Seroprevalence of rubella virus antibodies among pregnant women in the Center and South-West regions of Cameroon

Seroepidemiology study of rubella virus antibodies among neonates and pregnant women at hospitals in Henan province, China

Rubella virus infection can cause vertical transmission to the fetus during pregnancy. In China's Henan province, rubella surveillance needs to be well-established. In this research, a total of 1933 neonates and 2502 pregnant women were enrolled, and their sera for IgG and IgM antibodies against rubella were tested by chemiluminescence assay. Of 1933 neonates' sera tested, the seropositive of rubella IgG was 68.7%. The seroprevalence of rubella IgM in neonates was 0.4%. 30.9% of neonates had negative results for IgG and IgM antibodies. Two thousand five hundred and two pregnant women participated in the serosurvey, and 79.3% were rubella IgG positive. Rubella IgG seropositivity in pregnant women differed by age and number of births. 0.8% of the pregnant women had positive results for IgM against the rubella virus. The seronegative of rubella IgG and IgM antibodies in pregnant women was 19.8%. Due to the negative rubella-specific IgG antibody, many neonates remain at risk of rubella virus infection. Rubella virus continues to spread since some neonates and pregnant women with rubella-specific IgM antibody positive have been detected. Rubella vaccination may be introduced for childbearing-age women to increase immunity levels against rubella with periodic sero-surveillance.

Seroprevalence of rubella virus infection among antenatal care clients of Halaba Town public health facilities, southern Ethiopia

Rubella virus infection during pregnancy has several effects on the developing fetus. However, little is known about the epidemiology of the infection in Ethiopia. A cross-sectional study was conducted to assess the seroprevalence of rubella virus infection on consecutive 299 pregnant women attending antenatal care clinics in public health facilities in Halaba Town, Southern Ethiopia. Structured questionnaires were used to collect information on socio-demographic and reproductive characteristics. Venous blood samples were collected, and sera were tested for anti-rubella IgM and IgG using the enzyme-linked immunosorbent assay. Anti-rubella IgG and IgM were detected in 265 (88.6%) and 15 (5.0%) of 299 participants, respectively. Pregnant women in their first trimester [crude odds ratio (cOR) = 4.26; 95% CI (1.47, 12.4)] were at increased risk of having anti-rubella IgM compared to those in their second and third trimesters. Urban residents [cOR = 4.06; 95% CI (1.94, 8.47)] were with a higher percentage of IgG positivity compared to rural residents. Anti-rubella IgG positivity was higher in housewives [cOR = 2.94; 95% CI (1.07, 8.04)] compared to self-employed women. Our findings showed a high prevalence of rubella virus exposure, and considerable percentages of recent infection and susceptible women to contracting the infection, emphasizing the importance of congenital rubella syndrome in the research area.

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.

The Burden of Likely Rubella Infection among Healthy Pregnant Women in Abakaliki, Ebonyi State, Nigeria

The first 140 days of pregnancy are critical as regards rubella virus infection because of the likelihood of a poor pregnancy outcome. This study was undertaken to investigate the likelihood of exposure to poor pregnancy outcomes due to seroprevalence of rubella among selected pregnant women attending Mile Four Hospital, Abakaliki, Ebonyi State, Nigeria. The seroprevalence of rubella immunoglobulin M (IgM) antibodies was investigated among pregnant women. A total of 187 sera samples collected from the women were screened for rubella virus IgM antibody using the enzyme-linked immunosorbent assay (ELISA). The results obtained were analyzed using SPSS. The chi square test was performed at a $P$ value of 0.05 significance and at a 95% confidence interval. Of the 187 pregnant women, 35 (18.72%) were positive for the rubella virus. Pregnant women within 26–30 years of age had the highest prevalence (26.15%), while those aged 35–40 years had the least prevalence. Married women had the highest prevalence (20.0%), followed by singles (16.67%) and widows (15.38%), while divorced pregnant women recorded the least prevalence (9.20%). Pregnant women with no formal education were more predisposed to rubella virus (22.22%) infection compared to their educated counterparts. Occupationally, full-time housewives had the highest prevalence (24.26%). The infection rates seemed to wane as pregnancy advanced. The first trimester had the highest prevalence (21.88%), followed by the second trimester (18.84%) and the third trimester (17.44%). Pregnant women living in urban areas had higher IgM seroprevalence (20.18%) than those in rural areas (16.67%). Furthermore, grand multigravidas were more infected (22.73%) than primigravidas (14.52%) and multigravidas (20.39%). The seroprevalence of rubella in this study was high, and it calls for general surveillance and mass immunization of children and females of childbearing age in the area to help reduce the incidence of congenital rubella syndrome.

