Infectious Diseases Flashcards
1
Q
Biggest risk factor for invasive mould infections
A
Graft vs Host Disease.
severe grade 3-4(C-D)
GVHD which is classified as:
erythroderma + bilirubin 100
-300 +severe diarrhoea
2
Q
Encapsulated organisms
A
S. pneumoniae
N. Meningiditis
H. Influenzae
3
Q
Organisms that are silver stain positive
A
Bacteria - Pseudomonas, Legionella, H. pylori, Bartonella and Treponema,
fungal - Pneumocystis, Cryptococcus, and Candida.
4
Q
Quantiferon gold negative in HIV patient. Develops lymphadenopathy after starting treatment. ?Cause.
A
TB - due to IRIS.
Quantiferron gold can be negative in HIV
5
Q
Treatment of c.diff
A
- Vancomycin or fidaxomicin
2. Faecal transplant
6
Q
Treatment for ventilator associated enterococcus
A
Linezolid
Daptomycin is inactivated by surfactant
7
Q
Difference between E. Faecium and E. Faecalis.
A
Faecium = monster. High resistance. Faecalis = less resistance
8
Q
MOA of Gentamicin
A
Inhibition of protein synthesis by binding to 30S subunit
9
Q
CNS infection with high opening pressure
A
TB
Cryptococcus
10
Q
Type of meningitis which steroids are contraindicated
A
Cryptococcal meningitis
11
Q
Reasons to delay anti-retro viral therapy in HIV
A
TB meningitis
Cryptococcal meningitis
Treat for at least 6 weeks
12
Q
CMV treatment in D+/R- renal transplant
A
Oral valganciclovir
13
Q
Type of malaria that causes hypoglycaemia
A
M. Falciparum
14
Q
Penicillin’s do not easily cross the BBB. Why are penicillin’s used in the treatment of meningitis?
A
Inflammation on the meninges causes increased permeability of the BBB
15
Q
For plasmodium ovale and Vivax, which agent needs to be used to prevent recurrence and why?
A
Primaquine - to eliminate liver hypnozites of ovale and vivax.
16
Q
Alcohol rub is not effective in killing which pathogen
A
C.diff
17
Q
Cephalosporin active against pseudomonas
A
Cefepime
Ceftazidime
18
Q
Cephalosporin active against MRSA
A
Ceftaroline
19
Q
NAP1 strain of C.diff
A
produces a binary toxin
20
Q
Order of pneumovax post splenectomy
A
- conjugate
2. Polysaccharide
21
Q
HIV testing in pregnant women requires what type of test
A
Western blot
22
Q
How does VRE form.
A
Vancomycin works on Enterococcus by binding to cell wall precursor molecules.
VRE forms by changing the structure of the cell wall precursor proteins to ones that Vancomycin cant bind to.
23
Q
Extensively drug resistant TB
A
Resistant to:
- Rifampicin
- Isoniazid
- Moxifloxacin
- Amikacin
24
Q
Antibiotic inactivated with surfactant
A
Daptomycin
25
oral agent for MRSA
Bactrim
26
Management of HIV in pregnancy
Start ART
Give additional zidovudine IV in 3rd trimester if viral load >1000.
Post exposure prophylaxis for baby after birth
27
Cause of TB reactivation in Anti-TNF therapy
reduced macrophages and lymphocytes in lungs.
| maintenance of TB granulomas
28
E.coli producing shiga toxin gene
O157:H7
29
Recurrent meningitis cause
HSV2
30
Gentamicin efficacy pharmacodynamics
Cmax/MIC
31
Empiric therapy for GPC meningitis
4g Ceftriaxone + Vancomycin + dexamethasone
32
Mx of anaerobic aspiration pneumonia
Clindamycin
33
What is Panton-Valentine leukocidin
A toxic produced by Staph Aureus that causes pyodermic infections (pus).
Works by leukocyte destruction and tissue necrosis
34
Staph aureus toxin that allows pulmonary infection
alpha- haemolysin
35
Live vaccines
```
Varicella/ VZV
Japanese encephalitis
MMR
BCG
oral typhoid
Rotavirus
yellow fever
```
36
EBV infects which cell type
B cells
37
Bacteria which can be found intracellularly
```
Listeria
Mycobacteria
Brucella
rickettsia
chlamydia
```
38
Endotoxins are produced by what type of bacteria
Gram negative bacteria + Listeria
39
Treatment for Listeria
Ampicillin/Ben Pen
| - resistant to Cephalosporins
40
Cell type affected in PML
Oligodendrocyte
41
Pathophysiology of Toxic shock and super antigens
Super antigen - eg staph aureus.
