PULM: RTIs - I, II, III Flashcards
discuss strep pyogenes in terms of
- hemolysis
- resistance/sensitivities
- virulence factors
graim +, cocci chains
- beta hemolytic
- bacitracin (A-disc) sensitive
- virulence factor: M-proteins
what is the most common cause of a LRT infection?
pneumonia
what are the most important immune cell in the LRT and what does it do?
alveolar macrophage
- prevent infections: phagocytize microbes before they can act
what are the two main modes of transmission of respiratory tract infections?
inhalation
aspiration
characterize the parts of the respiratory tract in terms of whether they are most commonly infected by
- viruses
- bacteria
bacterial:
- epiglottis: epiglottitis/croup
- trachea- pertussis/whooping cough
viral:
- larynx - laryngitis
- trachea- croup
- bronchi - bronchitis
- Bronchioles- bronchiolitis
common cold
- occurs during what time of year
- pathogenesis?
- what are the main etiological agents & the differences between them
- occurs during the winter
- contamination by aerosols/repsiratory droplets. etiological agents bind to their receptors & cause cells to slough off
- etiological agents:
1. rhinovirus (m/c) - naked RNA - pathogenesis - binds to ICAM-1 receptor
- presentation - NO fever
- SARS-Cov-2 - naked RNA
- pathogensis - binds to ACE-2 receptor with its “spike” protein
- presentation - FEVER, plus:
- loss ot taste/smell
- shortness of breath
summer grippe
- is prevalent during what time of the year?
- pathogenesis?
- etiological agents?
- what presentation?
- seen during the summer
- agents/pathogenesis:
- virus (enteroviruses - entero, echo, cocksackie) ingested via fecal-oral route
- infect epithelial cells of GI tract
- cause HIGH fever, malaise, GI disruption/nausea
- infect epithelial cells of GI tract
complication of the common cold?
rhino, SARs-CoV-2
- exntension of infection to LRT
- blockage of eustachian tubes
what is the best way to prevent summer grippe?
avoid food and water sources contaminated with feces
contrast the common cold and summer grippe based on
- prevalent season
- means of spread
- m/c agents
- presentation
- prevention
common cold:
- winter
- spread via respiratory droplets
- rhinovirus (ICAM), SARS-covid (ACE-2)
- presentation: none / moderate fever
- SARS: loss of taste / smell, shortness of breath
- prevention - sanitization
summer grippe:
- summer
- spread via fecal-oral
- echovirus, enterovirus, cocksackie
- prsentation: HIGH fever + GI issues (N&V)
- prevention - dont drink suspect water
what is rhinosinusitis?
inflammation of nasal cavity (rhinitis) + at least one paranasal sinus (sinusitis)
viral vs bacterial rhinosinusitis
- which is more common
- which is more severe
- what are the m/c agents of each?
- acute viral rhinosinusitis - more common
- rhino, adeno, parainfluenza, RSV
- acute bacterial rhinosinusitis - more severe / longer lasting
- commonunity aquired - S, pneumo, H. flu,** **M. catarrhalis
- nosocmial: gram -
- post-dental: anaerobic
pathogenesis of rhinosinusitis
- typicaly triggered by a viral URI (rhino, adeno, RSV)
- etiological agent causes inflammation
- sinus secretion cant drain
- pressure builds –> facial pain, aural fullness, ocular issues
major manifestations of rhinosinusitis
- Aural fullness
- Facial pain
- Fever
- Myalgias
what are the major diagnostic indicators (seen in physical exam) of rhinosinusitis?
both: unilateral facial swelling / facial pain / aural fullness
- adults (> 7 days): TOOTH PAIN
- children (10-14 days): HIGH FEVER
- other: ocular (diplopia, infraorbital hypothesia), altered mental status
rhinocerebral mucormycosis - most common etiological agents?
- rhizopus/rhizomucor (most common)
- asperilliguis
- fursarium
rhinocerebral mucormycosis is seen in what patients?
almost exclusively immunocomporised patients
- diabetetics (with DKA)
- transplant recipients
- cancer - lymphoma/leukemia
- chronic use of glucocoritcoid/deferoxamine
pathogenesis of rhinocerebral mucormyocisis
- fungal spores (likely rhizopurus) are inhaled
- spores germinate –> form hyphae –> hyphae invade nasal cavity/sinuses –> get into blood veseels –> cause necrosis
clinical presentation of rhinocerebral mucormycosis
- start of with rhinosinusitis symptoms
- bloody nasal discharge develops
- then:
- dusky/necrotic nasal turbinates
- black eschar on palate (hemipalatal necrosis)
- ocular problems
prevention and therapy for rhinosinusitis
- prevention
- correct septal deviations
- plug nose when jump in pool
- control allergic rhinitis, proper dental management
- treatment -
- viral - manage symptoms
- bacterial - give antibiotics
prevention and treatment of rhinocerebral mucormycosis
- prevention: encourage diabetics to maintain good control over their serum glucose
- treatment: URGENT
- aggressive surgical debridement
- high dose antifungal (amphotericin B)
Which of the following is considered a severe symptom of acute rhinosinusitis?
