Dot-ELISA using the outer membrane complex antigens of Neisseria meningitidis as a target was standardized for rapid detection of meningococcal-specific antibodies in human serum. We investigated the level of meningococcal-specific IgG, IgA, and IgM in serum using dot-ELISA with outer membrane antigens prepared from Neisseria meningitidis serotype B:4.19:P1.15,3,7,9 (a strain isolated from a Brazilian epidemic). The dot-ELISA is based on the same principles as the standard ELISA and is useful for detection of anti-N. meningitidis B antibodies in serum of patients with meningococcal infections. For the assay, outer membrane complexes (OMCs) were absorbed by nitrocellulose membrane and blocked with a 5% skim milk solution. Serum samples were drawn upon hospital admission and during convalescence from patients with meningococcal septicemia, and single samples were drawn from uninfected controls. We retrospectively examined a total of 57 serum samples: 35 from patients infected with N. meningitidis B, 12 from patients infected with Haemophilus influenzae b, and 10 from health individuals. When performed at room temperature, dot-ELISA took approximately four hours to perform, and the optimum antigen concentration was 0.42 µg per dot. The specificity of IgG, IgM, and IgA demonstrates that dot-ELISA using OMCs from N. meningitidis B as a target is suitable for serologic verification of clinically suspected meningococcal disease in patients and for titer determination of antibodies produced during different phases of natural infection. Furthermore, the sensitivity of dot-ELISA was comparable to that of standard ELISA. Overall, dot-ELISA is simple to perform, rapid, and low cost. Further validation of the test as a screening tool is required.

OBJECTIVE: To evaluate the immunogenicity of a combined DTPa-HB vaccine co-administered with Haemophilus influenzae type b conjugate vaccine (PRP-T) in Brazilian infants. MATERIAL AND METHODS: A prospective and open clinical study, in which 110 infants were immunized with a three-dose primary vaccination regime at two, four and six months of age and with a single booster vaccination. Blood samples were drawn immediately before the first dose, one month after the third dose, at the time of the booster dose and one month after the booster to assess seropositivity and antibody geometric mean titers (GMTs) of antibodies for diphtheria, tetanus, hepatitis B, Haemophilus influenzae type b and for the three pertussis antigens: Pertussis Toxin (PT), Filamentous Hemagglutinin (FHA) and Pertactin (PRN). RESULTS: Among the original 110 infants, 93 completed the study. Seropositivity was 100% for all seven involved antibodies, after the primary vaccination course. At the time of the booster dose, all antibodies (except diphtheria 33.7% and anti-PT 59%) were seropositive for more than 94% of subjects. After the booster, seropositivity increased to 100% for all antibodies. The GMT of these antibodies followed a similar pattern, with a strong increase after the primary course, followed by a second increase after the booster dose. At this time, GMT was2- to 7-fold higher than after the primary course, for all vaccine components. CONCLUSIONS: Concomitant administration of DTPa-HB and Hib vaccines elicited strong seroprotection for all the antigenic components. No interference with antibody response was evident. The vaccines provided high immunogenicity, following both the primary vaccinations and the booster dose.

We evaluated the clinical presentation and determined the ocular and neurologic sequelae in children with congenital toxoplasmosis in Brazil, taking into consideration the shortage of national publications on this disease. Follow-up evaluations were made of 43 children with congenital toxoplasmosis referred to Santa Casa de São Paulo, during a period of at least five years. Selection of the cases was based in clinical and laboratory criteria. A clear predominance of children with subclinical presentation of the disease at birth (88%) was found. Of the 43 children, 22 (51%) developed neurological manifestations. Using skull radiography, we detected neuroradiologic alterations in seven children (16%) and with tomography in 33 children (77%). Neurological sequelae were identified in 15 children (54%) in the group with cerebral calcifications and in 7 (47%) in the group without cerebral calcifications. We observed chorioretinitis in 95% of the cases. Reactivation of cicatricial lesions and the emergence of new ocular lesions were observed in five cases. The most frequent neurological manifestation was a delay in neuropsychomotor development. Most remarkable was the finding that cerebral calcifications were not associated with a higher incidence of neurological sequelae among the children. Chorioretinitis was the main ocular sequel of the infection, found in nearly all children; it can manifest years from birth, even in children submitted to specific therapy during the first year of life, highlighting the importance of a follow-up of these children.

