Prevalence of serum antibodies to cytomegalovirus in pregnant women in Sapporo, Japan

Suppression of human trophoblast syncytialization by human cytomegalovirus infection

INTRODUCTION

Placental dysfunction triggers fetal growth restriction in congenital human cytomegalovirus (HCMV) infection. Studies suggest that HCMV infection interferes with the differentiation of human trophoblasts. However, the underlying mechanisms have not been clarified. This study investigated the impact of HCMV infection on gene transcriptomes in cytotrophoblasts (CTBs) associated with placental dysfunction.

METHODS

CTBs were isolated from human term placentas, and spontaneous syncytialization was observed in vitro. The transcriptome profiles were compared between CTB groups with and without HCMV infection by cap analysis gene expression sequencing. The effect of HCMV infection on trophoblast differentiation was evaluated by examining cell fusion status using immunocytochemical staining for desmoplakin and assessing the production of cell differentiation markers, including hCG, PlGF, and soluble Flt-1, using ELISA.

RESULTS

The expression of the genes categorized in the signaling pathways related to the cell cycle was significantly enhanced in CTBs with HCMV infection compared with uninfected CTBs. HCMV infection hindered the alteration of the gene expression profile associated with syncytialization. This suppressive effect under HCMV infection was concurrent with the reduction in hCG and PlGF secretion. Immunostaining for desmoplakin revealed that HCMV infection reduced the cell fusion of cultured CTBs. These findings imply that HCMV infection has a negative impact on syncytialization, which is indispensable for the maintenance of villous function.

DISCUSSION

HCMV infection interferes with gene expression profiles and functional differentiation of trophoblasts. Suppression of syncytialization may be a survival strategy for HCMV to expand infection and could be associated with placental dysfunction.

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

Background

Cytomegalovirus (CMV) is one of the most frequent pathogens for congenital infections. Most cases of congenital CMV infection (cCMV) are asymptomatic at birth, but sensorineural hearing loss (SNHL) or neurodevelopmental delay can appear later in childhood. This prospective study examined the practicability of serological screening for anti-CMV immunoglobulin (Ig) G and anti-CMV IgM in pregnant women.

Methods

A total of 11,753 pregnant women were examined for CMV IgG and CMV IgM during the first or second trimester. When IgM was positive, IgG was reevaluated more than two weeks later. When IgG was negative, IgG was reevaluated in the second or third trimester. All neonates from mothers with positive/borderline IgM or IgG seroconversion underwent polymerase chain reaction assay for CMV using urine samples to diagnose cCMV. Levels of IgG and IgM were compared between mothers with and without cCMV. Receiver operating characteristic (ROC) curves for IgM titers were analyzed.

Results

Eight of 500 neonates (1.6%) born from mothers with positive IgG and positive IgM, and 3 of 13 neonates (23.1%) born from mothers with IgG seroconversion were diagnosed with cCMV. Neither IgM titers nor IgG titers differed significantly between cCMV and non-cCMV groups. The area under the ROC curve was 0.716 and the optimal cut-off for IgM was 7.28 index (sensitivity = 0.625, specificity = 0.965, positive predictive value = 0.238, negative predictive value = 0.993). Titers of IgG were not frequently elevated in pregnant women with positive IgM during the observation period, including in those with cCMV. All 11 cCMV cases were asymptomatic at birth and none had shown SNHL or developmental delay as of the last regular visit (mean age, 40 months).

Conclusions

Seroconversion of CMV IgG and high-titer IgM during early pregnancy are predictors of cCMV. High IgM titer (> 7.28 index) is a predictor despite relatively low sensitivity. Levels of IgG had already plateaued at first evaluation in mothers with cCMV. Maternal screening offered insufficient positive predictive value for diagnosing cCMV, but allowed identifying asymptomatic cCMV cases in an early stage.

Emergence of Cytomegalovirus Mononucleosis Syndrome Among Young Adults in Hong Kong Linked to Falling Seroprevalence: Results of a 14-Year Seroepidemiological Study

Background

Cytomegalovirus (CMV) mononucleosis is a manifestation of primary CMV infection. This study aims to establish the link between long-term population CMV seroepidemiological trends and incidence of CMV mononucleosis requiring hospitalization. Furthermore, by analyzing serial laboratory data of patients hospitalized with CMV mononucleosis, we aim to provide insights into the natural history of this syndrome.

Methods

We conducted a 14-year observational study in a tertiary hospital in Hong Kong. Cytomegalovirus immunoglobulin G data of 2349 adults were analyzed for trends in CMV susceptibility during the study period. The clinical features, risk factors, antiviral treatment data, and laboratory findings of 25 adult patients presenting with CMV mononucleosis during this period were retrieved.