The toxin has direct activation of MHC2 which activates a variable part of the T-cell beta chain, causing activation of a very high number of T cells.
42
MOA of tetanus toxin
sustained excitatory discharge of alpha motor neurons
43
Toxin associated with HCC
aspergillus toxin
44
Management for genital warts (HPV)
Imiquimod
45
Management for Pediculosis Pubis (pubic lice) and scabies.
Permethrin
46
Management for Syphilis
Benzathine Penicillin
47
Management for Chlamydia
STAT Azithromycin or 1 week Doxycycline
48
Management for gonorrhoea
STAT Ceftriaxone + Azithromycin or 1 week doxycycline.
49
Management for Lymphogranuloma venereum
doxycycline
50
Presentation of Lymphogranuloma venereum (type of chlamydia)
lymphangitis, areas of necrosis occur within the nodes, followed by abscess formation
51
Symptoms of HIV myelopathy
A vacuolar myopathy, seen in AIDS.
spastic paraparesis is accompanied by loss of vibration and position sense and urinary frequency, urgency, and incontinence. Upper-extremity function is usually normal.
52
HIV drug causing lipoatrophy
zidovudine
53
Sign of c.diff on colonoscopy
pseudomembranous colitis
54
Infection unique to sickle cell anaemia
Salmonella Osteomyelitis
55
Management of meningococcal exposure
Cipro or Ceftriaxone + Meningococcal vaccination.
56
Meningococcal vaccine available
Conjugate vaccine - Meningococcal C + tetanus toxin
Combo vaccine - Haemophillus influenzae B + Meningococcal C + tetanus toxin
Combination Vaccine - Meningococcal A, C, W, Y
Meningococcal B vaccine
57
treatment of strongyloides
ivermectin
58
Syphilis screening test
EIA
59
Syphilis monitoring tests
RPR, VDRL
60
Test for Cryptococcus
Latex agglutination test (good for detecting Cryptococcus, bad for detecting meningococcus)
ELISA
61
hole punch brain
neurocysticercosis
62
Jarisch-Herxheimer reaction
Occurs when Abx are given in Syphilis - causes release of endotoxins resulting in flu like symptoms
63
Mechanism of Penicillin resistance
Cleavage of the β-lactamring by β-lactamases (penicillinases)
PBP mutations
64
Carbapenem side effects
Secondary fungal infections [11]
CNS toxicity: can lower seizure threshold at high serum concentrations
Highest risk: imipenem
Lowest risk: meropenem
65
Bezlotoxumab MOA
is a human IgG1 monoclonal antibody which binds to C. difficile toxin B
66
Mx of Schiotosomiasis
Praziquantel
67
Polyenes (Amphotericin) MOA
Binds to ergosterol in the fungal cell wall forming pores.
68
Polyenes (Amphotericin) SE
```
Arrhythmias
Hearing loss
Infusion reactions
Nephrotoxicity
Neurotoxicity
```
69
Azoles MOA
Reduces activity of fungal cytochrome P450, reducing ergosterol formation
70
Azoles SE
```
Hepatotoxicity
Gynaecomastia
Long QT
Hypokalemia
Visual changes - voriconazole
```
71
Echinocandins MOA
Inhibit Beta-glucan synthesis in cell wall
72
Echinocandins SE
Hepatotoxic
Flushing
Hypotension
Fever
73
Drug used in invasive aspergillosis
Voriconazole
74
Mx of systemic candidiasis
- IV Amphotericin B
- ECHO
- Ophthalmoscopy
75
Mx Cryptococcus
first 2 weeks - Amphotericin B + flucytosine
| Ongoing - Oral fluconazole
76
Post exposure prophylaxis of varicella
- varicella vaccine -> IF significant exposure within the last five days. (not pregnant or immunocomprimised)
- If unable to have vaccine --> varicella immune globulin (Varizig) if it can be given within 10 days of exposure.
- For sufficient immunity in immunocomprimised patients, they must have adequate IgG titres AND Hx of vaccination/ exposure.
77
Most common pathogen in febrile neutropenia
Staph Epidermidis
78
Most common cause of travellers diarrhoea
E.coli
79
Management of Staph prosthetic joint infections.
MSSA - Fluclox
MRSA - Vanc
For patients with S. aureus PJI and residual hardware following surgery - adjunctive use of rifampin + Ciprofloxacin - for BIOFILM.
80
Cause of false positive HIV test
CAR-T therapy
81
Empirical Mx of septic arthritis/ Osteomyelitis
- surgical drainage
| - IV fluclox 4-6 hourly
82
In hospital Mx of Malaria
IV Artesunate
IV Ceftriaxone
Paracetamol
83
Rifaximin increases the risk of what infection.
