Etiology of Orphan Community-based Meningitis and Meningo-encephalitis.

Community-based meningitis and meningo-encephalitis are defined by the presence of more than 10 leukocytes per mL of cerebrospinal fluid (CSF), eventually reported to the number of red blood cells. They can be associated with encephalitis, defined by cerebral or cerebellar dysfunction in the case of the transmission. The evolution includes death, what makes the seriousness of this clinical situation. However the diagnostic performance of meningitis and meningo-encephalitis in a patient without contact with a care structure is less than 25% resulting in empirical support in half of the patients. Indeed, the microbiological diagnosis of meningitis and transmission target currently only five pathogens including HIV positive resulted in a significant change to support the patient in three areas, decision of hospitalization, decision of isolation and antibiotic or antiviral treatment decision. A weekly epidemiological monitoring of the microbiological diagnosis of meningitis and meningo-encephalitis has enabled us to see a mismatch between a curve of requests for analyses and a flat curve of produced diagnoses. This discrepancy is interpreted as indicating a community outbreak of meningitis or meningo-encephalitis non-diagnosed by routine methods, called orphan meningitis or orphan meningo-encephalitis. On this observation, our research project is to improve the performance of the etiological diagnosis of community-based meningitis or meningo-encephalitis. To do this, we will evaluate the diagnostic performance of an advanced technique, using a non-invasive sample, the pharyngeal swab from the patient, to find micro-organisms that are not part of the commensal flora of the pharynx and who are responsible for undetected in routine meningitis. Indeed the main pathogens and meningitis (enterovirus, pneumococcus, meningococcus) transmission give a pharyngeal carriage before being responsible for meningitis or meningo-encephalitis. These bacteria are Coxiella burnetii, Bartonella spp., Tropheryma whipplei, Leptospira spp. and Borrelia spp.