
- person to person
What is the most common pathogen of bacterial acute pharyngitis?
Strep pyogenes
What percent of both adults and children cause viral pharyngitis?
90 and 60-75%
What are the virulence factors for step pyogenes?
M protein Lipoteichoic acid Fibronectin binding protein Capsule has hyaluronic acid Protease Hylauronidase
What does hyaluronic acid do for strep pyrogenes?
Inhibits phagocytosis
what are common findings with person with pharyngitis either bacterial or viral?
ST
F
Edema
Hyperemia
What sx’s strongly suggest viral pharyngitis?
Conjunctivitis Cough Hoareness Inflammation of MM Diarrhea
What re some sx’s of bacterial pharyngitis?
- F
- Severe pain (sudden onset ST)
- HA
- N
- V
- AP
What can one find on PE with bacterial pharyngitis?
Red tonsils with exudate
-enlarged and tender cervical LN’s
What does the rapid strep test look for?
Ag detection
How do we treat bacterial and viral pharyngitis?
Penicillin or erythromycin
Symptomatic with NSAIDs and warm saline gargles
What is the tree for Strep pyogenes?
Bacteria–> gram +–> cocci–> catalase neg–> Beta-hemolytic–> bacitracin sensitive
What can cause scarlet fever?
ssa
speA
speC
- toxins that are superantigens
What is catalase?
Turns peroxide and o2 into water and o2
- gives you bubbles
What is peroxidase?
turns peroxide and O2 into water
What is the tree for diphtheria?
Bacteria–> gram +–> bacilli–> non-spore forming–> non-motile
What sx’s is diptheria infection similar to?
Pharyngitis but also:
- Nasal discharge
- malaise
- Difficulty breathing/rapid breathing
What is unique to diphtheria on PE?
Thick grey membrane covering the back of the throat
What toxin does diphtheria have?
A B toxin
Binding and active toxin which prevents protein elongation
What is croup?
Bark like cough with a fever of 38-39
- Restlessness
- SOB
how does it present?
usually with cold like sx’s amd a bark like cough 2-3 days later
what is common finding on PE for Croup?
Inspiratory stridor at nest with nasal flaring and intercostal retractions
- usually at night
What are some other sx’s of croup?
Lethargy or agitation
- hypoxia
- tachyphea and cardia
- fever
- pallor
- hypotonia
- cyanosis
What is the prognosis of croup?
peak at 3-5 days and resolve in 4-7 days
Who gets croup?
Children from ages 6 months to 3 years
- F»>M
- late fall and early winter
What causes croup?
- Parainfluenza virus at any time of year
- influenza virus winter and early spring
- Respiratory syncytial virus in winter and early spring
What is the treatment for croup? what do you do if this doesn’t work?
Symptomatic treatment
- try corticosteroids and nebulized epi
- O2 with ventilation support
What is the tree for respiratory syncytial virus?
Virus–> helical nucleocapsit–> enveloped–> SS neg–> Nonsegmented–> Paramyxoviridae–> pneumovirus
What is a syncytium?
Multinucleated cell that can result from multiple cell fusions of uninuclear cells
What is the virulence factor for RSV?
F proteins–> surface protein
- cause nearby cell membranes to fuse
What is palivizumab?
Monoclonal ab (IgG1k) produced by recombinant DNA to attack A antigenic site of F protein
Who gets epiglottis?
Most often in children
What usually cause epiglottis?
beta-hemolytic steptococci–> group a, b and c
- H. Influenzae type B
What is the treatment for epiglottitis?
secure airway
-Broad spec with 2’ or 3’ gen cephalospirings with penicllinase resitant penicillins
How doe we type H influenzae?
Capsule
- A thru F
how can one diff from croup and epiglottis?
Drooling and super sudden onset in epiglottis
