Níveis de anticorpos contra o antígeno de superfície do vírusda hepatite B (anti-HBs) em escolares da primeira série do ensino fundamental, no município de Vitória, com e sem helmintos intestinais e/ou reação sorológica positiva para Toxocara
Helminth infection induces immunomodulation that can interfere with immune mechanisms that maintain immunological memory, thus its interference in the efficacy of hepatitis B vaccine is possible. Objectives. To investigate the possibleeffects of helminth infection on the response of HBV vaccine, anti-HBs titers were evaluated in a sample of healthy seven years old school children, in whom intestinal helminthes and a positive serology for anti-Toxocara antibodies were investigated. Material and methods. One hundred ninety five school children, from 8 elementary schools at the metropolitan area of Vitoria, vaccinated after birth with recombinantHBV vaccine, were tested for anti-Toxocara antibodies with an ELISA IgG (CELISA, Cellabs Pty Ltda. Brokvale, Australia) and had stool examinations for detection of intestinal helminthes (sedimentation method). Anti-HBs and anti-HBc were tested with commercial kits (Axsym Ausab and Axsym Core, Abbot). Serum hemoglobin and leucocyte counts were done by routine methods. Results. 103 children were maleand the mean of ages was 7.27 years. Nutritional status was satisfactory as demonstrated by medians of serum hemoglobin and blood lymphocytes (respectively 12.g/dL and 2415/mm3). Stool examinations demonstrated at least one helminth in 40children and the serology for anti-Toxocara antibodies was positive (optical density above 0,500) in 90 children. The presence of at least one helminth and/or a positive serology for anti-Toxocara antibodies was present in 100 children. The geometric mean of anti HBs titers was 22,64 UI/L and 65 (33,84%) children had titers of anti-HBs lesser than 10 IU/L. All children were anti-HBc negative. There was notsignificant differences in prevalence of intestinal helminthes and/or a positive serology for anti-Toxocara antibodies between children with anti-HBs titers lower or higher than 10 IU/L. Conclusion. Intestinal helminthes and/or presence of anti-Toxocara antibodies did not interfere with the titers of anti-HBs in children vaccinated at birth with recombinant HBV vaccine, evaluated seven years after vaccination. Thefrequency of anti-HBs titers below 10 IU/L observed in the present study was similar to that observed in other countries, where it was investigated in similar samples in relationship to age and time after vaccination.
Advisor:Rodrigo Ribeiro Rodrigues; Aparecida das Graças Carvalho Gomes; Fausto Edmundo Lima Pereira
School:Universidade Federal do Espírito Santo
Source Type:Master's Thesis
Keywords:hepatitis B vaccine anti-HBs Toxocara infection
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