Increases risk of MRSA
84
Empirical therapy for Candida Auris
Echinocandins (Micafungin)
85
Most common cause of portal hypertension worldwide
Schistosomiasis
86
Incubation and symptoms of Leptospirosis
Incubation 7-30days
| Sympt: Conjunctival haemorrhage, GIT symptoms, aseptic meningitis.
87
Long term Rifaximin use (used for hepatic encephalopathy) can lead to resistance of what organism?
Staph aureus
88
HIV testing method
Test ELISA antigen and antibody
89
Treatment of Listeria
Penicillin's - usually ampicillin
90
Management of animal bite
Prophylaxis - Augmentin DF or Doxy/Cipro with Metro/Clinda for anaerobes.
91
Organisms with low ID50
Shigella, coxiella burnetti, EHEC, M bovis, TB, Rickettsia
92
Diseases caused by Human T lymphocyte virus 1.
Adult T cell leukemia-lymphoma (ATL) and HTLV-I-associated myelopathy (HAM), also known as tropical spastic paraparesis (TSP)
93
When is tetanus immunoglobulin required?
When the wound is deep/contaminated and patient has had <3 tetanus doses.
94
Infections needing droplet precautions
```
B - Bordatella pertussis
I - Influenza/ Cold viruses
R - Rhinovirus
D - Diptheria
M - Mumps
A - adenovirus
N- Neisseria Meningitis
```
95
Infections needing airborne precautions
T -Tuberculosis
E
M - Measles
P - Pox - chicken pox, small pox.
96
Reason why Ceftriaxone and Paracetamol are given in Malaria treatment
Ceftriaxone - high risk of bacterial co-infection
| Paracetamol - reduces risk of haemorrhagic AKI
97
Reasons to add Vancomycin in neutropenic sepsis
- suspected catheter‐related infections
- known colonisation or recent positive blood culture with a resistant organism.
- haemodynamic instability
- recently taken cipro or Bactrim
98
Timing for pneumococcal vaccinations in splenectomy
Vaccines to be given 8 weeks apart - first the conjugate vaccine then the polysaccharide.
Vaccines to be given atleast 14 days before or 7 days after splenectomy.
99
Pneumococcal conjugate vaccine is conjugated to which protein
diphtheria toxin like protein.
100
Risk of vertical transmission of HIV in UNTREATED patient.
perinatal period - 25%
breast feeding - 15%
If treated with suppressed viral load <1%
101
MOA of Aertemisinins in malaria therapy
Artemisinins appear to act by binding iron, breaking down peroxide bridges, leading to the generation of free radicals that damage parasite proteins.
102
Why are Aertemisinins used in combination only?
To prevent rapid formation of resistance
103
Most common infectious agent in post influenza pneumonia
Staph aureus
104
Most common bug causing empyema
Strep pneumonia
105
N. meningitidis gram stain
Gram negative diplococci.
| Associated with petechial rash
106
Method of diagnosing culture negative endocarditis
16S RNA PCR
107
Features of "severe" c.diff
- Shock/hypotension
- Ileus
- megacolon
- WCC >15
Abx therapy - non-severe 10 days
108
Most common organisms in chronic granulomatous disease.
1. aspergillus
2. staph aureus
3. Pseudomonas
4. Serratia
5. Nocardia
109
Most common organism in viral meningitis
Enterovirus
110
Increased risk of which organism causing meningitis on TNFa inhibitors
Listeria meningitis
111
Which type of meningococcal does the vaccine not cover?
meningococcal B
112
Treatment for HSV 1 meningitis
Aciclovir
113
Teratment for HSV 6 meningitis
Gancyclovir
114
EEG pattern in HSV encephalitis
periodic lateralising epileptiform discharges
115
Gene in CJD
PRNP gene
116
Treatment of TB meningitis
Rifampicin
Isoniazid
Pyrazinamide
Streptomycin/ Moxifloxacin
Replace ethambutol as it has poor CNS penetration
117
HRZE side effects
R - drug interactions
I - B6 deficiency causing peripheral neuropathy, Hepatitis
P - hyperuricemia, GI upset, hepatitis
E - optic neuritis
118
Mx for ABPA
Itraconazole + steroids
119
Ix for aspergillus
galactomannan, beta D glucan
120
In which disease do you see elementary and reticulate bodies?
