Infectious Disease Flashcards
This deck covers Chapters 121-130 in Rosens, compromising all of infectious disease.
1
Q
A 62 yo female had a tooth pulled 4 days ago. She now has severe neck pain with swelling. It feels woody on palpation.
Answer the following:
- Diagnosis
- Etiology
- Symptoms
- Treatment
A
Diagnosis
- Ludwig’s angina
Etiology
- Deep space infection
- Submental, submandibular, sublingual spaces
- Mixed flora (GAS, Bacteroides)
- Typically from intra-oral/intra-pharyngeal sources
Symptoms
- Swelling
- Fever
- Shortness of breath
- Impaired neck mobility
- Toxic appearing
Treatment
- Pip-Tazo + Vancomycin + Clindamycin
- ENT Consult in ED
- Awake fiberoptic intubation, if necessary
2
Q
You diagnose a 14-year-old female with pertussis. She lives at home with her parents and a 6-month-old brother.
Outline the stages of Pertussis and your management
A
Stages
- Catarrhal (1-2 weeks) - infectious
- Paroxysmal phase (1-2 months)
- Convalescent phase
Management
- Booster vaccine
- Azithromycin (5 days)
- Notify public health
- Self-isolation for 3 weeks
- All close contacts receive booster vaccine and Azithro
- Household
- Daycare
- Child < 1-year-old
- 3rd-trimester pregnancy
3
Q
A 35-year-old male presents with a wound. Explain your approach to tetanus prophylaxis
A
If wound clean and:
- Immunized <10 years ago = do nothing
- Immunized >10 years ago = Td vaccine
- Never immunized = Td vaccine
If wound dirty and:
- Immunized <5 years ago = do nothing
- Immunized >5 years ago = Td vaccine
- Never immunized = Td vaccine + HTIG
- HTIG dose = 250 U IM
Dirty Defined As:
- > 6 hours old
- > 1 cm deep
- Contaminated (dirt, feces, soil, saliva)
- Puncture
- Stellate
- Avulsions
- Denervated
- Ischemic
- Infected
- Missiles
- Crush
- Burns
- Frostbite
4
Q
A kid comes in walking with a limp. Severe decreased ROM of the hip. He is febrile. You suspect a septic hip.
What criteria can be used to diagnose this?
A
Kocher Criteria
NEWF
- NWB on the affected side
- ESR > 40
- WBC > 12
- Fever (T >38.5)
5
Q
Describe the signs and symptoms of Ebola. How long after a possible exposure should you be worried?
A
Ebola Virus
Transmission
- Human-to-Human
- Direct contact with blood + bodily fluids
Incubation Period
- Up to 3 weeks
Who to suspect it in
- Travel to an endemic country
- Contact with confirmed Ebola patient and symptomatic
Symptoms
- Sudden onset fever, malaise, myalgia, severe H/A
- Conjunctivitis, pharyngitis, N/V/D
- Hepatic + renal impairment
- Maculopapular or petechial rash
- Mucosal bleeding (50%)
- Multiorgan failure, shock, and death
6
Q
Describe the epidemiology, pathophysiology, and clinical features of Staphylococcal Scalded Skin Syndrome (SSSS)
A
Epidemiology
- Children (6 months – 6 years)
- Mortality = 3%
- Adults
- Mortality = 50%
Pathophysiology
- Toxin-producing S. aureus
- Epidermolytic toxin A or B
- Acts on Desmoglein 1 protein (Dsg1)
- Results in the separation of the skin
Clinical Presentation
- Positive Nikolsky’s sign
- Erythema
- Blisters, bullae, and vesicles
7
Q
List FIVE DDx for tetanus
A
- Strychnine Poisoning
- Dystonic Reaction
- Hypocalcemia
- Status Epilepticus
- Rabies
8
Q
What is the most common cause of focal intracranial mass lesions in HIV infection?
A
Toxoplasmosis
- Parasitic disease
- Poorly cooked food w cysts or cat feces exposure
- ½ of people are infected by toxo but have no symptoms
Clinical
- Headache
- Fever
- Altered mental status
- Seizures, focal deficits
CT (with contrast) Features
- Ring enhancing lesions
- Multiple lesions
- Basal ganglia and corticomedullary area
Treatment
- Pyrimethamine 100-200mg PO then 50-100 mg/day
- Sulfadiazine 4-8 g/day PO
- Folinic acid 1 mg/day PO (prevents pancytopenia)
9
Q
List FOUR clinical and FOUR lab findings that are criteria for severe malaria and poor prognosis
A
Clinical
- GCS <11
- Weakness
- Seizures (>2/day)
- Pulmonary edema (Hypoxia + RR >30)
- Bleeding
- Shock
Lab
- Hypoglycemia (<2.2 mmol/L)
- Acidosis (Base Deficit >8, Bicarb <15, Lactate >5)
- Anemia (HgB <70 adults, <50 children under 12, HCT <15%)
- Renal impairment (Cr >265, BUN >20)
- Bilirubin >50
- Parasite count >10% (for P. falciparum)
10
Q
What is the causative agent in RMSF? How does it cause disease? What is the vector?
