Severe Fetal Symptomatic Infection from Human Cytomegalovirus following Nonprimary Maternal Infection: Report of Two Cases.

INTRODUCTION: Human cytomegalovirus (HCMV) is the most common congenital infection, especially severe after a maternal primary infection; sequelae in neonates born to mothers experiencing a nonprimary infection have been already reported. Hereby, two cases of severe fetal HCMV disease in seroimmune gravidas referred to our Unit are described. CASES PRESENTATION: Case 1: A fetus at 21 weeks' gestation with signs of anemia and brain abnormalities at ultrasound, described at magnetic resonance (MR) imaging as ependymal irregularity and bilateral asymmetric parenchymal thinning; amniotic fluid sample was positive for HCMV although the woman had a previous immunity; after termination of pregnancy, autopsy demonstrated a thicken layer of disorganized neurons on the right cortical plate, while on the left, there was a morphological pattern coherent with polymicrogyria. Case 2: A fetus at 20 weeks' gestation with anemia, moderate atrioventricular insufficiency, hepatosplenomegaly but no major cerebral lesions. Fetal blood was positive for HCMV, although unexpected for prepregnancy maternal immunity, and intrauterine transfusion was needed. A cesarean section at 34 weeks' gestation was performed due to worsening condition of the fetus, who had a birthweight of 2,210 g and needed platelet transfusions, but MR examination and clinical evaluation were normal. CONCLUSION: The impact of nonprimary maternal infection on pregnancy outcome is unknown and fetal brain damage in HCMV seroimmune transmitter-mothers can occur as a consequence of maternal reinfection or reactivation for a hypotetic different role of HCMV-primed CD4+ or CD8+ T-cells in fetal brain, with progressive brain lesions coexistent in the first case and with severe unexpected anemia in the second case. A previous maternal HCMV immunity should not exempt to test anemic fetuses for such infection, nor to consider a potential transplacental transmission.

Human Cytomegalovirus Genomes Sequenced Directly From Clinical Material: Variation, Multiple-Strain Infection, Recombination, and Gene Loss.

The genomic characteristics of human cytomegalovirus (HCMV) strains sequenced directly from clinical pathology samples were investigated, focusing on variation, multiple-strain infection, recombination, and gene loss. A total of 207 datasets generated in this and previous studies using target enrichment and high-throughput sequencing were analyzed, in the process enabling the determination of genome sequences for 91 strains. Key findings were that (i) it is important to monitor the quality of sequencing libraries in investigating variation; (ii) many recombinant strains have been transmitted during HCMV evolution, and some have apparently survived for thousands of years without further recombination; (iii) mutants with nonfunctional genes (pseudogenes) have been circulating and recombining for long periods and can cause congenital infection and resulting clinical sequelae; and (iv) intrahost variation in single-strain infections is much less than that in multiple-strain infections. Future population-based studies are likely to continue illuminating the evolution, epidemiology, and pathogenesis of HCMV.

Virus and Antibody Dynamics in Travelers With Acute Zika Virus Infection.

Background: To improve our understanding of the natural history of Zika virus (ZIKV) infection in humans, we described the dynamics of ZIKV RNA shedding in different body fluids and antibody responses in patients with acute infection. Methods: Twenty-nine adults with travel-associated infection and 1 case of sexual transmission were enrolled and followed up with weekly ZIKV RNA testing in blood, urine, saliva, and semen samples and antibody testing. Results: ZIKV RNA was detected in plasma, urine, and saliva of 57%, 93.1%, and 69.2% of participants, with estimated median times to clearance of 11.5 days (interquartile range [IQR] 6-24 days), 24 days (IQR, 17-34), and 14 days (IQR, 8-31), respectively. In 2 pregnant women, ZIKV RNA persisted in blood until delivery of apparently healthy infants. ZIKV RNA was detected in semen of 5 of 10 tested men; median time to clearance was 25 days (IQR 14-29), and the longest time of shedding in semen was 370 days. In flavivirus-naive patients, the median times to detection of ZIKV nonstructural protein 1 (NS1)-specific immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies were estimated as 8 days (IQR, 5-15 days) and 17 days (IQR, 12-26 days), respectively. ZIKV NS1 IgM antibodies were undetectable in patients with previous dengue. Conclusions: Prolonged viremia and ZIKV RNA shedding in urine, saliva, and semen occur frequently in patients with acute ZIKV infection. At the time of diagnosis, about half of patients are ZIKV IgM negative. ZIKV NS1 IgM antibodies remain undetectable in patients with previous dengue. Estimates of the times to viral clearance and seroconversion are useful to optimize diagnostic algorithms.

