Cytomegalovirus-related childhood mortality in Australia 1999-2011

Estimates of congenital cytomegalovirus-attributable infant mortality in high-income countries: A review

As many as 5%-10% of infants with symptomatic congenital cytomegalovirus (cCMV) disease, or 0.4%-0.8% of all liveborn infants with cCMV infection, die in early infancy in high-income countries. However, estimates are uncertain due to several potential biases that can result from data limitations and study designs. First, infants with cCMV infections who die prior to diagnosis, which usually occurs at 1-4 weeks after birth, may be excluded from both the count of deaths and the denominator of cCMV births, resulting in left truncation and immortal time biases. These 'biases' are features of the data and do not reflect bias on the part of researchers, but understanding the potential existence of threats to validity can help with interpretation of findings. Left truncation of infant deaths occurring prior to diagnosis of cCMV can result in understatement of the burden of infant deaths due to cCMV. Conversely, overestimation of infant deaths associated with symptomatic cCMV may occur in clinical case series owing to greater representation of relatively severely affected infants owing to ascertainment and referral biases. In this review, we summarise the characteristics of 26 studies that reported estimates of cCMV-associated infant deaths, including potential biases or limitations to which those estimates may have been subject. We discuss study designs whose implementation might generate improved estimates of infant deaths attributable to cCMV. More complete estimates of the overall public health impact of cCMV could inform current and future screening, prevention, and vaccine research.

Vaccine value profile for cytomegalovirus

Cytomegalovirus (CMV) is the most common infectious cause of congenital malformation and a leading cause of developmental disabilities such as sensorineural hearing loss (SNHL), motor and cognitive deficits. The significant disease burden from congenital CMV infection (cCMV) led the US National Institute of Medicine to rank CMV vaccine development as the highest priority. An average of 6.7/1000 live births are affected by cCMV, but the prevalence varies across and within countries. In contrast to other congenital infections such as rubella and toxoplasmosis, the prevalence of cCMV increases with CMV seroprevalence rates in the population. The true global burden of cCMV disease is likely underestimated because most infected infants (85-90 %) have asymptomatic infection and are not identified. However, about 7-11 % of those with asymptomatic infection will develop SNHL throughout early childhood. Although no licensed CMV vaccine exists, several candidate vaccines are in development, including one currently in phase 3 trials. Licensure of one or more vaccine candidates is feasible within the next five years. Various models of CMV vaccine strategies employing different target populations have shown to provide substantial benefit in reducing cCMV. Although CMV can cause end-organ disease with significant morbidity and mortality in immunocompromised individuals, the focus of this vaccine value profile (VVP) is on preventing or reducing the cCMV disease burden. This CMV VVP provides a high-level, comprehensive assessment of the currently available data to inform the potential public health, economic, and societal value of CMV vaccines. The CMV VVP was developed by a working group of subject matter experts from academia, public health groups, policy organizations, and non-profit organizations. All contributors have extensive expertise on various elements of the CMV VVP and have described the state of knowledge and identified the current gaps. The VVP was developed using only existing and publicly available information.

The long-term burden of congenital cytomegalovirus: Hospitalisation and mortality in a population-based matched cohort study

AIM

Congenital cytomegalovirus (cCMV) infection can result in considerable morbidity and mortality. However, the impact of cCMV on health system utilisation beyond infancy is poorly defined. Here we sought to describe the burden of cCMV health service use and mortality using linked population-based datasets.

METHODS

The design was a matched cohort study using record-linked administrative datasets. Participants included all children aged 0-15 years identified through the New South Wales (NSW), Australia, Admitted Patient Data Collection who were hospitalised with an admission code for cCMV infection between 2001 and 2011. Participants were then matched by age, sex and birth postcode quintile using Socio-Economic Indexes for Area, to children randomly selected from the NSW Perinatal Data Collection, excluding those with central nervous system infections or cerebral palsy. We calculated rate ratios (RR) for hospital admissions adjusted for preterm birth, the median length of stay, cost weights of admission and odds ratio (OR) for deaths.