A
Rickettsia rickettsii
- Obligate intracellular bacteria
- Invades vascular endothelium causing vasculitis
Vector
- Rocky Mountain wood tick (Dermacentor andersoni)
- Dog tick (Dermacentor variabilis)
11
Q
List the culprit organisms and treatment regimens for septic arthritis if the Gram’s stain shows:
- Gram + cocci
- Gram – cocci (sexually active patient)
- Gram – bacilli
- Gram + bacilli
A
Gram + cocci
- S. aureus
Gram – cocci (sexually active patient)
- N. gonorrhea
Gram – bacilli
- E. coli, P. aeuriginosa
Gram + bacilli
- P. acnes
12
Q
List SIX rashes that can affect hands/soles of feet
A
- Secondary syphilis
- RMSF
- Coxsackie (HFM)
- Smallpox
- Kawasaki
- Meningococcemia
- Endocarditis
- DIC
13
Q
What are the TWO pneumococcal vaccines available in Canada? When are they indicated?
A
PREVNAR-13
- Pneumococcal 13-valent conjugate vaccine
- Used to prevent IPD (invasive pneumococcal disease)
- Indications:
- All infants at 2 mo, 4 mo, 12 mo
PNEUMOVAX-23
- Pneumococcal 23-valent polysaccharide vaccine
- Indications
- All adults ≥ 65 years
- ‘Other’: homeless, alcoholic, smoker, drug user
- Immunocompetent adults + high risk for IPD
- Immunocompromised adults + high risk for IPD
14
Q
List potential regimens for drug-resistant TB
A
Usually ‘RIPE’, replace I with a fluoroquinolone.
- Rifamipin
- Pyrazinamide
- Ethambutol
- Fluoroquinolone
15
Q
List FOUR features of osteomyelitis on plain XR
A
- Involcrum (Periosteal reaction)
- Lucent areas
- Lytic lesions surrounded by dense sclerotic bone
- Sequestra
- Deep soft tissue swelling & fascial plane separation
- Altered fat interfaces
16
Q
Provide a differential diagnosis for respiratory infections in HIV+ patients based on CD4 count
A
CD4 >200
- Regular pneumonia
CD4 <200
- PCP, Histo, Cryptococcus, TB
CD4 <50
- PCP, MAC, CMV, and everything above
17
Q
What is the typical presentation of septic arthritis (clinical or lab)?
A
Symptoms
- Fever
- Joint pain
- Malaise
Lab Tests (C’s)
- Cell count (WBC >50 cutoff)
- Crystals
- Chemistry (Lactate, glucose, protein)
- Culture
- Gram stain
18
Q
What are 5 complications of pertussis? How is it diagnosed?
A
Diagnosis
- NP swab + PCR (3-7 days for results)
Complications
- Respiratory failure
- Hernias
- Hemoptysis
- Pneumothorax
- Subcutaneous emphysema
19
Q
Your patient has a parasitemia of 15% and it’s falciparum. Outline your management.
A
Severe Malaria Treatment (AM QD)
- Option A (‘AM’): Artesunate + Malarone IV
- Preferred
- Option B (‘QD’): Quinidine + Doxycycline IV
- Admit to ICU
20
Q
How would you treat meningococcemia? Are steroids indicated for bacterial meningitis?
A
Treatment
- Ceftriaxone 2g IV q12h
- Vancomycin 15 mg/kg q12h
- Dexamethasone 8 mg IV
* Decreased mortality in S. pneumoniae
* Decreased hearing loss in H. influenzae
21
Q
Outline your management of a patient with tetanus
A
Supportive Care
- Muscle spasms
- Benzodiazepines (*diazepam is the best-studied)
- Dantrolene (adjunct)
- MgSO4 (improved spasm control)
- Airway Protection (if above fails)
- Avoid sux
- Autonomic instability
- Labetalol or propranolol
Elimination of Tetanospasmin (TS) & Active Immunization
- HTIG 250 IU IM
- Neutralizes any circulating toxin
- Neutralizes toxin at the site of production
- Reduces mortality
- Td 0.5 mL IM
- Give at a separate site
Prevention of further toxin production
- Wound debridement
- Metronidazole 500 mg IV/PO Q6H (drug of choice)
- Avoid PCN which inhibits GABA and synergizes with TS
22
Q
Discuss Rabies post-exposure prophylaxis
A
Wound Care
- Scrub with soap/water
Tetanus prophylaxis
- Td 0.5 mL IM (if not vaccinated)
Human Rabies IG (HRIG)
- HRIG 20 IU/kg
- Infiltrate full dose into and around the wound
- Remainder is given IM
Human Diploid Cell Vaccine (HDCV)
- If never vaccinated:
- Days 0, 3, 7, 14, 28 (5 doses)
- If previously vaccinated:
- Days 0 and 3 (2 doses)
23
Q
Chikungunya. Describe its vector, duration of illness, and complications.
A
Vector
- Aedes mosquitoes
Symptoms
- Fever - usually ends abruptly after 2 days
- Arthralgia/Arthritis - significant
- Headache
- Insomnia
- Rash
Diagnosis
- Serology, RT-PCR
Treatment
- NSAIDs
Complications
- Myocarditis
- Hepatitis
- Nephritis
- Meningitis
- Guillain-Barré syndrome
- Cranial nerve palsies
24
Q
What is the causative agent in Diphtheria? Explain the pathophysiology, types of disease, and management.
A
Etiology
- Corynebacterium Diptherae
Types
- Respiratory Diphtheria
- Greatest toxicity
- Pharyngeal, Nasal, Laryngeal
- Cutaneous Diphtheria
- Least toxic
Pathophysiology
- Produces exotoxin that inhibits cellular protein synthesis
- Affects: Nervous System + Heart + Kidneys
Treatment
- Erythromycin 50 mg/kg/day
- Diphtheria antitoxin
- Vaccinate
- Self-isolation
- Notify Public Health
- Vaccinate close contacts
25
Which ONE parasite is well known to cause cardiomyopathy?
