Serological screening of immunoglobulin M and immunoglobulin G during pregnancy for predicting congenital cytomegalovirus infection

Decoding human cytomegalovirus for the development of innovative diagnostics to detect congenital infection

Cytomegalovirus is the most common cause of congenital infectious disease and the leading nongenetic etiology of sensorineural hearing loss. Although most infected neonates are asymptomatic at birth, congenital cytomegalovirus infection is responsible for nearly 400 infant deaths annually in the United States and may lead to significant long-term neurodevelopmental impairments in survivors. The resulting financial and social burdens of congenital cytomegalovirus infection have led many medical centers to initiate targeted testing after birth, with a growing advocacy to advance universal newborn screening. While no cures or vaccines are currently available to eliminate or prevent cytomegalovirus infection, much has been learned over the last five years regarding disease pathophysiology and viral replication cycles that may enable the development of innovative diagnostics and therapeutics. This Review will detail our current understanding of congenital cytomegalovirus infection, while focusing our discussion on routine and emerging diagnostics for viral detection, quantification, and long-term prognostication. IMPACT: This review highlights our current understanding of the fetal transmission of human cytomegalovirus. It details clinical signs and physical findings of congenital cytomegalovirus infection. This submission discusses currently available cytomegalovirus diagnostics and introduces emerging platforms that promise improved sensitivity, specificity, limit of detection, viral quantification, detection of genomic antiviral resistance, and infection staging (primary, latency, reactivation, reinfection).

Proteomic Analysis Reveals Novel Plasma Biomarkers for Neurological Complications in Patients With Congenital Cytomegalovirus Infection

BACKGROUND

Congenital cytomegalovirus (cCMV) infection is a leading cause of nonhereditary neurological complications. When considering antiviral treatment, it is important to differentiate between symptomatic and asymptomatic patients. This study aimed to identify candidate plasma biomarkers for neurological complications of cCMV infection using proteomic analysis.

METHODS

This study retrospectively enrolled five patients with symptomatic cCMV infection, four with asymptomatic cCMV infection with isolated sensorineural hearing loss (SNHL), and five with asymptomatic cCMV infection. The plasma samples were collected during neonatal period. The peptides were analyzed using liquid chromatography-mass spectrometry. The concentrations of differentially expressed proteins were validated using an enzyme-linked immunosorbent assay.

RESULTS

A total of 456 proteins were identified and quantified. The levels of 80 proteins were significantly different between patients with and without cCMV-related symptoms including isolated SNHL. The levels of 31 proteins were significantly different between patients with and without neuroimaging abnormalities. The plasma concentrations of Fms-related receptor tyrosine kinase 4 in patients with cCMV-related symptoms were significantly higher than those in patients with asymptomatic cCMV infection. Moreover, plasma peptidylprolyl isomerase A levels were significantly higher in patients with neuroimaging abnormalities than in those without.

CONCLUSIONS

Proteomic analysis of patients with cCMV infection showed that Fms-related receptor tyrosine kinase 4 and peptidylprolyl isomerase A could be novel diagnostic biomarkers for neurological complications of cCMV infection.

Diagnosing congenital cytomegalovirus infections using archived dried blood spots: A 15-year observational study, Portugal

BACKGROUND

Cytomegalovirus (CMV) is a leading cause of congenital infections. Dried blood spots (DBS) collected in the first week of life (Guthrie cards) have been used in the diagnosis of CMV infection outside the three-week window period following birth. The present work summarizes the results of a 15-year observational study in which DBS from 1388 children were used for a late diagnosis of congenital CMV infection.

METHODS

Three groups of children were studied: (i) symptomatic (with symptoms at birth or late sequelae) (N = 779); (ii) born to mothers with serological profile of primary CMV infection (N = 75); (iii) without any information (N = 534). A highly sensitive method of DNA extraction (heat-induced) from the DBS was used. CMV DNA was detected by a nested PCR.

RESULTS

In total CMV DNA was detected in 7.5% (104/1388) of children. Symptomatic children showed a low rate of CMV DNA detection (6.7%) than children born to mothers with serological profile of primary CMV infection (13.3%) (p = 0.034). Sensorial hearing loss and encephalopathy were the two clinical manifestations with the highest CMV detection rate (18.3% and 11.1%, respectively). Children whose mothers had a confirmed primary infection showed a higher rate of CMV detection (35.3%) when compared with children whose mothers had a not confirmed primary infection (6.9%) (p = 0.007).

