Infectious Disease Flashcards
Virus causing myocarditis most commonly
Coxsackie B (HFM - coxsackie A16 and enterovirus 71 - meningitis)
Ganiciclovir s/e
BM suppression
Treatment hep c
Can give birth naturally (5%)
Interferon and ribavirin
BF contraindicated in..
HIV
Most common LRTI in HIV
Lymphoid interstitial pneumonitis
Measles infectious period
5 days either side of rash (morbiliform)
Rubella worse in T1 causes
IUgR, SNHL, brain, heart, cataract, LFT
Congenital varicella
Limb defects, pox lesions (risk only 2%)
Mother at risk varicella to neonate when?
5 days before and 2 after
Complications include Ramsay hunt
H pylori related to which ca
Gastric lymphoma MALT
Gram negative curved
Neisseria meningitidis gram stain
Gram negative diplococcus
Antibiotic if strep pneumoniae high grade resistance or meningitis
Vancomycin
Sickle cell with salmonella get..
Osteomyelitis (5% bacteraemia)
Brain abscess higher risk
CHD
Treat with met and cef
Gonorrhoea conjunctivitis
Day 2-3 thick risk corneal ulcer and visual loss
Tx with ceftriaxone
LP not contraindicated in
Mild drowsiness or bulging fontanelle
School exclusion pertussis
Until 5 days after Tx started
Aminoglycosides mechanism of action
Bind to 30s ribosome, inhibit protein synthesis
Effect due to peak level and some post antibiotic effect
Penicillins and most other abx effectiveness related to
Time above MIC
Strep pneumoniae resistance from
Altered PBP - insert neucleotides to cause decreased affinity
(Same as MrSA)
HiB resistance from
Production of beta lactamase
Pseudomonas resistance from
DNA gyrase mutation Efflux pump (Pumping antibiotics out of cytoplasm) and decreased permeability
ESBL resistance from
Modifying structure of beta lactamase
TB under 5 if exposed
Treat all with isoniazid
Pseudomonas treatment
Ceftaz
Beta lactams MIC
Time above MIC (dose interval with no post abx effect)
Macrolides, carbapenem and glycopeptides also
Aminoglycosides Killing mechanism
Concentration dependent AUC/MIC
Post abx effect
(Also fluroquinolones)
Cell wall abx
Penicillin Cephalosporins Meropenem Aztreonam Vanc Teicoplanin Bacitracin
Quinolone mechanism of action, resistance and example of an antibiotic
DNA gyrase
Resistance from DNA gyrase mutation
Fluroquinolone
RNA polymerase affected therefore no mRNA synthesis abx mechanism?
Rifampicin (never use alone)
Folic acid metabolism abx mechanism
Cotrimoxazole (Trimethoprim sulfonamides)
Chloramphenicol mechanism of action
Transacetylase and protein synthesis 50S
Ribosome protein synthesis abx mechanism of action 50S and 30S
30S
SAT
Spectinomycin Aminoglycosides tetracycline
50S MOCKA Macrolides Oxazolidinones Chloramphenicol / Clindamycin Kerolides Azithromycin
Gram negatives intrinsic resistance to
Vancomycin we not effective cell wall properties
Pseudomonas intrinsic resistance to..
Cefotaxime low affinity for PBP and low permeability
Enterococci intrinsic abx resistance to..
Cefalosporins low affinity for enterococcus PBP
E. coli resistance to beta lactams
B lactamase
MRSA resistance due to
Altered receptor binding PBP (transpeptidases) I.e. Altered binding site
Resistance to all penicillin and cephalosporins
Tx: erythromycin, clinda, doxy (stains teeth), cotrimox
Gentamicin
Vancomycin (bacterical against most except enterococci)
MIC => 2 is?
Resistant in meningitis
1 is cutoff in non-meningitis
Pneumococcal resistance to abx mechanism
Decreased affinity of penicillin binding proteins
Carbapenems can treat ESBL?
Yes it is the drug of choice
How does tamiflu work
Competitive inhibitor neuraminidase (prevents release of new virus from cells)
(Also site of action for amantidine and ramantidine)
Current flu strains
H1N1
H3N2
Flu B
HHV8 is responsible for..
Karposis sarcoma
Inv candidiasis Tx or high risk
Amphotericin B (covers most sp)
(Fluconazole for Candida albicans not invasive)
Candida kruse and glabrata use caspofungin due to resistance
Toxoplasmosis mother treated with
Spiromycin
Linezolid
Oxazolidinones
Good abx if can’t have vancomycin
SE reversible optic neuritis and irreversible peripheral neuropathy
No herd immunity with what
Tetanus toxin
Effectiveness of varicella vac
> 95% preventing serious disease
Vaccinate ? Weeks per transplant
4 (2w-3m)
Vertical transmission rates HIV
15-50%
Prevented by IV zidovudine and LSCS with no BF and infant chemoprophylaxsis (risk reduced to 1%)
TB treatment
Pulmonary 6m
2m isoniazid and rifampicin and pyrazinamide (RIP)
Meningitis and disseminated
Other 12m as above but also ethionamide (RIPE)
(Prothionamide)
Hansen disease (leprosy)
Salmon coloured fine scale rash central clearing
Ulnar nerve dysfunction
50-60% of what will have meningococcal
Alternative haemolytic complement test
Swimmers ear treatment
Swimmers ear treatment Clioquinol + flumethasone (Locorten Vioform) 2 to 3 drops 2 times daily
or
Dexamethasone + framycetin + gramicidin (Sofradex) 2 to 3 drops, 3 to 4 times daily.
Cat scratch disease main organism
Bartonella henselae gram negative rod
Antibiotics not usually used
alopecia, scale, and adenopathy is diagnostic of this condition…
Treatment?
Kerion
Treat with terbinafine
Gardasil against which HPV strains and how does vaccine work
contain HPV virus like particles (VLPs), composed of L1
protein (component of outer layer of virus) aggregated into
clumps to mimic outer structure of HPV virion
16, 18, 6, 11
CMV disease > 1 month think
HIV
Ganciclovir
Side effects of antiretrovirals
GI, hepatitis, skin (SJS), lipid, lipodystrophy
IE causative organisms
Strep and SA
Enterococcus
HACEK are gram negative coccobacilli (Haemophilus
aphrophilus,Actinobacillus
actinomycetemcomitans,
Cardiobacterium hominis,
Eikenella corrodens,
Kingella kingae)
Invasive candida Tx
Caspofungin (doesn’t penetrate csf or urine)
How to differentiate toxo, CMV and rubella
Rubella no microcephalic and no intracranial calcium
Toxo no cardiac and 85% appear normal at birth
CMV no bones, no cardiac and NO CATARACTS
Treating maternal toxo
- Spiramycin 3g/day
- Aim is to reduce transmission to fetus
• rationale: lag time between maternal and fetal infection
• continue throughout pregnancy
• does not cross the placenta so does not treat fetus
• Pyrimethamine 25mg/day (potentially teratogenic – after 18 weeks
gestation) plus Sulphadiazine 4g/day
• Added if amnio PCR positive / fetal infection confirmed
• Supplement with folinic acid (leucovorin) – protects marrow
• monitor FBC weekl
Brain eating amoeba
Naegleria infection
Facial nerve palsy can indicate
Lyme disease