Medicine- Infectious Diseases Flashcards
1
Q
Sepsis definition
A
Severe organ dysfunction resulting from dysregulated host response to infection
2
Q
Sofa score for sepsis- criteria
A
- Resp rate >22 2. Systolic BP <100mmHg 3. Altered mentation (GCS<15)
3
Q
Pathophysiology of sepsis
A
Bacteremia - local immune response - pro-inflammatory cytokine release - spread of immune response beyond local environment - unregulated, exaggerated systemic immune response - vasodilation and hypotension - distributive shock and reduced O2 delivery to tissues - anaerobic metabolism and lactic acid production - metabolic acidosis - multiple organ failure
4
Q
Erythema migrans + cranial nerve lesion, name the likely infection
A
Lyme Disease
5
Q
Cat scratch disease organism
A
Bartonella henselae
6
Q
Rocky Mountain Spotted Fever- organism and treatment
A
Rickettsia rickettsii Rx Doxycycline
7
Q
Rocky Mountain Spotted Fever Investigations
A
Skin biopsy and serology (indirect fluorescent antibody test)
8
Q
Rocky Mountain Spotted Fever vector
A
Ticks (Dermancentor)
9
Q
Features of secondary syphilis (3)
A
- Maculo-papular non-pruritic rash including palms and soles
- Generalized lymphadenopathy, low grade fever, malaise, headache, aseptic meningitis, ocular/otic syphilis
- Condylomata lata: painless, wart-like lesion on palate, vulva, or scrotum (highly infectious)
10
Q
Confirmatory investigations for syphilis
A
- TPI (T pallidum immobilization assay)
- FTA-ABS (fluorescent treponema antibody absorption)
- Darkfield microscopy with silver stain (Warthin-starry stain)
11
Q
Diagnosis of Lyme disease
A
by enzyme linked immunosorbent assay for Borrelia burgdorferi
12
Q
TB risk factors
A
- Immunocompromised/ (especially HIV, including extremes of age)
- Immunosuppressed (TNF inhibitors, glucocorticoids)
- Silicosis
- Chronic kidney disease requiring dialysis
- Diabetes
- Malignancy and chemotherapy
- Substance use (e.g. drug use, alcoholism, smoking)
- At risk pop- indigenous, E European
- Crowded accommodation IVDU Homeless
13
Q
Classic triad on CXR of active TB
A
apical-posterior infiltrates
lung volume loss
cavitation
14
Q
TB Rx
A
TB Treatment RIPE Rifampin, INH, Pyrazinamide, Ethambutol
15
Q
Viral load in HIV is a measurement of what?
A
HIV RNA
16
Q
What is the confirmatory test for HIV?
A
Western blot confirmation by detection of antibodies to at least two different HIV protein bands (p24, gp41, gp120/160); specificity >99.99%
17
Q
Initial screening test for HIV
A
Enzyme linked immunosorbent assay (ELISA) detects serum antibody to HIV; sensitivity >99.5%
18
Q
Pneumocystis jiroveci treatment first line
A
TMP/SMX Trimethoprim + sulfamethoxazole
19
Q
Pneumocystis jiroveci classic X-Ray findings
A
Interstitial pneumonia
20
Q
The leading cause of meningitis in patients with HIV
A
Crypotoccus sp
21
Q
Rx of cryptococcus in HIV+ men
A
Amphotericin B (+ flucytosine) is used in the first 2 wk for induction therapy; limited duration dt SFX Switch to fluconazole for at least 8 wk as consolidation therapy, then continue at lower dose for prolonged maintenance
22
Q
Rx invasive aspergillosis
A
Voriconazole or amphotericin B
23
Q
Leprosy Rx
A
Dapsone & rifampicin
24
Q
Clostridium tetani- type of organism
A
motile, spore forming, anaerobic Gram-positive bacillus
25
The action of tetanus toxin
Toxin travels via **retrograde axonal transpor**t to the CNS where it irreversibly binds presynaptic neurons to **prevent release of inhibitory neurotransmitters** (e.g. GABA) Results in **disinhibition of spinal motor reflexes** which results in tetany and autonomic hyperactivity
26
Diagnosis of tetanus
Clinical CK may be elevated
27
Management of tetanus
Stop toxin production
**Wound debridement** to clear necrotic tissue and spores
Antimicrobial therapy: **IV metronidazole**; IV penicillin G is an alternative
Neutralize unbound toxin with **tetanus immune globulin** (TIg)
Supportive therapy: **intubation**, spasmolytic medications (benzodiazepines), quiet environment, cooling blanket Control autonomic dysfunction: - and -blockade (e.g. labetalol), magnesium sulfate
28
Empiric therapy for bacterial meningitis \>3months of age
age \>3 mo: ceftriaxone + vancomycin
29
Most commonly affected valve in infective endocarditis
MV
30
Minor Duke criteria for infective endocarditis
1. **Predisposing condition** (abnormal heart valve, IVDU)
2. **Fever** (38.0°C/100.4°F)
3. **Vascular phenomena**: major arterial emboli, septic pulmonary infarcts, mycotic aneurysms, ICH, conjunctival hemorrhages, Janeway lesions
4. **Immunologic phenomena**: glomerulonephritis, rheumatoid factor, Osler’s nodes, Roth’s spots
5. **Positive blood culture** but not meeting major criteria OR serologic evidence of active infection with organism consistent with IE
31
Modified Duke Criteria- number for a definite Dx of Infective Endocarditis
2 major OR 1 major + 3 minor OR 5 minor
32
The organism responsible for most cases of non-gonococcal arthritis in adults
staph aureus
33
Characteristics of infected synovial fluid
opaque, increased WBCs (\>15,000/mm3: likelihood of infection increases with increasing WBCs), PMNs \>90%, culture positive
34
Most common cause of cellulitis
Beta-hemolytic streptococci
35
Diagnosis of necrotising fasciitis
Clinical
36
Typical cause of monomicrobial infection in necrotising fasciitis
Group A Strep
37
Blind Rx of necrotising fasciitis
meropenem or piperacillin/ tazobactam + clindamycin IV
38
Influenza incubation period
incubation period 1-4 d
39
Gold standard diagnostic test for influenza
nasopharyngeal swabs for RT-PCR (gold standard)
40
For whom is influenza vaccine indicated?
