Rubella seroprevalence in pregnant women at the military teaching hospital, Rabat, Morocco Bouchra Belefquih a, ⁎, Jalal Kasouati b , Taoufik Doblali a , Nadia Touil a , Mohamed R. Tagajdid a , Hakima Kabbaj c , Hicham El Annaz a , Saad Mrani a a Virology Department, Mohammed V Military Teaching Hospital, Faculty of Medicine and Pharmacy, Mohamed V University, Rabat, Morocco b Epidemiology Department, Mohammed V Military Teaching Hospital, Faculty of Medicine and Pharmacy, Mohamed V University, Rabat, Morocco c Microbiology Department, Rabat Specialities Hospital, Faculty of Medicine and Pharmacy, Mohamed V University, Rabat, Morocco article info Article history: Received 9 April 2012 Received in revised form 22 August 2012 Accepted 26 October 2012 Keywords: Congenital rubella syndrome Morocco Rubella seroprevalence Rubella vaccine Although rubella infection is often mild, it remains a major cause of severe neonatal defects, which are classified as congenital rubella syndrome (CRS) [1]. Although rubella and CRS are not in- cluded in the surveillance system in Morocco, a retrospective as- sessment of the CRS burden in the country estimated its incidence at 8.1–12.7 cases per 100 000 live births [2]. Most rubel- la immunization studies in Morocco were performed before 2003. Therefore, recent epidemiological data are required for health planners. A retrospective cross-sectional study was conducted. All preg- nant women who had undergone rubella serology screening at the virology department of the Mohammed V Military Teaching Hospi- tal, Rabat, Morocco, during a 30-month period between January 1, 2009, and June 30, 2011, were included in the study. The hospital provides services for a region covering approximately 49 000 deliv- eries each year. Data collection was carried out using data records of rubella serology and the clinical data records of pregnant women following provision of verbal consent. Complete clinical data were available from January 2011 onward. Anti-rubella immunoglobulin G (IgG) titers were measured in serum samples using a commercial enzyme-linked immunosor- bent quantitative assay kit (Enzygnost; Siemens, Erlangen, Ger- many) following the manufacturer's guidance. Rubella immune status was considered negative (susceptible) if lower or equal to 10 IU/mL, and positive (immune) if higher than 10 IU/mL. Re- peated tests for the same woman were not considered to evaluate seroprevalence. Statistical analysis was performed using SPSS version 13.0 (IBM, Armonk, USA). The association between seronegative rubella results and sociodemographic characteristics was evaluated using the χ 2 test and Fisher exact test for qualitative variables and the t test for quantitative variables. P b 0.05 was considered statistically significant. A total of 3884 serum samples were sent to the virology de- partment for rubella serology within the study period. A total 2553 of these tests were from 2284 pregnant women. Assuming that prenatal care covers only 46% of pregnant women in Morocco, the study population represents 10% of the medically followed pregnancies in the laboratory catchment area. Descriptive data are shown in Table 1. Of the 2284 pregnant women, 2061 (90.2%) women were immune to rubella infection and 223 (9.8%) were susceptible. There was no evidence of recent infection within the study period. Before 2003, rubella immunization campaigns were organized to target women of childbearing age. The measles, mumps, and rubella (MMR) vaccine has been used increasingly in the private sector in Moroccan cities since 1987; however, up until 2002, only about 5% of the birth cohort had been vaccinated against rubella nationwide (Aventis Pasteur, written communication, 2003). In the public sector, routine immunization of children aged 6 years against rubella was introduced in 2003. To the best of the authors’ knowledge, this is the first rubella seroprevalence study conducted among pregnant women in Mo- rocco since 2003. Indeed, the data collected before 2003 among women of childbearing age showed 66.5%–85.5% seropositivity for anti-rubella virus IgG. Rubella seroprevalence reported in pre- vious international studies ranged between 85.5% and 93% [1,3]. Comparison of seroprevalence levels between studies is difficult owing to the different designs, sampling, timing of studies in rela- tion to previous outbreaks, variability of laboratory procedures, and titer cut-off points used to define positivity of anti-rubella IgG. However, the rubella seroprevalence found in the present population (90.2%) was comparable with the results from other countries with similar vaccination strategies, and was quite high compared with previous Moroccan studies. This may be explained by an increase in the rubella vaccination coverage in the country. However, since the present study was conducted ret- rospectively among pregnant women, the results should be interpreted with caution and may not be generalized to the whole population. In data from some countries, rubella seropositivity seems to in- crease with age [4]. However, in other studies, such as the present study, no significant differences between age groups were reported [4]. This is probably owing to the early exposure of children and ado- lescents to rubella infection; in adulthood, the seropositivity rate seems to stabilize. Settlement, education level, and self-reported vaccine history did not influence rubella seroprevalence in the present study, as reported elsewhere [2]. This may reflect low levels of knowledge about rubella, signaling that more health education campaigns and screening for women of childbearing age are needed. The present study also revealed that 78.4% (29/37) of pregnant women who were seronegative in their first pregnancy were not immunized against rubella. The WHO recommends that such women must be vaccinated before discharge from hospital in order to achieve 100% seroprevalence [1]. However, even in ⁎ Corresponding author at: Villa 52, lotissement El Hanae, Rue Ouled Mesbah, Nahda 2, Rabat, Morocco. Tel.: +212 6 60 15 63 71. E-mail address: bbelefquih@yahoo.fr (B. Belefquih). 191 BRIEF COMMUNICATIONS