Rubella seropositivity in the United States, 1988-1994

Prevalence of preconception TORCH infections and its influential factors: evidence from over 2 million women with fertility desire in southern China

BACKGROUND

TORCH (Toxoplasma gondii [TOX], Cytomegalovirus [CMV], Rubella virus [RV], and Herpes simplex virus [HSV]) represents pathogens known to traverse the maternal-fetal barrier and cause severe neonatal anomalies. We aimed to assess the prevalence of preconception TOX, CMV, and RV infections among women with fertility desire in southern China, and identify related risk factors.

METHODS

Data were obtained from a population-based cross-sectional study conducted as part of the National Free Preconception Health Examination Project. Women planning to conceive within the next 6 months in Guangdong Province were enrolled between 2014 and 2019. Information on sociodemographic, gynecological, and obstetric characteristics was collected. Sera were analyzed for TOX IgG, CMV IgG, and RV IgG antibodies using an enzyme-linked immunosorbent assay. Descriptive, univariate, and multivariate logistic regression analyses were performed to assess the association between TORCH infections and related factors.

RESULTS

Among 2,409,137 participants, the prevalence of IgG antibodies for TOX, CMV, and RV was 3.20% (95% CI: 3.18-3.22%), 77.67% (95% CI: 77.62-77.71%) and 76.03% (95% CI: 75.98-76.07%), respectively. Of all participants, 141,047 women (5.85%, 95% CI:5.83-5.88%) reported a history of immunization for RV. Women living in the Pearl River Delta, a more developed region, have significantly lower vaccination rates than those living in other regions. The seropositivity of TOX IgG was highest among women aged 35 years and above, with primary or lower education levels, and rural registration. Factors such as being older, having a higher educational level, and being of other ethnicities were associated with a higher prevalence of naturally acquired CMV and RV infections. Women living in the Pearl River Delta showed a higher risk of TOX, CMV, and RV infections, with aORs of 2.21, 4.45, and 1.76, respectively. A history of pregnancy, gynecological diseases, and sexually transmitted infections were potentially associated with TORCH infections, but this association varied across pathogens.

CONCLUSION

The findings of this study update the baseline of preconception TORCH infections among women with fertility desire in southern China, helping to estimate the risk of congenital infection and guide the development and implementation of effective prevention measures for preconception TORCH infections.

Socioeconomic Status Is Associated With Antibody Levels Against Vaccine Preventable Diseases in the Netherlands

Background: We investigated whether low socioeconomic status (SES), which is associated with reduced health and life expectancy, might play a role in increased risk for infectious diseases. Therefore, we explored the association between SES and immunoglobulin G (IgG) levels against various pathogens.

Methods: We analyzed the association between SES [educational level and net household income (NHI)] and serum IgG concentration against measles, mumps, rubella, varicella, Haemophilus influenzae type B (HiB), pneumococcus, meningococcus serogroup C (MenC), and cytomegalovirus (CMV) collected within a national cross-sectional serosurvey (2006/2007) using linear regression analyses among non-vaccinated individuals.

Results: Higher educational level was associated with higher IgG concentrations against measles (GMC ratio 1.34, 95% CI 1.18–1.53) and rubella (1.13, 1.02–1.25) compared to low education level. In contrast, higher education level was associated with lower IgG concentrations against pneumococcus (0.78, 0.70–0.88), MenC (0.54, 0.44–0.68), and CMV (0.23, 0.18–0.31) compared to low education level. This pattern was also evident when NHI was used as SES indicator.

Conclusion: Our study suggests that socioeconomic status is associated with antibody levels in a pathogen-dependent manner. The results suggest that differences in serological response upon infection or differences in exposure might be involved in the variation in IgG levels between SES groups.

Lack of immunity against rubella among Italian young adults

BACKGROUND

To support the evaluation of the 2010-15 National Plan for Measles and Congenital Rubella Elimination, the authors designed and performed a serosurveillance survey to verify the immunity/susceptibility rate against rubella among Apulian young adults.