An autochthonous sexually transmitted Zika virus infection in Italy 2016.

We describe two cases of Zika virus infection involving an Italian patient returning from the Dominican Republic and his wife, who remained in Italy and had not travelled to Zika virus endemic areas in the previous months. The infection was transmitted through unprotected sexual intercourse after the man's return to Italy.

Human Cytomegalovirus-Specific Memory CD4+ T-Cell Response and Its Correlation With Virus Transmission to the Fetus in Pregnant Women With Primary Infection.

BACKGROUND: Primary human cytomegalovirus (HCMV) infection during pregnancy is the major cause of congenital viral sequelae. The HCMV-specific T-cell response may have a role in the prevention of virus transmission to the fetus. METHODS: HCMV-specific memory T cells were investigated in the second month after primary infection onset in 44 pregnant women (15 transmitting the infection to the fetus) and 8 pregnant women with remote infection. Peripheral blood mononuclear cells were stimulated for 12 days with peptide pools of HCMV proteins IE-1, IE-2, and pp65, and subsequently restimulated for 24 hours with the same peptide pools in a cultured enzyme-linked immunospot (ELISPOT) assay. RESULTS: In pregnant women with primary infection, the cultured ELISPOT assay detected a higher T-cell response to pp65 than to IE-1 or IE-2, whereas in remote infection pp65-, IE-1-, and IE-2-specific T cells were detected at comparable levels. During primary infection, the cultured ELISPOT response was mainly mediated by CD4+ T cells, and was lower than in remote infection. Strikingly, the cultured ELISPOT response to pp65 (but not to IE-1 or IE-2) was significantly higher in nontransmitting mothers. To detect other factors potentially associated with nontransmission, different serological parameters were analyzed. Only immunoglobulin G avidity index was higher in nontransmitting mothers, who showed also a lower DNAemia level. These 2 parameters remained associated with congenital infection in multivariate analysis. CONCLUSIONS: Determination of HCMV-specific T cells by cultured ELISPOT, in pregnant women with primary HCMV infection, in association with avidity index and DNAemia may help to assess the risk of HCMV fetal transmission.

Zika virus isolation from semen.

Zika virus (ZIKV) can be sexually transmitted and replicative particles were first detected in a semen sample from a patient during the 2013-14 French Polynesia outbreak. Here we describe the virus isolation from semen of a patient returning to Italy from Brazil.

Risk of congenital disease in 46 infected fetuses according to gestational age of primary human cytomegalovirus infection in the mother.

Given the difficulty in establishing the exact time of HCMV transmission from mother to fetus, HCMV intrauterine infection was investigated in 46 infected fetuses/newborns by correlating maternal and fetal parameters with clinical outcome according to the time interval between the onset of maternal infection and prenatal diagnosis. In detail, 17/28 (60.7%) asymptomatic and 18/18 (100%) symptomatic fetuses/newborns were infected as a consequence of a primary maternal HCMV infection acquired ≤8 weeks of gestational age, while 11/28 (39.3%) asymptomatic and 0/18 (0%) symptomatic fetuses/newborns were congenitally infected when maternal infection was acquired >8 weeks' gestation. Symptomatic fetal infections appeared to be associated with a maternal primary infection occurring at ≤ 8 weeks' gestation. Cordocentesis performed at 20 weeks' gestation should be restricted to high risk infected fetuses.

