Infectious d/o Flashcards
What is the MC cause of CAP?
Streptococcus pneumoniae
What is the most common bacteria in pts with CAP and other lung disease?
Haemophilus influenzae
What is the MC cause of atypical (walking) pneumonia?
Mycoplasma pneumonia
Which pneumonia bacteria is related to outbreaks assocated with water supply?
Legionella pneumophila
Which pneumonia is seen post viral illness?
Staphylococcus aureus
What 4 other bacterias can cause pneumonia?
Chlamydia pneumoniae
Klebsiella pneumoniae
Anaerobes
Pseudomonas aeruginosa
Which viral pneumonia is MC in infants/small children?
RSV and parainfluenza
Which viral pneumonia is MC in adults?
influenza
In all, which microbes cause CAP?
S pneumonia
mycoplasma, chlamydia, viral (in healthy)
H influenzae, M catarrhalis (in COPD)
Legionella
Klebsiella and GNR (in ETOH)
S aureus
In all, which microbes cause hospital acquired pneumonia?
Gm neg rods
Pseudomonas
Klebsiella
Enterobacter
Serratia
Acinetobacter
S aureus
so what is community acquired pneumonia (CAP)?
patient acquires pneumonia outside of hospital/nursing home OR within 48 hours of admission
What is nosocomial (hosp acquired) pneumonia?
pneumonia occurs more than 48 hours after admission
Which organisms are “typical” pneumonia?
S pneumo
H influenzae
Klebsiella
S aureus
Which organisms are “atypical” pneumonia?
Mycoplasma
Chlamydia
Legionella
Viruses
What are the clinical manifestations of typical pneumonia?
sudden fever
prod cough
pleuritic chest pain
tachycardia/pnea
Rigors
What are the clinical manifestations of atypical pneumonia?
low grade fever
dry, nonprod cough
myalgias, malaise, sore throat, HA, N/V/D
What will you see on PE with typical pneumonia?
signs of consolidation like bronchial breath sounds, dullness to percussion, inc fremitus, crackles
What will you see on PE with atypical pneumonia?
Normal!
maybe crackles or rhonchi
How ya gonna diagnose pneumonia?
CXR/CT: Exudative pleural effusion may be present. Abcess formation
Sputum culture
What will you see specifically on Klebsiella CXR/CT?
RUL with bulging fissure and cavitations
What if you sputum comes back rusty and blood tinged? What organism?
Strep pneumonia
Sputum is like currant jelly?
Klebsiella
sputum is green?
H influenzae
Pseudomonas
sputum is foul?
anaerobes
What abx will you give for CAP outpatient?
macrolide or doxycycline
What will you give for CAP inpatient?
B lactam + macrolide (or doxy)
OR broad spectrum FQ
What will you give for CAP in ICU?
B lactam + macrolide OR
b lactam + broad FQ
What will you give for hosp acquired?
Anti-pseudomonal B lactam + anti-pseudomonal AG or FQ
What will you add to hosp acquired pneumo if you suspect legionella? MRSA?
legionella: macrolide
MRSA: vancomycin
How else can you manage a pt with pneumonia?
02, IV fluids
What are the pneumococcal vaccines?
PCV13: in childhood vaccination
PPV23: used in adults
(2-64y with chronic disease, 65+ otherwise)
How common is TB?
Not that common in US, but one of the leading causes of death worldwide
How is TB transmitted?
Respiratory droplets of Mycobacterium
Must inhale the droplets
Who is at a greater risk for getting TB?
those exposed
those from high prev areas
those immunodeficient (HIV)
under 4y
IVDU
What is the pathophysiology of TB?
Inhalation of airborne droplets –> mycobacterium reaches alveoli, gets ingested by macrophages –> if bacteria remains viable, active infection occurs
There are three outcomes to getting infected. What are they?
Primary TB
Chronic (Latent) Tb
Secondary (Reactivation) TB
What is primary TB?
the outcome of the initial infection - usually self-limited
patients are contagious in this stage
common in <4y
What is chronic (latent) TB?
A pt gets the infection, but is able to control it
patients not contagious
(this happens about 90% of the time)
What is secondary (reactivation) tb?
a pt who had the latent infection now gets reinfected
patients are contagious
common in HIV, elderly, malignancy, steroid use
When TB is active, what are the clinical manifestations?
- Pulmonary sx: chronic prod cough, chest pain, hemoptysis
- Constitutional sx: night sweats, fever/chills, fatigue, anorexia, wt loss
What will you see on PE with TB?
Signs of consolidation: rales/ronchi, dullness
What is extra-pulmonary TB?
When it affects any organ system
e.g. Pott’s dz affects vertebrae
What do you use to screen for TB?
