A systematic review and meta-analysis of the prevalence of human cytomegalovirus shedding in seropositive pregnant women.

The detection of human cytomegalovirus (HCMV) in an individual's bodily fluid by culture techniques or through HCMV DNA detection by polymerase chain reaction, is known as HCMV shedding. Human cytomegalovirus shedding has the potential to transmit HCMV infection, where an individual can become infected with HCMV through contact with the bodily fluid of another individual containing HCMV. Human cytomegalovirus shedding can occur in primary infection and in non-primary infection for individuals with prior infection (HCMV seropositive). Human cytomegalovirus infection causes few or no symptoms in a pregnant woman, but can cause significant harm to her foetus if congenital CMV (cCMV) infection occurs. The association between HCMV shedding in HCMV seropositive pregnant women and the vertical transmission of HCMV to result in cCMV infection is poorly investigated, challenged by a limited understanding of the distribution of HCMV shedding in HCMV seropositive pregnant women. We systematically reviewed the published literature to describe the prevalence of HCMV shedding in HCMV seropositive women during pregnancy up to delivery. This analysis identified nine studies that met our eligibility criteria. In these studies, the prevalence of HCMV shedding in any bodily fluid of HCMV seropositive women during pregnancy and at delivery ranged from 0% to 42.5%. A meta-analysis, performed on six of the nine studies with suitable sample sizes, estimated a pooled prevalence of 21.5% [95% CI 12.7%,30.3%]. To our knowledge, this is the first review to systematically search the literature to summarise the prevalence of HCMV shedding in HCMV seropositive pregnant women. These estimates can help in the development of disease burden models and therapeutic or preventative strategies against cCMV infection in the context of non-primary maternal HCMV infection.

Learning from the experiences of pregnant women participating in a research study investigating human cytomegalovirus shedding: A qualitative study.

Transmission of human cytomegalovirus (CMV), from a pregnant woman to her fetus can cause congenital CMV infection, with life-long problems in some infected children. The presence of CMV in an infected individual's bodily fluid is known as shedding. An individual can become infected with CMV through contact with another individual who is shedding CMV in their bodily fluid, and the avoidance of contact with infected fluids may reduce the risk of infection. We explored the experiences of pregnant women taking part in a study investigating CMV shedding, to identify the potential facilitators and barriers towards engaging pregnant women with CMV risk-reduction measures. Twenty pregnant women participated in semi-structured, end-of-study, telephone interviews, analysed using thematic analysis. They participated in an observational study investigating CMV shedding in pregnant women previously infected with CMV living with young children. Participating women considered that CMV testing of themselves and their newborns was a benefit of participation, without raising additional concerns. They identified that their participation was contingent on a balance of convenience and inconvenience, and benefits and risks. Participation increased their awareness of their hygiene-based practices, leading to behavioural modifications that put them in contact with urine and saliva of their children without instructions to do so. These behavioural modifications might interfere with household routines. However, they recognised it to be a time-limited risk-reduction measure, and felt empowered by the knowledge they had gained through study participation and the support they had received from their partners. Participating women gained an increased awareness of their behaviour, resulting in behavioural modification without instructions to do this, in line with previous findings that trial participation can impact on participants' thinking about their behaviour with a possibility to influence change. Maternal research and risk-reduction measures should be centred around being informative, convenient, empowering, and supportive.

Managing challenges in congenital CMV: current thinking.

Congenital human cytomegalovirus (CMV) infection is the most common congenital infection, affecting around 1 in 200 infants in high-income settings. It can have life-long consequences for up to one in four children, including sensorineural hearing loss and neurodisability. Despite the frequency of congenital CMV and the severity for some children, it is a little-known condition by pregnant women, families and healthcare providers. Timely diagnosis of CMV infection in pregnancy is important to facilitate consideration of treatment with valaciclovir, which may reduce the risk of transmission to the fetus or reduce the severity of the outcomes for infected infants. Recognition of features of congenital CMV is important for neonatologists, paediatricians and audiologists to prompt testing for congenital CMV within the first 21 days of life. Early diagnosis gives the opportunity for valganciclovir treatment, where appropriate, to improve outcomes for affected infants. Further research is urgently needed to inform decisions about antenatal and neonatal screening, long-term outcomes for asymptomatic and symptomatic infants, predictors of these outcomes and optimal treatment for women and infants.

Vestibular and balance dysfunction in children with congenital CMV: a systematic review.