Results

Susceptibility to CMV infection among the adult population aged 18-45 in Hong Kong increased from 14.5% in 2004 to 32.2% in 2012-2017 (P < .001), and this led to doubling of observed CMV mononucleosis incidence among inpatients in our center during the study period. All patients with CMV mononucleosis were hospitalized for investigation of fever of unknown origin. Household contact with young children was the most common risk factor followed by recent overseas travel. Derangement of liver function tests was universally observed and was more severe than in previously published western CMV mononucleosis patient cohorts. Most patients showed clinical improvement within the third week of illness.

Conclusions

We conclude that increasing CMV susceptibility among young adults in Hong Kong has resulted in a rising observed incidence of CMV mononucleosis, which is typically a self-limited illness characterized by anicteric hepatitis.

Rapid increase in the serum Cytomegalovirus IgG avidity index in women with a congenitally infected fetus

BACKGROUND

Human Cytomegalovirus (CMV) is the virus most frequently responsible for severe diseases of the fetus and newborn. The reported intrauterine transmission rate of CMV following primary maternal infection is approximately 40%. Invasive techniques are needed for the prenatal diagnosis of congenital CMV infection.

OBJECTIVES

The aim of this study was to evaluate whether the rapidity of change in the CMV IgG avidity index (AI) is associated with the presence of congenital CMV infection among mothers with suspected primary CMV infection.

STUDY DESIGN

The serum CMV IgG AI was repeatedly measured in 17 pregnant women with positive or borderline test results for CMV IgM together with an initial IgG AI value of <40%. Their neonates underwent polymerase chain reaction analyses for the presence of CMV DNA in the urine. The rapidity of change in the IgG AI per 4 weeks was defined as the ΔAI (%). The ΔAI of women with congenital CMV infection was compared with that of women with no infection.

RESULTS

The ΔAI of nine mothers with congenital CMV infection (median,15.7%; range,7.8-42.8%) was significantly higher than that of eight mothers with no infection (median, 6.5%, range, 2.0-8.8%; p<0.001). The incidences of congenital CMV infection were 100.0%, 16.7%, and 0.0% among mothers with a ΔAI of >10, 5-10, and <5%, respectively.

CONCLUSIONS

Measurement of the ΔAI in pregnant women might be useful for estimating the risk of mother-to-neonate CMV transmission.

Cytomegalovirus seroprevalence in pregnant women and association with adverse pregnancy/neonatal outcomes in Jiangsu Province, China

Background

In this study, we aimed to determine the provincial population-based seroprevalence in pregnant women and to further explore the association of maternal CMV infection status and adverse pregnancy/neonatal/growth outcomes in Jiangsu, China.

Methods

In this case-control study, the sera from 527 pregnant women with adverse pregnancy/neonatal outcomes and 496 mothers of healthy infants in Jiangsu Province, collected at gestation age of 15–20 weeks, were tested for anti-CMV IgG, IgM and IgG avidity. Adverse pregnancy/neonatal outcomes were identified based on pregnancy/neonatal outcomes.

Results

The overall seroprevalence of anti-CMV IgG was 98.7%, with 99.4% and 98.0% in the case and control groups, respectively (P = 0.039). The prevalence of anti-CMV IgG+/IgM+, was higher in the case group than that in the control group (3.8% vs. 1.6%, P = 0.033). Anti-CMV IgG avidity assay showed that none in the control group were primarily infected, but five (0.9%) in the case group underwent primary infection (P = 0.084); all five infants of these women presented severe adverse neonatal/growth outcomes. Exact logistic regression analysis showed that anti-CMV IgG+/IgM+ was associated with adverse pregnancy/neonatal/growth outcomes (aOR = 2.44, 95% CI 1.01–6.48, P = 0.047). Maternal low education level and prior abnormal pregnancies also were risk factors for adverse pregnancy/neonatal outcomes.

Conclusions

In populations with very high prevalence of latent CMV infection, active maternal CMV infection during pregnancy might be a risk factor for adverse pregnancy/neonatal outcomes.

Changes in cytomegalovirus seroprevalence in pregnant Japanese women-a 10-year single center study

BACKGROUND

Human cytomegalovirus (CMV) causes congenital infections during pregnancy, and seroepidemiological data are important for estimating the risk of infection. However, only a few reports of CMV seroprevalence exist for pregnant Japanese women.

