Primary Maternal Infection Research Articles

Diagnostic et prise en charge de l'infection congénitale à cytomégalovirus

AbstractCongenital cytomegalovirus (CMV) infection affects almost 1 % of newborns, with a risk of sequelae of 17-20 %. Primary maternal infection during the first trimester of pregnancy is the most significant risk factor for severe disease. To prevent primary maternal infection, primary prevention strategies (hygiene and information measures) have been shown to be effective but are still insufficient. Although not yet recommended by the health authorities, screening enables cases of primary maternal infection to be detected as early as possible, so that transmission can be prevented by administering valaciclovir. This strategy has proved effective, reducing maternal-fetal transmission of CMV by 70 %. Screening is based on CMV serology (IgG and IgM), supplemented by IgG avidity testing if IgM are present. It is essential that screening and initiation of treatment should be as early as possible to optimize the efficacy of this strategy. PCR on amniotic fluid, proposed in the case of a first trimester maternal primary infection, can be used to diagnose fetal infection. It is also indicated in the event of abnormalities detected on ultrasound. CMV infection in newborns can be confirmed by PCR on saliva or urine, and treatment with valaganciclovir can be initiated in cases of symptomatic congenital infection.

Discrimination of primary and chronic cytomegalovirus infection based on humoral immune profiles in pregnancy.

BACKGROUNDMost humans have been infected with cytomegalovirus (CMV) by midlife without clinical signs of disease. However, in settings in which the immune system is undeveloped or compromised, the virus is not adequately controlled and consequently presents a major infectious cause of both congenital disease during pregnancy as well as opportunistic infection in children and adults. With clear evidence that risk to the fetus varies with gestational age at the time of primary maternal infection, further research on humoral responses to primary CMV infection during pregnancy is needed.METHODSHere, systems serology tools were applied to characterize antibody responses to CMV infection in pregnant and nonpregnant women experiencing either primary or chronic infection.RESULTSWhereas strikingly different antibody profiles were observed depending on infection status, limited differences were associated with pregnancy status. Beyond known differences in IgM responses used clinically for identification of primary infection, distinctions observed in IgA and FcγR-binding antibodies and among antigen specificities accurately predicted infection status. Machine learning was used to define the transition from primary to chronic states and predict time since infection with high accuracy. Humoral responses diverged over time in an antigen-specific manner, with IgG3 responses toward tegument decreasing over time as typical of viral infections, while those directed to pentamer and glycoprotein B were lower during acute and greatest during chronic infection.CONCLUSIONIn sum, this work provides insights into the antibody response associated with CMV infection status in the context of pregnancy, revealing aspects of humoral immunity that have the potential to improve CMV diagnostics.FUNDINGCYMAF consortium and NIH NIAID.

Antiviral Treatment and Risk of Hearing Loss in Asymptomatic and Mild Symptomatic Infants With Congenital Cytomegalovirus.

To assess hearing outcomes at 24 months of age in infants with mild congenital cytomegalovirus (cCMV) infection, depending on whether they have received antiviral treatment or not. A retrospective study within the European Registry of Children with cCMV was performed. Included children had cCMV diagnosed in utero/in the first 21 days of life, with normal physical examination, alanine aminotransferase <80 U/L and platelets >100,000 cs/mm3 and absence of hearing loss (HL) at birth. Cranial ultrasound (cUS) and/or cranial magnetic resonance imaging was normal or with minor findings (isolated lenticulostriate vasculopathy and/or germinolysis/caudothalamic or subependymal cysts, and/or focal/multifocal white matter involvement). The main outcome was the presence of HL at 24 months of age. One hundred ninety-six patients met inclusion criteria. A total of 34.7% received antiviral treatment with valganciclovir/ganciclovir. Children treated had lower gestational age, birth weight and head circumference, and maternal primary infection was less frequent. Among treated children, 21.3% presented minor findings in cUS versus 6.3% in nontreatment group (P = 0.003). Nine patients (4.6%) developed HL at 24 months. Among children with HL, 20% presented minor findings in cUS versus 11.3% in non-HL group (P = NS). HL rate was similar in treated and nontreated groups (4.6% vs. 6.3%; P = 0.6). One-third of the children were treated with antivirals and infants with minor neuroimaging findings at birth were more likely to receive antiviral. There were no differences in the prevalence of HL at 2 years of age between treated and not-treated children. Minor neuroimaging findings were not clearly associated with an increased risk of delayed onset HL.

