Determinação do AgHBs na grávida. Estudo epidemiológico de 1000 casos.

Resumo

There are some arguments concerning prenatal Hepatitis B testing: universal screening versus testing of risk groups. A thousand parturients were evaluated in order to assess the sensitivity of risk factors in the identification of Hepatitis B surface antigen (HBsAg) positive women. To achieve that purpose they were questioned regarding risk factors and blood samples were collected for HBsAg testing. Thirty two HBsAg positive parturients were identified. A larger number of HBsAg positive was found amongst women included in the class 5 of the Graffard scale (p = 0.005), or referring contact with patients with hepatitis (p = 0.01). These risk factors identified no more than 17 of the 32 positive mothers (sensitivity = 53%). None of the other risk factors proved significant. The entire questionnaire allows a sensitivity of 87.5% but presents a specificity of 22.5%. In this population, risk factors are not a good method of screening HBsAg positive women. A universal screening must be undertaken in order to prevent vertical transmission of the virus and to detect families in risk.