OBJECTIVES

The purpose of this study was to assess CMV seroprevalence in pregnant Japanese women.

STUDY DESIGN

This cross-sectional study involved pregnant Japanese women who delivered from 2003 to 2012 at our hospital (n=15,616). Among these women, 14,099 (90.3%) underwent tests for the presence of CMV IgG. Those with an equivocal test result were excluded (n=195) from this analysis, leaving a study sample of 13,904 Japanese pregnant women. The prevalence of CMV IgG was also assessed by calendar year, age, and parity.

RESULTS

The overall CMV IgG prevalence rate was 66.0%. CMV IgG prevalence significantly decreased over the course of 10 years from 2003 to 2012 (from 69.9% in 2003 to 65.2% in 2012) (p<0.001). Adjusted odds ratios for CMV IgG positivity in women aged <25, 25-30, 35-40, and >40 years were 1.66 (95%CI: 1.25-2.20), 1.20 (95%CI: 1.07-1.35), 1.16 (95%CI: 1.07-1.26), and 1.44 (95%CI: 1.28-1.62), respectively, compared to women aged 30-35 years. Adjusted odds ratios for CMV IgG positivity for a parity of 1, 2, and ≥3 were 1.14 (95%CI: 1.06-1.23), 1.52 (95%CI: 1.32-1.77), and 2.54 (95%CI: 2.69-3.84), respectively, compared to nulliparous women.

CONCLUSION

We found that 34% of pregnant Japanese women were susceptible to CMV infection. Calendar year, maternal age, and parity were significantly associated with changes in CMV seroprevalence among this population.

Seroepidemiological survey of cytomegalovirus infection among pregnant women in Nagasaki, Japan

BACKGROUND

Epidemiology of cytomegalovirus (CMV) infection varies widely, depending on ethnicity and socioeconomic status. A seroepidemiological survey was conducted to determine CMV infection among pregnant women in Nagasaki Prefecture, Japan.

METHODS

We measured serum CMV-specific immunoglobulin (Ig) M and IgG at the first and third trimesters. IgG avidity was determined when both CMV-IgG and CMV-IgM were positive.

RESULTS

Of 339 pregnant women, 296 (87.3%) were CMV-IgG-positive at the first trimester. Of 267 paired sera, one (0.37%) had CMV-IgG seroconversion, another one (0.37%) had CMV-IgM seroconversion, and 12 had both CMV-IgG and CMV-IgM, two (0.75%) of whom had low IgG avidity, suggesting recent infection. Thus, the incidence of primary CMV infection during pregnancy was 0.74-1.5%. Assuming the rate of in utero transmission following maternal primary infection to be approximately 40%, the incidence of congenital infection is estimated to be 0.3-0.6%.

CONCLUSION

Although CMV seroprevalence among pregnant women has been decreasing in industrialized regions including other parts of Japan, CMV-seroprevalence remains high in Nagasaki. Thus, epidemiology of CMV infection seems variable within Japan, a country generally considered to be ethnically and socioeconomically homogeneous. However, 40-80 infants may be congenitally infected and 15-27% (or 6-22) of them may ultimately suffer from certain neurological sequelae annually in Nagasaki Prefecture, so where annual live births are approximately 13,300, congenital CMV infection seems to be a significant public health problem in such an apparently low-risk region as Nagasaki.

Seroepidemiologic study of human cytomegalovirus in pregnant women in Valiasr Hospital of Kazeroon, Fars, Iran

BACKGROUND

Cytomegalovirus (CMV) is a common opportunistic infection among HIV-infected individuals, a major source of serious complications among organ-transplant recipients, and a leading cause of hearing loss, vision loss, and mental retardation among congenitally infected children. Women infected for the first time during pregnancy are especially likely to transmit CMV to their fetuses.

OBJECTIVE

In this study, it was aimed to determine the rate of CMV seroprevalence in pregnant women, the prevalence of maternal CMV infection and also the incidence of congenital CMV infection in their newborns in the Kazeroon, south of Iran.

METHODS

Between January 2007 and July 2007, all (n = 1472) pregnant women who attended the obstetric ward of Valiasr hospital in Kazeroon for delivery, were enrolled in this study, and according to the presence or absence of anti CMV-IgM and CMV-IgG, were classified as seropositive, seronegative and having active maternal CMV infection. Differentiation of primary and recurrent CMV infection in women with both CMV-IgM (+) and CMV-IgG (+) antibody was determined by the avidity index (AI) of anti-CMV IgG.

