During an outbreak of hepatitis B virus (HBV) infection in a hemodialysis unit, patients were assessed for serological viral markers and vaccination status. HBV infection was identified in 26 patients. Twenty of these were positive for hepatitis B surface antigen (HBsAg), and 6 were negative for HBsAg but positive for IgM antibody to hepatitis B core (anti-HBc) and HBV DNA. The primary source of infection was not clearly identified, although 2 patients were suspected to be the index cases. A multiple logistic regression analysis revealed low anti-HBs titers and vaccination status to be independently associated with the risk of acquiring HBV infection. Both the high prevalence of HBV infection (31%) detected in this unit and the low vaccine response (53%) observed reinforce the importance of universal and preventive measures in controlling HBV infection. The detection of HBV DNA in HBsAg-negative/IgM anti-HBc-positive patients emphasizes the value of anti-HBc testing in the routine screening of HBV in hemodialysis units.

A previous seroepidemiological study in the rural zone of Vargem Alta (ES) SouthEast of Brazil, showed a prevalence of up to 9% of hepatitis B surface antigen (HBsAg) in some areas. One hundred susceptible children aging 1 to 5 years old were selected and immunized with a recombinant DNA hepatitis B vaccine (Smith-Kline 20 mcg) using the 0-1-6 months vaccination schedule. Blood samples were collected at the time of the first vaccine dose (month 0) in order to confirm susceptible individuals and 1,3,6 and 8 months after the first dose , to evaluate the antibody response. Our results showed that two and five months after the second dose, 79% and 88% of children seroconverted respectively, reaching 97% after the third dose. The levels of anti-HBs were calculated in milli International Units/ml (mIU/ml) and demonstrated the markedly increase of protective levels of antibodies after the third dose. These data showed a good immunogenicity of the DNA recombinant hepatitis B vaccine when administered in children of endemic areas.

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An excess of hepatitis cases, in the research center of Petrobrás located in the Fundaão Island, within the city of Rio de Janeiro, was notified during the second half of March 1980. In recent years this center has had an average of four cases per year, but between March 5th and April 25th, sixteen cases were reported. The cause and possible source of infection were investigated. A serologic diagnosis of hepatitis A was made by showing IgG serum antibodies against this virus in patients. No subclinical cases among a group of 60 healthy employees could be identified. A questionnaire was circulated to investigate a possible commom source of infection. Evaluation of the water supply system indicated that it had recently been contaminated. Information obtained from other medical services in the island failed to reveal that the episode was part of a larger outbreak.
Durante a 2ª quinzena de março de 1980, foi notificada a ocorrência de casos de hepatite, no Centro de Pesquisa da Petrobrás localizado na Ilha do Fundão, na cidade do Rio de Janeiro. Nos últimos anos, este Centro apresentou uma média de ocorrência de quatro casos de haepatite por ano, mas no período de 5 de março a 25 de abril foram observados 16 casos. A causa e a possível fonte desta infecção foram investigadas. O diagnóstico sorológico para Hepatite A, dos pacientes, foi feito pela determinação de anticorpos IgM específicos para este vírus. Não foi identificado nenhum caso subclínico entre um grupo de 60 empregados saudáveis. Uma possível fonte de infecção comum foi investigada por meio de um questionário. As análises feitas no sistema de água indicaram uma contaminação recente. As informações obtidas de outros serviços médicos da mesma localidade não mostraram nenhuma ocorrência que sugerisse um surto

Immune response against hepatitis B vaccine (CLB 3mg) was evaluated in 59 hemodialysis patients and 20 occupational risk personnel. Seroconversion was induced in 52.5% and 70.0% respectively. Twelve months after the first dose, 37.5% of patients and 60.0% of occupational risk personnel had detectable anti-HBs level. Antibody level was expressed in sample ratio units (SRU). Considering only the responders, in the patients group 38.7% had a low anti-HBs response (2.1-9.9 SRU) 32.3% a medium response (10-99.9 SRU) and 29.0% a high response (>100 SRU) while in occupational risk personnel these values were 14.3%, 64.3% and 21.4% respectively. The authors suggest the use of HBV vaccines with more elevated HBsAg concentration or a reinforced immunization schedule to improve the anti-HBs response not only for patients but also for healthy persons.

By the method of affinity chromatography a partially purified antigen was obtained after passing the plasma of an asymptomatic carrier of HBsAg through a column of Sepharose 4B linked to angi-HBs. This antigen was inoculated in rabbits using a schedule of 1,0 mg in the first dose and 4 other doses of 0,5 mg with intervals of approximately 15 days. Observing that blood samples collected after the 5th inoculation showed no change in antibody levels, the animals were bled on the 62th day and these immune sera were standardized with the following tests for the detection of HBsAg: Reverse passive hemagglutination (R-PHA) - using specific gamma globulin that was obtained from rabbit sera by affinity chromatography and reaching an optimal concentration of 10 micrograms/ml to sensitise SRBC at 5% fixed in glutaraldehyde. Counter immuno electrophoresis (CIEP) - using the rabbit immune sera diluted to 1/20 as a reagent for the detection of HBsAg. The immune sera was also used to conjugate new Sepharose 4B for affinity chromatography and was found having a linking capacity of approximately 0,5 to 1,0 mg of HBsAg per ml of Sepharose after complete saturation.