Tularemic meningitis in a child with mononuclear pleocytosis

Neuroinvasive Francisella tularensis Infection: Report of 2 Cases and Review of the Literature

BACKGROUND

Neuroinvasive infection with Francisella tularensis, the causative agent of tularemia, is rare. Establishing clinical suspicion is challenging if risk factors or clinical features classically associated with tularemia are absent. Tularemia is treatable with antibiotics; however, there are limited data to inform management of potentially fatal neuroinvasive infection.

METHODS

We collected epidemiologic and clinical data on 2 recent US cases of neuroinvasive F. tularensis infection, and performed a literature review of cases of neuroinvasive F. tularensis infection published after 1950.

RESULTS

One patient presented with focal neurologic deficits and brain lesions; broad-range molecular testing on resected brain tissue detected F. tularensis. The other patient presented with meningeal signs; tularemia was suspected based on animal exposure, and F. tularensis grew in cerebrospinal fluid (CSF) culture. Both patients received combination antibiotic therapy and recovered from infection. Among 16 published cases, tularemia was clinically suspected in 4 cases. CSF often displayed lymphocytic pleocytosis. Among cases with available data, CSF culture was positive in 13 of 16 cases, and F. tularensis antibodies were detected in 11 of 11 cases. Treatment typically included an aminoglycoside combined with either a tetracycline or a fluoroquinolone. Outcomes were generally favorable.

CONCLUSIONS

Clinicians should consider neuroinvasive F. tularensis infection in patients with meningitis and signs suggestive of tularemia or compatible exposures, lymphocyte-predominant CSF, unrevealing standard microbiologic workup, or lack of response to empiric bacterial meningitis treatment. Molecular testing, culture, and serologic testing can reveal the diagnosis. Favorable outcomes can be achieved with directed antibiotic treatment.

Cerebral abscesses complicating tularemia meningitis

Tularemia meningitis is a distinctly rare entity with only 14 cases reported in the literature, half of which occurred prior to 1950. In this case we provide the first description of cerebral microabscesses which occurred as a complication of tularemia meningitis.

A case of tularemia meningitis in Sweden

Tularemia meningitis occurred in a previously healthy 64-year-old man from Northern Sweden. The patient was immunocompetent and recovered without sequelae. The bacterial isolate conformed by most criteria with the Euro-Asian biovar Francisella tularensis var. palaearctica. Tularemia meningitis may mimic meningitis caused by Mycobacterium tuberculosis.