Global seroprevalence of rubella among pregnant and childbearing age women: a meta-analysis

Successful Elimination of Endemic Rubella in the WHO European Region. Is It Proper to Remove the Recommendation for Preconceptional Immunization?

BACKGROUND

Rubella is a contagious viral infection that has garnered significant attention in the field of public health due to its potential consequences, especially during pregnancy. In recent decades, it has been recommended that non-immune women receive immunization during the preconceptional and/or postpartum periods. The goal of this strategy is to prevent primary rubella infection in order to protect pregnant women against congenital rubella syndrome. In November 2022, the WHO's Regional Verification Commission declared the elimination of rubella infection in Italy. In recent years, the main migration flows to Italy have originated from regions where rubella has not yet been eliminated and where no program is in place to achieve this goal.

OBJECTIVE

The aim of this study was to retrospectively assess rubella immunity in pregnant women who have attended three delivery centers in Rome over the past three years, from January 2021 to May 2023.

METHODS

Data about the rubella serological status of 7937 non-consecutive pregnant women were collected. Univariate analysis was performed to verify any difference between the study groups in terms of age distribution.

RESULTS

Anti-rubella IgG antibodies were found in 7224 (91%) women while 713 (9%) were susceptible to rubella (IgG negative), without differences in terms of immunity rate between Italian and non-Italian women. Age analysis showed a statistically significant older age of immune women than receptive women and of Italian immune women than non-Italian immune women.

CONCLUSIONS

The National Plan for the Elimination of Measles and Congenital Rubella aimed to achieve a percentage of susceptible women of childbearing age below 5%. These data indicate the relevance of maintaining the recommendation for preconceptional rubella vaccination in Italy.

Screening for TORCH Antibodies in Croatian Childbearing-Aged Women, 2014-2023

TORCH infections usually result in mild maternal morbidity, but may cause severe congenital abnormalities. Therefore, it is important to detect maternal infections, monitor the fetus after the disease has been recognized, and define the seronegative women who are at risk of primary infection during pregnancy. From 2014 to 2023, serum samples from 1032 childbearing-aged and pregnant women (16-45 years) were tested for IgM/IgG antibodies to the most common TORCH pathogens: Toxoplasma gondii, rubella virus (RUBV), cytomegalovirus (CMV), and herpes simplex viruses (HSV-1 and HSV-2). The overall IgG seroprevalence rates were 20.1% for T. gondii, 91.3% for RUBV, 70.5% for CMV, 66.8% for HSV-1, and 3.5% for HSV-2. Only HSV-2 seroprevalence was age-related, with a significant progressive increase in seropositivity from 0% in those aged less than 26 years to 9.3% in those older than 40 years. The seroprevalence of T. gondii was higher in residents of suburban/rural areas than in residents of urban areas (27.4% vs. 17.1%). In addition, participants from continental regions were more often toxoplasma-seropositive than those from coastal regions (22.2% vs. 15.3%). HSV-1 seroprevalence was also higher in suburban/rural areas (71.7% vs. 64.7%). Obstetric history was not associated with TORCH seropositivity. Univariate and multivariate risk analysis showed that suburban/rural areas of residence and continental geographic regions were significant risk factors for T. gondii seroprevalence. Furthermore, suburban/rural area of residence was a significant risk factor for HSV-1 seroprevalence, while older age was a significant risk factor for HSV-2 seroprevalence. A declining trend in the seroprevalence of all TORCH pathogens was observed compared to previous Croatian studies (2005-2011). Similarly, the proportion of women simultaneously IgG-seropositive to two or three pathogens decreased over time. The maternal serology before pregnancy could potentially reduce the burden of congenital TORCH infections.

Rubella seroprevalence among pregnant women in the region of Rabat, Morocco: a cross-sectional study

OBJECTIVES

The aim of the present research is to update data on the seroprevalence of rubella and to identify the associated risk factors among pregnant women in the Rabat region of Morocco in order to take immediate action to monitor the virus.

DESIGN

A cross-sectional study.

SETTING

The study was conducted at Ibn Sina University Hospital and at referral healthcare centres in the region of Rabat.

PARTICIPANTS

A total of 502 pregnant women (mean age 29.7±6.3 years, range 17-44 years) attending the maternity department during 8 months were selected for serological testing.

OUTCOME MEASURES

A structured questionnaire was used to obtain sociodemographic, reproductive and clinical characteristics after obtaining written informed consent. Venous blood samples were collected to determine rubella-specific IgG antibodies using an automated chemiluminescent microparticle immunoassay (ARCHITECT i1000SR and i2000SR, Abbott Diagnostics).