METHODS

The study was carried out from May 2011 to June 2012 in the Department of Transfusion Medicine/Blood Bank of Policlinico General Hospital in Bari. Subjects were enrolled by a convenience sampling. For each enrolled patient a 5 ml serum sample was collected and tested for anti-rubella IgG. The geometrical means (GMT) of anti-rubella IgG was calculated. T student test or ANOVA test, when appropriate, was used to compare the means of age per gender and GMT of anti-rubella IgG titres per age classes. Chi-square test was used to compare the proportion of anti-rubella IgG positive subjects per gender and per age classes. For all tests, a p value <0.05 was considered as significant.

RESULTS

At the end of the study 1764 subjects were enrolled, 1362 (77.2%) of which were male. The mean age was 38.4 ± 11.7 years (range: 17-65). 86.7% (95% CI = 85.0-88.2) had a positive titre of anti-rubella IgG. GMT of anti-rubella IgG titre was 4.3. The proportion of positive subjects was of 76.8% (n = 279/363; 95% CI = 72.2-81.1) in persons aged 18-26 years; 88.1% (n = 310/352; 95% CI = 84.2-91.3) in 27-35 year-old people; 88.5% (n = 464/524; 95% CI = 85.5-91.1) in 36-45 year-old people; 90.7% (n = 350/386; 95% CI = 87.3-93.4) among people aged 46-55 years and 90.6% (n = 126/139; 95% CI = 84.5-94.9) in 55-65 year-old people (Chi-square = 39.7; p < 0.0001). GMT of anti-rubella IgG titre was 4.3 (4.3 in male and 4.2 in female, t = 2.2; p = 0.03) and seems to differ dividing the enrolled subjects by age group (F = 14.3; p < 0.0001).

CONCLUSIONS

According to our data, too many women of child-bearing age are still unprotected from rubella in the elimination era and in this scenario the public health efforts should be oriented to catch-up activities.

Systematic Review of Measles and Rubella Serology Studies

Serological tests provide information about individual immunity from historical infection or immunization. Cross-sectional serological studies provide data about the age- and sex-specific immunity levels for individuals in the studied population, and these data can provide a point of comparison for the results of transmission models. In the context of developing an integrated model for measles and rubella transmission, we reviewed the existing measles and rubella literature to identify the results of national serological studies that provided cross-sectional estimates of population immunity at the time of data collection. We systematically searched PubMed, the Science Citation Index, and references we identified from relevant articles published in English. We extracted serological data for comparison to transmission model outputs. For rubella, serological studies of women of child-bearing age provide information about the potential risks of infants born with congenital rubella syndrome. Serological studies also document the loss of maternal antibodies, which occurs at different rates for the different viruses and according to the nature of the induced immunity (i.e., infection or vaccine). The serological evidence remains limited for some areas, with studies from developed countries representing a disproportionate part of the evidence. The collection and review of serological evidence can help program managers identify immunity gaps in the population, which may help them better understand the characteristics of individuals within their populations who may participate in transmission and manage risks.

Seroepidemiology: an underused tool for designing and monitoring vaccination programmes in low- and middle-income countries

Seroepidemiology, the use of data on the prevalence of bio-markers of infection or vaccination, is a potentially powerful tool to understand the epidemiology of infection before vaccination and to monitor the effectiveness of vaccination programmes. Global and national burden of disease estimates for hepatitis B and rubella are based almost exclusively on serological data. Seroepidemiology has helped in the design of measles, poliomyelitis and rubella elimination programmes, by informing estimates of the required population immunity thresholds for elimination. It contributes to monitoring of these programmes by identifying population immunity gaps and evaluating the effectiveness of vaccination campaigns. Seroepidemiological data have also helped to identify contributing factors to resurgences of diphtheria, Haemophilus Influenzae type B and pertussis. When there is no confounding by antibodies induced by natural infection (as is the case for tetanus and hepatitis B vaccines), seroprevalence data provide a composite picture of vaccination coverage and effectiveness, although they cannot reliably indicate the number of doses of vaccine received. Despite these potential uses, technological, time and cost constraints have limited the widespread application of this tool in low-income countries. The use of venous blood samples makes it difficult to obtain high participation rates in surveys, but the performance of assays based on less invasive samples such as dried blood spots or oral fluid has varied greatly. Waning antibody levels after vaccination may mean that seroprevalence underestimates immunity. This, together with variation in assay sensitivity and specificity and the common need to take account of antibody induced by natural infection, means that relatively sophisticated statistical analysis of data is required. Nonetheless, advances in assays on minimally invasive samples may enhance the feasibility of including serology in large survey programmes in low-income countries. In this paper, we review the potential uses of seroepidemiology to improve vaccination policymaking and programme monitoring and discuss what is needed to broaden the use of this tool in low- and middle-income countries.