Miscarriage following dengue virus 3 infection in the first six weeks of pregnancy of a dengue virus-naive traveller returning from Bali to Italy, April 2016.

We report miscarriage following dengue virus (DENV)-3 infection in a pregnant woman returning from Bali to Italy in April 2016. On her arrival, the woman had fever, rash, asthenia and headache. DENV RNA was detected in plasma and urine samples collected the following day. Six days after symptom onset, she had a miscarriage. DENV RNA was detected in fetal material, but in utero fetal infection cannot be demonstrated due to possible contamination by maternal blood.

Diagnostic and prognostic value of molecular and serological investigation of human parvovirus B19 infection during pregnancy.

To define diagnostic and prognostic markers of parvovirus B19 (B19V) fetal infection, two groups were investigated: 1) pregnant women with specific symptoms or contacts with symptomatic households (n=37); 2) mothers with pathological ultrasound findings and the relevant fetus at the time of prenatal diagnosis (n=16). In the first group, diagnosis of B19V infection was achieved using IgM detection in 29/37 (78.3%) of patients, while B19V DNA was detected in 36/37 (97.3%) of infected women. In the second group, intrauterine infection was investigated by amniocentesis (n=5), cordocentesis (n=3) or both (n=5). Median B19V DNA load in amniotic fluid was 8.2x107 copies/ml and in fetal blood was 2x109 copies/ml. Maternal blood was positive for B19V DNA (median 3.8x104 copies/ml) in 14/16 (87.5%) women examined. At time of fetal US investigation, all mothers were B19V IgG positive and B19V IgM were detected in 10/16 (62.5%), while fetal B19V IgG and IgM were detected in 1/8 (12.5%) and 5/8 (62.5%), respectively. Phylogenetic analysis revealed that all B19V maternal and fetal strains belonged to genotype 1A. Diagnosis of maternal, fetal and neonatal B19V infection should be based on both IgM and DNA detection. Prognostic markers of congenital B19V infection need to be defined.

Maternal, fetal, and neonatal parameters for prognosis and counseling of HCMV congenital infection.

To investigate retrospectively the prognostic significance of maternal, fetal, and neonatal parameters and clinical outcome in 150 HCMV congenital infections during the period 1995-2009. HCMV fetal infection was investigated in amniotic fluid and fetal blood samples. HCMV congenital infection was confirmed in newborn urine and blood samples. Symptomatic infection was defined in HCMV-infected fetuses and in infected newborns on the basis of physical and instrumental findings. Follow-up at 3, 6, 12 months, and then annually up to school age, included clinical evaluation, funduscopic, audiologic, neurologic, and cognitive assessment. Overall, 122/150 (81.3%) newborns were asymptomatic and 28/150 (18.7%) were symptomatic at birth. The best prognostic maternal parameter of symptomatic infection at birth was gestational age at infection (P = 0.037). The best fetal virological markers were HCMV DNA levels in amniotic fluid (P < 0.001), antigenaemia levels (P = 0.007), HCMV DNA levels in blood (P = 0.004), and HCMV-specific IgM index values (P = 0.002). The only significant neonatal parameter was HCMV DNA level in blood [P = 0.006; OR, 3.62 (95% CI, 1.46-8.97)]. Symptoms at birth correlated significantly with long-term sequelae (P = 0.021). A trend towards a risk of sequelae in early (n = 15/58 examined) versus late (n = 6/57 examined) maternal infection was documented. The risk of symptomatic congenital infection at birth increased linearly with the number of significant maternal, fetal, and neonatal parameters.

Congenital Cytomegalovirus Infection With Isolated "Minor" Lesions at Fetal Magnetic Resonance Imaging: Long-Term Neurological Outcome.

