[Infection/immunity by hepatitis B virus in an adult population of Havana City. Cuba 1995]. / Infección/inmunidad por el virus de la hepatitis B en una población adulta de Ciudad de La Habana. Cuba 1995.

The results of a study of markers of infection/immunity by hepatitis B virus in a community of the health area in "Cristobal Labra" polyclinics, City of Habana in 1995. The studied healthy adult population was not included in any vaccination strategy with hepatitis B vaccine. Two markers were studied: Hepatitis B surface antigen and its corresponding antibody (anti-HBs). HBsAg-positivity was 1.05% and anti-HBs positivity was 13.39%. Of anti-HBs-positive cases, 13.39% had titers from 10-50 UI/L and the rest (43.68%) had titers over 50 UI/L.

[Filter paper sampling for the detection of anti-hepatitis A IgM antibodies]. / Toma de muestra en papel de filtro para la detección de anticuerpos IgM antivirus de la hepatitis A.

The usefulness of the whole sample taking in filter paper for the detection of anti-HAV IgM is described. 168 serum and filter paper samples were simultaneously compared. No alterations were observed in the specificity of the enzyme-linked immunosorbent assay for the catchment of IgM in the 52 samples of the control group or in the other 116 from patients with clinical suspicion of acute viral hepatitis. A sensitivity, specificity and coincidence of 100% was obtained on comparing the filter paper with the dilution 1:500 with the serum. The correlation established between the values of optical density of the positive results to anti-HAV IgM, the filter paper at dilution 1:500 and the serum was of 0.895. On applying this type of sample taking in a group of hospitalized patients, 100% of coindicence with clinical suspicion was attained. Besides, it was proved its usefulness for the diagnosis of a viral hepatitis outbreak. According to our results, it is recommended the introduction of this type of sample taking in the diagnosis of hepatitis A.