Using Locally Derived Seroprevalence Data on Measles, Mumps, Rubella, and Varicella by Birth Cohort to Determine Risks for Vaccine-Preventable Diseases During International Travel

BACKGROUND

Measles, mumps, rubella, and varicella (MMRV) were common childhood diseases in the United States prior to the introduction of their respective vaccines. Measles was declared eliminated in the United States in 2000. However, 628 cases were reported in 2014, the majority of which have been linked to international travel. The study team set out to investigate the seroprevalence of MMRV in our local population to determine whether such a process can lead to meaningful recommendations for assessing travelers at risk.

METHODS

We conducted a cross-sectional seroprevalence study using a quota sampling method. A total of 460 leftover serum samples were collected from individuals born prior to 1996, who live in the Lehigh Valley region of southeast Pennsylvania. The samples were allocated to five birth-year cohorts, and the seroprevalence of each cohort to MMRV was compared. Additionally, overall seroprevalence of each disease was compared with data from prior national studies. Gender differences within each birth cohort were also assessed.

RESULTS

The overall seroprevalence values of measles, mumps, rubella, and varicella were 85.8, 82.8, 96.6, and 97.4%, respectively. There were significant associations between seroprevalence and birth cohort for measles (p = 0.01) as well as mumps (p = 0.037). The overall seroprevalence for our study sample was significantly different from the national seroprevalence results of measles, mumps, and rubella.

CONCLUSIONS

Our study showed dramatically lower immunity rates for measles and mumps than those shown by prior national seroprevalence studies. The rates in many of the later birth cohorts born after 1966 were significantly lower than the rates reported as necessary to sustain herd immunity. Given that patients' immunization records are not always available or complete, collecting local seroprevalence data may be necessary to more accurately recommend antibody testing and vaccination during pre-travel assessments.

Evaluation of rubella immunity in a community prenatal clinic

Since the introduction of the Rubella vaccine in 1969, prevalence of congenital Rubella syndrome (CRS) has greatly declined in the United States. However, reports of sporadic adult cases of the disease and frequent identification of non-Rubella immune (NRI) women in prenatal units may result in outbreak of CRS in susceptible communities. Identifying populations with high rates of NRI will assist in evidence-based public health intervention that may prevent epidemic of CRS in the United States. Method. This is a retrospective, cross-sectional study involving chart audit of Rubella screening results of 642 women who attended a high-risk prenatal care at a northwestern Iowa clinic between January 1 and December 31, 2007. Results. NRI was found in 6.9% of the study population. The highest prevalence rate of 10.2% was found among adolescents. NRI was highest among Native American women at 17.3%, compared to Whites 7.3%, African Americans 5.9%, and Hispanics 4.6%. Multivariate analysis demonstrated that Native Americans were 2.5 times more likely to be NRI compared to Whites (OR 2.7; 95% CI: 1.1, 6.6). Conclusion. This study demonstrated higher rate of non-Rubella immunity among adolescent pregnant women and supports Rubella booster immunization for all non-pregnant teenage women. The observed high rate of NRI among Native Americans may require further studies and evaluation of Rubella vaccination programs in tribal communities.

Medical practices for prevention of perinatal infections in Puerto Rico

Recommendations for screening for maternal infections and interventions to prevent disease in the fetus or newborn have been in place in Puerto Rico for more than 10 years. However, compliance with these recommendations has not been widely documented. We evaluated compliance with rubella/hepatitis B prenatal screening and vaccination recommendations, assessed hospital screening practices for syphilis and HIV, and determined risk factors for suboptimal prenatal care. Records of a random, stratified sample of 2003 pregnant women delivering in eight maternity hospitals in Puerto Rico in 2002 were reviewed. Obstetric prenatal and postnatal records were also reviewed when rubella/hepatitis B surface antigen (HBsAg) screening was not available at the hospital, and to document rubella postpartum vaccination (PPV). Prenatal screening rates were 98.4% for rubella and 98.8% for HBsAg. Overall, 5.4% [95% CI 4.4, 6.5] of women were susceptible to rubella. No eligible women received rubella PPV at the hospital and only 1.5% had documented rubella vaccine prescription at the obstetric records. Only one woman was found to be HBsAg positive and her newborn was adequately treated. However, only 0.9% newborns born to mothers with unknown HBsAg status received hepatitis B vaccine. Screening was documented in 85.7% of the hospital records for HIV and 87.9% for syphilis. Suboptimal prenatal care was more likely among teenagers, low-educated women, and women with >3 previous pregnancies. Screening rates for rubella and hepatitis B were high; however, implementation of recommendations for prevention of rubella and hepatitis B needs to be improved.