RESULTS

Antirubella IgG antibodies (≥10 IU/mL) were found in 408 (85.9%) pregnant women examined. The rate of susceptibility to rubella virus infection among pregnant women was found to be 14.1%. These protective rates were found to differ significantly between uneducated pregnant women (80.9%) and those with university-level education (95.5%) (p=0.02). Pregnant women in the 17-24, 25-34 and 35-44 years age groups accounted for 92.5%, 85.2% and 82.8%, respectively (p=0.015). Also, IgG seropositivity status was found to differ significantly between multiparous (83.3%) and primiparous (92.5%) pregnant women (p=0.01). None of the other characteristics was significantly associated with rubella infections.

CONCLUSION

Vaccination programmes need to be updated to ensure that campaigns reach their specified goals. Thus, implementing an effective, large-scale screening programme for congenital rubella infection in different regions of Morocco is highly recommended. On the other hand, seronegative pregnant women should be given special preventive care and health education about rubella transmission and congenital rubella syndrome sequelae.

Rubella virus IgM and IgG antibodies with avidity in pregnant women and outcomes at a tertiary facility in Ghana

BACKGROUND

Congenital rubella syndrome (CRS) is a recognised cause of childhood deafness and blindness caused by the transplacental transmission of rubella virus during pregnancy. Women in the reproductive age group, and by extension their unborn babies may therefore be at increased risk. The prevalence of Rubella virus specific IgM and IgG antibodies, including IgG avidity, was determined in pregnant women attending the antenatal clinic at a Teaching Hospital in Ghana.

METHODS

One hundred and forty-five women in their second and third trimesters of pregnancy from the outpatient clinic were recruited over a period of 2 months after written informed consent was obtained. Study participants completed a questionnaire and venous blood drawn for IgM, IgG, and avidity testing using SERION ELISA (SERION® Immunologics, Würzburg, Germany). Babies of mothers with positive or indeterminate IgM and low avidity IgG antibodies were offered specialist cardiological, ophthalmological or hearing assessment during follow up.

RESULTS

One hundred and twenty-eight (88.3%) had only IgG antibodies, 5 (3.4%) had IgM and IgG antibodies, while 12 (8.3%) had no antibodies. No patient had IgM antibodies alone. Ten women (6.9%) had indeterminate levels of IgM antibodies. Majority of the women had high avidity IgG antibodies, while 5 (3.4%) had low avidity antibodies. No patient had IgM with low avidity antibodies. There was no statistical association between socio-demographic factors and the presence of IgM, IgG (low or high avidity) antibodies. Of all the children followed, none had the clinical definition of CRS.

CONCLUSIONS

Consistent with the World Health Organization elimination strategy for measles and rubella viruses, non-immune women in the reproductive age group should be vaccinated. The immunization programme should be expanded to include teenagers and adults. Though Congenital Rubella Syndrome was not detected, the risk still remains.

Reduction in Rubella Virus Active Cases among Children and Adolescents after Rubella Vaccine Implementation in Tanzania: A Call for Sustained High Vaccination Coverage

Rubella virus (RV) infection in susceptible women during the first trimester of pregnancy is associated with congenital Rubella syndrome (CRS). In countries where a vaccination program is implemented, active case surveillance is emphasized. This report documents the magnitude of active cases before and after vaccine implementation in Tanzania. A total of 8750 children and adolescents with signs and symptoms of RV infection were tested for Rubella IgM antibodies between 2013 and 2019 using enzyme immunoassay followed by descriptive analysis. The median age of participants was 3.8 (IQR: 2−6.4) years. About half (4867; 55.6%) of the participants were aged 1−5 years. The prevalence of RV active cases was 534 (32.6%, 95% CI: 30.2−34.9) and 219 (3.2%, 95% CI: 2.7−3.6) before and after vaccine implementation, respectively. Before vaccination, the highest prevalence was recorded in Pemba (78.6%) and the lowest was reported in Geita (15.6%), whereas, after vaccination, the prevalence ranged between 0.5% in Iringa and 6.5% in Pemba. Overall, >50% of the regions had a >90% reduction in active cases. The significant reduction in active cases after vaccine implementation in Tanzania underscores the need to sustain high vaccination coverage to prevent active infections and eventually eliminate CRS, which is the main goal of Rubella vaccine implementation.