Chlamydia
121
STI causing rash on palms and soles
Syphilis
122
Definition of "severe" malaria
Neuro - GCS <11 , Generalised weakness preventing movement , > 2 convulsions in 24hrs
Haem - Hb <50, Jaundice (from haemolysis), Significant bleeding.
Parasitaemia >10%
Shock related - Acidosis , Hypoglycaemia , AKI, APO.
123
Travel bug with long incubation
malaria
124
Least severe form of malaria
F. malariae
125
Malaria prophylaxis and duration
Hydroxychloroquine - start 2 weeks before and continue 4 weeks after.
Doxycycline - start 2 days before and continue 4 weeks after.
126
Differentiating features of Typhoid
Rose spots
Constipation
Intestinal haemorrhage/ perforation.
127
Management of typhoid (ABx)
Ceftriaxone
| Ciprofloxacin
128
Gram stain of Typhoid
gram negative bacillus
129
Gram stain and management of Rickettsia
GNB, treat with doxycycline.
130
Management for Campylobacter (Abx)
Azithromycin
131
Management for shigella (Abx)
Ciprofloxacin
132
frequency of HIV testing for patients on PrEP
3 monthly
133
HIV drug causing neural tube defects
Dolutegravir
134
When is dolutegravir + TDF preferred over dolutegravir + lamivudine
Based on the results of two large, randomized controlled trials that showed that a two-drug regimen of DTG plus lamivudine (DTG/3TC) was noninferior to DTG plus tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC)
except for individuals:
1. With pre-treatment HIV RNA >500,000 copies/mL;
2. Who are known to have active hepatitis B virus (HBV) coinfection; or
3. Who will initiate ART before results of HIV genotype testing for reverse transcriptase or HBV testing are available.
135
What to do if household contact of immunocompromised patient develops a rash post varicella vax
Cover rash
Avoid immunocompromised pt for duration of rash
No immunoglobulin required as disease will be mild
136
HIV infection prophylaxis by CD4 count
CD4 <200 - Bactrim for PJP/ Toxo
| CD4 < 50 - Azithromycin for MAC
137
High risk areas for melioidosis
Thailand
| Northern Territory
138
Melioidosis gram stain and appearance
a Gram-negative rod with a characteristic "safety pin" appearance (bipolar staining).
139
Presentation of Melioidosis
Pneumonia + abscesses in spleen and prostate
140
Melioidosis treatment
Ceftazidime or Meropenem
141
"booster" HIV drugs
cobicistat and ritonavir
142
Testing required before Abacavir therapy
HLA-B5701
143
Types of DNA transfer of bacteria (3)
Transformation - bacteria take up free DNA in the environment
Transduction - transfer of DNA between bacteria by a virus (bacteriophage)
Conjugation - bacteria TF DNA via plasmids
144
Treatment of SBP
Ceftriaxone or Cefotaxime
145
SBP prevention
Bactrim or Norflox
146
New NEJM trial treatment for multi and extensively drug resistant TB
bedaquiline, pretomanid, and linezolid
147
Which organisms does Bactrim cover
```
PJP
Toxoplasmosis
MRSA
Nocardia
Listeria
```
148
When to add Gentamycin in feberile neutropenia
Sepsis
149
Febrile neutropenia prophylactic agents
- posaconazole
- valaciclovir
- ciprofloxacin
150
Opportunistic infection commonly seen in heart lung transplants
Toxoplasmosis - treat with Bactrim
151
Endocarditis treatment
- Staph
- Strep
- Enterococcus
- HACEK (slow growing)
- Emperical
- Staph - Flucloxacillin or Cephazolin. Vancomycin if MRSA or penicillin allergy.
- Strep - Ben Pen + Gent or Ben Pen + Ceft
- Enterococcus - Ben Pen + Gent or Vanc + Gent if penicillin allergy
- HACEK (slow growing) - Ben Pen if penicillin sensitive, Ceftriaxone if not.
- Emperical - Ben Pen + Fluclox + Gent.
152
Post exposure prophylaxis for Meningococcal
Rifampicin/ Cipro/ Ceftriaxone
153
Post exposure prophylaxis for Haemophilus influenza B
Rifampicin/ Ceftriaxone
154
2nd line therapy for CMV
Foscarnet
155
Supplement which helps recovery in measles
Vit A
156
Antigen to test for in dengue
NS1
157
complication of zika virus in pregnancy
microcephaly
158
HLA protective in HIV
HLA-B5701
159
SE Ritonavir
GI side effects
| metabolic syndrome
160
Which TB drugs are most hepatotoxic
1. Pyrazinamide
| 2. Isoniazid
161
MOA of Oseltamivir
Is a neuraminidase inhibitor - stops the new virus budding off the host cell.