CONCLUSION

The present work emphasises the importance of testing DBS in symptomatic children even a long time after symptoms onset and in children born to mothers with serologic diagnosis of maternal primary CMV infection when they miss the diagnosis during the three-week window following birth.

Revision of Cytomegalovirus Immunoglobulin M Antibody Titer Cutoff in a Maternal Antibody Screening Program in Japan: A Cohort Comparison Involving a Total of 32,000 Pregnant Women

Cytomegalovirus (CMV) is associated with congenital infections. We aimed to validate the revised CMV immunoglobulin (Ig) M titer cutoff for IgG avidity measurements as a reflex test in maternal screening to identify women with primary CMV infection and newborn congenital cytomegalovirus (cCMV). We screened maternal CMV antibodies (the Denka assay) in Japan, from 2017 to 2019, using a revised IgM cutoff (≥4.00 index). Participants were tested for IgG and IgM antibodies, and for IgG avidity if IgM levels exceeded the cutoff. We compared these with corresponding results from 2013 to 2017 based on the original cutoff (≥1.21) and recalculated using the revised cutoff. Newborn urine CMV DNA tests were performed for women with low avidity (≤35.0%). Among 12,832 women screened in 2017-2019, 127 (1.0%) had IgM above the revised cutoff. Thirty-five exhibited low avidity, and seven infants developed cCMV. Of 19,435 women screened in 2013-2017, 184 (1.0%) had IgM above the revised cutoff, 67 had low avidity, and 1 had cCMV. The 2017-2019 results were not significantly different from the 2013-2017 results. The revised IgM cutoff improves maternal screening in identifying primary infection and newborn cCMV; however, further study related to other assays than Denka is required.

Serological response to COVID-19 pneumonia and increasing severity over 18 months in a prospective cohort of hospitalized patients

In this study, we present an 18-month serological follow-up of 294 patients with COVID-19 pneumonia. The aim was to assess the dynamics of serological response and its correlation with clinical worsening, as well as to describe clinical worsening determinants. Results of the study showed an early immunoglobulin M response, which clearly diminished starting at 4 months, but nonetheless, a small group of patients remained positive. As for immunoglobulin G, levels were higher up to 6 months in patients who presented clinical worsening during hospitalization. High titers of the immunoglobulin were maintained in all patients during follow-up, which would indicate that humoral immunity due to infection is long-lasting. Male sex, presence of myalgias and extensive radiological affectation were significantly correlated with clinical worsening.

Prevalence of congenital cytomegalovirus infection according to the type of maternal infection in Japan

INTRODUCTION

Variable rates of cytomegalovirus (CMV) seropositivity in mothers from different individual's background may translate to distinct epidemiological patterns of congenital CMV infection.

METHODS

The prospective cohort study was conducted in Japan to evaluate the prevalence of vertical transmission rate according to the type of maternal infection. Post hoc power as a follow-up analysis was evaluated to compare the statistical power with other studies from France, Finland and Brazil. One thousand one hundred sixty-three pregnant women were measured IgG, IgM and IgG avidity index. The urine samples of neonates of these women were evaluated using polymerase chain reaction to diagnose the vertical transmission.

RESULTS

The prevalence of congenital CMV infection in the study population was 0.4%. The proportions of patients with primary and nonprimary infections were 60% and 40%, respectively, with a maternal seroprevalence of 82.5%. The rate of vertical transmission among the seronegative pregnant women before pregnancy was statistically higher than that among the seropositive pregnant women before pregnancy (p < 0.05), with a study power of 52.7%. The same difference was observed in France and Finland for maternal seroprevalence of 61% and 72% and statistical power of 56.9% and 66.7%, respectively.

CONCLUSION

The maternal seroprevalence of the present study conducted in Japan was much higher than that of studies in France and Finland. Nevertheless, seronegative pregnant women had a higher risk of vertical transmission before pregnancy.

Cross-sectional study to assess awareness of cytomegalovirus infection among pregnant women in Germany

BACKGROUND

Study aimed to assess awareness of congenital cytomegalovirus (CMV) infection and its determinants in pregnancy.

METHODS

Cross-sectional survey was conducted in five hospital-based maternity units in Germany. Pregnant women attending the maternity departments completed interviewer/self-administered survey questionnaire. High-risk group was defined according to contact with children under five years of age (at home or at work). Quantitative analyses using multivariable logistic regression were performed.

