Cure of Listeria monocytogenes Meningitis after Early Transition to Oral Therapy

Abstract

Due to its lethality, Listeria monocytogenes infection of the central nervous system (CNS) typically is treated parenterally. We describe a case of L. monocytogenes meningitis cured with trimethoprim-sulfamethoxazole (TMP-SMX) utilizing early oral therapy on an outpatient basis. A 64-year-old woman was hospitalized with an acute onset of fever and personality change. She had a history of hypertension and rheumatoid arthritis controlled with weekly methotrexate without recent exposure to corticosteroids or tumor necrosis factor-alpha antagonists. Ten days before the current illness, she experienced a 3-day, self-limited episode of fever, vomiting, and diarrhea. The day of admission, her family noted the abrupt onset of bizarre behavior. She began attempting to rearrange furniture and shouting obscenities, which progressed into incoherent speech. After witnessing a fall without head strike, her family brought her to the hospital. At the time of admission, she was confused. Her temperature was 39.3°C. She had nuchal rigidity and photophobia without focal neurological findings. The peripheral leukocyte count was 15,600 cells/mm3 (79% neutrophils, 5% bands, and 14% lymphocytes). A noncontrast computed tomography (CT) examination of the head was unremarkable. Cerebrospinal fluid (CSF) contained 545 leukocytes/mm3 (77% neutrophils), a protein level of 209 mg/dl, and a glucose level of 62 mg/dl (serum glucose, 128 mg/dl). Gram stain showed few leukocytes but no organisms. After obtaining a history of oro-labial swelling following penicillin, the patient was given intravenous vancomycin, moxifloxacin, and TMP-SMX (15 mg/kg of body weight TMP daily in four divided doses). Dexamethasone and acyclovir were also administered for the first 48 h. After L. monocytogenes was isolated from the CSF, treatment was continued with TMP-SMX alone. Within 4 days she was afebrile, alert, and oriented and no longer had nuchal rigidity. In face of the rapid clinical response and with the availability of reliable family members to ensure adherence, the patient was discharged on hospital day 5 on oral TMP-SMX (three single-strength tablets every 6 h) to complete 3 weeks of treatment. She was completely well at an office visit 1 week after completing therapy and by phone interview 6 weeks after completion. No controlled trials exist to establish a drug of choice, mode of delivery, or optimal duration of therapy for CNS listeriosis. Ampicillin is the preferred and most widely used agent; many authorities recommend the addition of an aminoglycoside to ampicillin for at least the first week in treatment of CNS infection (4). For patients with penicillin hypersensitivity, TMP-SMX is the treatment of choice. Comparable levels of TMP-SMX are attained in the CSF with oral and intravenous administration (1). There have been several reported cases of L. monocytogenes meningitis treated successfully with oral TMP-SMX or TMP alone (Table ​(Table1).1). Together with this report, they suggest that oral TMP-SMX can be an efficacious and inexpensive therapeutic option for patients who demonstrate rapid clinical response to intravenous therapy and in whom good adherence is expected. TABLE 1. Cases of L. monocytogenes meningitis treated with oral TMP-SMX