Prenatal and postnatal antiviral therapies for the prevention and treatment of congenital cytomegalovirus infections.

Congenital cytomegalovirus infection (cCMV) is the leading infectious cause of sensorineural hearing loss and lifelong neurodevelopmental disabilities. Studies suggest antiviral therapy can prevent fetal infection after maternal primary infection, as well as halt the progression of hearing loss and neurodevelopmental disabilities in newborns with symptomatic cCMV. With growing worldwide momentum on early detection and diagnosis of cCMV, this review describes the exciting recent advances in antiviral therapies in CMV infected pregnant mothers and babies, as well as emerging evidence on anti-CMV vaccines. New opportunities for prenatal and neonatal interventions have driven a rising interest in screening and identification of asymptomatic CMV infection. Routine screening of pregnant women to identify primary infection in first trimester is now advocated in Western Europe but has yet to be examined from a public health perspective in other regions. Evidence is emerging for maternal valaciclovir therapy to prevent fetal infection after a maternal primary CMV infection in the first trimester of pregnancy. For those infants who are born with symptomatic cCMV, a 6-month course of valganciclovir, started within the first 4 weeks of life, and possibly up to 13 weeks of life, is the current recommended therapy. However, there is unclear evidence for the benefit of treatment for asymptomatic cCMV and cCMV with isolated hearing loss. Research to identify more effective antivirals and an effective CMV vaccine continues. More research is needed to determine the region-specific applicability of the new European recommendations for routine CMV screening in pregnancy. Areas of uncertainty in postnatal management include timing of initiation, duration of treatment and identifying pediatric subgroups that benefit from modification of the standard treatment recommendations.

Seroprevalence of cytomegalovirus among pregnant women in Singapore

BackgroundCytomegalovirus (CMV) is the most common congenital infection in pregnancy with potential long-term adverse effects on the fetus. There is limited data on CMV seroprevalence in pregnant women in Singapore, with last reported study dating back over two decades. We look at the latest CMV seroprevalence in antenatal population in Singapore.MethodsBetween January 2021 and August 2021, 385 pregnant women receiving antenatal care at Singapore General Hospital were randomly selected for CMV IgG test to be performed on their blood samples collected during the first trimester of their pregnancies. Positivity for CMV IgG represents past exposure prior to pregnancy.ResultsOverall CMV seroprevalence was 71.7% (276/385) (95% CI 067, 0.76, p value < 0.001). The trend of CMV IgG positivity increased with age, 68.3% (95% CI 0.60, 0.76, p value < 0.001) in those aged 20–29, 72.5% (95% CI 0.66, 0.78, p value < 0.001) in the 30–39 age group, and 79.0% (95% CI 0.67, 0.76, p value 0.012) in women over 40.ConclusionsThere is a declining trend in CMV seroprevalence among pregnant women in Singapore, which indicates that a substantial portion of this population faces the risk of primary maternal CMV infection during pregnancy. Emerging research suggests that prenatal treatment with valacyclovir effectively reduces the likelihood of vertical transmission. Considering this evidence, it is imperative to reevaluate the recommendations for universal maternal CMV screening during pregnancy.

Maternal Cytomegalovirus (CMV) Serology: The Diagnostic Limitations of CMV IgM and IgG Avidity in Detecting Congenital CMV Infection.