RESULTS

One thousand two hundred thirty-three pregnant women were included. 48.5% (n = 598) of women reported any knowledge about risk of CMV infection during pregnancy. CMV infection was less known than other infections or diseases (education about toxoplasmosis 95.5% (n = 1,177), listeriosis 60.5% (n = 746). 38% (n = 468) of participants received education about CMV. CMV awareness was associated with the level of education and employment in childcare or medical care. Only 32% (n = 394) of the women made use of serological screening for CMV during pregnancy (individual health service). 40.8% (n = 503) of pregnant women were classified as high-risk group. They had significantly higher knowledge and education about CMV, and msignificantlycant more often use of the serological screening.

CONCLUSIONS

Less than half of pregnant women surveyed were aware of potential risk associated with CMV infection during pregnancy. In our study,one-third third of pregnant women made use of the serological screening for CMV. Regarding the lack of current consensus on the role of serological CMV screening for pregnant women, hygiene preventive measures are the only evidence-based recommendation for pregnant women and knowledge increase could potentially have major public health impact.

Inconsistent Provider Testing Practices for Congenital Cytomegalovirus: Missed Diagnoses and Missed Opportunities

Newborn congenital cytomegalovirus (cCMV) screening programs have been found to increase the rates of early diagnosis and treatment. In North America, newborn cCMV screening programs have not been widely implemented, leaving healthcare providers to rely on clinical suspicion alone to prompt testing. This study sought to examine healthcare providers' cCMV testing practices at a quaternary children's hospital. A retrospective review of the electronic health record was completed for eligible infants over a six-year period. Bivariate calculations and analyses were performed. Between 2014 and 2019, a total of 40,091 infants were cared for at the study institution, of which 178 were tested for cCMV and 10 infants were diagnosed with cCMV. Isolated small-for-gestational age was the most common indication (53/178) to prompt testing. Overall, the cCMV testing rate was 4.5 tests per 1000 infants, with a resulting diagnostic prevalence of 0.2 cases per 1000 infants, which is 15-fold lower than the expected prevalence. Providers relying on clinical suspicion alone are infrequently testing infants for cCMV, resulting in missed diagnoses and missed opportunities for treatment. Systematic cCMV screening practices may improve diagnosis, treatment, and childhood outcomes.

Early immune surveillance to predict cytomegalovirus outcomes after allogeneic hematopoietic stem cell transplantation

Background

There is no method of predicting human cytomegalovirus (HCMV) outcomes in allogeneic hematopoietic stem cell transplant recipients clinically, leading in some cases to excessive or insufficient antiviral therapy. We evaluated the early immune response of recipients with disparate HCMV outcomes.

Methods

The HCMV outcomes of recipients were determined by long-term monitoring of HCMV DNA levels posttransplant. HCMV IgG and IgM concentrations at 1 week before and 1 week after transplantation, absolute lymphocyte counts, and HCMV-specific IFN-γ secreting cells at 1 month posttransplant were evaluated based on HCMV outcome.

Results

All recipients were negative for HCMV IgM. Significant differences between recipients with and without HCMV reactivation were observed in pre- and post-transplant HCMV IgG antibody levels, absolute lymphocyte counts, and HCMV-specific IFN-γ secreting cells (P &lt; 0.05). HCMV IgG antibody levels significantly increased after transplantation in recipients with HCMV reactivation (P = 0.032), but not in those without reactivation. Multivariate analysis revealed that except for the absolute lymphocyte count these biomarkers were related to HCMV reactivation, independent of other clinical factors. In time-to-event analyses, lower levels of these biomarkers were associated with an increased 150-day cumulative incidence of HCMV reactivation (log-rank P &lt; 0.05). In recipients with HCMV reactivation, the duration of HCMV DNAemia had negative correlation with HCMV-specific IFN-γ-secreting cells (P = 0.015, r = -0.372). The relationships between the peak HCMV DNA load and absolute lymphocyte count and HCMV-specific IFN-γ-secreting cells followed the same trends (P = 0.026, r = -0.181 and P = 0.010, r = -0.317).

Conclusions

HCMV IgG, absolute lymphocyte count, and HCMV-specific IFN-γ secreting cells represent the humoral and cellular immune response. Early monitoring of these immune markers could enable prediction of HCMV outcomes posttransplant and assessment of the severity of HCMV DNAemia.

