[Intrafamilial contagion with the hepatitis B virus]. / Contagio intrafamiliar del virus de la hepatitis B.

BACKGROUND: A study of the intrafamilial transmission of the hepatitis B virus (HBV) and its relationship with the viral replication and epidemiological factors. METHODS: The intrafamilial transmission of 106 chronic carriers of HBV was evaluated: 79 were asymptomatic carriers (AC) and 27 had chronic liver disease (CLD). Overall 347 relatives of the first group individuals and 112 of the second group were investigated. In the index cases, all HBV markers were investigated, and also DNA-HBV in those with CLD. In the relatives, HBsAg, HBsAc and HBcAc were investigated. Also, a survey to evaluate the influence of socioeconomic and cultural factors was also carried out. RESULTS: The prevalence of markers was significantly higher in the relatives of patients with CLD (HBcAg, HBcAc and evidence of contact) followed by AC and controls. The most infective relation in AC was that of other contacts with significant differences from the mother-child relationship (HBsAc p less than 0.003, HBcAc p less than 0.01, and evidence of contact p less than 0.001). By contrast, in CLD the most infective relation was mother-child. The mother-child relation was more infective than the father-child one (HBsAg p less than 0.05, HBcAc p less than 0.03, and evidence of contact p less than 0.02). Regarding viral replication, it was found that the HBeAg and DNA positive patients were more infective. The prevalence of HBcAc and the evidence of contact increased with the time of living together of spouses. Finally, it can be stated in a general sense that, according to the results of the survey, the socioeconomic factors have a small influence on the familial transmission. CONCLUSIONS: The relatives of HBV carriers, particularly in the case of HC with high replication, have a high risk of transmission. Thus, their investigation and subsequent vaccination is mandatory.

[Immunological profile against the hepatitis B virus in different population groups (author's transl)]. / Determinación del perfil immunológico frente al virus HVB en grupos de población.

To study the immunological profile against the hepatitis B virus 742 sera (107 from the Renal Unit and 635 from other hospital services) were assayed for HBsAg, HBsAc, and HBcAc. The results obtained appear to indicate that the simultaneous determination of the three tests is unnecessary for diagnosis, although it is important for follow-up and prognosis. The isolated measurement of HBsAg is a good diagnostic test, but although it appears early it lasts little, a reason why it should perhaps be complemented with the other tests when considering the time factor. If only one technique is to be made available HBcAc determination seems necessary because it appears simultaneously with the HBsAg and it persists for a long time thereafter. A high degree of positivity of HBsAc and HBcAc was found in dialysis patients, a fact apparent also in the other population groups.

Detection of specific IgG and IgM antibodies in the haemagglutination inhibition test and the enzyme-linked immunoassay for the diagnosis of rubella infection.

A study has been carried out on the sera of 710 women who wished to know their state of rubella immunity using haemagglutination inhibition (HAI) and enzyme-linked immunoassay (ELISA) techniques. The majority of the women presented no symptoms. The ability of HAI to detect low antibody levels (1:8, 1:16) appears to be greater than that of Rubazyme ELISA IgG, employing the recommendations of the manufacturers. The correlation between HAI and IgG values above HAI titres of 1:16 is nearly 100%. In an additional study of 17 primary infections in pregnant women with definite rubella symptoms, the total titre of antibodies was determined by HAI and IgG and specific IgM with ELISA Rubazyme in successive samples. In four cases, IgM was clearly positive and no increase in either HAI or IgG antibodies could be demonstrated over three successive samples taken at an interval of 15 to 20 days. Therefore, we consider it necessary to determine IgM antibodies (evaluating these in the absence of the rheumatoid factor) in every doubtful case occurring in pregnant women, irrespective of whether clinical signs are present or not.