RESULTS

The rate of seropositivity was found as 97.69% and the rate of seronegativity as 2.31% in pregnant women. The prevalence of active maternal CMV infection was found as 4.35% and among these pregnant women, the incidence of primary and recurrent maternal CMV infection was 34.4% and 65.6% respectively.

CONCLUSION

Seroprevalence rate of CMV in pregnant women is high and most infections are recurrent. Thus, it does not seem to be cost-effective to screen all pregnant women for CMV infection, as in the other countries with high seropositivity rate.

Quantitative detection of HCMV-DNA in saliva from infants and breast milk on real-time polymerase chain reaction

BACKGROUND

The role of breast milk in viral transmission has not been fully studied. To determine the effect of breast milk on the establishment of primary human cytomegalovirus (HCMV) infection in term infants, HCMV-DNA was measured in breast milk and infant saliva.

METHODS

The study population consisted of 48 healthy term infants and their mothers. The copy number of HCMV-DNA in the infants' saliva and mothers' milk was measured on quantitative real-time polymerase chain reaction (PCR).

RESULTS

HCMV-DNA was detected in both saliva and breast milk from 21 infant-mother pairs, in milk only from four pairs, in saliva only from 12 pairs, and in neither from 11 pairs. HCMV-DNA was first detected in the saliva of 10 infants at age 4 months, seven infants at 7 months, 13 infants at 10 months, and three infants at 12 months. The viral loads peaked 4-10 months after birth, and thereafter decreased or became negative. The peak copy number and rate of HCMV-DNA detection in saliva were significantly related to peak copy number and rate of detection in the corresponding breast milk.

CONCLUSION

Thus, HCMV passed through breast milk 1-7 months after delivery affects the persistence and level of HCMV-DNA in infant saliva and is the most important route of primary infection.

High perinatal seroprevalence of cytomegalovirus in northern Taiwan

AIM

The living style, health-care system and socio-economic environments have changed substantially in Taiwan over past 20 years. This study was aimed to estimate the current perinatal cytomegalovirus (CMV) seroprevalence in northern Taiwan.

METHODS

In a Taiwan Birth Panel Study, 483 pairs of mothers and neonates were prospectively recruited from one tertiary medical center, one local hospital, and two obstetric clinics located in northern Taiwan from April 2004 through January 2005. Sera of their paired maternal and cord blood were tested by an enzyme-linked immunosorbent assay method for CMV IgG and IgM antibodies. Additional data were collected for health measures and epidemiological characteristics through trained interviewers utilising structured questionnaires.

RESULTS

Among 483 mothers studied, 93% were Taiwanese, 6.4% were immigrants from the south-eastern Asia and Mainland China, and 0.6% was aborigines. The seropositive rate of CMV IgG and IgM among the mothers was 91.1% and 3.5%, respectively. The immigrant mothers and the mothers younger than 20 years of age had a higher IgM seroprevalence (P < 0.05). Furthermore, 90.8% of the offspring had CMV IgG seropositivity and yet none of the neonates were CMV IgM positive.

CONCLUSION

The seroprevalence of CMV among childbearing women is high in northern Taiwan. The immigrant mothers and the teenage mothers appear to have higher seropositivity of CMV IgM.

New estimates of the prevalence of neurological and sensory sequelae and mortality associated with congenital cytomegalovirus infection

Congenital CMV is a major cause of neurological and sensory impairment in children. Reliable estimates of the prevalence of permanent sequelae and mortality associated with congenital CMV are needed to guide development of education and prevention programmes and to gauge the financial costs associated with this disease. To calculate such estimates, this review used data solely from studies in which children with congenital CMV were identified through universal screening. Based on 15 studies with a total of 117 986 infants screened, the overall CMV birth prevalence estimate was 0.7%. The percentage of infected children with CMV-specific symptoms at birth was 12.7%. The percentage of symptomatic children with permanent sequelae was 40-58%. The percentage of children without symptoms at birth who developed permanent sequelae was estimated to be 13.5%. The true burden of congenital CMV infection is unclear because data on important outcomes, such as visual impairment, are lacking and follow-up of infected children has been too short to fully identify late-onset sequelae. Therefore, the estimates of permanent sequelae associated with congenital CMV presented here are likely underestimates. Future studies should extend follow-up of CMV-infected children identified through universal screening and include the evaluation of visual impairment.