Susceptibility to Rubella Infection and Incidence of Congenital Rubella Infection: 6 Years Retrospective Study

Introduction

Rubella is considered one of the most serious and most common congenital infections. Despite global efforts for elimination, rubella cases are still being reported in many parts of the world. The purpose of this study is to determine the level of immunity to rubella in the community and most importantly among women at childbearing age in the eastern province of Saudi Arabia and compare it with the target set by the World Health Organization (WHO) along with the incidence of acute rubella infection and the associated congenital rubella infection and congenital rubella syndrome.

Methods

This is a retrospective cross-sectional study over the six years period (Jan 2014–Jun 2020) on all individuals tested for rubella IgM and IgG in a university teaching hospital.

Results

Nighty one percent (15,894/17,469) of the population tested showed evidence of rubella immunity with 8.8% (1546/17,469) being susceptible. Among women at childbearing age, susceptibility to rubella was higher with 9.2% (1220/13,278) of women showing no evidence of immunity. In addition, acute rubella infection was reported for 0.17% (29/17,469) of the population tested and 0.15% (20/13,278) in women at childbearing age. No cases of congenital rubella infection were reported in the study period.

Discussion

The level of Rubella immunity in the population is 91% and is less than the WHO target for rubella control therefore, risk of resurge of cases is present, indicating the need for continued national surveillance and more efforts to improve vaccination coverage in the kingdom.

Prevalence of Rubella Antibodies among Fertile Women in the West of Romania, 18 Years after the Implementation of Immunization

Seronegative women are susceptible to primary rubella virus (RV) infection during pregnancy, which can cause fetal damage. Vaccination represents the main strategy in rubella prevention. The aim of this study was to analyze changes in the rubella seroprevalence and identify populations with a high susceptibility to RV. A cross-sectional study was performed on 6914 Caucasian fertile women who had Toxoplasma gondii, other viruses, Rubella, Cytomegalovirus, and the herpes simplex virus (TORCH) screening in two distinct periods-1452 at the Timișoara Municipal Hospital, Romania (Group 1: 2008-2010) and 5462 at the laboratory Bioclinica S.A., Timișoara, Romania (Group 2: 2015-2018). The RV seroprevalence decreased (Group 1 versus Group 2; 94.1% (92.7-95.2) versus 91.4% (90.6-92.1), OR = 0.76 (p = 0.0007)). According to the year of birth and eligibility to vaccination program, RV seroprevalence rates were 82.4% (76.8-86.8)/1997-2004, 85.4% (80.5-89.3)/1995-1996, 90.1% (89.0-91.1)/<1989, and 95.8% (94.7-96.6)/1989-1994. No significant difference in the RV seropositivity according to the place of residence was found. The overall RV susceptibility increased from 2008-2010 to 2015-2018. The highest susceptibility was found in women born between 1997-2004 eligible for measles-mumps-rubella (MMR) vaccine through the family practice system and the lowest in women born between 1989-1994 eligible for monovalent rubella vaccine conducted in schools.

Factors Predicting Rubella Vaccination among Pregnant Women in Japan: an Interim Report from the Pregnant Women Health Initiative

Following the 2018 rubella outbreak in Japan, this study aimed to assess rubella prevention measures based on the vaccination and immunization status of pregnant women in Japan. Our cohort study involved 3 local core hospitals in Yokohama City, and a total of 666 pregnant women were recruited between June 2018 and September 2019 and answered an online questionnaire. In total, 67.5% of the pregnant women had received rubella vaccination. The rate of rubella vaccination among pregnant women in the present survey was lower than that among age-matched female participants in a nationwide survey conducted in 2018. Overall, the study results showed that pregnant women in their 20s had a higher vaccination rate than those in their 40s, women who were nonsmokers before pregnancy had a higher vaccination rate than those who were smokers, and pregnant women who were aware that rubella may affect their fetuses had a higher vaccination rate than those who were unaware of this. This survey elucidated multiple predictive factors for rubella vaccination among pregnant women in Japan. Our results confirm the recommendation that women considering pregnancy should be vaccinated against rubella.

