When should antibiotics be discontinued for an immunocompetent patient with signs of meningoencephalitis who undergoes an LP without prior administration of antibiotics and the CSF shows a neutrophilic pleocytosis, negative Gram stain, negative PCR Panel, and negative CSF culture at day 3-5?   

Occasionally, an immunocompetent pt with signs of meningoencephalitis will undergo an LP without prior administration of abx.

When the CSF shows:

1. Neutrophilic pleocytosis;
2. Negative Gram stain and negative cultures after 3-5 days, and;
3. Negative PCR Panel.

Assuming the pt’s blood cultures are also negative, at what point should abx be discontinued?

Several po abx penetrate the CSF well. Does pt's claim no abx were taken before coming to the ER matter? If so, is it our responsibility to attempt to verify this claim? And, if so again, how so?

Does the pt's age (>50 yo) or the time of year (i.e., late summer-early autumn) play in a role in the decision process?

I do not believe that the 2004 IDSA Guidelines discuss this clinical situation (I do not believe that the CSF PCR Panel was not widely available yet).

SMS