Cerebrospinal fluid findings in infants with pertussis or parapertussis(1))

Pertussis has been increasing in frequency and can cause protean manifestation in infants, often resulting in extensive laboratory evaluation.

We examined the prevalence of cerebrospinal fluid (CSF) anomalies in infants with pertussis and parapertussis over a 5-year period.

In total, 239 of 1489 children (16.1%) had a positive PCR for pertussis or parapertussis. Eighty-three percent were infants; the mean age of the 39 years who received a lumbar puncture (LP) was 43 days. Reasons for performing LP included apnea (62%), toxic appearance (38%), fever (26%), and altered mentation (10%); several had >1 indication for LP. Twenty-four (62%) children had elevated CSF protein. No child had hypoglycorrhachia, bacterial meningitis, bacteremia, or intracranial hemorrhage; one child had a urinary tract infection and five had pneumonia. Seven children had brain imaging performed; one had a subarachnoid hemorrhage and six had normal studies. Elevated age-normalized CSF protein was a common finding in infants with pertussis, potentially due to transfer across a damaged or immature blood-brain barrier. This finding was seen in the absence of concomitant bacterial infections or detectable intracranial anomalies.

While the diagnostic evaluation and clinical management of a toxic-appearing infant should not be limited by a positive pertussis or parapertussis PCR, it is useful for physicians to be cognizant that elevated CSF protein can be seen in association with these infections.