Syphilis + Meningitis Flashcards
The stages of syphilis
Sexually transmitted bacterial infection with Treponema pallidum
Incubation period: average 21 days
1. Primary Syphilis (localised): non painful chancre which resolves after 3-6 weeks
- Secondary Syphilis (disseminated): widespread maculopapular rash affecting PALMS AND SOLES. Can have other lesions like pustula, papulosquamous, condyloma lata (genital) patchy alopecia
- Latent - nil clinical symptoms but seropositivity
- Tertiary Syphilis: gumma (granulomatous lesions) and can deposit in multiple organs especially cardiovascular (aortitis, endarteritis, aortic aneurysm) and CNS (neurosyphilis)
Argll Robertson Pupils
- Bilateral miosis
- Accommodation reflex intact
- Direct and consensual reflex lost
Bacteria causing syphillis
Treponema pallidum
Has corkscrew and jack-knifing motility
Enters through microabrasions
Treatment of tertiary syphilis
IV benpen 1.8g q4hrly for 15 days
Steroid to prevent Jarish Herxheimer reaction
Diagnosis of syphilis
Diagnosis of active syphilis is confirmed with both:
- a positive nontreponemal test result (such as rapid plasma reagin [RPR] test)
- a positive treponemal test result (such as treponemal enzyme immunoassay [EIA], T. pallidum particle agglutination test [TPPA] or T. pallidum haemagglutination assay [TPHA]).
Treponemal and non-treponemal tests
Treponemal: EIA (enzyme immunoassay), TPPA (t pallidum particle agglutination), TPHA (t pallidum haemoagglutination assay)
Sensitive and specific but does not tell you about disease activity.
These remain positive forever.
Non treponemal: RPR (rapid plasma reagin), VDRL (venereal disease research laboratory)
Idea of disease activity, treatment outcome and reinfection. RPR later one.
Examination of cerebrospinal fluid is the only way to definitively diagnose neurosyphilis
Can take RPR 4 weeks to be positive
Features of neurosyphilis
- Acute meningeal syphilis: symptoms of acute meningitis (eg: neck stiffness, nausea)
- Meningovascular syphilis: subacute stroke, cranial neuropathies
Late (parenchymal) neurosyphilis
- Paretic neurosyphilis: chronic, progressive meningoencephalitis, resulting in widespread cerebral atrophy and major neurocognitive disorder
Early manifestations include personality changes and deficits of memory and judgement
Can cause neurologic symptoms including dysarthria, hypotonia, tremors
- Argyll Robertson Pupil
Bilateral miosis (constriction)
Pupils lose direct and consensual light reflex
Accommodation reflex intact - Tabes Dorsalis (syphilitic myelopathy): demyelination of the dorsal columns and the dorsal root ganglia
Impaired proprioception - progress sensory broad based ataxia (romberg positive)
Absent deep tendon reflexes
Loss of sensation
Charcot joint
Treatment of syphillis
- Early Syphilis: benzathine benzylpenicillin 2.4 million units IM as a single dose for patients and also sick contacts
- Late latent Syphilis: benzathine benzylpenicillin 2.4 million units IM once weekly for 3 weeks
Alternative: doxycycline
-Tertiary Syphilis:
IV benzylpenicillin 1.8g q4hrly for 15 days
Prednisone (15mg for 3 days) to reduce the likelihood of Jarisch-Herxheimer reaction
Acute transient systemic reaction to bacterial endotoxins and pyrogens that are released after initiation of abx therapy
Common organisms for meningitis
Treatment for meningitis
Adults < 60:
- Streptococcus pneumonia (GP)
- Neisseria meningitidis (GN diplococci)
- Less common: Haemophilus Influenza (GN rod), Listeria
Adults > 60
- Most common still streptococcus pneumonia
- Listeria monocytogenes (GP)
MOST COMMON: Strepococcus pneumoniae most common cause of bacterial meningitis
Consider listeria in elderly and immunocompromised - IV benpen
Treatment:
- IV Dex 10mg - should be given before or with first dose of abx
- IV ceftriaxone 2g BD
- If concerns of listeria (gram positive): add IV benpen/amoxicillin
- Add vancomycin (trough 15-20) if:
• Gram positive diplococci seen on gram stain or
• Pneumococcal antigen assay of CSF is positive
• Patient has known or suspected otitis media or sinusitis
• Recently treated with a beta-lactam abx
• This is to ensure that empirical therapy is adequate for Streptococcus pneumoniae isolates that have reduced susceptibility or resistance to penicillin or cephalosporins. Also consider vancomycin if Gram-positive cocci resembling staphylococci are seen on Gram stain, or if CSF tests are not possible because lumbar puncture is contraindicated.
- IV Acyclovir 10mg/kg TDS for viral/HSV
Complications of meningitis
Neurological sequalae - sensorineural hearing loss (most common) seizures - focal neurological deficit - infective - sepsis - intracerebral abscess - pressure - brain herniation - hydrocephalus
Patients with meningococcal meningitis are at risk of Waterhouse-Friderichsen syndrome (adrenal insufficiency secondary to adrenal haemorrhage).
What medication can you use if a patient is allergic to benzylpenicillin for syphilis?
Doxycycline
Early Syphilis:
- IM benzylpenicillin 2.4 million units single dose
- PO Doxycycline 100mg BD for 14 days
Late Latent Syphilis
- IM benzylpenicillin 2.4 million units weekly for 3 weeks
- PO Doxycycline 100mg BD for 28 days
Tertiary
- IV benpen 1.8g q4hrly for 15 days
Penicillin allerge - need to desensitise
Follow Up
- Repeat serology 3, 6, 12 months
- Treatment considered successful if at least 4 fold fall in nontreponemal titre
Meningitis investigations
Bacterial: high pressure, high protein, low glucose, WCC > 500, 90% PMN
Viral: normal or mildly increasd pressure, low protein, normal glucose, < 1000 WCC
Fungal/TB: WCC 100-500
TB meningitis or partially treated bacterial meningitis can have raised lymphocytes
TB meningitis
- Subacute presentation often in patients with no previous hx of pulmonary TB
- CSF: WCC 100-500 (LYMPHOCYTE PREDOMINANCE), CSF glucose <50% serum glucose, low protein
- TB culture sensitivity low, PCR sensitivity
- Tx: 9-12 months (as opposed to 6 months for uncomplicated)
Listeria meningitis
- Listeria monocytogenes gram positive cocci
- Resistant to cephalosporins so need to add IV benpen in high risk groups (age >50yo, immunocompromised, pregnant, heavy EtOh consumption)
- When listeria confirmed, can cease dex (only beneficial in pneumococcal meningitis)
Treatment for meningitis
- IV ceftriaxone 2g BD (if hypersensitive to penicillins = IV moxifloxacin) +
- IV dexamethasone 10mg q6hrly until pneumococcal ruled out - reduces mortality, hearing loss and neurological sequelae in pnuemococcal
If risk of ceftriaxone resistant pneumococcal (gram positive diplococci)
- IV vancomycin
If risk of listeria meningitis (>50yo, steroids or other immunosuppressants, ESRF, malignancy, cirrhosis, organ transplant, HIV/AIDS):
IV benzylpenicillin 2.4g q4hrly
Alternative: bactrim
Infection control of Neisseria meningitidis
- Droplet precaution until 24 hours of abx
- PEP for household contacts
PO Rifampicin 600mg BD for 4 doses
PO Ciprofloxacin 500mg once
IM Ceftriaxone 250mg
Vaccination:
- Pneumococcal vaccine
- Meningococcal conjugate ACWY
