Infection with Neisseria meningitidis group B has been difficult to detect, partly because this bacterial group's polysaccharide is a weak immunogen. This article describes work carried out to test a new procedure (MB-Dot-ELISA) employing a high-titered horse antiserum for detection of N. meningitidis group B antigens. The study assayed cerebrospinal fluid samples from 585 subjects, 574 with suspected meningitis cases and 11 with neurologic disorders. The results of the assay indicated a sensitivity of 0.991 and a specificity of 0.826. These results were superior to those obtained with latex agglutination and in substantial agreement with the results of counterimmunoelectrophoresis and bacteriologic methods. Overall, the MB-Dot-ELISA was found to be sensitive, inexpensive, and suitable for public health laboratory investigations.

La infección por Neisseria meningitidis del grupo B ha sido difícil de detectar, en parte porque el polisacárido de este grupo de bacterias es un inmunógeno débil. En este artículo se describe el análisis de la validez de una nueva prueba, la MB-Dot-ELISA, en la cual se emplea un antisuero de caballo de alta titulación para detectar antígenos de N. meningitidis del grupo B. En el estudio se valoraron muestras de líquido cefalorraquídeo de 585 personas, 574 de las cuales padecían presuntamente meningitis y 11, trastornos neurológicos. La sensibilidad de la prueba fue 0,991 y la especificidad, 0,826. Estos valores fueron más altos que los de la aglutinación en látex y son muy compatibles con los de la contrainmunoelectroforesis y los métodos de análisis bacteriológico. La prueba MB-Dot-ELISA es sensible, barata y apropiada para realizar investigaciones en los laboratorios de salud pública.

Oitenta amostras purulentas de líquido cefalorraquidiano (LCR) de pacientes com evidência clínica de meningite foram estudadas empregando-se Kit Directigen de aglutinação de latex (AL) para demonstrar antígeno bacteriano no LCR. Os resultados mostraram que o teste de AL apresentou melhor desempenho diagnóstico do que bacterioscopia através da coloração de Gram, cultura e imunoeletroforese cruzada (IEC) em relação à Neisseria meningitidis grupos B e C, e ao Haemophilus influenzae tipo b, e melhor do que coloração de Gram e cultura quando Streptococcus pneumoniae foi avaliado. A comparação dos resultados com os de cultura mostrou o maior nível de sensibilidade considerando-se N. meningitidis grupo C. Quanto à especificidade, os valores foram satisfatórios para todos os microrganismos testados. O grau de concordância K em relação à IEC exibiu melhores índices K de concordância para N. meningitidis grupos B e C.

Eighty purulent cerebrospinal fluid (CSF) samples from patients with clinical evidence of meningitis were studied using the Directigen latex agglutination (LA) kit to determine the presence of bacterial antigen in CSF. The results showed a better diagnostic performance of the LA test than bacterioscopy by Gram stain, culture and counterimmunoelectrophoresis (CIE), as far as Neisseria meningitidis groups B and C, and Haemophilus influenzae type b are concerned, and a better performance than bacterioscopy and culture considering Streptococcus pneumoniae. Comparison of the results with those of culture showed that the LA test had the highest sensitivity for the Neisseria meningitidis group C. Comparing the results with those of CIE, the highest levels of sensitivity were detected for N. meningitidis groups B and C. Regarding specificity, fair values were obtained for all organisms tested. The degree of K agreement when the LA test was compared with CIE exhibited better K indices of agreement for N. meningitidis groups B and C.

Amostras de líquido cefalorraquidiano (LCR) de 2083 pacientes com Síndrome de Imunodeficiência Adquirida (SIDA) e complicações neurológicas foram examinados durante um período de 7 anos (1984-1990). A porcentagem de pacientes que tiveram pelo menos um agente bacteriano cultivado do LCR foi de 6,2%. Mycobacterium tuberculosis foi o mais frequentemente isolado (4,3%), seguido do complexo Mycobacterium avium ou MAC (0,7%), de Pseudomonas spp (0,5%), Enterobacter spp (0,4%), e Staphylococcus aureus (0,3%). Entre 130 pacientes com cultura positiva, de 89 (68,5%) foi isolado M. tuberculosis e de 15 (11,6%) MAC. A frequência de isolamentos bacterianos aumentou de 1988 (5,2%) a 1990 (7,2%), particularmente devido ao maior isolamento de MAC. Os agentes bacterianos foram mais frequentemente isolados de pacientes na faixa etária de 21-30 anos e de mulheres (p<0.05).

Cerebrospinal fluid (CSF) samples from 2083 patients with acquired immunodeficiency syndrome (AIDS) and neurological complications were bacteriologically examined during a period of 7 years (1984-1990). The percentage of patients who had at least one bacterial agent cultured from the CSF was 6.2%. Mycobacterium tuberculosis was the most frequently isolated agent (4.3%), followed by Mycobacterium avium complex or MAC (0.7%), Pseudomonas spp (0.5%), Enterobacter spp (0.4%), and Staphylococcus aureus (0.3%). Among 130 culture positive patients, 89 (68.5%) had M. tuberculosis and 15 (11.6%) had MAC. The frequency of bacterial isolations increased from 1988 (5.2%) to 1990 (7.2%), partly due to the increase in MAC isolations. Bacterial agents were more frequently isolated from patients in the age group 21-30 years and from women (p<0.05).