PPD: Purified Protein Derivative
Give and examine in 48-72h
What is a + PPD test
>5mm with a strong suggestion of TB (e.g. HIV, family members w/ it, abn CXR)
>10mm for other high-risk populations
>15mm for everyone else
When will you see a false + PPD?
Chronic (latent) inf 2-4 weeks post exposure
What is the gold standard for dx of TB?
Acid-fast bacilli culture
done on 3 different occasions + all must be negative
What diagnostic measure do you use to EXCLUDE TB?
What would TB look like on this test?
CXR
Reactivation: upper lobe fibrocavitary
Primary: middle/lower lobe consolidation
How do you treat TB?
Tx duration is 3-6 mos
RIPE: Rifampin, INH, Pyrazinamde, Ethambutol
When is treated TB no longer infectious?
2 weeks after therapy begins
What’s broncholitis?
inflammation of the bronchioles (lower resp tract)
What is the pathophys of bronchiolitis?
your airways get obstructed because there is necrosis, which causes epithelium to slough off
there is also edema, causing narrowing
What causes acute broncholitis?
RSV MC
also adenovirus, influenza, parainfluenza
What are the risks for developing bronchiolitis?
infants 2mos-2y
exposure to cigs
no breastfeeding
premature
How is bronchiolitis transmitted?
HIGHLY contagious
trans by direct contact w/ secretions
usually fall to spring
What are clinical manifestations of bronchiolitis?
Fever
URI sx days before
respiratory distress inc. wheezing, tachypnea, nasal flaring, cyanosis
How do you dx bronchiolitis?
Nasal washings: using monoclonal Ab testing
CXR shows nonspecific findings
What’s the best predictor of bronchiolitis?
Pulse oximetry
02 < 96% admit to hosp
How do you tx bronchiolitis?
Supportive w/ 02, fluid, antipyretics
Meds (ehhhh): b agonists
Severe: ribavirin
How do you prevent bronchiolitis?
palivizumab prophylaxis
What are sequellae of bronchiolitis?
otitis media w/ strep
pneumonia (MC)
asthma later in life (MC)
What is acute bronchitis?
inflammation of trachea/bronchi
What causes acute bronchitis?
MC Viruses
Adenovirus, parainfluenza, coxsackie, rhinovirus, RSV
Can also be caused by bacteria (S pneumo, H inf, M cat, Mycoplasma)
When does acute bronchitis occur?
After URI
Clinical manifestations of acute bronchitis?
similar to pneumonia
Cough - hallmark
What is the gold standard diagnosis for acute bronchitis?
Clinical!!!!
CXR will be nonspecific or normal
How do you manage acute bronchitis?
fluids, rest, antitussive drugs +/- bronchodilators
NO abx if healthy adult
What is croup?
inflammation of the upper airway (larynx, subglottis, trachea)
When does croup occur?
After an acute viral infection
MC parainfluenza, also adenovirus
In what age group does croup occur?
6mos - 6y
What is the pathophys of croup?
Infection leads to subglottic larynx and trachea swelling (which causes the sx)
What are the sx of croup?
stridor, “barking” cough, hoarseness, dyspnea (worse at night)
maybe URI sx
How do you dx croup?
Usually clinical
BUT you’ll prob get a cervical XR and see a steeple sign (subglottic narrowing of trachea)
How do you treat croup?
cool, humidified air mist
oral steroids
02
What is acute epiglottitis (supraglottitis)?
inflammation of the epiglottis, causes swelling
emergency
What causes epiglottitis?
MC H influenzae type B
Who gets epiglottitis?
MC in children 3mos-6y
males 2x MC
in adults: DM is a risk
What are sx of epiglottitis?
Dysphagia, Drooling, Distress
Fevers, odynophagia, stridor, dyspnea, hoarseness, tripoding
How do you diagnose epiglottitis?
Laryngoscopy is definitive. Cherry red epiglottis with swelling
Lat Cerv XR: Thumb Sign
How do you treat epiglottitis?
Maintain airway
Dexamethasone can decrease airway edema
Tracheal intubation if severe
Abx: 2nd and 3rd gen cephalosporins
What is pertussis?
whooping cough!
highly contagious infection
What causes pertussis?
Who gets it?
Gm neg coccobaccilus
Children <2y
What are the sx of pertussis?
- catarrhal phase: URI sx 1-2 wks
- paroxysmal phase: severe paroxysmal coughing fits with inspiratory whoop; emesis after cough
- convalescent phase: cough and emesis resolve
How do you dx pertussis?
Nasopharyngeal swap w/in first 3wks
Severe lymphocytosis on CBC
How do you treat pertussis?
Supportive is the mainstay
Abx (although they don’t help sx, only contagiousness): macrolides 1st line, Bactrim as 2nd line
What are complications of pertussis?
pneumonia, encephalopathy, otitis media, sinusitis, seizures