[Should presumptive meningoencephalitis treatment in adults be active against Mycoplasma pneumoniae?]

Abstract

Introduction: Meningoencephalitis is the most common central nervous system complication caused by Mycoplasma pneumoniae. Its frequency is probably underestimated.

Objective: The study's aim was to determine the retrospectively incidence of M. pneumoniae meningoencephalitis among other cases of encephalitis diagnosed in infectiology, neurology and ICU at the Clermont-Ferrand University hospital in 2004 and 2005.

Design: A case of meningoencephalitis was defined by encephalopathy (altered level of consciousness and/or change in personality), with one or more of the following symptoms: fever, seizure, focal neurological findings, meningitis, electroencephalography or neuroimaging findings consistent with encephalitis. Tumor and hematoma diagnosed by scan were excluded. M. pneumoniae was considered as a possible cause when patients had positive serological test (IgM Elisa) and/or positive PCR results for the CSF.

Results: Four (8.3%) patients among 48 cases of encephalitis could have been caused by M. pneumoniae. All except one convulsed initially. Pneumopathy was found in two patients. All received a specific treatment later. Antibiotics seemed to influence evolution in only two patients. These 4 cases appeared during an epidemic between November 2004 and August 2005: 48 hospitalized adults had positive serological test for M. pneumoniae in 2005 and 15 in 2004, whereas the number of tests was the same in 2004 and in 2005.

Conclusions: M. pneumoniae should be investigated as a cause of meningoencephalitis if initial tests are negative, if patients have respiratory symptoms and in case of epidemic. Presumptive treatment of meningoencephalitis should include an antibiotic active against M. pneumoniae.