Evaluation of the anti-rubella immunity levels on a lot of 5,000 sera from women at procreative age, tested by HAI, in Romania.

From the study performed on a lot of 5030 sera, prelevated from women between 15-40 years old, tested by hemagglutination inhibition reaction (HAI), divided in 5 age groups of 5 years each, resulted that the percentage of women that can be considered immunologically protected against rubella (with HAI antibody titers greater than or equal to 1/20) varied between 79.5% (15-20 years of age group), and 75.3% (31-35 years of age group). The average percentage for the total lot was 76.7. The geometrical means (MGx/divided by SG) of the individual HAI titers ranged between extreme values of 54.2 (x/divided by 4.1) for the Group I, and 40.7 (x/divided by 3.8) for the Group IV, presenting the value of 44.4 (x/divided by 3.9) for the total lot. The covering coefficients of the protection limit, estimated at the level of geometrical means of antibody titers, ranged between 2.7 and 2.0, according to the age group, while the estimations made at the levels of the limits of the statistical range of one geometric standard deviation (MG x/divided by SG), presented values comprised between 11-8 and 0.7-0.5, respectively. On the basis of some theoretical mathematical models proposed in the literature (and using data resulted from the study performed), an attempt was made to approximate the rate of fetal exposure as well as the presumptive risk of congenital rubella syndrome (to 0/0000 live-born).