BACKGROUND: The prognostic relevance of fetal/early postnatal magnetic resonance (MR) imaging (MRI) isolated "minor" lesions in congenital cytomegalovirus (CMV) infection is still unclear, because of the heterogeneity of previously reported case series. The aim of this study was to report the imaging and long-term clinical follow-up data on a relatively large cohort of infected fetuses. METHODS: Among 140 CMV-infected fetuses from a single-center 12-year-long fetal MRI database, cases that showed isolated "minor" lesions at MRI, mainly represented by polar temporal lesions, were selected. MRI features were described, and clinical follow-up information was collected through consultation of medical records and telephone interview to establish the auditory and neurological outcome of each patient. RESULTS: Thirty-six cases were included in the study. The frequency of "minor" lesions increased progressively with ongoing gestational age in cases who underwent serial MR examination; 31% of cases were symptomatic at birth for unilateral altered auditory brainstem response. At long-term clinical follow-up, performed in 35 patients at a mean age of 64.5 months (range: 25 to 138), 43% of patients were asymptomatic and 57% presented with mild/moderate disability including hearing loss (34%), unilateral in all cases but one (therefore classified as severe), and/or minor cognitive and behavioral disorders (49%). CONCLUSIONS: Descriptive analysis of the type and modality of occurrence of "minor" lesions suggests performing serial fetal/postnatal MR examinations not to miss later-onset lesions. Follow-up data from the present cohort, combined with maternal/fetal factors and serologic-laboratory parameters may contribute to improve prenatal and neonatal period counselling skills.

Slow increase in IgG avidity correlates with prevention of human cytomegalovirus transmission to the fetus.

Following primary human cytomegalovirus (HCMV) infection, virus-specific IgG antibody shift from low to high avidity with individual variations in the rate of avidity maturation. The kinetics of the avidity maturation of IgG specific for HCMV nuclear antigen in pregnant women with primary infection was investigated. Absorbance values used for avidity index calculation of 286 sequential sera collected from 69 pregnant women with primary HCMV infection were retrieved. Percent difference in absorbance values of IgG antibody bound to the solid phase after urea treatment (IgG avidity) between early (T1, 0-90, median 31 days) and late (T2, 91-180, median 136 days) serum samples was calculated for each woman. Three groups of women were identified: 24/69 (34.8%) women showed high (>100%) avidity increase between T1 and T2 (pattern H), 29/69 (42%) low (<50%) increase (pattern L), and 16/69 (23.2%) intermediate increase (pattern I). Avidity values in T1 samples were significantly higher in women with pattern L compared to women with pattern H (P=0.01). Altogether, 28/69 (40.6%) women transmitted HCMV infection to their fetuses. Fetal infection preferentially occurred (P<0.01) in women with pattern H (15/24, 62.5%) compared with women with pattern L (7/29, 24.1%). In conclusion, different patterns of IgG avidity maturation can be detected following primary HCMV infection. Pregnant women with pattern H (rapid IgG avidity increase) appear to be at higher risk for fetal infection, whereas, pregnant women developing early antibody with high avidity appear to be at a lower risk of vertical transmission.

Treatment with valacyclovir during pregnancy for prevention of congenital cytomegalovirus infection: a real-life multicenter Italian observational study.