Objetivos: comparar as taxas de colonização e a resistência antimicrobiana de pneumococos em nasofaringe de crianças sadias e com pneumonia. Métodos: estudo de tipo transversal. As crianças sadias foram recrutadas em centros de vacinação (CV) e creches públicas (CP), selecionados aleatoriamente, e aquelas com pneumonia em emergências pediátricas. Foram utilizados swabs flexíveis de alginato para a colheita do material de nasofaringe. O isolamento e a identificação dos pneumococos seguiram procedimentos padronizados. As concentrações inibitórias mínimas (CIM) foram determinadas por microdiluição em placas. Resultados: foram estudadas 911 crianças, 429 sadias (60% portadoras de pneumococo, sendo 72% destas recrutadas em CP e 49% em CV) e 482 com pneumonia (50% de portadoras) (p=0,002). De 441 isolados com CIM determinadas, 198 (45%) apresentavam resistência intermediária, e 16 (4%) apresentavam resistência plena à penicilina. As taxas de resistência dos pneumococos isolados de portadores sadios e com pneumonia, respectivamente, foram: penicilina 48% (CV 37% e CP 55%) e 50% (p>0,05); eritromicina: 28% e 19% (p=0,05); cotrimoxazol 81% e 76% (p>0,05); cloranfenicol 6% e 7% (p>0,05), rifampicina 5% e 3% (p>0,05), ceftriaxone 2 e 4% (p>0,05) e vancomicina 0%, para ambos grupos. Foi constatada associação entre as resistências do pneumococo à penicilina, eritromicina e ao cotrimoxazol. Conclusões: a taxa de portador de pneumococos foi maior em crianças sadias do que naquelas com pneumonia. As resistências dos pneumococos à penicilina e ao cotrimoxazol foram elevadas, sobretudo entre os usuários de creches públicas.

Objectives: to compare colonization rates and antimicrobial resistance of nasopharyngeal pneumococci in healthy carriers and children with pneumonia. Methods: a cross-sectional study. Healthy subjects of this study were selected from randomly chosen immunization centers and day-care centers, and those with pneumonia were selected in pediatric emergency rooms. Flexible pernasal alginate swabs were employed to collect nasopharyngeal pneumococci specimens. Isolation and identification were performed according to standard procedures. Minimum Inhibitory Concentrations were assessed by microdilution techniques. Results: we studied 911 children, 429 healthy controls (60% of carriers, 72% attending day care centers and 49% recruited in immunization centers) and 482 children with pneumonia (50% of carriers) (P=0.02). The Minimum Inhibitory Concentration of penicillin to 441 isolates detected 198 (45%) of intermediate and 16 (4%) fully resistant pneumococci. Antimicrobial resistance rates of isolates from healthy carriers and children with pneumonia were, respectively: penicillin 48% (37% for immunization centers and 55% for day-care centers) and 50% (P>0.05), erythromycin 28% and 19% (P=0.05); cotrimoxazole 81% and 76% (P>0.05), chloramphenicol 6% and 7% (P>0.05), rifampin 5 and 3% (P>0.05) ceftriaxone 2 and 4% (P>0.05) and vancomycin 0% in both groups. An association among pneumococcal resistance to penicillin, erythromycin and cotrimoxazole was detected. Conclusions: pneumococcal carriage rate was higher in healthy children than in children with pneumonia. Penicillin and cotrimoxazole resistance rates were high, especially among those attending day-care centers.