- Coughing
- Tooth pain
- Purulent nasal discharge
- Nasal congestion
- Temperature= 37o C
tooth pain
A diabetic patient complains of fascial pain over his right maxillary sinus. Examination reveals a discolored palate and dusky turbinates. Most likely cause?
- Candida
- Aspergillus
- Fusarium
- Trichophyton
- Rhizopus
rhizopus
pharyngitis - most common etiological causes?
list characteritics of agents
- viruses > bacteria
- if bacteria s. pyogenes, n. gonorrhea
-
strep pyogenes: common
- A-disc (Group A Strep) sensitive, B-hemolytic, bacitracin sensitive, PYR +
-
neisseria gonorrhea: rare
- diploccocus, oxidase +, grows on Thayer Martin plates
-
strep pyogenes: common
- if bacteria s. pyogenes, n. gonorrhea
list the identifiers of strep pyogenes
- B-hemolytic
- A-disc (Bacitracin) sensitive (Group A strep)
- PYR positive
- CAMP negative
list the identifers for neisseria gonorrhea
- gram - diploccous
- oxidase positive
- Thayer-Martin plate growth
what symptoms indicate viral pharyngitis?
- CCC: conjunctivitis, cough, coryza
- hoarseness
- diarrhea
- anterior stomatitis (discrete ulcerative lesions on mouth)
what syptoms are indicative of strep throat (s. pyogenes pharyngitis0
- Sudden onset
- fever with severe pain
- nausea/vomitting
- SCARLITINIFORM RASH
symptoms of viral vs strep pharyngitis
- viral
- cough, coryza, conjuncivitis (CCC)
- diarrhea
- anterior stomatis/mouth ulcers
- s. pyogenes
- fever with severe pain
- nausea/vomitting
- scarlitiniform rash*
what manifestation is specific for strep pharyngitis?
scarlitiform rash
what are the possible manifestations of strep pharyngitis?
scarlett fever -scarlett rash, strawberry tongue, desquation, pastias lines
rhuematic fever
glomerulonephritis
supperative complications: peritonsillar absesses, cervical lymphadenitis, mastoiditis
is strep A more prevalent in adults or chidlren?
children
what patients need testing for Group A Strep and how is it done?
- dont need testing - if pharyngitis looks viral (CCC, oral ulcers, diarrhea)
- testing indicated - if pharyngitis looks bacterial
throat is swabbed and tested for GAS with RADT
Which of the following is the most common cause of pharyngitis?
- Bacteria
- Viruses
- Fungi
- Parasites
viruses
what are s. pyogenes virulence factors?
- M-proteins
- hyaluronic acid capsule
lemierre’s disease
- etiological agent
- presentation
- agent - fusobacterium necrophorum (gram - rod)
- presentation:
- sore throat –> neck swelling –> thrombophlebitis (clot) –> sepsis
- infection spreads to lungs, mediastinum
diphtheria
- etiological agent
- presentation
- treatment
- agent - cornyebacterium diptheria
- presentation:
- think unimmunized patients
- psuedomembrane
- (bull neck - regional lymphadenopathy
- palatine palsy - numb room of mouth
- treatment:
- give anti-toxoid antibody (DTaP vaccine works by injecting inactive toxoid to induce Ab production)
identify, note important characteristics
fusarium (fungus)
canoe-shaped macroconidia with septate hyphae
grow on SDA
identify, note important characteristics
aspergillus (fungus)
septate hyphae at 90 degrees
grows black & fuzzy under wood lamp
identify
what disease does this agent cause?
fusobacterium necrophorum (gram - rod)
causes lemierre’s disease
what is the most common cause of death in in diptheria patients?
myocarditis
which of the following is due to bacteria? what are the others due to?
- Common cold
- Summer grippe
- Acute rhinosinusitis
- Pharyngitis
- Diphtheria
- Common cold – rhino, SARS-Cov-2
- Summer grippe – entero, echo, cocksackie virus
- Acute rhinosinusitis – adeno, rhino, RSV
- Pharyngitis – viruses > s. pyogenes
- Diphtheria – c. diptheria
A patient presents with pharyngitis, runny nose, itchy eyes and cough. Which is the most likely cause of this patient’s current condition?
- Bacteria
- Viruses
- Fungi
- Parasites
- Prions
1.Bacteria
2.Viruses - cough, coryza, conjunctivitis
- Fungi
- Parasites
- Prions
