Diseases Flashcards
Risk factors for CNS infection (3)
Immunodeficiency, chronic otitis media, cranial trauma
Contraindications of lumbar puncture (2)
cerebral SOL, ↑ ICP
Normal opening presure of CSF
<15~18 mmHg
Normal white cell count in CSF
<5 (<30 for 1-month-old infants)
Pathogenesis of meningitis (molecular mechanism)
- meningeal invasion –> replicate in subarachnoid space
- bacterial cell wall, LPS… –> inflammation & endothelial cell damage
- ↑ BBB permeability –> hydrocephalus + cell swelling –> cerebral oedema
- vasculitis –> cerebral ischaemia
- metabolic distrubances –> vasodilation
–> ↑ ICP
- neuronal injury
Kernig sign
knee extension is painful –> indicate meningitis
Brudzinski sign
passive neck flexion elicits hip & knee flexion –> indicate meningitis
Bacteria causing acute meningitis in infants <3 months (3)
Strep. agalactiae, E. coli (MC), Listeria monocytogenes
Bacteria causing acute meningitis in children >3 months (4)
Strep. pneumoniae, Neisseria meningitidis, Haemophilus influenzae, TB
Bacteria causing acute meningitis in adults (5)
Strep. pneumoniae (MC), Neisseria meningitidis, Listeria monocytogenes, TB, Strep. suis
MC bacteria causing acute meningitis in infants <3 months
E. coli
MC bacteria causing acute meningitis in adults
Strep. pneumoniae
Bacteria causing procedure-related acute meningitis (3)
S. aureus, S. epidermidis, GNR
Which pathogen commonly causes deafness as complication after acute meningitis?
Strep. suis
Empirical antibiotics for acute bacterial meningitis
IV cefotaxime
Which acute bacterial meningitis has the highest mortality?
Pneumococcal meningitis
If a patient with pneumococcal meningitis shows penicillin and cefotaxime resistant, which antibiotics should be prescribed? (2)
vancomycin + rifampicin
Which acute bacterial meningitis commonly shows petechiae / purpura?
Meningcoccal meningitis
Treatment for meningcoccal meningitis
Penicillin G (cefotaxime if resistant)
Treatment for HiB meningitis
ampicillin (amoxicillin-clavulanate, cefotaxime if resistant)
Which acute bacterial meningitis is acquired through zoonosis?
Strep. suis
Acute viral meningitis causative agents (5) (which MC?)
Enterovirus (MC), HSV2, VZV, HIV, mumps virus
Treatment for cryptococcal meningitis
IV amphotericin + flucytosine
[AIDS] lifelong fluconazole maintenance
Subacute / chronic meningitis causative agents (2)
TB, Cryptococcus neoformans
Diagnosis for cryptococcal meningitis
[CSF] India ink, LAT, culture
[Blood] culture & stain
Causative agents for acute encephalitis (4)
HSV1,2, Rabies, Japanese encephalitis, Toxoplasma gondii
Empirical antimicrobial for acute encephalitis
IV acyclovir
MC cause of sporadic encephalitis
HSV1,2
Diagnosis for herpes encephalitis
[Onset] CSF HSV PCR
[at day 7 from onset] MRI/ CT/ EEG
[at day 14] intrathecal HSV Ab
Prophylaxis for rabies
killed rabies vaccine + HRIG (post-exposure)
Vector for Japanese encephalitis
Culex mosquito
Which virus causes acute focal encephalitis?
HSV1,2
Which virus causes acute pan-encephalitis? (2)
Japanese encephalitis virus, Rabies virus
MC CNS infection in AIDS patients
Toxoplasma encephalitis
Which parasite causes acute focal encephalitis?
Toxoplasma gondii
Pathogen for subacute sclerosing encephalitis
Meales virus (reactivation after years)
Pathogen for progressive multifocal leukoencephalopathy
JCV
Transmission for poliovirus
faecal-oral route
Pathogenesis of poliovirus
direct infection of ventral horn of spinal cord
Presentations of poliomyelitis (3)
fever, flaccid paralysis, respiratory dysfunction
Vaccines for poliovirus (2)
IM inactivated / oral live
Pathogenesis of tetanus
tetanospasmin: retrograde axonal transport from PNS to CNS –> - inhibitory neurons –> spasm
Disease with risus sardonicus
tetanus
Diagnosis of tetanus
clinical diagnosis only
Management for tetanus (4)
Tetanus toxoid vaccine, Tetanus immunoglobulin, ABx on wounds, supportive (e.g. muscle relaxant)
Causative agents of Guillain-Barre Syndrome (2+3)
Campylobacter jejuni, Mycoplasma pneumoniae
EBV, VZV, Dengue
Presentations of Guillain-Barre Syndrome
ascending paralysis, paraesthesia
Management for Guillain-Barre Syndrome
IVIG
At which lobe does HSV mostly cause encephalitis?
Temporal lobe
Definition of uncomplicated UTI
adult non-pregnant female with no structural / neurological dysfunction
Risk factors for UTI (6)
- female
- male before 3m old
- indwelling catheter
- urinatry tract obstruction
- vesiculoureteral reflux
- DM
MC bacteria for UTI
E. coli
Bacteria causing UTI in young sexually active women
S. saprophyticus
Bacteria causing urethritis in male suspected to be STD (3)
Neisseria gonorrhoeae, Chlamydia trachomatis, Ureaplasma urealyticum
Bacteria causing UTI (8)
E. coli, Klebsiella, Proteus, Pseudomonas
S. saprophyticus, S. aureus, Enterococcus, MTB
Parasite causing UTI
Schistosoma haematobium
3 common urinary specimen and usages
First pass urine: for urethritis
Mid-stream urine (MSU): for cystitis
Terminal urine: for prostatitis
Reasons for negative urine culture
- true absence of UTI
- recent ABx use
- diuresis
- fastigious organisms / TB
Asymptomatic significant bacteriuria does not require ABx Tx except: (2)
- Pregnancy
- Prior to urogenital procedure
Significant bacteriuria definition for MSU
10^5 CFU/mL (colony forming unit)
Treatment for urethritis
IM Ceftriaxone once, followed by oral doxycycline / azithromycin