RESULTS

There were 130 children with cCMV matched to 2672 children. Neonates (aged <1 month) with cCMV had twice the rate of admissions (RR 2.4 95%CI 2.0, 2.8) and children aged ≥ 5yr to < 15yrs with cCMV almost eight times the rate of admissions (RR 7.8 95%CI 5.1, 11.5). Children with cCMV had significantly higher cost weights of admissions and an increased risk of mortality (OR 18.4 95%CI 7.8, 43.6).

CONCLUSION

Throughout childhood, children with cCMV had higher rates of hospital admissions, higher admission cost weights and an increased risk of mortality compared with matched peers without cCMV.

Pregnant women's knowledge and behaviour to prevent cytomegalovirus infection: an observational study

OBJECTIVES

Congenital cytomegalovirus (cCMV) infection can negatively affect pregnancy outcomes, but may be prevented by simple precautions. Literature suggests that gynaecologists do not always adequately inform about preventive behaviour and most pregnant women have a low-level knowledge regarding cCMV infection. The aim of this study is to evaluate knowledge and risk behaviours related to cCMV infection in an unselected group of pregnant women.

METHODS

An institutional based cross-sectional study was conducted in three Maternal and Fetal Divisions in Rome between November and February 2019 on 296 pregnant women, their knowledge on cCMV was measured using six cytomegalovirus (CMV) related questions.

RESULTS

Out of the 296 respondents, 59.1% had heard, read or seen information about cCMV infection. Regarding the way of transmission, 96/296 (32.4%) correctly recognize children as a potential source of the infection but only 25/296 (8.44%) knew all prevention practices, 28/296 (9.5%) of women reported that they have never performed cCMV test during pregnancy.

CONCLUSIONS

The results of this survey show that knowledge on cCMV infection among pregnant women is poor. This highlights the need to improve counselling on all preventive practices for cCMV infection during perinatal care consultation.

Knowledge of congenital cytomegalovirus (CMV) in pregnant women in Australia is low, and improved with education

BACKGROUND

Cytomegalovirus (CMV) is the most common congenital infection and can cause hearing loss and neurodevelopmental disability in infected infants. International research shows women have limited knowledge about CMV.

AIMS

To assess pregnant women's knowledge and attitudes about CMV before and after provision of information.

MATERIALS AND METHODS

Cross-sectional survey of pregnant women between November 2017 and February 2018 at two Australian hospitals. Participating women completed an initial survey on maternal characteristics, knowledge of infections, and CMV risk behaviours. Participants were then given an information leaflet and completed a follow-up survey.

RESULTS

Four hundred and fifty-seven women completed the initial survey, of whom 73/457 (16%) had heard of CMV. Behaviours increasing risk of CMV transmission were common: 58% reported regularly kissing their child on the lips; 57% did not always wash their hands after changing a wet nappy. Knowledge about CMV significantly improved after reading the leaflet in the 145 women completing the follow-up survey. More women correctly identified that CMV could cause deafness in a baby (35% before, 85% after), was spread by saliva (38% vs 94%) or urine (27% vs 86%) and prevented by hand-washing (55% vs 99%; all P < 0.001).

CONCLUSION

Knowledge about CMV was low in pregnant women. An educational leaflet was effective in improving knowledge.

Risk Factors, Geographic Distribution, and Healthcare Burden of Symptomatic Congenital Cytomegalovirus Infection in the United States: Analysis of a Nationally Representative Database, 2000-2012

OBJECTIVE

To assess risk factors, geographic distribution, length of stay, and total charges per case of symptomatic congenital cytomegalovirus infection (cCMV).

STUDY DESIGN

We performed retrospective analyses of serial cross-sectional data using the Kids' Inpatient Database, a nationally representative sample of US pediatric hospital discharges, from 2000, 2003, 2006, 2009, and 2012. Symptomatic cCMV was identified via use of the International Classification of Diseases, Ninth Revision, Clinical Modification code 771.1 among records with in-hospital birth that were accompanied by 1 or more characteristic symptoms. Demographic characteristics were compared with multivariable logistic regression. Temporal trend was assessed using linear regression. Charges were adjusted for inflation to 2012 US dollars.