Vaccine for influenza A and B viruses is recommended annually for all ages 6 mo (according to TN)
41
Clinical evidence of consolidation
dullness to percussion, bronchial breath sounds, crackles
42
Airborne infections
M. tuberculosis, disseminated VZV, measles
43
Things you can't see on a gram stain
Mycobacteria Ricketsii Chlamydia Mycoplasma Treponema
44
Anaerobic gram positive rods
Clostridium sp C. difficile C. tetani C. botulinum C. perfringens
45
Aerobic gram negative cocci
Neisseria N. meningiditis N. gonorrhoeae Moraxella M. catarrhalis
46
Shigella- describe the organism
Aerobic gram negative rod
47
Listeria- describe the organism
Aerobic gram positive rod
48
Campylobacter-describe the organism
Aerobic gram negative rod
49
What is a typical source of vibrio vulnificus septicaemia?
Eating raw oysters
50
First line treatment for anogenital warts (HPV)
Podophyllotoxin 5% solution
51
TOC for dental abscess
Clindamycin, or amoxycillin/ clavulanate
52
Management of infectious tenosynovitis
Surgery and IV Abx
53
What does positive Hep B surface antigen imply?
That the individual is infectious
54
What does the presence of hep B surface antibody imply?
That the individual is immune, either through previous infection or vaccination
55
What do IgG antibodies indicate in Hep B serology?
Chronicity IgM signifies acute infection
56
Screening for asymptomatic bacteriuria - which conditions?
All immunosuppressed pts whether through meds or pathology Pregnancy Renal transplant pts
57
The DOC for lung abscess
Clindamycin
58
Characteristics of giardiasis
non-bloody, watery diarrhoea, abdominal cramps, foul flatus, vomiting, fever and malaise.
Stools are malodorous, mushy and greasy.
Anorexia, fatigue and weight loss common.
59
Characteristics of campylobacteriosis
inflammatory sometimes bloody diarrhoea or dysentery syndrome 1-3 days post ingestion of infected food (poultry)
60
Characteristics of amebic colitis
Gradual onset over 1-2 weeks (cf bacterial dysentery). Cramp abdominal pain, watery or bloody diarrhoea, anorexia/ weight loss. Fever in about 30%
61
What is elevated in 90% of HIV pts with PCP?
LDH
62
Diagnosis of PCP
Examination of induced sputum
63
Pasteurella multocida is associated with what?
Cat bites
64
What tends to cause rapid onset nausea, diarrhoea + vomiting?
staphylococcal food poisoning
65
What is the cause of tinea versicolor?
Malassezia yeast
66
Prophylactic Rx for contacts of ppl with meningococcal meningitis should include what?
Rifampicin
67
The most frequent cause of urethritis in men
Chlamydia
68
Combination of DKA and sinus inflammation might indicate what?
Mucormycosis
69
Management of Mucormycosis
surgical debridement and IV amphoteracin B
70
Prophylaxis of mycobacterium avium intracellulare in HIV pt with a CD4 \<50
Azithromycin
71
Diagnosis of pseudomembranous colitis \*hot topic\*
cytotoxin assay of the stool
72
Management of pseudomembranous colitis
Stop antibiotics and give oral vancomycin
73
Treatment for gonorrhoea
Ceftriaxone IM as a single dose
74
TOC for lung abscess
Clindamycin
75
A drug approved for HIV associated lipodystrophy
Tesamorelin
76
If someone presents with a dirty wound + hx of tetanus vx, when would you re-administer the vaccine?
If the vaccine was **\>5 years** ago
77
Fungal disease associated with bats and birds
Histoplasmosis
78
What Ix is necessary in a sexually active woman of repro age with LUTS?
HCG
79
Sputum culture for Legionella sp should be on which medium?
