Treatment failure and recurrent human listeriosis.

We review 12 patients and report an additional two new patients, each of whom had two episodes of listeriosis. In seven patients the two episodes were due to the same strain of Listeria monocytogenes, and we speculate that this was a reactivation of the original infection. In one patient, isolates of L. monocytogenes from the two episodes differed, suggesting a chance reinfection. Twelve of the patients in this series received inappropriate therapy. Ampicillin plus an aminoglycoside for three to four weeks remain the treatment of choice.