Congenital cytomegalovirus (cCMV) is a common congenital viral infection. Testing for cCMV usually begins with assessing maternal CMV serology, specifically IgM and IgG antibodies. A negative maternal CMV IgM suggests a low risk of recent maternal CMV infection, thereby suggesting a low risk of cCMV in the fetus. Consequently, cCMV is often ruled out when maternal CMV IgM is negative. In our perinatal autopsy and placental pathology database, we identified 5 cases of cCMV despite negative maternal CMV IgM results in the second trimester. In all 5 cases, fetal abnormalities were first detected by ultrasound in the second trimester, prompting maternal CMV testing. Since second trimester maternal CMV IgM was negative in all cases, cCMV was considered unlikely, thus precluding further prenatal CMV testing in 4 of these cases. The diagnosis of cCMV was subsequently made through placental and/or autopsy examinations. Following this diagnosis, retrospective CMV serology and IgG avidity testing was performed on stored frozen first-trimester maternal blood samples in 3 cases. Among these, the first-trimester samples in 2 cases were IgG+, IgM+, and exhibited low IgG avidity, suggesting a primary maternal CMV infection around the time of conception. In the third case, both first and second-trimester maternal blood samples were IgG+, IgM-, and showed high IgG avidity, suggesting a non-primary maternal CMV infection (i.e., reactivation or reinfection of CMV). A negative maternal CMV IgM in the second trimester cannot exclude cCMV infection. While CMV IgG avidity testing and analysis of stored frozen first-trimester maternal blood samples provide valuable insights, they have limitations. CMV PCR performed on amniotic fluid is a useful prenatal diagnostic tool. For cases of unexplained fetal abnormalities or death, autopsy and placental examination are recommended.

Manifestações clínicas e o manejo da Infecção Congênita pelo Citomegalovírus: Uma revisão sistemática.

Objective: The general objective of the present study is to analyze the scientific production on Congenital Cytomegalovirus Infection, seeking to identify the main clinical manifestations, as well as the main methods used in the treatment of this pathology. Methodology: It is a systematic review focused on understanding the main aspects of Congenital Cytomegalovirus. The research was guided by the question: "What are the main signs and symptoms of congenital Cytomegalovirus infection in the pediatric population, as well as what are the therapeutic resources used in clinical practice?". To find answers, searches were performed in the PubMed database using four descriptors combined with the Boolean term "AND". This resulted in 194 articles. 23 articles were selected for analysis. Results: Sequelae of congenital cytomegalovirus (cCMV) can occur in primary and non-primary maternal infections, and primary infections present a higher risk of transplacental transmission. Prenatal and neonatal screening is not routinely recommended due to the absence of preventive medication and difficulty in predicting sequelae. Sensorineural hearing loss is the most common sequelae, occurring in both symptomatic and asymptomatic cases. Antiviral treatments are promising but carry significant risks, and vaccination remains a developing challenge. Conclusion: Congenital CMV infections affect child development. Diagnostic advances, such as PCR, improve detection, but the lack of a vaccine and the need for preventive education are challenges. Antiviral treatment is effective, but requires close monitoring, so a multidisciplinary approach is essential to mitigate the impacts of congenital CMV and improve children's quality of life.

Cytomegalovirus-Specific Hyperimmune Immunoglobulin Administration for Secondary Prevention after First-Trimester Maternal Primary Infection: A 13-Year Single-Center Cohort Study.

Primary cytomegalovirus infection during pregnancy has a high risk of vertical transmission, with severe fetal sequelae mainly associated with first-trimester infections. We conducted a retrospective analysis of 200 IU/kg cytomegalovirus-specific hyperimmune globulin (HIG), used in first-trimester maternal primary infections for congenital infection prevention. The primary outcome was vertical transmission, defined as neonatal viruria or positive amniocentesis if pregnancy was discontinued. HIG, initially administered monthly and since 2019 biweekly, was discontinued in negative amniocentesis cases. Women declining amniocentesis and positive amniocentesis cases with normal sonography were offered monthly HIG until delivery as a treatment strategy. The total transmission rate was 29.9% (32/107; 10 pregnancy terminations with positive amniocentesis, 18 completed pregnancies with positive amniocentesis and 4 declining amniocentesis). Maternal viremia was the only factor associated with fetal transmission (OR 4.62, 95% CI 1.55-13.74). The transmission rate was not significantly different whether HIG was started during the first or second trimester (28.2% vs. 33.3%; p = 0.58), or between monthly and biweekly subgroups (25.7% vs. 37.8%, p = 0.193). Pre-treatment maternal viremia could inform decisions as a predictor of congenital infection.

