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Based on the symptoms name the respiratory infection.
A. Nasal obstruction, nasal discharge =>
B. Hoarseness =>
C. Sore throat, red throat (with or w/out exudate) =>
D. Cough, chest pain, rales =>
E. Hoarseness, barking cough, stridor (infants) =>
F. Nonproductive cough, substernal pain =>
G. Cough, dyspnea, wheezing =>
- A. common cold
- B. laryngitis
- C. pharyngitis
- D. pneumonia
- E. croup
- F. tracheobronchitis
- G. bronchiolitis
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Which of the following is not an upper respiratory infection (URI)?
cold, bronchitis, otitis, pinche cabronitis, sinusitis, pharyngitis, epiglottitis
pinche cabronitis
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Is the common cold a viral or bacterial infection?
viral (lasts 7-10 days)
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What microbial agent fits the following description and what illness is the result?
Single-stranded, + sense, RNA, non-enveloped, replicates in nose, distributed worldwide, peaks seasonally, over 100 defined stereotypes, optimum temp for replication is 33 degrees C,
Rhinoviruses (of the Picornaviridae family) => common cold (most common cause)
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Put the following series of events in the pathogenesis of the common cold in correct chronological order.
1) Virus binds to host immune cell receptor ICAM-1 => gains entry into cell => replicates
2) Virus introduced into nasal passage escapes host defense
3) Activation of kinins results in inflammatory events => symptoms
4) Mucociliary action transports virus from anterior nares to nasopharynx
2, 4, 1, 3
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Which two events are mismatched with their symptoms?
A. dilation of vessels : nasal obstruction
B. transudation of plasma : sore throat
C. stimulation of seromucous glands : mucous in nose
D. stimulation of pain fibers : rhinorrhea
- B. transudation of plasma : rhinorrhea
- D. stimulation of pain fibers : sore throat
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What is the most common complication of Rhinovirus infections?
Exacerbations of chronic bronchitis--40% (followed by acute bacterial otitis media, asthma exacerbations in children >2, and acute bacterial sinusitis)
-
What is the diagnosis and treatment of Rhinovirus?
diagnosis: made on basis of clinical syndrome (nasal swab is possible but rarely performed)
treatment: mostly symptomatic, intranasal interferon (vaccine not available)
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Your Pt has a lower respiratory infections caused by a common cold virus that has: a lipid bilayer envelope; round, pleomorphic medium-sized virions; and is the largest known RNA genome-single-stranded. What is this virus?
Coronavirus (either the 229 E or OC 43 strain)
-
What is the deal w/ SARS?
It was a new infection from an unrecognized strain of the coronavirus, first seen in china in 11/02, that led to several outbreaks in other cities. (8000 cases leading to 800 deaths)
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Major causes of pharyngitis?
mostly viral and Grp A strep
-
Streptococci hemolytic patterns on sheep blood agar: distinguish between
Alpha,
Beta,
Gamma hemolysis.
- Alpha hemolysis - partial; greening of the agar
- Beta hemolysis - complete; clearing of the agar
- Gamma hemolysis - no hemolysis
-
Name the pathogen:
most common bacterial cause of pharyngitis
most common in 5-15 yr. age group
characterized by fever, sore throat, red swollen pharynx, yellow-white exudate and cervical lymphadenopathy
Treated w/ penicillins to avoid complications
Streptococcus pyogenes
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A pt comes in and thinks they have Grp A strep pharyngitis. What characteristics should be present if the Pt is correct?
- Sudden onset
- fever
- headache
- N/V/D
- pharyngeal inflammation
- discrete exudate
- tender cervical nodes
- NOT cough, congestion or conjunctivitis
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Penicillin is given to Pts w/ Grp A strep to avoid what complications?
Abscesses, otitis media, sinusitis, acute rheumatic fever, acute glomerulonephritis
-
Name the pathogen:
asymptomatic in infnants and children
teenage/young adults get IM
those w/ poor hygiene or crowding are protected by early infections
transmitted by salivary exchange (blood spread has been reported)
- EBV (epstein-barr virus)
- IM = infectious mononucleosis
-
Name the pathogen:
incubation period: 5-7 weeks
replicates in epithelial cells or oropharynx
spreads to B lymphocytes (in lymph nodes, spleen, or liver)
EBV
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Name the illness.
