Evaluation of anti-varicella antibody in young women before their marriage: A sero-epidemiologic study in Iran.

BACKGROUND: Chickenpox during pregnancy can cause severe complications in both the mother and her baby. However, no complications will occur in a mother with proper immunity. Therefore, physicians and health systems can make better decisions when they know the immunologic status of the women in a community.

OBJECTIVES: We conducted this study to clarify the Varicella zoster virus (VZV) immune status of engaged women in Iran.

STUDY DESIGN: This cross-sectional descriptive study was carried out on 334 young women who intended to marry between 2006 and 2008. The subjects' VZV-immunoglobulin G (IgG) and demographic characteristics were evaluated.

RESULTS: The mean age of the subjects was 20.5+/-4.9 years and their mean anti-varicella value was 86.22+/-71.05 U ml(-1). Of 333 young women studied, 242 (72.7%) were positive, 89 (26.7%) were negative for anti-varicella antibody and two were equivocal (0.6%). The rate of immunity increased with increasing age; all of the subjects over 35 years of age were immune to varicella. The positive predictive value (PPV) for self-reported history of chickenpox in subjects was estimated to be 79.5% and the negative predictive value (NPV) of a negative or uncertain disease history was 30.5%. A higher immune ratio was seen in women with more siblings.

CONCLUSIONS: The difference in the proportion of VZV-immune people in our country versus developed countries may be due to the introduction of varicella vaccine in developed nations. The mean age at first pregnancy in Iran is 25.7 years and the results of our study indicate that more than one-fourth of these women are not immune to varicella. We therefore recommend vaccination in women, especially those who are under 35 years of age. Number of siblings and positive history of varicella infection may be the indicators to determine the immunity level of a pregnant woman who has had contact with a patient with chickenpox.