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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
Which of the following is not an upper respiratory infection (URI)?
cold, bronchitis, otitis, pinche cabronitis, sinusitis, pharyngitis, epiglottitis
Is the common cold a viral or bacterial infection?
viral (lasts 7-10 days)
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)
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
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
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)
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)
Major causes of pharyngitis?
mostly viral and Grp A strep
Streptococci hemolytic patterns on sheep blood agar: distinguish between
- 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
A pt comes in and thinks they have Grp A strep pharyngitis. What characteristics should be present if the Pt is correct?
- Sudden onset
- pharyngeal inflammation
- discrete exudate
- tender cervical nodes
- NOT cough, congestion or conjunctivitis
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)
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.
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?
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)
- 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
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
- 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)
- liver ( mild increase in AST & ALT),
- 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)
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?
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?
- linear, ds DNA genome
- Resistant to many physical and chemical agents
- 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.
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?
- pharyngoconjunctival fever
What is the pathogen and illness associated w/
unilateral conjunctivitis lasting 1-2 wks
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?
- 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
Eye infection: syphilis, HSV, VZV
Iridocyclitis (uveal tract)
Eye infections: TB, CMV, HSC, VZV, histoplasma, candida, toxoplasma
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
more common in adults
facial pain, HA, upper teeth pain, opacity by transillumination
antibiotics don't help much
Dyshpagia, drooloing stridor
acute airway obstruction (medical emergency)
lateral neck x-ray
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)
fastidious (due to need of growth factors X and V)
antigen detection possible
What major diseases can be caused by H influenzae?
- Septic arthritis
- bacterial conjunctivitis
- bacterial epiglottitis
- buccal cellulitis
- (pneumonia, bronchitis, sepsis)
Hib vaccine targets what?
H influenzae type b (extremely important vaccine)
Name the pathogen/illness
Gram neg. coccobacilli
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%)
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
- 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
- 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
- 2/3 of infants get PIV3 (not very serious)
- causes Croup
What are the symptoms of Croup caused by parainfluenza virus?
- barking cough
- 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)
- 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