RESULTS

We identified 1349 cases of symptomatic cCMV (SE 56). Symptomatic cCMV was associated with non-Hispanic black race (OR 1.70; 95% CI 1.37-2.10), government-sponsored insurance (OR 1.95; 95% CI 1.34-2.83), and birth in the American South and West (OR 1.68, 95% CI 1.35-2.09 and OR 1.61, 95% CI 1.23-2.09, respectively). In-hospital mortality and preterm birth rate ranged from 3.2%-6.8% and 50.4%-59.2%, respectively, without temporal changes. The geometric mean of total charges per case doubled from $45 771 (SE $8509) in 2000 to $89 846 (SE $10 358) in 2006 (P = .002) but did not change from 2006 to 2012. Length of stay in days was 15 (IQR 8-22) in 2000, 27 (IQR, 9-51) in 2009, and 18 (IQR, 8-47) in 2012.

CONCLUSIONS

Symptomatic cCMV was associated with non-Hispanic black race, low socioeconomic status, and birth in the American South and West and resulted in substantial healthcare burden.

Knowledge of congenital cytomegalovirus (cCMV) among physical and occupational therapists in the United States

Congenital cytomegalovirus (cCMV) infections cause more children to have permanent disabilities than Down Syndrome, Fetal Alcohol Syndrome, Spina Bifida, and pediatric HIV/AIDS combined. The risk of infection during pregnancy can be significantly decreased using universal precautions, such as thorough handwashing and cleansing of surfaces and objects that have come into contact with infected body fluids. Children under 3 years of age are commonly asymptomatic excretors of CMV, with the highest viral loads present in saliva. Pediatric therapists have regular close contact with young children, and are thus likely at elevated occupational risk of acquiring CMV. Our objective was to evaluate therapist knowledge of cCMV and its transmission. We recruited American Occupational Therapy Association (AOTA) and American Physical Therapy Association (APTA) members via electronic newsletters and printed flyers from April to September 2015. Participants completed an online, anonymous 24-question survey using Survey Monkey. We compared responses between groups and previously published CMV awareness data using binomial tests of difference of proportions and multiple logistic regression. Our study identified both a low level of therapist awareness and poor demonstrated understanding of cCMV. Self-reported cCMV awareness amongst therapists was greater than awareness in the general population, and equivalent to awareness amongst health care professionals. Whereas 52% of participants self-reported awareness of cCMV, only 18% demonstrated understanding of the behavioral modes of CMV transmission. Fewer therapists reported awareness of cCMV than other, less prevalent conditions. Higher levels of health risk knowledge were associated with greater contact with children. Most participants reported learning about cCMV from the workplace. The knowledge gaps between self-reported awareness of cCMV and demonstrated understanding of modes of transmission described by our results emphasize the need for additional training of therapists. cCMV is preventable, and accurate knowledge of modes of transmission is crucial for the health of practitioners and clients.

The obstetrician, congenital cytomegalovirus, clinical and diagnostic approaches to the pregnant woman

There is low awareness of congenital cytomegalovirus (CMV) in Australia. Routine pregnancy serological screening for CMV is not recommended, but all pregnant women should be given advice about CMV prevention. Obstetricians may be asked to see a pregnant woman when serology suggests CMV infection or when features of fetal infection are present on ultrasound. If maternal CMV infection is confirmed, the timing of infection (pre-pregnancy or gestation of pregnancy), must be determined to predict the fetal risks. In addition, it is important to establish whether maternal infection is primary or reactivation. If there is fetal infection, ultrasound can be used to attempt to establish whether the fetus may have been affected. Serial serology, CMV IgG avidity, maternal viraemia (using serum PCR), amniotic fluid CMV PCR, serial fetal ultrasounds, and possibly fetal MRI (magnetic resonance imaging) are investigations that may be useful to predict neonatal outcomes. Timely and accurate counselling is important to optimise maternal and neonatal management.