**Chagas Disease**
**Parasite**
* Trypanosoma cruzi
**Symptoms**
* Acute (1 – 2 months)
* Fever
* Facial and dependent extremity edema
* HSM, LAD
* Peripheral smear: lymphocytosis
* Elevated LFTs
* Chronic (25% of patients)
* Cardiac
* Invasion of muscle + fibrosis/inflammation
* Bradycardia, BBBs, Heart blocks, VT/VF
* GI symptoms
**Treatment**
* Nifurtimox 2 mg/kg PO QID x4 months
* Alternative: Benznidazole
26
Describe the clinical presentation and treatment of cryptococcal infection in HIV infected patients.
**Clinical Presentation**
* Fever
* Headache
* Visual disturbance
* Seizures
* Usually CD4 \< 100
* Causes focal or diffuse meningoencephalitis
**Treatment**
* 3 phases: induction, consolidation, maintenance
* If abnormal mental status
* Amphotericin B 0.7 mg/kg/day IV
* +/- 5-Flucytosine
* If normal mental status
* Fluconazole 400 mg/day PO
27
List guidelines for the management after accidental exposure to TB at work? What FOUR populations get PEP?
**If exposed at work**
* Get a TB skin test early for baseline
* Re-test in 3 months to see if there is the conversion
**PEP INH**
1. Significant exposure in PPD Negative person
2. PPD Negative who converts after exposure
3. PPD Positive and no pre-exposure PPD available
4. Immunocompromised \<35 yo
28
Outline the WHO pandemic phases
**Phase 1**
* Infection in animals only
**Phase 2**
* Isolated animal-to-human transmission
**Phase 3**
* Sporadic human-to-human transmission
* Not enough for community outbreak
**Phase 4**
* Human-to-human transmission
* Able to sustain community-level outbreaks
**Phase 5**
* Human-to-human transmission
* Spread to 2+ countries in one WHO region
**Phase 6**
* Human-to-human transmission
* Spread to at least two WHO regions
29
Outline the stages of HIV infection as per the CDC surveillance case definitions
**Stage 1**
* CD4 \>500
* No AIDS-defining illness
**Stage 2**
* CD4 200-499
* No AIDS-defining illness
**Stage 3**
* CD4 \<200
* Any AIDS-defining illness present
30
List SIX complications of severe P. falciparum malaria
1. Cerebral malaria
* Cerebral edema + encephalopathy
2. Metabolic acidosis
3. Severe anemia
4. Pulmonary edema
5. Hypoglycemia
6. AKI
7. DIC
8. Death
31
Name 4 complications of measles.
1. Sub-acute sclerosing panencephalitis (SSPE)
2. Laryngitis
3. Tracheobronchitis
4. Pneumonitis
5. Secondary bacterial pneumonia
6. Encephalomyelitis
7. Vitamin A deficiency & blindness
32
List signs & symptoms of RMSF
**Constitutional**
* Fever, malaise
**Neurologic**
* H/A, meningismus, cerebral vasculitis
* Ataxia
**Cardiac**
* LV dysfunction
* Arrhythmias (1st deg AVB, A fib)
* Cardiac enlargement on CXR
* ECG: nonspecific ST-T changes
**Pulmonary**
* Interstitial pneumonitis
**MSK**
* Severe myalgias
**Hematologic**
* DIC (fulminant cases)
**Dermatologic**
* Rash
* Initially:
* 1 – 5 mm pink to red macules
* Blanches
* Begins on ankles & wrists
* Palms + Soles (50%)
* Spreads centripetally to forearms, legs, thigh, trunk +/- face
* Enhanced by warm compresses
* Not palpable
* 2 – 3 days
* Becomes maculopapular
* Deepens in redness
* Palpable
* No longer blanches
**Rumpel-Leede phenomenon**
* Rash enhanced by tourniquet or BP cuff
* Distal shower of petechiae that occurs immediately after release of a tourniquet or BP cuff
33
List 10 conditions that require droplet precaution
1. Adenovirus, respiratory strains
2. Bocavirus
3. Coronavirus
4. Diphtheria, pharyngeal
5. H. influenzae, in children
6. Human metapneumovirus
7. Influenza, seasonal, avian
8. Meningococcus
9. Monkeypox
10. Mumps
11. Mycoplasma pneumoniae
12. Parainfluenza virus
13. Parvovirus B-19
14. Pertussis
15. Plague, pneumonic
16. RSV
17. Rhinovirus
18. Rubella
19. SARS
20. Smallpox
21. Streptococcus, Group A
22. Scarlet fever
23. Viral hemorrhagic fevers
34
List EIGHT DDx for botulism
1. GBS
2. Tick paralysis
3. Myasthenia gravis
4. Lambert-Eaton syndrome
5. Diphtheria
6. Brainstem CVA
7. Anticholinergics
8. Organophosphates
9. Dystonic reactions
10. Heavy-metal poisoning
11. Mg toxicity
12. Paralytic shellfish poisoning
35
List 8 risk factors for necrotizing fasciitis (NF)