BACKGROUND: Valacyclovir is the only treatment demonstrated to be effective for the prevention of vertical transmission of cytomegalovirus within a clinical randomized, placebo-controlled trial and has been reimbursed by the Italian National Health System since December 2020. OBJECTIVE: This study reported the results of a real-life Italian multicenter observational study on cytomegalovirus infection in pregnancy evaluating the effect of the introduction of valacyclovir in the clinical practice for the prevention of vertical transmission of cytomegalovirus. STUDY DESIGN: The outcomes of women who received valacyclovir treatment and their fetuses or newborns were compared with those of a retrospective cohort observed between 2010 and 2020 who did not receive the antiviral treatment. The inclusion criterion was the diagnosis of cytomegalovirus primary infection occurring in the periconceptional period or up to 24 weeks of gestation. The primary outcome was the transmission by the time of amniocentesis. The secondary outcomes were termination of pregnancy, transmission at birth, symptomatic infection at birth, and a composite outcome (termination of pregnancy or transmission at birth). RESULTS: A total of 447 pregnant women from 10 centers were enrolled, 205 women treated with valacyclovir (called the valacyclovir group, including 1 twin pregnancy) and 242 women not treated with valacyclovir (called the no-valacyclovir group, including 2 twin pregnancies). Valacyclovir treatment was significantly associated with a reduction of the diagnosis of congenital cytomegalovirus infection by the time of amniocentesis (weighted odds ratio, 0.39; 90% confidence interval, 0.22-0.68; P=.005; relative reduction of 61%), termination of pregnancy (weighted odds ratio, 0.36; 90% confidence interval, 0.17-0.75; P=.0021; relative reduction of 64%), symptomatic congenital cytomegalovirus infection at birth (weighted odds ratio, 0.17; 90% confidence interval, 0.06-0.49; P=.006; relative reduction of 83%). The treatment had no significant effect on the rate of diagnosis of congenital cytomegalovirus infection at birth (weighted odds ratio, 0.85; 90% confidence interval, 0.57-1.26; P=.500), but the composite outcome (termination of pregnancy or diagnosis of congenital cytomegalovirus infection at birth) occurred more frequently in the no-valacyclovir group (weighted odds ratio, 0.62; 90% confidence interval, 0.44-0.88; P=.024). Of note, the only symptomatic newborns with congenital cytomegalovirus infection in the valacyclovir group (n=3) were among those with positive amniocentesis. Moreover, 19 women (9.3%) reported an adverse reaction to valacyclovir treatment, classified as mild in 17 cases and moderate in 2 cases. Lastly, 4 women (1.9%) presented renal toxicity with a slight increase in creatinine level, which was reversible after treatment suspension. CONCLUSION: Our real-life data confirm that valacyclovir significantly reduces the rate of congenital cytomegalovirus diagnosis at the time of amniocentesis with a good tolerability profile and show that the treatment is associated with a reduction of termination of pregnancy and symptomatic congenital cytomegalovirus infection at birth.

Identifying high-confidence variants in human cytomegalovirus genomes sequenced from clinical samples.

Understanding the intrahost evolution of viral populations has implications in pathogenesis, diagnosis, and treatment and has recently made impressive advances from developments in high-throughput sequencing. However, the underlying analyses are very sensitive to sources of bias, error, and artefact in the data, and it is important that these are addressed adequately if robust conclusions are to be drawn. The key factors include (1) determining the number of viral strains present in the sample analysed; (2) monitoring the extent to which the data represent these strains and assessing the quality of these data; (3) dealing with the effects of cross-contamination; and (4) ensuring that the results are reproducible. We investigated these factors by generating sequence datasets, including biological and technical replicates, directly from clinical samples obtained from a small cohort of patients who had been infected congenitally with the herpesvirus human cytomegalovirus, with the aim of developing a strategy for identifying high-confidence intrahost variants. We found that such variants were few in number and typically present in low proportions and concluded that human cytomegalovirus exhibits a very low level of intrahost variability. In addition to clarifying the situation regarding human cytomegalovirus, our strategy has wider applicability to understanding the intrahost variability of other viruses.

Amniotic fluid biomarkers predict the severity of congenital cytomegalovirus infection.