Seroprevalence of rubella infection after national immunization program in Taiwan: vaccination status and immigration impact

Rubella vaccination was implemented nationwide in 1992 in Taiwan. A cross-sectional survey was conducted to determine the age-specific seroprevalence of anti-rubella in female students aged 7-22 years old and women of reproductive age in Taipei County. Seropositivity of anti-rubella antibodies was defined as a serum IgG level > or =10 IU/ml tested by enzyme immunoassay. Information on possible predictors of anti-rubella seronegativity was obtained from structured questionnaire interview. Multivariate-adjusted odds ratios (ORm) with their 95% confidence interval (CI) were derived for each predictor using multiple logistic regression analysis. A total of 826 female students and 318 women were recruited. Anti-rubella seropositive rates were 98.3% (282/287), 99.6% (234/235), 96.8% (179/185), 92.4% (110/119), 81.4% (197/242), and 89.5% (68/76) for the age groups of 7-9, 11-13, 15-17, 19-22, 25-33, and 34-44 years old, respectively. Among female students, negative serology for rubella antibodies was associated significantly with the age group and foreign nationality of mother, showing ORm (95% CI) of 1.2 (1.06-1.27) for each year increase in age, and 20.9 (6.31-68.97), respectively. Among women at the reproductive age, low maternal education level 91.6 (9.12-920.74), unmarried status 21.2 (6.16-72.89), and no rubella vaccination 98.9 (11.64-840.25) were associated significantly with an increased evidence of seronegativity to rubella. The National Rubella Vaccination Program has led to herd immunity of school girls. However, in order to eradicate the Rubella syndrome, greater effort is required to vaccinate foreign brides in Taiwan.

Rubella Immunity Levels in the United States Population: Has the Threshold of Viral Elimination Been Reached?

After the 1989-1991 rubella resurgence, rubella vaccination efforts targeted children and women of childbearing age. Utilizing National Health and Nutrition Examination Survey data collected during 1988-1994 and 1999-2004, we assessed whether US levels of rubella seropositivity are consistent with rubella elimination and whether changes are consistent with immunization efforts. Serum samples with rubella antibody levels > or =10 IU tested by rubella immunoglobulin G enzyme immunoassay were considered to be positive. In 1999-2004, the overall age-adjusted rubella seropositivity level was 91.3% (95% confidence interval [CI], 90.5%-92.1%), a significant increase from 88.1% (95% CI, 86.9%-89.1%) in 1988-1994 (P<.001). Among children, seropositivity was highest in children 6-11 years of age (96.2%), followed by adolescents 12-19 years of age (93.7%). Both groups showed significant increases in immunity levels, in comparison with those in 1988-1994 (P<.001). Among adults, seropositivity among women increased (from 88.9% to 91.5%; P=.015), and there was no change among men (from 87.8% to 88.0%; P=.84). In 1999-2004, population rubella immunity levels were at or above the modeled threshold for elimination of rubella virus transmission. Increases in immunity levels are consistent with vaccination efforts.