Sero-prevalence of rubella among pregnant women in Sub-Saharan Africa: a meta-analysis

Background: Rubella continues to be a leading cause of vaccine-preventable congenital birth defects and permanent organ damage, especially in developing countries. For women who are infected with the rubella virus (RV) before conception or during the first trimester of pregnancy, the unborn child has up to a 90% probability of developing congenital rubella syndrome. There are limited data on the seroprevalence of the rubella virus among pregnant women in Sub-Saharan Africa. Therefore, the aim of this study was done to determine the pooled seroprevalence of rubella among pregnant women in Sub-Saharan Africa. Methods: The PRISMA guidelines protocol was followed to write the systematic review and meta-analysis. Published studies were searched in Medline, PubMed, Google scholar, advance google and Cochrane Library. The search terms on the databases are: "rubella"OR "rubeo*", "rubella"AND"seroepidemiology", "seroprevalen *" OR "prevalen*", "seroprevalen *" OR "seroimmun*", "rubella antibod*"AND "pregnan*", "seroprevalen *" AND "sub-Saharan Africa".The heterogeneity of studies was weighed using Cochran's Q test and I² test statistics. Publication bias was assessed by using Egger's and Begg's test. Results: Twenty-eight studies were included in this meta-analysis. The pooled seroprevalence of anti-RV IgG among pregnant women in Sub-Saharan African was 89.0% (95%CI: 84.6-92.3), and the pooled prevalence of anti-RV IgM among pregnant women in Sub-Saharan Africa was 5.1% (95%CI: 2.6-9.9). Conclusion: This meta-analysis showed that seronegativity and acute infection with RV among pregnant women in sub-Saharan Africa is high compared to other studies and the WHO threshold among women of child-bearing age. This finding calls for primary health care providers to make the community aware of this rubella-susceptible group and its healthcare burden, with the desired outcome that sub-Saharan Africa countries would introduce an implementation strategy for rubella vaccination of pregnant women and women of child-bearing age.

Recent trends in seroprevalence of rubella in Korean women of childbearing age: a cross-sectional study

OBJECTIVES

The aim of this study was to investigate the immunity against rubella using the serological status of rubella-specific IgG antibodies (antirubella IgG) in Korean women of childbearing age (15-49 years).

DESIGN

Retrospective cross-sectional study.

SETTING

Population-based cross-sectional study in South Korea.

PARTICIPANTS

Between January 2010 and December 2017, test results from Korean women aged 15-49 years who had visited an obstetric private clinic (nationwide institutions) and had requested rubella-specific IgG antibody tests from Green Cross Laboratories were obtained from the laboratory information system.

RESULTS

Between 2010 and 2017, antirubella IgG test results from 328 426 Korean women aged 15-49 years who had visited private obstetric clinics (1438 institutions nationwide) were retrospectively analysed by tested year, age, cohort and geographic regions. Over the 8-year study period, the rate of unimmunised women ranged from 7.8% to 9.7%. Multivariable-adjusted logistic regression models showed that the odds of being immune to rubella (positive and equivocal results of antirubella IgG test) were lower in 2017 compared with 2010, in women in their 40s, in a pre-catch-up cohort and in women living in Incheon, Busan, South Gyeongsang, North and South Jeolla and Jeju provinces (p<0.0001).

CONCLUSIONS

In consideration of the factors associated with prevalence of women unimmunised to rubella, future public health efforts should be focused on catch-up activities. The results of this study could be used to strengthen disease control and prevent rubella, including a nationwide immunisation programme.

Rubella seroprevalence in pregnant women living with and without HIV in Soweto, South Africa

OBJECTIVES

Rubella infection during pregnancy may cause foetal death or congenital rubella syndrome. In South Africa, the national public immunization programme does not include rubella vaccination. The aim of this study was to evaluate rubella sero-epidemiology in pregnant South African women living with and without HIV.

METHODS

Serum samples obtained from women living with HIV (n=552) and without HIV (n=552) were tested for rubella immunoglobulin G antibodies using an ELISA. The proportions of women with seronegative titres (<8IU/ml) and seropositive titres (≥11IU/ml), and geometric mean titres (GMT) were compared by age group and HIV status.

RESULTS

The overall proportion of rubella seropositivity was 97.8%. The proportion of seropositive women increased with age group (18-25 years: 97.0%; 26-32 years: 97.7%; 33-40 years: 99.3%; p=0.047 after adjusting for HIV status). Similar proportions of women living with and without HIV were seropositive.

CONCLUSIONS

Rubella immunity was high among South African pregnant women living with and without HIV in the absence of rubella vaccination in the public immunization programme. However, a lower percentage of younger women had seropositive titres, indicating the need for routine rubella vaccination after an increase in vaccine coverage rates.