Pre-existing maternal IgG antibodies as a protective factor against congenital cytomegalovirus infection: A mother-child prospective cohort study

Background

An understanding of the correlation between maternal immunity and congenital cytomegalovirus (CMV) infection is critical for informing the design and evaluation of an effective maternal vaccine. This study aimed to quantitatively measure the protective effect of pre-existing maternal immunity against congenital CMV (cCMV) infection.

Methods

A mother-child cohort study was conducted in three maternal and child health hospitals in China from 2015 to 2018. Pregnant women were consecutively enrolled, and anti-CMV pp150 IgG concentration at early, middle and late gestational ages were evaluated. Their newborns were screened for cCMV infection by CMV-DNA testing of saliva and urine.

Findings

In total, 6729 pregnant women were enrolled, and 6602 of them (98·11%) were positive for CMV IgG at their early gestational age visit (median time: 13 gestational weeks (GW); time range: 6–25 GW). In total, 6228 live newborns were born to seropositive mothers, and 48 (0·77%) of these infants were diagnosed with cCMV infection. The geometric mean concentration (GMC) of CMV IgG at an early gestational age in the women who delivered cCMV-positive newborns (i.e., the transmitters) was 8·54 IU/mL; this was significantly lower than the GMC in the non-transmitters (11·01 IU/mL; P=0·04). In early gestation, the risk of cCMV infection decreased as maternal IgG antibody levels increased (P=0·020); however, the same was not true in middle or late gestation (P>0·05). Using receiver operating characteristic analysis, a CMV IgG concentration of 12·83 IU/mL was established as the optimal diagnostic threshold. Compared to lower levels of CMV IgG (<12·83 IU/mL) in seropositive pregnant women, higher maternal CMV IgG levels (≥12·83 IU/mL) were associated with a 50% reduction in cCMV infection risk in infants (relative risk=0·50; 95% confidence interval: 0·27–0·93; P=0·028).

Interpretation

For seropositive women, a higher level of CMV IgG at an early gestational age is associated with a lower risk of cCMV infection in their newborns.

Funding

National Natural Science Foundation of China; Science and Technology Key Project in Fujian Province; Merck Sharp & Dohme Corp., Kenilworth, NJ, USA; Fieldwork Funds for graduate students of Xiamen University.

Nedd8-Activating Enzyme Is a Druggable Host Dependency Factor of Human and Mouse Cytomegalovirus

Human cytomegalovirus causes diseases in individuals with insufficient immunity. Cytomegaloviruses exploit the ubiquitin proteasome pathway to manipulate the proteome of infected cells. The proteasome degrades ubiquitinated proteins. The family of cullin RING ubiquitin ligases (CRL) regulates the stability of numerous important proteins. If the cullin within the CRL is modified with Nedd8 ("neddylated"), the CRL is enzymatically active, while CRLs lacking Nedd8 modifications are inactive. The Nedd8-activating enzyme (NAE) is indispensable for neddylation. By binding to NAE and inhibiting neddylation, the drug MLN4924 (pevonedistat) causes CRL inactivation and stabilization of CRL target proteins. We showed that MLN4924 elicits potent antiviral activity against cytomegaloviruses, suggesting that NAE might be a druggable host dependency factor (HDF). However, MLN4924 is a nucleoside analog related to AMP, and the antiviral activity of MLN4924 may have been influenced by off-target effects in addition to NAE inhibition. To test if NAE is indeed an HDF, we assessed the novel NAE inhibitor TAS4464 and observed potent antiviral activity against mouse and human cytomegalovirus. Additionally, we raised an MLN4924-resistant cell clone and showed that MLN4924 as well as TAS4464 lose their antiviral activity in these cells. Our results indicate that NAE, the neddylation process, and CRLs are druggable HDFs of cytomegaloviruses.

Congenital Cytomegalovirus Infection Burden and Epidemiologic Risk Factors in Countries With Universal Screening: A Systematic Review and Meta-analysis

IMPORTANCE

Congenital cytomegalovirus (cCMV) infection is the most common congenital infection and the leading acquired cause of developmental disabilities and sensorineural deafness, yet a reliable assessment of the infection burden is lacking.

OBJECTIVES

To estimate the birth prevalence of cCMV in low- and middle-income countries (LMICs) and high-income countries (HICs), characterize the rate by screening methods, and delineate associated risk factors of the infection.

