[Strategies for the prevention of congenital rubella]

Screening for rubella in the beginning of pregnancy includes at least one assay for rubella antibodies. If a significant level of antibodies is found, two strategies are possible: 1) to consider the patient as protected if there is no other sign of rubella, or 2) to assess the date of the infection in all cases, repeating the serological tests. In this paper we study the cost of this second strategy. Using a theoretical model of the rubella infection we calculated that the incidence of congenital rubella would be 9 cases in 10 000 newborns in populations with 10% of susceptible women at the age of 25. We studied the cost-effectiveness of a screening strategy including a second assay for rubella antibodies (inhibition of hemagglutination) after a positive one. This strategy is 10% more sensitive than a single test. Nevertheless, the cost of one case of congenital rubella prevented by this strategy is 13.3 higher than the cost of a case prevented by a strategy including the vaccination of boys and girls at the age of 2 years and of girls at the age of 12. Thus, the vaccination strategy is a priority for rubella prevention while the multiplication of the screening test is not a priority.