High rate of rubella seronegativity in perinatally-infected HIV women of childbearing age: A case-control study

Rubella infection is a vaccine preventable disease. Maternal infection during pregnancy may lead to congenital infection and severe foetal malformations. Thanks to antiretroviral therapy, perinatally HIV-infected women have better prognosis and are now experiencing pregnancy. We evaluated the rate of rubella seronegativity in a cohort of HIV perinatally-infected women of childbearing age. A high rate of seronegativity was found in this group as compared to age-matched non-perinatally infected HIV-infected women (34.5% vs 6.90%, p < 0.01). MMR administration before rubella testing was identified in 75.8% of perinatally-infected women (22/29) with a mean of 2 doses (range: 1-3 doses). HIV perinatally-infected women of childbearing age should be screened repeatedly for rubella immunity.

Rubella serosurvey and factors related to vaccine hesitancy in childbearing women in Italy

Voluntary termination of pregnancy (VTP), pre-conception and post-partum phases, as well as Occupational Medicine consultation for healthcare workers are opportunities for screening and vaccinating rubella seronegative childbearing women. However, data about vaccination acceptance following these phases is rarely reported. A retrospective study over a 2-year period (2016-2017) was performed, evaluating the prevalence of rubella seronegative women which underwent VTP (wVTP), mothers in early puerperal phase (mEPP) and childbearing healthcare workers (CbHW) aged 15-49 years. Anti-rubella vaccination rates and factors associated with vaccine hesitancy (VH) were investigated. Anti-rubella IgG titres were assessed in 8623 women. Seroprevalence of rubella susceptibility was 7.9% (wVTP 6.4%; mEPP 17.4%; CbHW 9.3%). Anti-rubella vaccination rates were found to be different in the three groups (wVTP 37.1%; mEPP 10.9%; CbHW 25.4%), specifically in 2016 and among women born in Italy. VH rate was higher in 2017, especially among wVTP and CbHW. Anti-rubella vaccination rates in wVTP vs. mEPP was higher in women born in Italy but not in those born abroad. Multivariable analyses demonstrated significantly higher risk of VH for mEPP (OR 8.2; 95% CI: 3.9-16.9) and women reporting history of allergy to drugs, food or environmental agents (OR 2.7; 95% CI: 1.4-5.1). During the analyzed period childbearing women included in this study were not adequately protected against rubella. Anti-rubella vaccination rates were widely unsatisfactory. Being mEPP and reporting allergy were significantly associated to higher rates of VH. Tailored strategies targeting on vaccine safety are needed for retention of these women in immunisation programmes.

Seroprevalence data at a private teaching hospital in Kenya: An examination of Toxoplasma gondii, cytomegalovirus, rubella, hepatitis A, and Entamoeba histolytica

Background

Relevant seroprevalence data for endemic pathogens in a given region provide insight not only into a population’s susceptibility to acute infection or risk for reactivation disease but also into the potential need for policy initiatives aimed at reducing these risks. Data from sub-Saharan Africa are sparse and since Aga Khan University Hospital Nairobi is an internationally accredited hospital equipped with a laboratory electronic medical record system, analysis of pertinent local seroprevalence data has been made possible.

Methods

We have analyzed serology data from laboratory electronic records at a 300 bed tertiary private teaching hospital in Kenya for the dates, 2008 to 2017 for Toxoplasma gondii, cytomegalovirus, and rubella, which were used primarily for antenatal screening. We also analyzed the data from hepatitis A and amebiasis serologies, which were used primarily for diagnostic purposes.

Results

For T. gondii, cytomegalovirus, and rubella, we used IgG serology to determine seroprevalence, finding rates of 32%, 86%, and 89%, respectively. There was no significant age-related difference in the 20 to 49 year old age range for any of these three pathogens. Of the Hepatitis A IgM tests that were ordered, 33% were positive with a peak positive rate of 70% in the five to nine year old age range. The seroprevalence of amebiasis was 4% and all cases of seropositivity were accompanied by compatible clinical illness (hepatic abscess).

Conclusions

These data provide insight into seroprevalence rates of selected pathogens that can be used to guide screening and diagnostic laboratory testing as well as private and public immunization practices.

Surveillance of microcephaly and selected brain anomalies in Argentina: Relationship with Zika virus and other congenital infections

BACKGROUND

Zika virus (ZIKV) vertical transmission may lead to microcephaly and other congenital anomalies. In March and April 2016, the first outbreak of ZIKV occurred in Argentina. The objective was to describe the surveillance of newborns with microcephaly and other selected brain anomalies in Argentina, and evaluation different etiologies.