The Effect of Valacyclovir on Secondary Prevention of Congenital Cytomegalovirus Infection, Following Primary Maternal Infection Acquired Periconceptionally or in the First Trimester of Pregnancy: An Individual Patient Data Meta-analysis

The Effect of Valacyclovir on Secondary Prevention of Congenital Cytomegalovirus Infection, Following Primary Maternal Infection Acquired Periconceptionally or in the First Trimester of Pregnancy: An Individual Patient Data Meta-analysis

Indirect impact of SARS-CoV-2 pandemic on incidence of maternal primary cytomegalovirus and Toxoplasma gondii infection in pregnancy.

Public health interventions promoted during the SARS-CoV-2 pandemic to control viral spread have impacted the occurrence of other communicable disease. Yet no studies have focused on perinatal infections with the potential for neonatal sequelae, including cytomegalovirus (CMV) and Toxoplasma gondii (TG). Here we investigate whether incidence rates of maternal primary CMV and TG infection in pregnancy were affected by the implementation of pandemic-related public health measures. A retrospective study including all pregnant women with confirmed primary CMV or TG infection in pregnancy, managed between 2018 and 2021 at two university centers. The incidence rate was calculated as the number of CMV and TG infections per 100 consultations with a 95% confidence interval (CI). Data were compared between pre-pandemic (2018-2019) and pandemic (2020 and 2021) years. The Newcombe Wilson with Continuity Correction method was employed to compare incidence rates. The study population included 215 maternal primary CMV and 192 TG infections. Rate of maternal primary CMV infection decreased in 2021 compared with 2018-2019 (4.49% vs 6.40%, attributable risk [AR] 1.92, P = 0.019). By contrast, the rate of TG infection substantially increased in 2020 (6.95% vs 4.61%, AR 2.34, P = 0.006). Close contact with cats was more common among patients with TG infection in 2020 and 2021 than among pre-pandemic TG-infected women (26.3% and 24.4% vs 13.3%, P = 0.013). Pandemic-related public health interventions and associated behavioral and lifestyle changes exerted a divergent effect on the incidence of primary CMV and TG infection in pregnancy, likely due to modulation of exposure to risk factors for these infections.

Predictors of the Outcome at 2 Years in Neonates With Congenital Cytomegalovirus Infection.

Approximately 20% of neonates with congenital cytomegalovirus (cCMV) develop long-term sequelae. The ability to accurately predict long-term outcomes as early as the neonatal period would help to provide for appropriate parental counseling and treatment indications. With this study, we aimed to identify neonatal predictive markers of cCMV long-term outcomes. As this study's subjects, we chose neonates diagnosed with cCMV in 13 hospitals throughout France recruited from 2013 to 2017 and evaluated for at least 2 years with thorough clinical, audiology, and imaging evaluations and psychomotor development tests. A total of 253 neonates were included, and 3 were later excluded because of the identification of a genetic disorder. A total of 227 were followed up for 2 years: 187/227 (82%) and 34/227 (15%) were infected after a maternal primary or nonprimary infection, respectively, 91/227 (40%) were symptomatic at birth, and 44/227 (19%) had cCMV sequelae. Maternal primary infection in the first trimester was the strongest prognosis factor (odds ratio = 38.34 [95% confidence interval, 5.02-293], P < .001). A predictive model of no risk of sequelae at 2 years of age according to normal hearing loss at birth, normal cerebral ultrasound, and normal platelet count had 98% specificity, 69% sensitivity, and 0.89 area under the curve (95% confidence interval, 0.83-0.96). In the studied population, children with normal hearing at birth, normal platelet count at birth, and a normal cranial ultrasound had no risk of neurologic sequelae and a low risk of delayed unilateral sensorineural hearing loss. The use of this model based on readily available neonatal markers should help clinicians establish a personalized care pathway for each cCMV neonate.

Maternal and congenital human cytomegalovirus infection: laboratory testing for detection and diagnosis.

