The best questions often stem from the inquisitive learner. As educators, we love—and are always humbled by—those moments when we get to say, “I don’t know.” For some of these questions, you may already know the answers. For others, you may never have thought to ask the question. For all, questions, comments, concerns, and critiques are encouraged. Welcome to the Kids Korner.

Question: After the administration of antibiotics, how long will the meningitis/encephalitis PCR panel remain positive for bacterial pathogens after lumbar puncture?

Many emergency department settings now have access to the FilmArray Meningitis/encephalitis Panel for testing on CSF after lumbar puncture. This polymerase chain reaction (PCR) panel was approved in 2016 and we do not endorse or oppose it—we simply have access to this test at our hospital, like many other hospitals. It tests for six bacteria, seven viruses, and one fungus. Studies have evaluated and continue to evaluate its effects on duration of antibiotic therapy, length of stay, etc. We sought to explore the duration of time that it remains positive for tested cerebrospinal fluid bacterial pathogens after antibiotic administration. According to a 2020 meta-analysis that included eight studies with 3,059 total patients (1,085 pediatric), the pooled sensitivity and specificity of this PCR test is 90 percent (95 percent CI, 86–93 percent) and 97 percent (95 percent CI, 94–99 percent), respectively.¹ Regarding the duration of a positive bacterial PCR result after administration of antibiotics, we were unable to find any studies that answered this question, so the answer appears to remain unknown at this time.

Summary

We are unable to find any studies that address the length of time that the CSF meningitis/encephalitis PCR panel remains positive after antibiotic administration.

Dr. Jones is assistant professor of pediatric emergency medicine at the University of Kentucky in Lexington.

Dr. Cantor is professor of emergency medicine and pediatrics, director of the pediatric emergency department, and medical director of the Central New York Regional Poison Control Center at Upstate Medical University in Syracuse, New York.

References

1. Tansarli GS, Chapin KC. Diagnostic test accuracy of the BioFire FilmArray meningitis/encephalitis panel: a systematic review and meta-analysis. Clin Microbiol Infect. 2020;26(3):281-290.