1. DM
2. Vascular insufficiency
3. Immunosuppression
4. Penetrating trauma
5. Post-surgical
6. Varicella infection (+NSAIDs!!)
7. IVDU
8. Burns
9. Childbirth
36
Staphylococcal scalded skin syndrome vs. TEN
**Staph Scalded Skin Syndrome**
* + Nikolski
* Oral mucosal sparing
* Unwell, but not shocky
* No history of drug exposure
* Responds to antibiotics
**Toxic Epidermal Necrolysis**
* + Nikolski at the lesion
* Full-thickness of skin
* Oral mucosal regions involved
* Very unwell
* Drug exposure
37
List 5 host and 5 environmental risk factors for tuberculosis
**Environmental Factors**
1. Close contacts
2. Health care workers
3. Birth in TB endemic area
4. Overcrowding/poor ventilation
5. Low SES
6. Homeless
7. Longterm care facilities
8. Prisons
**Host Factors**
1. HIV+
2. Elderly
3. IVDU
4. Steroid use, immunosuppressive tx
5. DM2
6. Hematologic malignancy
7. Malnourished
38
What are the characteristics of neonatal & infant bone infections? How does this differ compared to children aged 1 – 17 years & adults?
**Neonates/Infants**
* Spreads from metaphysis to the epiphysis
* Vessels cross growth plate
* No pressure-related necrosis
* Cortex allows the release of pressure
* Develop abscesses; Involucrum formation
**Children Age 1 – 17 Years**
* No spread to the epiphysis
* Epiphyseal plate = avascular
* No pressure-related necrosis
* Cortex still allows the release of pressure
* Subperiosteal abscess formation
**Adults**
* Spread from metaphysis to epiphysis again
* Due to anastomosis of vessels across the plate
* Pressure-related necrosis
* No abscess formation
39
List EIGHT tick-borne illnesses (disease & pathogen)
1. Lyme - Borrelia burgdorferi
2. Tularemia - Francisella tularensis
3. RMSF - Rickettsia rickettsii
4. Q fever - Coxiella burnetii
5. Human monocytic ehrlichiosis - Ehrlichia chaffeensis
6. Human granulocytic anaplasmosis - Anaplasma phagocytophilum
7. Babesiosis - Babesia microti
8. Colorado tick fever - Orbivirus
9. Tick paralysis - Ixobotoxin
40
In a confirmed case of meningococcemia, what is the prophylaxis and who should get it?
**Indications**
* Household contacts, daycare/nursery contacts
* HCWs with intimate exposure (intubation, suctioning etc.)
**Prophylaxis**
* Ciprofloxacin 500 mg PO x1
* Adults only
* Rifampin 10 mg/kg (max 600 mg) Q12H x4 doses
* Warn patients that secretions will be orange
* Ceftriaxone 250 mg IM
* If \<12 years old: 125 mg IM
* Use in pregnancy
41
Discuss MERS-CoV transmission and symptoms.
**MERS-CoV (Coronavirus)**
**Transmission**
* Human-to-human (typically in healthcare settings)
**Suspect In**
* Travel to Middle East + respiratory symptoms
* Being in a healthcare facility or contact with camels
**Symptoms**
* Fever, cough, SOB
* Pneumonia is common
* +/- N/V/D
* Can get severe pneumonia, ARDS, sepsis
42
Use Waldvogel’s system to classify osteomyelitis
* Hematogenous
* Contiguous
* Person with Vascular Insuffiency
43
List and describe the FOUR forms of tetanus
**Generalized Tetanus**
* Spasms throughout the body
* Trismus (lockjaw; masseter spasm)
* Sardonic smile (risus sardonicus; facial muscles)
* Opisthotonos (looks like decorticate posturing)
**Localized Tetanus**
* Persistent muscle spasms close to site of injury
* May progress to generalized tetanus
**Cephalic Tetanus**
* CN palsies + muscle spasms
* Most common = CN VII (mimics Bell’s palsy)
* Rare variant of localized tetanus
* 1/3 recover, 2/3 develop generalized tetanus
**Neonatal Tetanus**
* Irritability + poor feeding (1st week of life)
44
Describe the stages of Lyme disease. How do you diagnose?
**Lyme Disease**
**Stages**
* **Early**
* Erythema migrans
* **Disseminated**
* ****Carditis
* Neuro (meningitis, CN palsy)
* Arthritis
* **Late Lyme**
* ****Arthritis
* Fatigue
* Neurocognitive deficits
**Diagnosis**
* Clinical (erythema migrans + history)
* Serology (two-tier strategy):
* Step 1: ELISA (if negative, stop)
* Step 2: Western blot (confirmatory)
* Must interpret serology within clinical context:
* IgM (peaks 3 – 6 weeks)
* IgG (seen at \> 2 months; peaks 12 months)
* IgM alone at \> 4 weeks is a false positive
* IgG may persist for years
45
What are the THREE distinct clinical stages of pertussis?
**Catarrhal**
* 1-2 weeks
* Infective
* URTI symptoms
**Paroxysmal**
* 1-2 weeks
* Not infective
* Coughing and whoop
**Convalescent**
* Coughing for 90 days
46
Cellulitis vs. Necrotizing Fasciitis vs. Myonecrosis
**Cellulitis**
* Superficial
* Predisposing trauma
* May need I+D
* Staph/Strep
**Necrotizing**
* Deep soft tissue infection
* Trauma, surgery, DM
* Needs surgical debridement + ABx
* Mixed anaerobic
**Myonecrosis**
* Through fascia into muscular layers
* Trauma, contaminated wounds
* Clostridia, anaerobes
47
What is an involucrum? What are sequestra?
**Involuvrum**
* Formation of new periosteum in osteomyelitis
* "Periosteal reaction"
**Sequestra**
* Ischemic bone separates from the rest of the bone
* Seen in advanced or chronic osteomyelitis
48
How do you differentiate periorbital vs. orbital cellulitis?
