LATEX PARTICLE AGGLUTINATION-TEST IN THE DIAGNOSIS OF HAEMOPHILUS-INFLUENZAE TYPE-B, STREPTOCOCCUS-PNEUMONIAE AND NEISSERIA-MENINGITIDIS-A AND NEISSERIA-MENINGITIDIS-C MENINGITIS IN INFANTS AND CHILDREN

The knowledge of purulent meningitis etiology is essential in deciding the immediate therapy; in developing countries, however, the etiologi cal agent identification does not reach 60% of the cases. A comparativ e study using the latex particle agglutination test (LPAT) in cerebros pinal fluid (CSF) for the diagnosis of meningitis due to Haemophilus i nfluenzae type b, Streptococcus pneumoniae or Neisseria meningitidis A and C was carried out in Belo Horizonte MG, Brazil. CSF culture was u sed as a gold-standard. Two hundred and ninety-nine children, ranging from 3 months to 14 years of age, were included in the investigation. One hundred and forty-four presented a positive CSF culture for the ab ove mentioned bacteria; the remaining presented meningitis due to othe r organisms (other bacteria or viral) or a normal CSF. The sensitivity and the specificity of LPAT was 95.7 and 100.0% for N. meningitidis C , 95.2 and 100.0% for H. influenzae type b and 86.5 and 100.0% for S. pneumoniae, respectively. When all three organisms were considered sim ultaneously, the sensitivity and the specificity was 93.0 and 100.0%, respectively. Taking into consideration a realistic estimate of diseas e prevalence in the community where the diagnostic test is being used, the positive predictive value and the posttest probability were estim ated as 36.7 and 47.1% for children < 5 years and as 21.3 and 35.1% fo r children < 14 years of age, respectively. LPAT is a useful diagnosti c test for meningitis due to the studied pathogens, especially in deve loping countries where laboratory facilities are limited.