Human cytomegalovirus (CMV) is the leading cause of congenital infection worldwide and the most common cause of non-genetic sensorineural hearing loss. As there is no vaccine or other specific intervention to prevent congenital CMV infection, there is a need to identify maternal and congenital infections with sensitive and specific testing as early as possible. There is no widely accepted practice for screening during pregnancy or in all newborns for identification of possible cases of congenital CMV. Currently, screening during pregnancy is limited to those identified as at risk followed by fetal and/or neonatal testing when congenital infection is suspected. This review focuses primarily on the current status of laboratory testing for diagnosis of maternal and congenital CMV infections. Primary maternal infection is best diagnosed using serologic testing, including CMV IgM, IgG, and avidity testing, while fetal infection should be assessed by nucleic acid amplification testing (NAAT) of amniotic fluid. Urine and saliva NAATs are the mainstay for diagnosis of congenital CMV in the first 3 weeks of life. Testing of dried blood spots can be useful for diagnosis of congenital CMV outside of the newborn period. The gaps in knowledge such as the prognostic value of viral loads in various sample types are addressed.

Impact of Cytomegalovirus (CMV) on an Academic Pediatric Infectious Diseases Outpatient Clinic Referral Population, 2005-2020: Will the Advent of Universal Congenital CMV (cCMV) Screening Change Clinical Practice Referral Patterns?

Cytomegalovirus (CMV) infections exert a substantial impact on the practice of pediatric infectious diseases. Although most infections in children are minimally symptomatic, several populations are at risk for CMV-associated disease, including immunosuppressed children, children with HIV infection, and, most significantly, children with congenital CMV (cCMV) infection. In spite of the ubiquitous nature of CMV infection, few studies have quantified the impact of CMV-associated care in a pediatric outpatient clinic setting. We evaluated the impact of CMV on clinical care in an outpatient clinic setting over a fifteen-year period at the University of Minnesota (UMN) Masonic Children's Hospital Pediatric Infectious Diseases (PID) Clinic. A retrospective review of clinic appointments identified 253 unique patients specifically evaluated over this time period for consideration of CMV infection. Of these, 242 were pediatric patients. The majority of the pediatric patients evaluated in the PID clinic were referred for either confirmed or suspected cCMV infection, including children referred for consideration of CMV as a potential reason for a failed newborn hearing screen (NHS) and/or for evaluation of CMV as a possible etiology for documented hearing loss. In total, 116 of the children evaluated during this time period (48%) were unequivocally confirmed as having cCMV infection, with an additional 37 (15%) presenting with presumed, probable, or possible cCMV infection. A total of 16 (7%) of the pediatric CMV cases were confirmed to be post-natally acquired infections. Of the 253 total patients, 11 (4%) of the referrals were for pregnant patients seeking advice about potential therapies in the setting of a known or suspected primary maternal infection during their pregnancies, with an attendant risk of fetal CMV infection. This overview of the demographics and referral patterns for patients evaluated for known or suspected CMV infections in a tertiary care center outpatient PID clinic will serve as a useful baseline assessment, even as future patterns of outpatient care are highly likely to evolve. We predict that PID clinic referrals for newborns identified by universal cCMV screening programs will result in a shift of the CMV outpatient population to healthier infants with clinically inapparent infections, and care will need to be taken by practitioners not to over-medicalize management for these asymptomatic newborns.

Congenital cytomegalovirus infection in newborns suspected of congenital rubella syndrome in Iran: a cross-sectional study

BackgroundFollowing rubella virus control, the most important cause of congenital infections is human cytomegalovirus (HCMV). Congenital CMV (cCMV) may happen both in primary and non-primary maternal infections. The present study aimed to screen cCMV in symptomatic newborns suspected of congenital rubella syndrome (CRS) in Iran.MethodsOut of 1629 collected infants' serum samples suspected of CRS but negative for rubella IgM, 524 samples were selected regarding cCMV complications. These samples were divided into two age groups: 1- one month and younger, 2- older than 1 month up to one year. Anti-HCMV IgM detection was performed on these serums. Then HCMV IgG avidity assay and HCMV DNA detection were carried out on all samples with positive and borderline results in IgM detection.ResultsHerein, 3.67% of symptomatic infants aged one month and younger had positive and borderline HCMV IgM, 12.5% of which had a low avidity index (AI). HCMV IgM detection rate among symptomatic infants older than one month to one year was 14.5%. Identified genotypes in this study were gB-1(63.63%), gB2 (18.18%), and gB3 (18.18%), respectively.ConclusionsThis comprehensive study was performed on serum samples of symptomatic infants clinically suspected of cCMV from all over Iran. There was a good correlation between serology findings and PCR.