Presents with: fever, malaise, fatigue, sore throat, pharyngitis, cervical adenitis, atypical nodes, splenomegally, hepatomegally, elevated LFTs (liver function tests)
Complications: severe dz (fever, fatigue, and malaise), airway obstruction, aseptic meningitis encephalitis.
Infectious mononucleosis
-
Whats the best way to test for mono in children over 5?
Rapid slide (spot) tests: 85-90% specific, response my be delayed so repeat test may be needed 1-2 wks later. (mono serology tests is one of the most overused, confusing and least understood tests performed, but may be necessary in young children)
-
Does HSV-1 or HSV-2 cause cole sores?
HSV-1
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Name the most likely pathogen.
Nonspecific fever, rash, conjunctivitis, pleurodynia, aseptic meningitis, pericarditis, myocarditis, enephalitis, fatal sepsis in newborns.
Enterovirus (coxsackie A and B)
-
With what clinical manifestations would you suspect enterovirus?
- Asymptomatic infection most likely
- nonspecific febrile illness
- pharynigits and URIs (more common than Grp A strep)
- Pneumonia
- Pleurodynia: Coxsackie B; fever severe knifelike chest pain
- Hand foot and mouth dz
-
What causes Herpanigina and what are the symptoms/physical presentation?
- Caused by Coxsackie A
- Fever, sore throat, dysphagia, vesicles in pharynx, palate, uvula, that can last for weeks.
-
How would you assess a Pt for sepsis?
- Take history
- Physical (temp, HR, RR)
- Draw blood for CBC w/ WBC differential
- Get CRP only if WBC and other changes are equivocal
- Consider cultures
- If Pt has difficulty breathing get electrolytes & arterial blood gas.
-
Describe physiologically how a fever (>38C) develops.
Cytokines & TLR/microb products => hypothal. endothelial activation => glial cAMP => altered temp set point
-
Describe physiologically what causes tachycardia (>90 b/min).
- 1) Cytokines, NO, others => vasodilation, permeability => fluid & proteins leak into tissues, increased vascular volume, high met. rate, low peripheral resistance, altered blood flow, low myocardial contractility, low blood return to heart, low BP => sympathetic activation => tachycardia.
- 2) fluid loss (sweating, n/v/d) => volume depletion => tachycardia
-
What causes Tachyapnea (>24 r/min)?
High vascular permeability => fluid in lungs, lung injury => poor gas exchange, high met. rate & poorly distributed blood flow => tissue anoxia => lactic acidosis => tachyapnea
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What causes Leukocytosis (>12 k/nL) or Leukocytopenia (<4k) or Bands (>10%)?
cytokines => high production of neutrophils & high recruitment to periphery => high neutrophil & band count (platelets can be high too, unless DIC has begun), high delivery to inflammation site, clumping => low neutrophil count
-
What is sepsis?
SIRS plus evidence of infection (SIRS = 2 or more of fever, tachycardia, tachyapnea, luekocytosis, leukocytopenia, or bands)
-
What is severe sepsis?
- Sepsis (SIRS + evidence of infection) + 1 or more of:
- Hypoxemia, Acute renal failure, thrombocytopenia, lactic acidosis
-
Hypoxemia
- lung fluid & injury => poor gas exchange
- V/Q mismatch
-
Acute renal failure (<0.5 ml/kg/hr with good hydration)
hypoxemia, hypotension & uneven blood flow => inadequate tubular oxygenation => injury or death of proximal tubular cells = ATN (acute tubular necrosis)
-
Thrombocytopenia ( <80k, 50% drop in 3 days)
- inflammation => intravascular coagulation with fibrin => platelet activation => more coagulation & inflammation, vascular blockage, thrombocytopenia.
- (also hemodilution)
-
Lactic acidosis (pH < 7.3 or lactate > 1.5nl (3.3 mmol/L))
poor blood flow, hypoxemia => tissue hypoxia => anaerobic metabolism => lactate
-
Septic shock = ?
Sepsis + systolic BP<90 or >40 mmHG decrease
-
What organs are affected in severe sepsis?