Buffered charcoal yeast agar
80
The best way to evaluate the severity of PCP pneumonia
Alveolar-arterial P02 difference
81
Management of latent TB infection in HIV
Isoniazid monotherapy
82
First line antibiotic therapy for animal bites
Amoxycillin-clavulanate
83
What type of virus is Epstein Barr?
Human Herpes Virus type 4 (dsDNA)
84
Fever + pharyngitis + lymphadenopathy (posterior cervical LNs) + fatigue
Infectious Mononucleosis
85
False negatives to the Monospot test (2)
1) Early infection (in which case re-test) 2) \<4 years old (look for EBV specific antibodies like IgM VCA or IgG (EBNA)
86
What are HIV+ pts with EBV at risk of developing?
Oral hairy leukoplakia
87
Pulmonary tuberculosis is associated with what as an occupational disease?
Silica dust exposure
88
Eaton's agar media can be used to grow what from sputum culture?
Mycoplasma pneumonia
89
Who tends to get mycoplasma pneumonia?
School kids, teenagers, military recruits
90
Most reliable diagnostic tests for mycoplasma pneumonia
PCR and DNA probes
91
A positive Widal test suggests what?
Typhoid fever
92
Main routes of spread Hep C
IVDU Tattoos Not sexual contact!
93
Investigation to assess severity of Hep C
Liver biopsy
94
Blind Rx meningitis in \>50s or immunocompromised pts
Vancomycin + ampicillin + ceftriaxone
95
Diagnostic investigation for osteomyelitis
X-Ray
96
X-Ray findings in osteomyelitis
* Soft tissue swelling
* Periosteal reaction
* Cortical irregularity
* Demineralisation
97
Should an adult with a reported history of VZV be offered the VZV vaccine?
Yes according to the CDC and Canada Q Bank because the history may be unreliable
98
For whom is pneumococcal 23-valent polysaccharide vaccine recommended
1. All adults over 65 2. Adults \<65 in care facilities or with LTCs that out them at risk 3. Alcoholics 4. Smokers 5. Homeless people 6. Asthma with COPD or on steroids 7. Drug users
99
Tinea versicolor
100
Erythema migrans
Lyme disease
101
Oral hairy leukoplakia
EBV infection in HIV
102
Secondary syphilis
103
Historical illustration of chancoid ulcer and buboes
104
Strawberry cervix, trichomonas
105
Tinea corporis ring worm
106
Argyll Robertson pupil
Tertiary syphilis
Accommodates but doesn't react
107
Pneumocystis carinii pneumonia
There are diffuse bilaterally symmetric interstitial patterns noted in the perihilar region and extending towards the periphery
108
Tetanus
109
Leprosy
Leonine facies
110
Darkfield microscopy
Treponema pallidum
Spirochaetes
111
Syphilitic aortitis
Tertiary syphilis
112
Teritary syphilis
Posterior column degeneration
Tabes dorsalis
113
TB- large cavitating lesion
114
The auramine-rhodamine fluoresecent stain for acid fast bacilli has now repaced the Ziehl-Neelsen stain for sputum because it has higher sensitivity for diagnosing TB. Cultures take 3-4 weeks to grow.
115
The PPD aka Mantoux test for TB
## Footnote
The initial test for screening pts for TB when primary Tb is suspected
116
This is the rapid ELISA HIV test, with 99.5% sensitivity, if positive arrange Western blot confirmation by detection of antibodies to at least two different HIV protein bands (p24, gp41, gp120/160); specificity \>99.99%
117
Aspergilloma.
## Footnote
Ball of hyphae in a pre-existing lung cavity
Symptoms range from asymptomatic to massive hemoptysis
CXR: round opacity surrounded by a thin lucent rim of air, often in upper lobes (“air crescent” sign)
118
Mucormycosis
Fungal pathogen of mold subtype
Usually caused by Rhizopus
Problematic in uncontrolled diabetics
Rx requires surgical debridement and IV amphoteracin B
119
Computer illustration of Borrelia burgdorferi bacteria, the cause of Lyme disease in humans. These spiral-shaped spirochaete bacteria are passed on to humans by tick bites, commonly Ixodes ricinus in Europe and Ixodes pacificus in North America.
120
Roth spots
Osler nodes
Janeway lesions
Splinter haemorrhages
Due to embolised bits of septic vegetation in infective endocarditis
121
Treatment of latent TB in healthy individuals
Isoniazid 9 months
122
What must always been done before a lumbar puncture?
Check for raised intracranial pressure.
Look for papilledema
123
Significance of numerous RBCs in serial CSF samples
Subarachnoid haemorrrhage
124
Significance of low glucose and PMN predominance in CSF sample
Bacterial meningitis
125
Significance of normal glucose and lymphocytic predominance in CSF sample
Aseptic (viral) meningitis
126
Risk factors for pyelonephritis
* Pregnancy
* Vesicoureteral reflux
* Anatomical abnormalities
* Indwelling catheters
* Kidney stones
127
Name the bug - an alcoholic with pneumonia
Klebsiella
128
Name the bug- infection in a burns patient
Pseudomonas
129
Name the bug- perianal itching
Enterobius vermicularis
130
Name the bug- raw pork
Trichinella spiralis