BACKGROUNDCytomegalovirus (CMV) is the most common intrauterine infection, leading to infant brain damage. Prognostic assessment of CMV-infected fetuses has remained an ongoing challenge in prenatal care, in the absence of established prenatal biomarkers of congenital CMV (cCMV) infection severity. We aimed to identify prognostic biomarkers of cCMV-related fetal brain injury.METHODSWe performed global proteome analysis of mid-gestation amniotic fluid samples, comparing amniotic fluid of fetuses with severe cCMV with that of asymptomatic CMV-infected fetuses. The levels of selected differentially excreted proteins were further determined by specific immunoassays.RESULTSUsing unbiased proteome analysis in a discovery cohort, we identified amniotic fluid proteins related to inflammation and neurological disease pathways, which demonstrated distinct abundance in fetuses with severe cCMV. Amniotic fluid levels of 2 of these proteins - the immunomodulatory proteins retinoic acid receptor responder 2 (chemerin) and galectin-3-binding protein (Gal-3BP) - were highly predictive of the severity of cCMV in an independent validation cohort, differentiating between fetuses with severe (n = 17) and asymptomatic (n = 26) cCMV, with 100%-93.8% positive predictive value, and 92.9%-92.6% negative predictive value (for chemerin and Gal-3BP, respectively). CONCLUSIONAnalysis of chemerin and Gal-3BP levels in mid-gestation amniotic fluids could be used in the clinical setting to profoundly improve the prognostic assessment of CMV-infected fetuses.FUNDINGIsrael Science Foundation (530/18 and IPMP 3432/19); Research Fund - Hadassah Medical Organization.

Kinetics of effector functions and phenotype of virus-specific and γδ T lymphocytes in primary human cytomegalovirus infection during pregnancy.

The T-cell response to human cytomegalovirus (HCMV) primary infection was analyzed in 27 pregnant women during the first year after primary HCMV infection. Pregnant women with remote HCMV infection were enrolled as controls. Interferon-γ-producing T cells were readily detected at levels comparable (CD4(+)) or higher (CD8(+)) than controls, whereas the CD4(+) and CD8(+) lymphoproliferative response as well as IL-2 production was significantly reduced with respect to controls for at least 9 months after infection. In addition, CD45RA re-expression as well as cytotoxic T lymphocyte activity and perforin expression were the major components of the adaptive CD4(+) and CD8(+) T-cell immune response, while Vδ2(-) γδ T-cell expansion in response to HCMV infection followed kinetics similar to that of CD8(+) T cells. Reduced CD45RA re-expression directly correlated with HCMV transmission to the fetus, thus providing an important prognostic parameter.

Pitfalls in the Serological Diagnosis of Primary Human Cytomegalovirus Infection in Pregnancy Due to Different Kinetics of IgM Clearance and IgG Avidity Index Maturation.

Primary infection occurs when seronegative women are infected by human cytomegalovirus (HCMV). Diagnosis of primary infection is based on the following: antibody seroconversion, presence of IgM and low IgG avidity index (AI), and presence of DNAemia. The kinetics of HCMV-specific IgM antibody and maturation of AI might be very rapid or long-lasting during primary infection, which makes serological diagnosis insidious. The aims of this study were as follows: (i) to report atypical kinetics of HCMV-specific IgM antibody and AI early after onset of primary HCMV infection in a population of pregnant women, and (ii) to assess the frequency of such results. Altogether, 1309 sequential serum samples collected from 465 pregnant women with primary HCMV infection were included in the study. As a general rule, using the LIAISON®CMVIgMII and LIAISON®CMVIgGAvidityII assays, virus-specific IgM antibody levels decreased, while IgG AI increased over time during the first three months after infection onset. However, early clearance of IgM antibody and/or early IgG AI maturation occurred in 46/426 (10.7%) women. In more details, 20/426 (4.7%) and 26/418 (6.2%) women had undetectable IgM antibody or high IgG AI, respectively, when tested within 1-3 months after well-defined infection onset. Twenty sera from as many women with high IgG AI by the LIAISON assay were further tested for IgG AI by VIDAS®CMVIgGAvidityII and Mikrogen recomLineCMVIgG Avidity assays. Comparable results were obtained with VIDAS, whereas 14/20 sera gave low AI with the Mikrogen assay. In conclusion, about 11% of pregnant women undergoing a primary HCMV infection showed misleading serological results. Additional and appropriate testing might help in reducing the risk of missing HCMV primary infection in pregnancy. Furthermore, preconceptional testing should be strongly recommended.