**Periorbital Cellulitis**
* Pre-septal (eyelid and surrounding tissues)
* No decreased VA
* No pain with EOM
* No proptosis
* Unilat erythema, swelling, warmth, tenderness of eyelid
* S. aureus, GAS
* Amox-Clav/Clindamycin
* Outpatient ophthalmology
**Orbital Cellulitis**
* Past the orbital septum
* Decreased VA
* Pain with EOM
* Proptosis
* Blurred vision, ophthalmoplegia, proptosis, and chemosis
* Toxic
* S. aureus, GAS, pneumococcus
* Ceftriaxone + Vancomycin IV
* add Flagyl if concerned re: CVST
* Inpatient ophthalmology
49
What is the incubation period for malaria? Dengue?
Dengue = \<10 days
Malaria = 11-21 days
50
Outline the doffing order for PPE
1. Gloves
2. Gown
3. Hand hygeine
4. Eye shield
5. Mask
6. Hand hygeine
51
Give 8 examples of persons at risk who should be tested for latent TB infection
1. Recent close contact
2. HCWs around active TB
3. Foreign-born from endemic areas
4. Homeless
5. Living/working in LTC facilities
6. HIV
7. Recent TB infection
8. IVDU
9. ESRD
10. DM
11. Immunosuppressants
12. Hematologic cancers
13. Malnourished
14. Recent weight loss \>10%
15. Gastrectomy/jejunoileal bypass
52
List SIX risk factors for developing active TB in a previously infected individual
1. HIV
2. IVDU
3. Cancer (especially head and neck)
4. ESRD
5. DM
6. Abnormal CXR
7. TB in the last 2 years
53
What is the treatment for PCP pneumonia?
**PCP Pneumonia**
* Immunocompromised patients, HIV CD4 \<200
* Pneumocystis jiroveci
* Gradual (3 weeks)
* Resp symptoms, cough, fever, progressive SOB
* Elevated LDH
* CXR = diffuse, bilateral, interstitial, or alveolar infiltrates
* Get HIV screen
**Treatment**
* Septra 20 mg/kg/day div TID
* 2 Septra DS tabs PO q 8hrs
* Steroids if:
* A-a O2 gradient ≥35 mmHg
* PaO2 \<70 mmHg
* Respiratory failure
54
List SEVEN AIDS-defining illnesses
1. Kaposi sarcoma
2. Oral candidiasis
3. CMV retinitis
4. CMV colitis
5. PCP pneumonia
6. MAC
7. CNS Lymphoma
8. Toxoplasmosis
9. Disseminated fungal infections
55
Give a differential for "cavitary" lung disease
**CAVITY**
* **C**ancer – bronchogenic, mets
* **A**utoimmune/granulomatous – Wegener’s, RA
* **V**ascular – septic/non-septic emboli
* **I**nfectious – TB, MRSA/MSSA, Klebsiella, Coccidiomycosis, cryptococcus, blasto
* **T**rauma – pneumatocele
* **Y**outh – CPAM, bronchogenic cyst
56
Identify the disorders caused by HHV strains
* HSV 1: Herpes labis
* HSV 2: Genital herpes
* HSV 3: VZV (chicken pox)
* HSV 4: EBV (Mononucleosis)
* HSV 5: CMV
* HSV 6: Roseola (6th Disease)
* HSV 7: Not a thing
* HSV 8: Kaposi Sarcoma
57
List 6 possible causes of ring-enhancing lesions on CT head.
1. Cerebral abscess
2. Tuberculoma
3. Neurocysticercosis
4. Toxoplasmosis
5. CNS Lymphoma
6. Fungal granulomas
7. Metastatic cancer
8. Glioblastoma
9. Sarcoidosis
10. Subacute infarct/hemorrhage/contusion
11. Demyelination (incomplete ring)
12. Radiation necrosis
13. Postoperative change
58
List 8 ABX with activity against MRSA
**PO**
1. TMP/SMX
2. Clindamycin
3. Doxycycline
4. Linezolid
5. Rifampin (IDSA says no)
**IV**
1. Daptomycin
2. Linezolid
3. Vancomycin
4. Dalbavancin
5. Oritavancin
59
A 42-year-old homeless male presents with muscular rigidity and a clenched jaw. He is tachycardic and mildly hypertensive. You notice that he has needle track marks and a sardonic smile.
Give a detailed explanation of why this patient is having muscle spasms.
**Wound Tetanus**
**Etiology**
* Clostridium tetanii
**Pathophysiology**
* Neurotoxin produced called tetanospasmin (TS)
* Binds motor nerve endings & moves to the CNS
* Binds inhibitory neurons and blocks release of inhibitory neurotransmitters (GABA + glycinergic)
* Motor neurons undergo sustained excitatory discharge
* This causes muscle spasms
60
How is Zika transmitted? What are the symptoms? What is the concerning complication?