Screening for vaginal shedding of cytomegalovirus in healthy pregnant women using real-time PCR: Correlation of CMV in the vagina and adverse outcome of pregnancy

The impact of cytomegalovirus (CMV) infection of the genital tract during pregnancy on adverse pregnancy outcomes is not understood fully. A real-time PCR assay was used to determine vaginal shedding of CMV in 993 healthy pregnant Japanese women and the results were compared with the outcome of pregnancy. CMV DNA was detected in 76 (7.7%) of the women. The outcome of pregnancy could be determined finally in 848 women, of whom 60 (7.1%) were CMV positive. The carriers of CMV had an increased miscarriage rate (RR 6.96, 95% CI 2.04-23.84, P < 0.01). These findings suggest that latent genital tract CMV infection predisposes to adverse pregnancy outcomes.

Cytomegalovirus excretion in pregnant women in the eastern Black Sea region of Turkey

AIM

The study was carried out to determine the viral excretion rate of cytomegalovirus (CMV) in pregnant women in the eastern Black Sea region of Turkey, and to observe how it compared with that in western countries.

METHOD

Cervical excretion of cytomegalovirus by pregnant women was studied employing a highly sensitive CMV detection assay supported with fluorescent labeled monoclonal antibody directed against an immediate early antigen, known as DEAFF (detection of early antigen by fluorescent foci assay) test.

RESULTS

CMV excretion rates during the third trimester of pregnancy were similar to the detection rates reported from most developed countries. Our results also showed that the rate of cervical CMV excretion was higher among pregnant women who had a history of more than one spontaneous abortion.

Chronological changes of incidence and prognosis of children with asymptomatic congenital cytomegalovirus infection in Sapporo, Japan

BACKGROUND

Chronological changes of the incidence of congenital cytomegalovirus (CMV) infection and the longitudinal prognosis in children with asymptomatic congenital infection were investigated.

METHODS

Congenital CMV infection, as demonstrated by isolation of the virus within the first week of life, was diagnosed in infants born in Sapporo, Japan, during the 26-year period between 1977 and 2002.

RESULTS

Congenital infection was diagnosed in 37 (0.31%) of 11,938 infants. Thirty-two infants were (86.5%) asymptomatic and 5 (13.5%) were symptomatic at birth.

CONCLUSIONS

Although a decrease in the total incidence of congenital CMV infection has been seen in recent years, screening of congenital infection at birth seems to be necessary to detect late-onset neurodevelopmental sequelae.

Frequency of human cytomegalovirus-specific T cells during pregnancy determined by intracellular cytokine staining

The characteristics of cytomegalovirus (CMV)-specific T-cell immunity was investigated in pregnant women with primary, latent, or reactivated CMV infection, and in a comparative group of non-pregnant women. Forty-six pregnant and 8 non-pregnant women were examined based on the presence of serum antibody activity against CMV and viral excretion in urine. The frequency of CMV-specific CD4(+) T cells in peripheral blood lymphocytes was determined by staining for intracellular cytokines, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha. There was no change in the frequencies of CMV-specific CD4(+) T cells in CMV-seropositive normal non-pregnant and pregnant women at any gestation. However, the frequency of CMV-specific CD4(+) T cells in pregnant women associated with CMV reactivation or reinfection was significantly higher than in CMV-seropositive normal pregnant and non-pregnant women. There were no CMV transmissions to the infants of all these women. These CMV-specific T cells responses in pregnant women may contribute some to block the intrauterine CMV infection in their infants.

Immunological evaluation and clinical aspects of children with congenital cytomegalovirus infection

To determine the ability of immunological response to human cytomegalovirus (CMV), the flow cytometric assay was evaluated as a tool for real-time monitoring of specific cellular immunity in children with congenital CMV infection. Longitudinal cohort study of 2 children with asymptomatic and 2 with symptomatic congenital CMV infection evaluated at birth and followed up with serial age-appropriate neurodevelopmental testing. Frequencies of CMV-specific CD4 (+) T cell in these children were detected by intracellular cytokines (ICC), interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha, staining. Findings detected by CT and MRI were the most sensitive predictor for neurodevelopmental prognosis. Frequencies of CMV-specific CD4(+) T cells detected by ICC, both IFN-gamma and TNF-alpha, were higher in 2 children with symptomatic congenital CMV infection than those in 2 children with asymptomatic congenital infection. Frequencies of CMV-specific CD4(+) T cells in 2 children with symptomatic congenital infection were significantly higher than those in 6 healthy children of 1 to 5-years of age with serum anti-CMV IgG antibody without serum anti-CMV IgM antibody and viral excretion in to urine (p < 0.01). The ICC assay reflects immunological activity against CMV infection in children with asymptomatic or symptomatic congenial infection. Categorizing findings obtained by the ICC assay may helps to determine the prognosis of children with congenital CMV infection.