Evaluation of Rooming-in Practice for Neonates Born to Mothers With Severe Acute Respiratory Syndrome Coronavirus 2 Infection in Italy.

Importance: The management of mother-infant dyads during the ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic constitutes a major issue for neonatologists. In mothers with SARS-CoV-2 infection, current recommendations suggest either to separate the dyad or encourage protected rooming-in under appropriate precautions. No data are available regarding the risk of mother-to-infant transmission of SARS-CoV-2 during rooming-in. Objective: To evaluate the risk of postnatal transmission of SARS-CoV-2 from infected mothers to their neonates following rooming-in and breastfeeding. Design, Setting, and Participants: A prospective, multicenter study enrolling mother-infant dyads from March 19 to May 2, 2020, followed up for 20 days of life (range, 18-22 days), was performed. The study was conducted at 6 coronavirus disease 2019 maternity centers in Lombardy, Northern Italy. Participants included 62 neonates born to 61 mothers with SARS-CoV-2 infection who were eligible for rooming-in practice based on the clinical condition of the mother and infants whose results of nasopharyngeal swabs were negative at birth. Exposures: Mothers with SARS-CoV-2 infection were encouraged to practice rooming-in and breastfeeding under a standardized protocol to minimize the risk of viral transmission. Main Outcomes and Measures: Clinical characteristics and real-time reverse transcriptase-polymerase chain reaction for SARS-CoV-2 on neonatal nasopharyngeal swabs at 0, 7, and 20 days of life. Results: Of the 62 neonates enrolled (25 boys), born to 61 mothers (median age, 32 years; interquartile range, 28-36 years), only 1 infant (1.6%; 95% CI, 0%-8.7%) was diagnosed as having SARS-CoV-2 infection at postbirth checks. In that case, rooming-in was interrupted on day 5 of life because of severe worsening of the mother's clinical condition. The neonate became positive for the virus on day 7 of life and developed transient mild dyspnea. Ninety-five percent of the neonates enrolled were breastfed. Conclusions and Relevance: The findings of this cohort study provide evidence-based information on the management of mother-infant dyads in case of SARS-CoV-2 maternal infection suggesting that rooming-in and breastfeeding can be practiced in women who are able to care for their infants.

Onset of valganciclovir resistance in two infants with congenital cytomegalovirus infection.

Ganciclovir and its prodrug valganciclovir are elective treatments for cCMV. Neonates with important symptoms undergo 6 months of therapy to ameliorate/prevent symptoms and late sequelae, but evidence of resistance is emerging. Over the last 5 years, we took care of 59 cCMV infants and experienced two cases of resistance among nine cCMV infants receiving long-term valganciclovir therapy. In the first case, valganciclovir therapy was prolonged beyond 6 months due to severity of symptoms, control of viral load, and absence of adverse events. Resistance was detected in the 8th month of therapy. In the second case, after a significant reduction following valganciclovir administration and no adverse events, CMV viral load suddenly increased in the 6th month of therapy due to resistance. Both events were associated with UL97 gene mutation. The cCMV infants, affected by severe symptoms, remained in a steady state during treatment, and their later neurological development was coherent with initial seriousness of diagnosis. Prolonged therapeutic exposure may therefore be a risk for resistance, suggesting that constant dosage/weight adjustments, monthly surveillance of viral load, and therapeutic drug monitoring could be proposed to monitor resistance onset and optimize the therapy regime. The risk-benefit ratio for long-term therapy, including the possibility of resistance onset, alongside SNHL and neurodevelopmental improvement, should also be evaluated.