[Efficiency of prevaccination screening of anti-HBc in the anti-hepatitis B vaccination programs]

Background: The convenience of carrying out pre-vaccination screening of VHB markers depends on the relative costs of screening and vaccination and also on the prevalence of susceptible subjects in each group of the population. The aim of the present work was to analyse the efficiency of pre-vaccination screening of antiHBc in Catalonia in 1991.
Methods: The per-unit cost of screening was calculated at 1366 ptas. The formula applied was: cost per-unit of screening + (1-X) x the cost per-unit of vaccination of anti-HBc (-) = cost of vaccinating the group. “X” being the threshold of prevalence of markers below which screening cases to be efficient. This prevalence is compared with those expected in the groups of the population to be vaccinated.
Results: By applying the above-mention ned formula and taking into account costs in time and travel of the people to be vaccinated, a prevalence threshold of 23% is obtained. This prevalence is much higher than that found in adolescents and students of medicine and nursing, similar to that found in health professionals and lower than that of other risk groups.
Conclusions: Systematic screening of anti-HBc is only recommended in groups of the population where a prevalence higher than 20-25% can be expected. Below this threshold vaccination without previous study of markers is more efficient. This enormously simplifies the strategies of universal vaccination of children, adolescents or both.