**Zika Virus**
* Arbovirus (arthropod-borne virus)
**Transmission**
* Transmitted by a mosquito - Aedes
* Direct human-human spread – sexually
* Perinatal transmission recently reported
**Symptoms**
* Rash
* Conjunctivitis
* Arthralgias
* 80% asymptomatic
* **Associated with microcephaly**
61
Compare and contrast Cellulitis vs. erysipelas
**Cellulitis**
* Extends into SC tissue
* Blanching erythema
* Flat
* Poorly demarcated
* S. aureus/Strep
* Keflex/Ancef
**Erysipelas**
* Superficial
* Indurated
* Raised
* Sharply demarcated
* S. pyogenes (GAS)
* PCN G
62
Compare and contrast:
* Staphylococcal Scalded Skin Syndrome (SSSS)
* Staphylococcal TSS
* Streptococcal TSS
**SSSS**
* 6 months to 6 years typically
* Niksolski +
* Mucosal sparing
* Not shocky, kids look miserable but not dying
* **Epidermolytic Toxin A and B**
**Staph TSS**
* Probable case = 4 clinical + lab
* Confirmed case = 5 clinical + lab
* Clinical Criteria
* Fever
* Rash
* Desquamation
* Hypotension
* 3+ of:
* GI (Vomiting/Diarrhea)
* MSK (Myalgia or CK \>2x ULN)
* Mucous membrane hyperemia
* Renal (BUN or Cr \>2x ULN)
* Hepatic (LFTs/Bili \>2x ULN)
* Platelets \<100
* Altered LOC
* Laboratory Criteria
* Cultures negative for alternative pathogens
* Serology negative for RMSF, leptospirosis, measles
* Usually from a wound or a foreign body
* **TSST-1 toxin**
**Streptococcal TSS**
* Probable case = Clinical + GAS from non-sterile site
* Confirmed case = Clinical + GAS from sterile site
* Clinical Criteria
* Hypotension
* 2+ of:
* Renal impairment (Cr \>177)
* Coagulopathy (Platelets ≤100 or DIC)
* Liver (LFTs or Bili \>2x ULN)
* ARDS
* Erythematous macular rash
* Soft tissue necrosis
* Laboratory Criteria
* Isolation of GAS
* Usually more painful
* **Exotoxin A and B**
63
List 6 of the most common animal reservoirs for rabies transmission to humans
1. Bat
2. Raccoon
3. Skunk
4. Fox
5. Dog
6. Cats
7. Coyotes
8. Wolves
9. Some cases of cattle and horses
64
A patient being treated with doxy for Lyme feels like hot garbage the next day: is this normal?
**Jarisch-Herxheimer Reaction**
* Reaction occurs 24 hours after ABx against spirochetes
* Dying bacteria release pyrogens
**Symptoms**
* Malaise, chills, myalgias, headache
* Fever, tachycardia, tachypnea, hypotension
* Mild leukocytosis
65
List the 4 clinical stages of rabies
**Incubation**
* Duration dependent on proximity to CNS
* Closer to the brain is shorter
**Prodrome**
* Headache, runny nose, sore throat, myalgias, GI symptoms, back pain, muscle spasms, agitation, anxiety
* Paresthesias, pain, or severe itching at the bite
**Acute Neurologic Illness – 2 forms**
* **Furious** (Encephalopathic) – 80%
* Agitation, hydrophobia (can’t swallow), extreme irritability, hyperexcitability with periods of lucidity, tachycardia, tachypnea, fever, hallucinations, seizures, ataxia, weakness, arrhythmias
* **Dumb** (Paralytic) – 20%
* Prominent limb weakness, fever, no hydrophobia
**Coma**
66
At what point should HIV infected patients be started on prophylaxis for specific opportunistic infections?
**CD4 \<200**
* Septra for PCP
**CD4 \<100**
* Septra for Toxo
**CD4 \<50**
* Azithromycin for MAC
67
Describe measles (Rubeola) re: etiology, incubation period, symptoms, management & FOUR complications
**Spread**
* Airborne respiratory droplets
**Incubation**
* 10 – 14 days
**Symptoms**
* Cough, coryza, conjunctivitis, fever
* Koplik spots (pathognomonic)
* Rash:
* Starts on head/face to trunk to extremities
* Macular or maculopapular
* Becomes confluent as it progresses
**ED Management**
* Airborne precautions
* Supportive care
* Notify public health
**Complications**
1. Diarrhea
2. AOM
3. Pneumonia
4. Encephalitis
5. Optic neuritis
6. Stillbirth
68
List common classes of HIV medication
* Nucleoside reverse transcriptase inhibitors (NRTIs)
* Non-nucleoside reverse transcriptase inhibitors (NNRTIs)
* Protease inhibitors (PIs)
* Integrase strand transfer inhibitors (INSTIs)
69
List one organism that can cause SSTI from wound exposure to SEAWATER and one from FRESH WATER.
**Seawater**
* Vibrio (Doxycycline)
**Freshwater**
* Aeromonas (Ciprofloxacin)
70
What is Nikolsky’s Sign?