Congenital Rubella Syndrome Surveillance After Measles Rubella Vaccination Introduction in Yogyakarta, Indonesia

BACKGROUND

Congenital rubella syndrome (CRS) is a fatal disease causing severe congenital defects. Indonesia had the highest CRS cases in the world in 2016 with a commitment to achieve elimination of rubella disease by 2020, through the campaign and introduction of measles rubella (MR) national vaccination program in 2017 and 2018. This study aimed to describe the impact of the national vaccination campaign by conducting surveillance of CRS cases and comparing the incidence of new CRS cases before and after the MR vaccination campaign.

METHODS

From July 2015 to July 2020, we conducted surveillance of CRS in Yogyakarta. Suspected patients underwent complete clinical examinations. Serology was tested for the presence of IgM and IgG antibodies against rubella. Descriptive analysis was used to characterize the demographic and clinical characteristics of the cases before and after the MR vaccination campaign.

RESULTS

The study involved 229 infants who were suspected for CRS. Laboratory-confirmed cases were found in 47 of them (20.86%). Most of the laboratory-confirmed cases (55.3%) were reported among 1-5 months old infants. Common clinical features among laboratory-confirmed cases included structural heart defects in 43 (91.4%). There was a significant decrease (60.9%) of CRS incidence from 0.39 per 1000 live births in the precampaign era to 0.08 in the postcampaign era (P = 0.00).

CONCLUSION

There has been a significant declining number of CRS cases based on pre- and post-MR vaccination campaign in Yogyakarta, Indonesia. An effective surveillance system will help monitor the number of CRS cases.

Mechanism of heparin interference in detection of LIAISON® Rubella IgM

AIMS

To investigate the effects of heparin in detection of LIAISON® Rubella IgM (Rub-M) and the mechanism of interference.

METHODS

Different concentrations of lithium heparin and sodium heparin were added to ten serum samples. The relative light units (RLU) value of Rub-M was measured using the LIAISON XL detection system. Different levels of IgM serum were incubated with magnetic particle in Rub-M detection kit at 4 °C for 4 h, blocking anti-human IgM-specific antibodies coated on the surface of magnetic particle. Separately, the rubella virus antigen in Rub-M detection kit was replaced by phosphate-buffered saline (PBS). The RLU values of LIAISON® Rub-M of original serum and serum containing various concentrations of heparin were measured after the above two different treatments.

RESULTS

The RLU value of LIAISON® Rub-M increased with the increase of heparin content lower than 40 IU/mL, and reached a peak value at 40-50 IU/mL. The RLU value of LIAISON® Rub-M then decreased with the decrease of heparin concentration. When rubella virus antigen was replaced by PBS, the RLU value of LIAISON® Rub-M of serum samples containing 40 IU/mL heparin decreased significantly. The blocking concentration of IgM increased gradually, and the RLU value of LIAISON® Rub-M of seven serum samples containing 40 IU/mL heparin also decreased gradually.

CONCLUSION

Plasma with heparin cannot be used to the detection of LIAISON® Rub-M. Heparin may participate in the reaction by binding with rubella virus antigen and anti-human IgM-specific antibodies coated on the surface of magnetic particle, thus affecting the detection results.