DATA SOURCES

MEDLINE/PubMed, Scopus, and Cochrane Database of Systematic Reviews databases were searched from January 1, 1960, to March 1, 2021, and a total of 1322 studies were identified.

STUDY SELECTION

Studies that provided data on the prevalence of cCMV derived from universal screening of infants younger than 3 weeks were included. Targeted screening studies were excluded.

DATA EXTRACTION AND SYNTHESIS

Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline was followed. Extraction was performed independently by 3 reviewers. Quality was assessed using the Newcastle-Ottawa Scale for cohort studies. Random-effects meta-analysis was undertaken. Metaregression was conducted to evaluate the association of sociodemographic characteristics, maternal seroprevalence, population-level HIV prevalence, and screening methods with the prevalence of cCMV.

MAIN OUTCOMES AND MEASURES

Birth prevalence of cCMV ascertained through universal screening of infants younger than 3 weeks for CMV from urine, saliva, or blood samples.

RESULTS

Seventy-seven studies comprising 515 646 infants met the inclusion criteria from countries representative of each World Bank income level. The estimated pooled overall prevalence of cCMV was 0.67% (95% CI, 0.54%-0.83%). The pooled birth prevalence of cCMV was 3-fold greater in LMICs (1.42%; 95% CI, 0.97%-2.08%; n = 23 studies) than in HICs (0.48%; 95% CI, 0.40%-0.59%, n = 54 studies). Screening methods with blood samples demonstrated lower rates of cCMV than urine or saliva samples (odds ratio [OR], 0.38; 95% CI, 0.23-0.66). Higher maternal CMV seroprevalence (OR, 1.19; 95% CI, 1.11-1.28), higher population-level HIV prevalence (OR, 1.22; 95% CI, 1.05-1.40), lower socioeconomic status (OR, 3.03; 95% CI, 2.05-4.47), and younger mean maternal age (OR, 0.85; 95% CI, 0.78-0.92, older age was associated with lower rates) were associated with higher rates of cCMV.

CONCLUSIONS AND RELEVANCE

In this meta-analysis, LMICs appeared to incur the most significant infection burden. Lower rates of cCMV were reported by studies using only blood or serum as a screening method.

Seroprevalence of CMV IgG and IgM in Korean women of childbearing age

BACKGROUND

The aim of this study was to investigate the seroprevalence of cytomegalovirus (CMV) infection using the serologic status of CMV IgG and IgM antibodies in Korean women of childbearing age.

METHODS

We retrospectively reviewed CMV IgG and IgM test results from Korean women aged 15-49 years who underwent testing between January 2009 and December 2019. Seroprevalence of CMV IgG and IgM by year and age was investigated.

RESULTS

The study period was 11 years, and among 6837 samples tested, 95.8% were CMV IgG-positive. The seropositivity in women aged 15- <20 years was significantly lower (77.5%) than older age groups. Among 6837 total CMV IgG tests, 75.9% (5186) had concurrently measured CMV IgM results among which 2.4% were IgM-positive.

CONCLUSION

Considering the low CMV seropositivity of women younger than 20 years, they may need prenatal education for CMV infection.

The value of interleukin-6 (IL-6) within 6 hours after birth in the prompt diagnosis of early-onset neonatal sepsis

BACKGROUND

To investigate the value of interleukin-6 (IL-6) for neonates within 6 hours after birth in the prompt diagnosis of early-onset neonatal sepsis (EONS).

METHODS

The clinical and laboratory data of 129 neonates in the neonatal intensive care unit (NICU) of our center from March 31, 2017, to February 29, 2020, were retrospectively analyzed. These patients were divided into two groups on their disease conditions: the EONS group (n=66) and the healthy control group (n=63). All enrolled patients were born in our hospital's Obstetrics Department and were admitted to the NICU within 2 hours after birth. The first session of the blood test was conducted within 4-6 hours after birth for the measurements of IL-6, C-reactive protein (CRP1), serum amyloid A1 (SAA1), and serum immunoglobulin M (IgM). The second session of the blood test was performed 12-24 hours after birth for procalcitonin (PCT), CRP2, and SAA2. All the tests were completed in our clinical laboratory. The non-parametric test (Mann-Whitney U test) was used to compare all parameters between these two groups. The receiver operating characteristic (ROC) curves were drawn to compare the diagnostic sensitivities and specificities. The pairwise comparisons of the ROC curves were on the MedCalc18.2.1 software. A P value of <0.05 was considered statistically significant.

