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Use of a latex agglutination test in rapid diagnosis of acute meningitis
Abstract:
Capsular antigens of Neisseria meningitidis groups A, B, C, Y and W135, Streptococcus pneumoniae and Haemophilus influenzae were searched in CSF specimens of 66 patients with acute meningitis, using a latex agglutination test. Simultaneously CSF samples were processed for Gram stain and culture. Blood cultures were also performed in all patients. The test was positive in 43 (82.7%) samples: N. meningitidis-19, S. pneumoniae-18 and H. influenzae-6. In 32 samples the result of the test was concordant with CSF or blood culture. In 11 cases the test was positive but CSF or blood cultures were negative. Gram stain was diagnostic in 13 (25%) samples in which the latex agglutination test was also positive, and were negative in the remaining cases. There were six false negative tests. In 17 cases the test, culture and Gram stain were simultaneously negative: 14 cases corresponded to viral meningitis, and the three other were unidentified purulent meningitis. Concluding, the test was useful in early aetiologic diagnosis of acute meningitis, but the occurrence of false negative results requires a complete bacteriological study.
Insights
A latex agglutination test aids in the early diagnosis of acute meningitis by detecting bacterial antigens. However, false negatives necessitate complete bacteriological studies for accurate identification.
Area of Science:
- Microbiology
- Infectious Diseases
- Clinical Diagnostics
Background:
- Acute meningitis poses a significant diagnostic challenge.
- Rapid and accurate etiological diagnosis is crucial for effective treatment and patient outcomes.
Purpose of the Study:
- To evaluate the utility of a latex agglutination test for the rapid detection of common bacterial meningitis pathogens.
- To compare the sensitivity and specificity of the latex agglutination test against Gram stain and culture methods.
Main Methods:
- A latex agglutination test was employed to detect capsular antigens of Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae in cerebrospinal fluid (CSF) from 66 acute meningitis patients.
- CSF samples underwent Gram stain and culture, and blood cultures were performed concurrently.
Main Results:
- The latex agglutination test showed a positivity rate of 82.7% (43/66), identifying Neisseria meningitidis (19), Streptococcus pneumoniae (18), and Haemophilus influenzae (6).
- Concordance with culture results was observed in 32 samples, while 11 samples were positive by latex agglutination but negative by culture.
- Gram stain was diagnostic in 25% of cases, and six false-negative latex agglutination tests were recorded. Viral meningitis was diagnosed in 14 cases where all tests were negative.
Conclusions:
- The latex agglutination test is a valuable tool for the early etiological diagnosis of acute bacterial meningitis.
- The potential for false-negative results underscores the importance of comprehensive bacteriological investigations, including culture, to confirm or exclude bacterial meningitis.