Congenital herpes simplex with ophthalmic and multisystem features: a case report

BackgroundNeonatal herpes simplex virus (HSV) infection is rare and has significant morbimortality rates. Approximately 85% of newborns are infected intrapartum, and risk factors for mother-to-child transmission include vaginal delivery, primary maternal infection, and prolonged rupture of membranes. Neonatal HSV can manifest with isolated mucocutaneous lesions, neurological involvement, or disseminated disease. In general, herpetic infection can cause blepharoconjunctivitis or keratitis. We report a rare case of congenital herpes with ophthalmologic manifestations and multisystemic involvement.Case presentationA preterm infant, born at 32 weeks and 2 days, with presumed neonatal infection developed intestinal and respiratory complications, as well as hyperemic lesions on the left nostril and oral mucosa. An ophthalmological assessment was requested and brought up the suspicion of HSV infection, indicating empirical treatment with endovenous acyclovir. Later, a new ocular examination was suggestive of panuveitis. Afterward, serum IgM antibodies to HSV-1 and HSV-2 were positive. Proper antiviral therapy led to an improvement in the condition.DiscussionNeonatal herpes is associated with a high risk of persistent skin lesions, long-term neurological disability and other lasting sequelae. It is essential to consider HSV infection in cases of neonatal conjunctivitis, especially in patients with an epithelial defect and no improvement after initial treatment with topical or systemic antibiotics.ConclusionsIn the management of neonatal HSV, early diagnosis is essential for the timely initiation of antiviral therapy. Our report highlights that ocular assessment can be crucial in the correct diagnostic investigation of this condition.

The Utility of Maternal TORCH Screening Due to Obstetrical Indications in Detecting Congenital Infections: A Retrospective Observational Study.

The diagnostic yield of TORCH screening for obstetrical indications is unclear. We evaluated TORCH testing results among women with intrauterine growth restriction (IUGR), polyhydramnios and oligohydramnios; and associations with congenital infections in neonates. This retrospective single-center study included all the women diagnosed with IUGR, polyhydramnios or oligohydramnios who underwent serological TORCH testing during 2010-2019. TORCH screening included Toxoplasma, cytomegalovirus (CMV), rubella IgM and IgG. The data, which were cross-referenced with data of neonates with congenital TORCH infections during the same period, included indications for neonatal testing, sonographic findings and neonatal ophthalmologic and hearing findings. Six women of 771 (0.8%) were diagnosed with primary TORCH infection: 4 (0.5%) with toxoplasmosis, and 2 (0.3%) with CMV. None had a confirmed congenital infection. The rates of positive maternal TORCH screening in IUGR and polyhydramnios were 2.1% and 0.6%, respectively. Maternal TORCH infection was not identified in any woman with oligohydramnios or severe polyhydramnios. None of the neonates with congenital infection were screened for TORCH during pregnancy due to polyhydramnios, oligohydramnios or IUGR. Among the neonates with congenital CMV, the most common indication for performing neonatal CMV polymerase chain reaction was suspected primary maternal infection during pregnancy due to symptomatic CMV. No incidences of congenital rubella were noted in the last decade in our medical center. Our results suggest that routine TORCH screening in pregnancies complicated with IUGR, polyhydramnios or oligohydramnios should be avoided. Suggestive maternal symptoms and specific fetal sonographic features should prompt testing for CMV and Toxoplasma infection.