Easy separation of the outer portion of the epidermis from the basal layer when pressure is applied
**DDx**
* SSSS
* TEN/SJS
* Pemphigus Vulgaris
* Bullous Pemphigoid
71
Outline your management for (a) an adult patient with botulism and (b) infant botulism
**Management of Adult Botulism - Food Borne**
* Equine trivalent antitoxin 10 mL vial
* Neutralizes only circulating toxin
* No effect on bound toxin
* Saline enemas & cathartics
* To cleanse GI tract
* Ensure you avoid Mg-containing cathartics (hyperMg can worsen muscle weakness)
**Management of Adult Botulism - Wound**
* Equine trivalent antitoxin 10 mL vial
* Neutralizes only circulating toxin
* No effect on bound toxin
* Antibiotics
* PCN
* Wound care
* Soap, water, tetanus
**Management of Adult Botulism - Iatrogenic**
* Equine trivalent antitoxin 10 mL vial
* Neutralizes only circulating toxin
* No effect on bound toxin
**Management of Infantile Botulism**
* BabyBIG
* Pooled plasma from immunized adults with high titers of antibodies to toxins A+B
**Airway**
* FVC \<20 mL/kg = intubate
* MIP \<30 cmH2O = intubate
* MEP \<40 cm H2O = intubate
72
List SIX parasites that cause fever
1. Plasmodium species (Malaria)
2. Borellia species (Lyme)
3. Schistosomiasis
4. African trypanosomiasis
5. Trypanosoma cruzi (Chagas)
6. Leishmaniasis
7. Toxoplasma gondii (Toxoplasmosis)
8. Entamoeba histolytica (Amoebic liver abscess)
73
List 5 conditions that must be placed on airborne precautions
1. Measles
2. Monkeypox
3. Tuberculosis (Pleuropulmonary or laryngeal)
4. Smallpox
5. Varicella-zoster virus
* Varicella (chickenpox)
* Zoster, disseminated
* Zoster, in an immunocompromised patient
6. COVID-19/SARS/Ebola during aerosolizing procedures
74
What are some features of Dengue?
## Footnote
**Transmission**
* Aedes mosquito
**Incubation**
* \<12 days
**Symptoms**
* Severe flu-like illness
* Fever
* Headache
* N/V/D, Abdo pain
* Myalgias, Arthralgias
* Rash
**Phases**
1. Febrile
2. Critical
* Plasma leak, low PLT, low WBC, severe dehydration
* \<5% will develop hemorrhage or shock
3. Recovery/Convalescence
75
A vet student is going to an area endemic with rabies. How would you prep her?
HDCV 1 mL IM (Deltoid)
* Days 0, 7, and 21 or 28 (3 doses)
76
Describe the symptoms of food-borne botulism
Person eats canned food with preformed toxin
**Symptoms (18 – 36 h later)**
* Early
* Weakness, malaise, light-headed, n/v, constipation
* Neurologic
* CNS affected first
* Diplopia, blurred vision, dysphonia, dysphagia, dysarthria
* Vertigo (common)
* Ocular signs
* Ptosis
* EOM palsies
* Dilated + fixed pupils
* Weakness
* Symmetrical, descending
* UE \> LE; proximal \> distal
* Classic: neck muscles often weak
* DTRs have variable findings (normal, depressed or absent)
* Sensory exam is NORMAL
* ANS parasympathetic blockade
* Decreased salivation; ileus; urinary retention
77
What are FIVE risk factors for TSS?
1. Tampons
2. Nasal packing
3. EtOH abuse
4. Immunocompromise
5. DM
6. COPD
78
How is malaria diagnosed?
**Thick & Thin Smears**
* Smears q12h until 3 sets negative
**Thick smear**
* Maintains the integrity + morphology of RBCs so that parasites are visible within RBCs (SCREENING)
* Estimates parasite density
**Thin smear**
* Allows identification of malaria species
* Measures parasite density
79
Outline your management of TSS (Strep and Staph)
1. IV O2 Monitors
2. Blood cultures
3. Fluids MAP \>65
4. Pressors
5. Antibiotics
* Pip-Tazo 4.5g IV q6h
* Vancomycin 15 mg/kg IV q12h
* Clindamycin 900 mg IV q8h
6. Strep = IVIG?
80
List criteria for a positive tuberculin skin test
* \>5 mm in immunosuppressed, HIV, CXR abnormal
* \>10 mm in foreign-born, IVDU, HCWs, LTC residents
* \>15 mm everyone else
81
What is the surviving sepsis 1-hour bundle?
**SSC Hour-1 Bundle of Care Elements**
1. Lactate
2. Blood cultures
3. Antibiotics
4. Crystalloid (30 mL/kg)
5. Vasopressors for MAP \>65
What international group has been critical of this approach?
* American College of Emergency Physicians (ACEP)
82
List FIVE causes of fever in a returning traveler
1. Malaria (20-30%)
2. Traveler’s diarrhea/Gastroenteritis (10-20%)
3. Respiratory tract infections (10-15%)
4. Dengue fever (5%)
5. Enteric fever
83
Who is at risk for a more severe course of influenza?
1. Age \>65
2. Age \<2
3. Chronic lung disease (asthma, COPD)
4. Chronic CV, renal, or hepatic disease
5. Sickle cell anemia
6. Diabetes
7. Immunosuppression (steroids, HIV, etc.)
8. Pregnancy
9. Long-term ASA use
10. Neuromuscular or seizure disorders
84
What are the WHO criteria for a positive HIV diagnosis?
**HIV Laboratory Criteria**
* Combination immunoassay that detects HIV-1 and HIV-1 antibodies and HIV-1 p24 antigen
* If positive, goes on to differentiate HIV-1 from HIV-2
* Nucleic acid testing if indeterminate
85
What is the causative agent in botulism? What is the mechanism? List and describe the FIVE forms of botulism.
