CSF Testing Common in Some Children but Positive Results Rare

By David Douglas

July 26, 2019

NEW YORK (Reuters Health) - Nonculture infection tests of cerebrospinal fluid (CSF) in otherwise healthy children very rarely yields results requiring clinical intervention, according to new research.

Such tests are frequently ordered on lumbar-puncture specimens concurrently with routine CSF cell counts, Dr. Jennifer L. McGuire of Perelman School of Medicine in Philadelphia and colleagues note in JAMA Network Open, online July 19.

The researchers analyzed records of nonculture CSF infection testing in immunocompetent children with normal CSF cell counts who underwent lumbar puncture between 2007 and 2016. After exclusions for those with indwelling CSF shunts and other applications, a total of 4,083 children underwent 4,811 procedures.

Normal cell counts were defined as CSF white blood cell counts lower than 5/uL and CSF red blood cell counts lower than 500/uL. Cell counts were elevated in 1,480 and normal in the remaining 3,331 procedures.

At least one nonculture CSF infection test was performed on 1,270 (38.1%) of the lumbar-puncture specimens with normal cell counts. Only 18 of these (1.4%) had at least one nonculture infection test with a positive result. Eight children were discharged before the results were available.

Ultimately only two children with positive test results, one with CSF HSV PCR, and the other with CSF measles IgG, required medical intervention, but had other clear clinical and neuroradiographic signs of infection. Six children had positive results that did not affect their medical treatment.

Among limitations of the study, the researchers concede that "given the variation in CNS pathogen prevalence in different source populations, these data may not be completely generalizable to all tertiary care pediatric hospitals."

Dr. McGuire told Reuters Health that "the yield of sending non-culture CSF infection testing on spinal fluid from children with healthy immune systems and normal CSF cell counts is very low. Therefore, rather than ordering these tests across the board at the time of lumbar puncture, we hope these data help clinicians take a more nuanced approach to testing."

"By delaying the decision to send these tests until CSF cell counts are available, unless they have a specific, active clinical concern for an infection," she concluded, "we could dramatically improve our value-based care."

SOURCE: https://bit.ly/2SFngnY

JAMA Netw Open 2019.