[1426] Fatal Acute Meningitis: Pathology and Etiologic Diagnosis.

Jeannette Guarner, Lindy Liu, Julu Bhatnagar, Tara Jones, Mitesh Patel, Marlene DeLeon-Carnes, Sherif R Zaki. Emory University, Atlanta, GA; Centers for Disease Control and Prevention (CDC), Atlanta, GA

Background: Fatal acute bacterial meningitis has decreased significantly due to vaccinations and early diagnosis and treatment. We studied the pathology of fatal acute bacterial meningitis cases sent to the CDC in order to define the frequency of the different bacterial infections encountered in the last 10 years and associated pathologic features.
Design: The data base was searched for all cases from 2000 to 2009 with a diagnosis of meningitis or meningoencephalitis. Of 118 cases, 29 had acute inflammation in the meninges and demographic, pathologic, immunohistochemical (IHC) and molecular data was assessed. Excluded cases had meningoencephalitis with mononuclear inflammation (58 cases), granulomatous inflammation (21), meningeal hemorrhage (7), or no slides available for review (3).
Results: There were 11 pediatric and 18 adult patients from both the U.S. (27) and Taiwan (2). Streptococcus pneumoniae was the cause of meningitis in 16 patients and Neisseria meningitidis in 8 patients. The following bacteria were found in one case each: Streptococcus suis, Streptococcus mitis, Staphylococcus aureus and Fusobacterium. In one case Gram positive cocci were present but no specific etiologic agent could be determined. The age of the patients with N. meningitidis was lower (mean 15.6 years, range 7 to 29) than the age (33.9 years, range 1 week to 68 years) for the patients with meningitis due to other bacteria. The table shows the frequency of different pathologic findings and the usefulness of the different tissue-based diagnostic modalities. Other features included 3 (17%) cases with S. pneumoniae that had meningeal hemorrhages and 2 (25%) cases with N. meningitidis that had leukocytosis.

 TotalSevere meningeal inflammationParenchymal inflammationPositive Gram stain resultPositive Steiner stain resultIHC positivePCR positive
Streptococci1814 (78%)8 (44%)5 (28%)7 (47%)17 (94%)15 (83%)
Neisseria86 (75%)3 (37%)2 (25%)2 (28%)7 (87%)7 (87%)
Other33 (100%)3 (100%)3 (100%)1 (33%)1 (33%)1 (33%)

Conclusions: S. pneumoniae continues to be the most frequent cause of fatal acute bacterial meningitis followed by N. meningitidis. Infiltration of the inflammation into the superficial cortex was frequent in these cases. Gram stains were positive in one third of cases while silver stains had higher positive rates. Organism specific diagnosis was possible in 96% of cases with acute meningeal inflammation using IHC and PCR.
Category: Infections

Wednesday, March 2, 2011 1:00 PM

Poster Session VI # 234, Wednesday Afternoon


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