- Lungs (ARDS)
- brain,
- heart,
- kidney,
- liver ( mild increase in AST & ALT),
- GI,
- Hematologic
- Immunologic (diminished function)
-
What is required to diagnose a Pt w/ MODS (multiorgan dysfunction syndrome)?
- Intervention in at least 2 organs:
- ARDS, dialysis, gastric ulcers req. transfusion, DIC, Coma, Juandice (bili >8 mg/dL), shock not responsive to pressors.
-
Causes of Sepsis & what to look for
- pneumonia, empyema, peritonitis, pyelonephritis (dysuria, costovertebral angle tenderness), meningitis (headache, stiff neck, meningismus), brain abscess, endocarditis
- Clues from skin: rash, erythema, line site erythema, tenderness, crepitus, petechiae.
-
What are some of the treatments for Sepsis and septic shock? (other than the obvious of treating organs as they fail, adequate O2, BP, etc)
- Find & treat infection (may need to drain abscess.
- Activated protein C (avoids DIC), glucocorticosteroids.
- Avoid very high fever
- (DO NOT USE: inhibitors of TNF, IL-1, PAF, bradykinin, ibuprofin, IL-10, high dose glucocorticosteroids, or high dose oxygen delivery)
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Effusions in Sepsis are usually exudates made by infections or inflammation, what does one find in an exudate?
- Albumin in fluid similar to blood
- High total protein, high LDH (lactic dehydrogenase)
- abundant neutrophils
-
Tachyapnea, low pH, high blood lactate and a high anion gap indicate what?
Metabolic acidosis
-
What is a normal anion gap, and how do you calculate Anion gap?
- 8-16 (too high of an anion gap => acidosis)
- Na - (HCO3 + Cl)
-
ARDS, acute pancreatitis, aspiration pneumonitis, trauma (major surgery w/out infection), anaphylaxis, adrenal insufficiency, and acute liver failure mimic what serious diagnosis?
Septic shock
-
Adenovirus biology
- non-enveloped
- pentons
- linear, ds DNA genome
- Resistant to many physical and chemical agents
-
Adenovirus epidemiology
- 50% asymptomatic
- 6 mo. to 5 yrs => most infected
- resp. dz -- winter/spring
- Pharyngocunjunctival fever -- summer
- Gastroenteritis -- no pattern
- Transmission: direct contact, fecal-oral and water/equipment
- Risk factors: crowded, low socioeconomic
-
What pathogen fits the following description.
10 day incubation
persistent lymphocytic infections
epithelial cell necrosis
can circumvent host's immune system by binding to MHC class I molecules reducing expression on cell surface.
Adenovirus
-
Describe the pathway of an adenovirus infection.
- penton binds to resp. or GI epithelial cells =>
- internalized by receptor mediated endocytosis=>
- disruption of endosome=>
- escape into cytoplasm=>
- DNA replication in host cell nucleus=>
- viral assembly and release of virions (10^5)
-
What are the clinical syndromes of adenovirus?
- URIs
- Tonsillitis
- Pneumonia
- pharyngoconjunctival fever
-
What is the pathogen and illness associated w/
unilateral conjunctivitis lasting 1-2 wks
pre-auricular lymphadenopathy
sore throat
epidemics occur following swimming pool exposure
Adenovirus => pharyngoconjunctival fever
-
What is the difference between keratoconjunctivitis and pharyngoconjunctival fever?
Kera- mostly in adults, photophobia, spread of hands my medical personnel, contaminated opthalmic solutions, common use bathrooms.
-
What pathogen can cause hemorrhagic Cystitis? and what are they symptoms?
- Adenovirus
- Symptoms: Gross hematuria, urgency, frequency, fever (male predilection, seen following bone marrow and renal transplantations)
-
Who is adenovirus usually detected?
Its not, but there are antigen detection tests as well as serotype tests.
-
Besides adenovirus, what other organisms can cause conjunctivitis?
