Viral meningitis laboratory findings

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Ahmed Elsaiey, MBBCH [2]

Overview

Viral meningitis lab tests include non specific blood tests like the cbc, blood culture, PT and PTT tests. Other tests include some tissues swabbing like the throat and nose swab to detect the viruses. PCR is also recommended for virus detection. CSF studies is the most important specific diagnostic test for the viral meningitis and it also differs it from other types of meningitis.

Laboratory findings

Non specific tests

Blood tests

It is performed routinely to any suspected meningitis patients. It includes the following:

CBC
Blood culture
PT and PTT
Glucose level
Creatine level

Virus detection

Virus may be detected through two ways:

Samples can be taken by different ways from the suspected meningitis patients to detect the virus causing the disease.They may be collected for testing by:^[1]
- Nose swabbing
- Throat swabbing
- Rectum swabbing
- Taking a stool sample
- Drawing fluid from around your spinal cord.

Polymerase Chain Reaction (PCR) can be used to detect the viruses in the blood. It can detect the DNA of the viruses like the enteroviruses and herpes simplex viruses.^[2]

Specific tests

Specific diagnostic tests include lumbar puncture with CSF examination. CSF examination findings in viral meningitis are as follows:


Cerebrospinal fluid level	Normal level	Viral meningitis^[3]
Cells/ul	< 5	>100
Cells	Lymphos:Monos 7:3	Lymphocytes>granulocytes
Total protein (mg/dl)	45-60	Normal or slightly elevated
Glucose ratio (CSF/plasma)^[4]	> 0.5	>0.6
Lactate (mmols/l)^[5]	< 2.1	< 2.1
Others	ICP:6-12 (cm H2O)	Throat swap

Video explaining the lumbar puncture procedure: {{#ev:youtube|weoY_9tOcJQ}}

References

↑ CDC https://www.cdc.gov/meningitis/viral.html Accessed on April 20, 2017
↑ Cantey JB, Mejías A, Wallihan R, Doern C, Brock E, Salamon D; et al. (2012). “Use of blood polymerase chain reaction testing for diagnosis of herpes simplex virus infection”. J Pediatr. 161 (2): 357–61. doi:10.1016/j.jpeds.2012.04.009. PMID 22608699.
↑ Negrini B, Kelleher KJ, Wald ER (2000). “Cerebrospinal fluid findings in aseptic versus bacterial meningitis”. Pediatrics. 105 (2): 316–9. PMID 10654948.
↑ Chow E, Troy SB (2014). “The differential diagnosis of hypoglycorrhachia in adult patients”. Am J Med Sci. 348 (3): 186–90. doi:10.1097/MAJ.0000000000000217. PMC 4065645. PMID 24326618.
↑ Leen WG, Willemsen MA, Wevers RA, Verbeek MM (2012). “Cerebrospinal fluid glucose and lactate: age-specific reference values and implications for clinical practice”. PLoS One. 7 (8): e42745. doi:10.1371/journal.pone.0042745. PMC 3412827. PMID 22880096.

[Viral_meningitis-1] CDC https://www.cdc.gov/meningitis/viral.html Accessed on April 20, 2017

[pmid22608699-2] Cantey JB, Mejías A, Wallihan R, Doern C, Brock E, Salamon D; et al. (2012). “Use of blood polymerase chain reaction testing for diagnosis of herpes simplex virus infection”. J Pediatr. 161 (2): 357–61. doi:10.1016/j.jpeds.2012.04.009. PMID 22608699.

[pmid10654948-3] Negrini B, Kelleher KJ, Wald ER (2000). “Cerebrospinal fluid findings in aseptic versus bacterial meningitis”. Pediatrics. 105 (2): 316–9. PMID 10654948.

[pmid24326618-4] Chow E, Troy SB (2014). “The differential diagnosis of hypoglycorrhachia in adult patients”. Am J Med Sci. 348 (3): 186–90. doi:10.1097/MAJ.0000000000000217. PMC 4065645. PMID 24326618.

[pmid22880096-5] Leen WG, Willemsen MA, Wevers RA, Verbeek MM (2012). “Cerebrospinal fluid glucose and lactate: age-specific reference values and implications for clinical practice”. PLoS One. 7 (8): e42745. doi:10.1371/journal.pone.0042745. PMC 3412827. PMID 22880096.

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