RESULTS

Gender, birth weight, and gestational age were matched between the EONS group and the control group (all P>0.05). The differences of IL-6, CRP2, PCT, and SAA2 were statistically significant between these two groups (all P<0.05), while there was no significant difference in CRP1, SAA1, and IgM (all P>0.05). The area under the ROC curve (AUC) is 1 (95% CI: 0.918-1.000), 1 (95% CI: 0.918-1.000), 1 (95% CI: 0.918-1.000), and 0.977 (95% CI: 0.878-0.999), respectively, for IL-6, CRP2, PCT, and SAA2. Pairwise comparisons among four biomarkers showed the diagnostic specificity and sensitivity of IL-6 were not significantly different from those of CRP2, PCT, and SAA2 (all P>0.05).

CONCLUSIONS

IL-6 is a quick and independent diagnostic biomarker for EONS, and its sensitivity and specificity are inferior to the conventional inflammation markers, including CRP, PCT, and SAA.

Positive predictive values of CMV-IgM and importance of CMV-IgG avidity testing in detecting primary infection in three different clinical settings. A French retrospective cohort study

BACKGROUND

Diagnosis of Cytomegalovirus (CMV) primary infection during pregnancy or in immunocompetent patients relies on serology with detection of specific CMV-IgG and IgM. In case of positive CMV-IgM in pregnant women, CMV-IgG avidity is now widely recommended, but in general population it is not currently performed.

OBJECTIVE

In this study, we aimed to determine CMV-IgM positive predictive values (PPV) in different clinical settings.

MATERIAL AND METHODS

We conducted a retrospective study on positive CMV-IgM in our virology laboratory from 2013 to 2019, in three clinical groups: screening in non-symptomatic pregnant women (group 1), pregnant women with ultrasound (US) abnormalities (group 2) and patients (general population) with clinical signs suggestive of CMV primary infection (group 3). CMV-IgG avidity had been performed in all cases allowing to evaluate PPV of positive CMV-IgM to diagnose CMV primary-infection in each group.

RESULTS

Between 2013 and 2019, 6859 serum samples were found positive for CMV-IgM and had been tested for CMV-IgG avidity, with 6560 sera for group 1, 30 for group 2 and 269 for group 3. Overall, low avidity confirming primary infection was observed respectively in 16.4 % for group 1, 36.7 % for group 2, and 35.3 % for group 3. CMV-IgM PPV was significantly lower in group 1 compared to groups 2 (p = 0.01) and 3 (p < 0.001).

DISCUSSION

Our observations highlight the major importance of including CMV-IgG avidity in the diagnostic algorithm, whatever the clinical situation (for immunocompetent patients), to confirm or exclude a recent CMV primary infection in case of positive CMV-IgM.

TORCH screening used appropriately in China?─three years results from a teaching hospital in northwest China

Objectives

TORCH infections caused by Toxoplasma gondii (TOX), rubella virus (RV), cytomegalovirus (CMV) and herpes simplex virus 1,2 (HSV-1,2) are associated with congenital anomalies. The study aimed to analyze the characteristics of TORCH screening in reproductive age women.

Methods

A total of 18,104 women (2015–2017) from a teaching hospital in Xi’an, China, were enrolled in the study. The characteristics of TORCH screening, i.e., the application of TORCH test, the seroprevalence, the impact of age, periods of gestation and woman with bad obstetric history (BOH) on the serological data were investigated.

Results

In the study, 319 women (1.76%) performed dynamic TORCH test. 51.66, 20.44 and 3.83% of the population did the test in the pre-gestation period, the first and third trimester, respectively. Quite a few pre-gestation women (29.74%) ignored screening of IgG antibodies. The overall IgG/IgM seropositvity of TOX, RV, CMV, HSV-1 and HSV-2 was 4.35%/0.35, 90%/0.63, 96.79%/0.97, 81.11%/0.14 and 6.1%/0.19%, respectively. The age-specific distributions and periods of gestation had no significant effect on the seroprevalence of TORCH agents, p>0.05. However, BOH was significantly associated with higher seropositvity of IgM (RV, CMV, HSV-1 and HSV-2) and IgG (CMV and HSV-1) antibodies, p < 0.05.

Conclusion

In Xi’an region, more attentions should be paid to TOX, CMV, HSV-2 and the women with BOH for TORCH screening. Meanwhile, a greater emphasis needs to be placed on TORCH test used inappropriately in China.