- Viruses: herpes simplex, varicella zoster
- Bacteria: strep pneumoniae, H influenzae, H aegyptius, Grp A strep, Staph aureus, Chlamydia trachomatis, Neisseria gonerrhoeae
- Fungi: aspergillus, fusarium
- Parasites: acanthamoeba
-
Eye infection by staph aureus
Blepharitis (eye lids)
-
Eye infection: S. aureus, strep pneumoniae
Dacrocystitis (tear ducts)
-
Eye infection: S aureus, Pseudomonas, candida
Enophthalmitis
-
Eye infection: syphilis, HSV, VZV
Iridocyclitis (uveal tract)
-
Eye infections: TB, CMV, HSC, VZV, histoplasma, candida, toxoplasma
choreoretinitis
-
What is the most common organism associated with Otitis Externa?
pseudomonas (typically from water)
-
What are the common causes of otitis media and what are some common features?
- 50% viral
- Bacteria: S. pneumo, H. flu, moraxella
- Follows uri's
- Ear pain/pulling
- 60% no fever
- Antibiotics little value
-
Name the pathogen.
Gram negative diplococci
lives in resp. tract
causes otitis, bronchitis, pneumonia, sinusitis, SBE, meningitis
Moraxella
-
What syndrome?
more common in adults
follows uri's
mostly viral
facial pain, HA, upper teeth pain, opacity by transillumination
antibiotics don't help much
Sinusitis
-
What syndrome?
Dyshpagia, drooloing stridor
acute airway obstruction (medical emergency)
lateral neck x-ray
protect airway
almost always caused by Haemophilus influenzae
-
-
Name the pathogen:
was THE major ped pathogen before immunization (meningitis)
Still a common cause of URI's
pleomorphic gram negative coccobacilli
type b is most important (encapsulated)
mousy odor
satellitism
fastidious (due to need of growth factors X and V)
antigen detection possible
Haemophilus influenzae
-
What major diseases can be caused by H influenzae?
- Septic arthritis
- bacterial conjunctivitis
- bacterial epiglottitis
- buccal cellulitis
- sinusitis
- otitis
- (pneumonia, bronchitis, sepsis)
-
Hib vaccine targets what?
H influenzae type b (extremely important vaccine)
-
Name the pathogen/illness
Bordatella _______
Gram neg. coccobacilli
Strictly aerobic
Slow growing; req. special media
Does not survive the environment; direct person-person spread
Adults are reservoirs, but kids have worse dz
Vaccine effective (immunization rates vary)
Highly contageous (90%)
300,000 deaths/yr
Pertussis
-
Describe how pertussis causes illness.
- Adheres to resp. ciliated epithelium and releases toxins
- Cytotoxin destroys cilia and cells
- Toxins enters circulation and may cause systemic effects
-
Clinical pertussis
- 7-10 day incubation
- Catarrhal stage: cold for 1-2 wks
- Paroxysmal stage: sudden cough, inspiratory whoop, vomiting, apnea (1-6 wks)
- Convalescent phase: prolonged cough for wks to months
-
How do you diagnose pertussis?
- Clinically diagnosis is most effective.
- Direct detection: fluorescent antibody tests
- Culture
- DNA amplification tests being developed.
-
Prevention of pertussis
- Whole cell vaccine (older, not as good)
- Acellular vaccine (Dtap-kids or Tdap-adults) -- much better than old vaccine, much less severe side effects
-
Parainfluenza virus
- 2/3 of infants get PIV3 (not very serious)
- causes Croup
-
What are the symptoms of Croup caused by parainfluenza virus?
- fever
- hoarseness
- barking cough
- stridor
- major cause PIV1 (then 2 and 3)
-
Treatment and diagnosis of parainfluenza virus
not much tx, diagnosis not usually necessary but culture is possible (antigen detection is less sensitive)
-
Mumps Virus
- winter/spring
- school-aged children--not very serious
- lifelong immunity follows natural infections
- seems to be coming back
-
Mumps virus pathogenesis
- Viral replication in resp. epithelial cells=> spread to regional lymph nodes=> plasma viremia=> dissemination to glandular and neural tissue
- Highly contagious
- Airborne resp droplets
- 18 day incubation
-
Mumps clinical syndromes
- fever, malaise, headache, ear pain
- salivary gland swelling (bilateral parotid swelling)
- extrasalivary gland manifestations
- (complications: gonads, pacreas, myocarditis, hearing loss)
-
Mumps virus diagnosis and treatment
- Parotitis -- halmark
- confirm w/ lab tests (culture is definitive test)
- Prevention: vaccine and boosters
- Treatment: symptomatic only
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