**Botulism**
**Organism**
* Clostridium Botulinum
**Mechanism**
* Neurotoxin binds **peripheral NMJ** + autonomic synapses
* Binds presynaptic nerves & becomes internalize
* Inhibits release of ACh
**Symptoms**
* CN palsies
* Parasympathetic blockade
* Descending, flaccid paralysis
**Types**
* Food-borne botulism
* Ingestion of preformed heat-labile toxin
* Not ingestion of spores or bacteria
* Home-canned foods
* Infant Botulism
* Age \<1 year (peak incidence = 2-6 months)
* Ingestion of spores causing in vivo toxin production
* Honey & corn syrup
* Wound botulism
* IVDU
* Unclassified Botulism
* Produces its toxin in vivo (rare illness)
* Inadvertent botulism
* Botox gone wrong
86
What 5 criteria must be met for to give lyme prophylaxis
1. Tick attached for \>24h
2. \<72h since tick removed
3. Right kind of tick (Ixodes scapularis)
4. Endemic area
5. No contraindications to **doxycycline**
87
# Define:
1. Bacteremia (fungemia)
2. SIRS
3. qSOFA and what score is bad
4. Sepsis
5. Septic Shock
6. How is organ dysfunction identified?
**Bacteremia**
* Presence of bacteria/fungus in blood cultures
**SIRS**
* 2+ of:
* Temperature \<36 or \>38
* WBC \<4 or \>12
* RR \>20 or PaCO2 \<32
* HR \>90
**qSOFA**
* Altered Mental status
* RR \>21
* BP \<100
* 2+ predicts mortality and long ICU stay
**Sepsis**
* Life-threatening organ dysfunction caused by a dysregulated host response to infection
**Septic Shock**
* Sepsis requiring:
* Vasopressors
* Lactate \>2 mmol/L without hypovolemia
**Organ Dysfunction**
* Increase in SOFA score ≥2 due to infection
88
What are 3 complications of chickenpox? What are 3 complications of shingles?
**Chickenpox (HSV 3 = VZV)**
1. Bacterial superinfection
2. Pneumonia
3. Otitis media
4. Encephalitis – diffuse vs acute cerebellar ataxia
5. Aseptic meningitis
6. Reye syndrome (ASA use)
7. Hepatitis
**Shingles**
1. Post-herpetic neuralgia (15%)
2. Zoster ophthalmicus
* Hutchinson’s sign
3. Ramsay-Hunt Syndrome
4. Reye Syndrome
* Fatty liver + severe encephalopathy
5. Necrotizing fasciitis
* VZV + NSAIDS = RF of nec fasc
89
Describe the typical child that gets infant botulism
* Usually 2-6 months
* Mom gave kid honey or corn syrup
* Organic market and feed their kid honeycomb
**Symptoms**
* Several days – weeks
* Weak cry, loss of head control, hypotonia
* Depressed DTRs, decreased tone on exam
* CN involvement: facial expression, ptosis, EOM
* Respiratory failure in 50%
90
Define ARDS
**Berlin Definition (2013)**
* Acute (within 1 week)
* Bilateral patchy infiltrates
* Not from cardiogenic pulmonary edema
* P/F ratio \<300 with PEEP 5 cmH2O
**Severity**
* Mild (200-300)
* Mortality 27%
* Moderate (100-200)
* Mortality 32%
* Severe (\<100)
* Mortality 45%
91
Provide FIVE DDx for respiratory diphtheria
1. Gonorrhea
2. Retropharyngeal abscess
3. Tonsilitis
4. Bacterial tracheitis
5. Epiglottitis
6. Vincent's angina
92
What are the first-line TB meds? List common side effects.
**RIPE**
* **R**ifampin
* **I**soniazid (Give pyridoxine)
* **P**yrazinamide
* **E**thambutol
Pregnant TB = TREAT!
* Don’t give pyrazinamide
**Side Effects of TB Meds**
**Rifampin**
* Discoloration of body fluid (orange/red)
**INH**
* Hepatotoxicity
* Peripheral neuropathy
* Use pyridoxine (B6) as treatment/prevention
**Pyrazinamide**
* Hepatotoxicity
* Polyarthralgias
**Ethambutol**
* Retrobulbar neuritis and color-blindness
93
What drugs can you prevent malaria with?
Preventing Malaria: A-B-C-D
* Awareness of risk
* Bite prevention
* Chemoprophylaxis
* Dx and Tx
**Doxycycline 100 mg PO daily**
* Start 1 day before; continue 4 weeks after return
**Mefloquine 250 mg PO weekly**
* Start 2.5 weeks before, continue 4 weeks after return
**Malarone 1 tab PO daily**
* Start 1 day before; continue 1 week after returning
94
List EIGHT risk factors for MRSA
1. Immunocompromised (HIV, transplant, etc.)
2. DM
3. IVDU
4. Fluoroquinolone use
5. Young children
6. Elderly
7. Dormitories (College/Military)
8. Jail
9. HCWs
10. African American, Native American, Pacific Islanders
11. Tattoo Recipients
95
Outline the diagnostic criteria for Staph TSS
Probable = Lab criteria + 4/5 clinical criteria
Confirmed = Lab criteria + 5/5 clinical criteria
**Clinical Criteria**
1. Fever \>38.9
2. Diffuse macular erythematous rash
3. Desquamation 1-2 weeks after the rash
4. sBP \<90
5. 3+ organ systems:
* GI: Vomiting/Diarrhea
* MSK: Myalgia or CK \>2x ULN
* Renal: Cr or BUN \>2x ULN
* Hepatic: LFTs/Bili \>2x ULN
* Blood: Plt \<100
* Neuro: AMS
* Derm: Mucous membranes red
**Lab Criteria**
* BCx and CSF culture-negative (unless staph)
* Measles, RMSF, Leptospirosis serology negative
96
Outline the diagnostic criteria for Strep TSS
1. Isolation of GAS
2. Hypotension
3. 2+ organ systems
* Renal impairment
* Coagulopathy
* Hepatic dysfunction
* ARDS
* Erythematous rash
* Soft tissue necrosis
