Baseline sero-survey of rubella virus prevalence in pregnant women in Harare and incidence of rubella in Zimbabwe during 2009-2011 measles outbreak.

Abstract

Rubella virus is a teratogen that may induce foetal death or Congenital Rubella Syndrome (CRS) in the newborn. A baseline sero-survey was carried out in Harare to determine the population susceptible to Rubella virus amongst pregnant women. A descriptive cross- sectional study was carried out on pregnant women between June and July 2012, to establish baseline data on the sero-prevalence of Rubella in pregnant women in Harare. A total of 51 pregnant women at various gestational ages were recruited from Rujeko and Rutsanana antenatal clinics. Also a retrospective analytical study was carried on the laboratory surveillance data of the Zimbabwean Measles/Rubella outbreak of 2009-2011 to assses the age groups affected by Rubella virus infection and Rubella incidence. A 3-5ml blood sample was collected from each consenting subject and serum assayed for Rubella IgG/IgM antibodies by indirect ELISA test. The seroprevalence of Rubella in pregnant women was 92.2%. This study found out that 7.8% of the pregnant women were susceptible to Rubella virus infection in Harare. In this study the seroprevalence of Rubella showed some fluctuations with an increase in age and parity, thus indicating that pregnant women were probably previously exposed to natural Rubella infection since there is no vaccination in Zimbabwe. There were no significant correlations between Rubella infection and age. Although the seronegative rate of Rubella is low, this study suggests the need for detection and vaccination of seronegative women of child bearing age. I concluded that Rubella virus immunity is still ˃80% in Zimbabwe as stated by the WHO Rubella virus antibody survey.