Seroepidemiology study of rubella antibodies among pregnant women from seven Asian countries: Evaluation of the rubella vaccination program in Taiwan

During 2003-2004, approximately 13% of birth in Taiwan was given by foreign-born females. The aims of this study were to compare the seroprevalence of rubella antibodies between Taiwan-born and foreign-born pregnant women and evaluate the effect of rubella vaccination program in Taiwan. We reviewed the rubella antibody test results of 5007 women during routine pregnancy check-ups at Fooyin University Hospital during 1999-2002. In Taiwan-born women, rubella antibody was undetectable in 29.2%, 7.3%, and 8.3% of the cohorts born before 1971, between 1971 and 1976, and after 1976, respectively. In the cohorts born between 1971 and 1976 and after 1976, pregnant women born in China, Vietnam, Indonesia, and Philippines had significant higher chances of being susceptible. Our results suggested that the voluntary adult vaccination program was not as effective as the school or wipe-out programs. Both Taiwanese women born before 1971 and foreign-born women were more likely to be susceptible to rubella. The introduction of 'catch-up' immunization program and enforcement of the checking of immunization record and/or blood test before pregnancy for these women are necessary in preventing CRS.

Low postpartum rubella vaccination rates in high-risk women, Miami, Florida, 2001

OBJECTIVE

To evaluate adherence to the Advisory Committee on Immunization Practices' recommendations on postpartum rubella vaccination in hospitals with a high proportion of foreign-born Latina mothers, the highest risk group for congenital rubella syndrome.

METHODS

In four large hospitals in Miami-Dade County, maternal medical records for births in 2001 were randomly selected. Using demographic information from birth certificates, vaccination information from medical records, and policy information from a hospital survey, postpartum rubella vaccination rates were characterized among women eligible for vaccination (non-immune and not screened) through univariate and multivariable analyses. Data collection was performed in 2002-2003 and the analysis was completed in 2004-2005.

RESULTS

Among 1991 women, 1209 (61%) were foreign born. Overall, 410 (21%) were eligible for vaccination, and of these 44 (11%) were vaccinated. Vaccination rates were not associated with maternal race/ethnicity or the existence of institutional standing-order vaccination policies. A vaccination order was recorded for 59% (240/410), but even in the presence of an order, only 17% (31/240) of those women were vaccinated.

CONCLUSIONS

Despite policies and standing orders to vaccinate, postpartum rubella vaccination rates were very low among all racial/ethnic subgroups in a sample of hospitals caring for high-risk, foreign-born women. These findings suggest that additional system-level interventions, such as comprehensive operational guidelines, must accompany standing orders to vaccinate rubella non-immune women postpartum.

Assessment of perinatal hepatitis B and rubella prevention in New Hampshire delivery hospitals

OBJECTIVE

To evaluate current performance on recommended perinatal hepatitis B and rubella prevention practices in New Hampshire.

METHODS

Data were extracted from 2021 paired mother-infant records for the year 2000 birth cohort in New Hampshire's 25 delivery hospitals. Assessment was done on the following: prenatal screening for hepatitis B and rubella, administration of the hepatitis B vaccine birth dose to all infants, administration of hepatitis B immune globulin to infants who were born to hepatitis B surface antigen-positive mothers, rubella immunity, and administration of in-hospital postpartum rubella vaccine to rubella nonimmune women.

RESULTS

Prenatal screening rates for hepatitis B (98.8%) and rubella (99.4%) were high. Hepatitis B vaccine birth dose was administered to 76.2% of all infants. All infants who were born to hepatitis B surface antigen-positive mothers also received hepatitis B immune globulin. Multivariate logistic regression showed that the month of delivery and infant birth weight were independent predictors of hepatitis B vaccination. The proportion of infants who were vaccinated in January and February 2000 (48.5% and 67.5%, respectively) was less than any other months, whereas the proportion who were vaccinated in December 2000 (88.2%) was the highest. Women who were born between 1971 and 1975 had the highest rate of rubella nonimmunity (9.5%). In-hospital postpartum rubella vaccine administration was documented for 75.6% of nonimmune women.

CONCLUSION

This study documents good compliance in New Hampshire's birthing hospitals with national guidelines for perinatal hepatitis B and rubella prevention and highlights potential areas for improvement.

Rubella immunoglobulin G antibody titers in children with seizures

The third National Health and Nutrition Examination Survey was utilized to assess serum rubella immunoglobulin G antibody titers in a representative sample of American children. Antibody titers were significantly lower in children with a history of seizures and in children treated for seizures compared to unaffected children, after adjustment for age, ethnicity, residence, and region (P=0.022 and 0.029, respectively). Children with the lowest antibody titers were non-Hispanic whites who had a history of seizures. The percentage of US adolescents and young adults with a history of seizures that may have insufficient immunity to rubella is estimated to be 14-50%.