METHODS

Participants were enrolled between April 2016 and March 2017.

CASES

newborns from the National Network of Congenital Abnormalities of Argentina (RENAC) with head circumference lower than the 3rd percentile according to gestational age and sex, or selected brain anomalies. Blood and urine samples from cases and their mothers were tested for ZIKV by real-time polymerase chain reaction (RT-PCR), antigen-specific Immunoglobulin M (MAC-ELISA) and plaque-reduction neutralization test (PRNT₉₀ ). Toxoplasmosis, rubella, herpes simplex, syphilis, and cytomegalovirus (CMV) infection were also tested.

RESULTS

A total of 104 cases were reported, with a prevalence of 6.9 per 10,000 [95% confidence interval (CI): 5.7-8.4], a significant increase when compared with the data prior to 2016, Prevalence Rate Ratio 1.7 (95% CI 1.2-2.3). In five cases positive serology for ZIKV (IgM and IgG by PRNT) was detected. The five cases presented microcephaly with craniofacial disproportion. We detected four cases of CMV infection, three cases of congenital toxoplasmosis, two cases of herpes simplex infection, and one case of congenital syphilis.

CONCLUSION

The prevalence of microcephaly was significantly higher when compared with the previous period. The system had the capacity to detect five cases with congenital ZIKV syndrome in a country with limited viral circulation.

Infectious causes of microcephaly: epidemiology, pathogenesis, diagnosis, and management

Microcephaly is an important sign of neurological malformation and a predictor of future disability. The 2015-16 outbreak of Zika virus and congenital Zika infection brought the world's attention to links between Zika infection and microcephaly. However, Zika virus is only one of the infectious causes of microcephaly and, although the contexts in which they occur vary greatly, all are of concern. In this Review, we summarise important aspects of major congenital infections that can cause microcephaly, and describe the epidemiology, transmission, clinical features, pathogenesis, management, and long-term consequences of these infections. We include infections that cause substantial impairment: cytomegalovirus, herpes simplex virus, rubella virus, Toxoplasma gondii, and Zika virus. We highlight potential issues with classification of microcephaly and show how some infants affected by congenital infection might be missed or incorrectly diagnosed. Although Zika virus has brought the attention of the world to the problem of microcephaly, prevention of all infectious causes of microcephaly and appropriately managing its consequences remain important global public health priorities.

Sociodemographic and economic characteristics of susceptibility to rubella among women preparing for pregnancy in rural China

OBJECTIVES

Infection with rubella virus during pregnancy can result in congenital defects and adverse pregnancy outcomes. The risk of rubella infection is greatly determined by the level of rubella antibodies in the serum. A survey of rubella antibody seronegativity rates was conducted in 780 000 women in rural China who were planning a pregnancy, in order to evaluate the herd susceptibility in different age groups and by high, middle, and low GDP per capita regions.

METHODS

In order to evaluate the herd susceptibility to rubella, a nationwide population-based study of rural Chinese women who were planning to have a baby and who were aged 21-49 years was instigated. As a part of the National Free Pre-conception Health Examination Project covering 29 provinces in 2012, a physical check-up program was provided to women who planned to become pregnant within the next 6 months. All medical data were from serological samples tested by ELISA, and the participants' immunity status was categorized based on levels of rubella antibodies. Economic data were also collected to explore the association between herd susceptibility and socioeconomic characteristics in the women of childbearing age.

RESULTS

A total 264 306 of 782 293 recruited women preparing for pregnancy tested susceptible to rubella (33.79%). The seronegativity rate in women with a history of vaccination was significantly lower than that in women who had not received the vaccination or did not know their vaccination history (23.76%, 33.70%, and 35.68%, respectively). The seronegativity rates were 26.89%, 37.86%, and 32.61% in high, middle, and low GDP per capita areas, respectively. After stratified analysis and adjusting for other factors by multiple logistic regression, the lower seronegativity rates in women in high GDP per capita regions compared to women in middle and low GDP per capita regions remained in the different age groups and subgroups of immunization history.

CONCLUSIONS

There is a clear difference in rubella-specific susceptibility among rural women preparing for pregnancy of different sociodemographic and economic backgrounds. The number of rubella-susceptible rural women preparing for pregnancy, especially in relatively low GDP per capita regions in China, was high. Offering rubella vaccination to women who are rubella-susceptible and who plan to become pregnant should become one of the priorities in the field of public health work in China.