[Meningitis with direct negative bacteriological examination. Prospective assessment of a decision making tree].
OBJECTIVE
Elaboration of a decision-making tree for differential diagnosis of bacterial and viral meningitis, when initial Gram's staining is negative. Method One-Year prospective study in an adult emergency department. Comparison with the immediately-preceding period.


RESULTS
56 patients were included. Only 4 bacterial meningitis, but none misdiagnosed. 86% sensitivity and 83% specificity for viral meningitis (n=40). Rate of patients hospitalised more than 24 hours decreasing from 62.5 to 41% (p=0.05). Antibiotic chemotherapy decreasing from 55 to 16% (p<0.001).


CONCLUSIONS
This decision-making tree safely allows emergency differentiation between bacterial and viral meningitis, when initial Gram's staining is negative. It consequently leads to decreased rates of useless hospitalisations and antibiotic treatments. We believe that this method can be helpful during outbreaks of viral meningitis.
Boutoille
David
D
Service de médecine interne B - maladies infectieuses et tropicales, Hôtel-Dieu, CHU, Nantes. david.boutoille@chu-nantes.fr
Struillou
Laurence
L
El Kouri
Dominique
D
Le Conte
Philippe
P
Touzé
Marie-Dominique
MD
Potel
Gilles
G
Baron
Denis
D
Raffi
François
F
D000328:Adult; D000465:Algorithms; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002097:C-Reactive Protein / Q000032:analysis; D002116:Calcitonin / Q000097:blood; D016009:Chi-Square Distribution; D003627:Data Interpretation, Statistical; D003661:Decision Support Techniques; D003937:Diagnosis, Differential; D006801:Humans; D007902:Length of Stay; D016920:Meningitis, Bacterial / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis* / Q000188:drug therapy / Q000628:therapy; D008587:Meningitis, Viral / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis* / Q000188:drug therapy / Q000628:therapy; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors
D000900:Anti-Bacterial Agents; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein