BACKGROUND: We describe a case of meningitis due to Haemophilus influenzae detected by BioFire FilmArray Meningitis/Encephalitis Polymerase Chain Reaction (PCR) panel on a cerebral spinal fluid sample collected from a repeated lumbar puncture.

CASE REPORT: A 69-year-old female with a history of diabetes mellitus was admitted to another hospital 5 months prior with altered mental status. After a lumbar puncture, she was diagnosed with meningitis and was treated with antimicrobials. The patient then presented to our hospital, and the initial lumbar puncture was unable to identify any specific organism. Another lumbar puncture was performed in order to be able to diagnose her with meningitis due to Haemophilus influenzae. The patient was, therefore, treated with ceftriaxone for 14 days, achieving a complete resolution of her symptoms.

CONCLUSIONS: This case highlights the clinical significance of repeating the lumbar puncture in cases of diagnostic uncertainty and discusses the likelihood of false-positive results on the BioFire FilmArray PCR panel and the importance of correlating diagnostic sensitivity with clinical manifestations.