Comparison of two serological screening strategies for cytomegalovirus primary infection in the first trimester of pregnancy

IntroductionCMV serology screening in the first trimester pregnancy is based on IgG and IgM testing followed by IgG avidity in cases with positive IgM. However, the sensitivity of this strategy to diagnose maternal primary infection has been questioned. The objective of the study was to compare this strategy 1 with a strategy 2 consisting of running avidity test on all samples with positive IgG (ignoring IgM results) using fully automated current generation CMV IgG, IgM and IgG avidity assays. Population and methods1516 consecutive pregnant women between 12 and 14 weeks were screened in one maternity. Strategy 1 was done prospectively with LIAISON® CMV IgG II and LIAISON® CMV IgM II, followed by LIAISON® CMV IgG Avidity II and VIDAS® CMV IgG avidity II testing in cases with positive or equivocal IgM. Strategy 2 was done retrospectively on the same population and consisted of running avidity with the LIAISON® CMV IgG Avidity II in all samples with positive IgG. ResultsThe sensitivity to diagnose a confirmed or a possible maternal primary infection in the first trimester was 91.6 % and 83 % for strategy 1 and 2 respectively (p > 0.99). Strategy 1 missed one possible primary infection and strategy 2 missed 2 confirmed primary infection. Inconclusive results happened in 0 and 0.7 % of samples with strategy 1 and 2 respectively. ConclusionThis study suggests that strategy 1 has better sensitivity and practicability than strategy 2. However, to achieve a good performance with strategy 1, using highly sensitive IgM assay is mandatory.

Relationship of maternal cytomegalovirus-specific antibody responses and viral load to vertical transmission risk following primary maternal infection in a rhesus macaque model.

Cytomegalovirus (CMV) is the most common congenital infection and cause of birth defects worldwide. Primary CMV infection during pregnancy leads to a higher frequency of congenital CMV (cCMV) than maternal re-infection, suggesting that maternal immunity confers partial protection. However, poorly understood immune correlates of protection against placental transmission contributes to the current lack of an approved vaccine to prevent cCMV. In this study, we characterized the kinetics of maternal plasma rhesus CMV (RhCMV) viral load (VL) and RhCMV-specific antibody binding and functional responses in a group of 12 immunocompetent dams with acute, primary RhCMV infection. We defined cCMV transmission as RhCMV detection in amniotic fluid (AF) by qPCR. We then leveraged a large group of past and current primary RhCMV infection studies in late-first/early-second trimester RhCMV-seronegative rhesus macaque dams, including immunocompetent (n = 15), CD4+ T cell-depleted with (n = 6) and without (n = 6) RhCMV-specific polyclonal IgG infusion before infection to evaluate differences between RhCMV AF-positive and AF-negative dams. During the first 3 weeks after infection, the magnitude of RhCMV VL in maternal plasma was higher in AF-positive dams in the combined cohort, while RhCMV glycoprotein B (gB)- and pentamer-specific binding IgG responses were lower magnitude compared to AF-negative dams. However, these observed differences were driven by the CD4+ T cell-depleted dams, as there were no differences in plasma VL or antibody responses between immunocompetent AF-positive vs AF-negative dams. Overall, these results suggest that levels of neither maternal plasma viremia nor humoral responses are associated with cCMV following primary maternal infection in healthy individuals. We speculate that other factors related to innate immunity are more important in this context as antibody responses to acute infection likely develop too late to influence vertical transmission. Yet, pre-existing CMV glycoprotein-specific and neutralizing IgG may provide protection against cCMV following primary maternal CMV infection even in high-risk, immunocompromised settings.

Asymptomatic CMV infection at birth following maternal primary infection despite valacyclovir treatment and a subsequent negative amniocentesis. Case report

Valacyclovir is currently the only pharmacological intervention demonstrated to reduce the risk of vertical CMV congenital infection within a randomized clinical trial in case of primary infection during pregnancy.So far, no data are available on the prognosis of children with congenital CMV infection diagnosed at birth after a negative amniocentesis whose mother were treated with valacyclovir during pregnancy, therefore it is essential to carry out a rigorous neurocognitive follow-up in these children in order to investigate the potential clinical consequence.

OP02.01: Effectiveness of valaciclovir for prevention of fetal infection following early gestational primary maternal cytomegalovirus infection

OP02.01: Effectiveness of valaciclovir for prevention of fetal infection following early gestational primary maternal cytomegalovirus infection