Central nervous system (CNS) infections are responsible for causing inflammatory conditions of the brain and/or meningeal tissues surrounding the brain (i.e., meningitis, encephalitis, meningoencephalitis).
Requests for CSF viral PCR are tested for Herpes simplex, Varicella zoster, Neisseria meningitidis, Enterovirus and Parechovirus. Additional PCR tests must be ordered separately.
Testing is performed daily on routine weekdays. Urgent/weekend testing by arrangement, after discussion with on-call Microbiologist.
HSV PCR
DNA detection by PCR provides a rapid and definitive diagnosis for the presence of HSV nucleic acid in CSF.
HSV types one and two are common human pathogens. Aseptic meningitis is usually caused by HSV2. HSV Encephalitis (HSVE) is usually caused by HSV1 in adults and HSV2 in neonates. HSVE is a serious infection that requires prompt diagnosis and treatment.
The detection of Herpes simplex virus DNA requires secondary testing that differentiates between types one and two.
PCR results should always be interpreted in conjunction with clinical history and symptoms.
Occasionally an HSV PCR will be negative early in the course of HSV encephalitis. If PCR is negative when the clinical suspicion is high, the PCR should be repeated on a different CSF sample collected 1-2 days later. If both samples are PCR negative, HSV encephalitis is unlikely.
A short period of Acyclovir therapy (up to 5 days) appears to have little effect on PCR sensitivity.
Enterovirus RT-PCR
This assay is used for the detection of Enteroviral RNA in CSF from patients with aseptic meningitis. This assay detects enteroviruses that most commonly cause enteroviral meningitis. Subtyping is not routinely available by PCR, if sample is positive a throat swab and faecal sample are requested for typing.
Parechovirus RT-PCR
Parechoviruses are in the same family of viruses as enteroviruses and can also cause meningitis. A separate PCR is required to detect them.
Neisseria meningitidis PCR
This PCR is useful for the diagnosis of meningococcal meningitis. PCR will allow the confirmation of the etiological agent when preceding antimicrobial therapy has inhibited growth. Confirmation of diagnosis is extremely important not only in the treatment of the patient but also in the management of contact tracing. Neisseria meningitidis is a notifiable infectious disease and should be reported to the Medical Officer of Health.
Microbiology - Virology
CNSP
Coxsackievirus PCR
Coxsackievirus RNA
Echovirus PCR
Echovirus RNA
Enterovirus PCR
Enterovirus RNA
Enterovirus RT-PCR
HSV PCR (CSF)
Meningococcal PCR
Neisseria meningitidis PCR
Parechovirus PCR
Parechovirus RNA
Varicella zoster encephalitis
Varicella zoster meningitis
Varicella zoster virus CSF PCR
1 day