OBJECTIVE: This systematic review evaluates vestibular and balance dysfunction in children with congenital cytomegalovirus (cCMV), makes recommendations for clinical practice and informs future research priorities. DESIGN: MEDLINE, Embase, EMCARE, BMJ Best Practice, Cochrane Library, DynaMed Plus and UpToDate were searched from inception to 20 March 2021 and graded according to Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) criteria. PATIENTS: Children with cCMV diagnosed within 3 weeks of life from either blood, saliva and/or urine (using either PCR or culture). INTERVENTION: Studies of vestibular function and/or balance assessments. MAIN OUTCOME MEASURES: Vestibular function and balance. RESULTS: 1371 studies were identified, and subsequently 16 observational studies were eligible for analysis, leading to an overall cohort of 600 children with cCMV. All studies were of low/moderate quality. In 12/16 studies, vestibular function tests were performed. 10/12 reported vestibular dysfunction in ≥40% of children with cCMV. Three studies compared outcomes for children with symptomatic or asymptomatic cCMV at birth; vestibular dysfunction was more frequently reported in children with symptomatic (22%-60%), than asymptomatic cCMV (0%-12.5%). Two studies found that vestibular function deteriorated over time: one in children (mean age 7.2 months) over 10 months and the other (mean age 34.7 months) over 26 months. CONCLUSIONS: Vestibular dysfunction is found in children with symptomatic and asymptomatic cCMV and in those with and without hearing loss. Audiovestibular assessments should be performed as part of neurodevelopmental follow-up in children with cCMV. Case-controlled longitudinal studies are required to more precisely characterise vestibular dysfunction and help determine the efficacy of early supportive interventions. PROSPERO REGISTRATION: CRD42019131656.

An observational, cohort, multi-centre, open label phase IV extension study comparing preschool DTAP-IPV booster vaccine responses in children whose mothers were randomised to one of two pertussis-containing vaccines or received no pertussis-containing vaccine in pregnancy in England.

An antenatal pertussis vaccination programme was introduced in 2012 in the UK in the context of a national outbreak of pertussis. It has been shown that a lower antibody response to primary immunisation can be seen for certain pertussis antigens in infants born to women who received pertussis-containing antenatal vaccines, a phenomenon known as blunting. The longer-term impact of this has not been documented previously, and accordingly was evaluated in this study. Children were predominantly recruited from a previous study in which their mothers had received acellular pertussis-containing antenatal vaccines (dTaP3-IPV [diphtheria toxoid, tetanus toxoid, three antigen acellular pertussis and inactivated polio] or dTaP5-IPV [diphtheria toxoid, tetanus toxoid, five antigen acellular pertussis and inactivated polio]), or no pertussis-containing vaccine. Blood samples were obtained prior to and one month after the acellular pertussis-containing preschool booster (dTaP5-IPV) was given at around age 3 years 4 months. Pre- and post-booster immunoglobulin G (IgG) geometric mean concentrations (GMCs) against pertussis toxin, filamentous haemagglutinin, fimbriae 2 & 3, and pertactin, were compared. Prior to the receipt of the preschool booster, there was no difference in the IgG GMCs against pertussis-specific antigens between children born to women vaccinated with dTaP3-IPV and dTaP5-IPV; however, IgG GMCs against pertussis toxin were significantly lower in children born to women vaccinated with dTaP3-IPV compared with children born to unvaccinated women (geometric mean ratio 0.42 [95 % CI 0.22-0.78], p = 0.03). One month after the receipt of the preschool booster there was no differences between the groups. The blunting effect of antenatal pertussis vaccine on pertussis responses in children can persist until preschool age, although it is overcome by the administration of a booster dose. ClinicalTrials.gov registration number: NCT03578120.

Neonatal listeriosis in the UK 2004-2014.

OBJECTIVE: To define the clinical features and outcomes of neonatal listeriosis, and identify the maternal risk factors to seek scope for improvement. METHODS: Neonatal listeriosis was identified prospectively from a United Kingdom neonatal infection surveillance network (neonIN) between 2004 and 2014. The participating neonatal units completed a study-specific proforma. RESULTS: The incidence of neonatal listeriosis was 3.4 per 100,000 live births. Of the 21 cases identified, 19 were confirmed with a median gestational age of 33 weeks and a median birth weight of 1960 g. The majority had clinical features (95%, 18/19), presented within the first 24 h (95%, 18/19), and received penicillin empirically (94%, 18/19). The neonatal case-fatality rate was 21% (24% if probable cases were included). A proportion of mothers were investigated (60%, 12/18) and diagnosed with listeriosis (58%, 7/12); 32% (6/19) were treated with antibiotics but only 33% (6/12) included penicillin. DISCUSSION: Despite its rarity and the prompt and appropriate use of antibiotics neonatal listeriosis has a high case-fatality rate. There is room for improvement in the adherence to the empiric antibiotic choice for puerperal sepsis, according to the national guidelines as this, would target listeriosis. Strategies should be in place to prevent pregnancy-associated listeriosis in higher risk population.