Are female daycare workers at greater risk of cytomegalovirus infection? A secondary data analysis of CMV seroprevalence between 2010 and 2013 in Hamburg, Germany

Cross-sectional study to assess awareness of cytomegalovirus infection among pregnant women in Germany

BACKGROUND

Study aimed to assess awareness of congenital cytomegalovirus (CMV) infection and its determinants in pregnancy.

METHODS

Cross-sectional survey was conducted in five hospital-based maternity units in Germany. Pregnant women attending the maternity departments completed interviewer/self-administered survey questionnaire. High-risk group was defined according to contact with children under five years of age (at home or at work). Quantitative analyses using multivariable logistic regression were performed.

RESULTS

One thousand two hundred thirty-three pregnant women were included. 48.5% (n = 598) of women reported any knowledge about risk of CMV infection during pregnancy. CMV infection was less known than other infections or diseases (education about toxoplasmosis 95.5% (n = 1,177), listeriosis 60.5% (n = 746). 38% (n = 468) of participants received education about CMV. CMV awareness was associated with the level of education and employment in childcare or medical care. Only 32% (n = 394) of the women made use of serological screening for CMV during pregnancy (individual health service). 40.8% (n = 503) of pregnant women were classified as high-risk group. They had significantly higher knowledge and education about CMV, and msignificantlycant more often use of the serological screening.

CONCLUSIONS

Less than half of pregnant women surveyed were aware of potential risk associated with CMV infection during pregnancy. In our study,one-third third of pregnant women made use of the serological screening for CMV. Regarding the lack of current consensus on the role of serological CMV screening for pregnant women, hygiene preventive measures are the only evidence-based recommendation for pregnant women and knowledge increase could potentially have major public health impact.

Prevalence, incidence, and risk factors associated with cytomegalovirus infection in healthcare and childcare worker: a systematic review and meta-analysis

BACKGROUND

Cytomegalovirus (CMV) is transmitted by direct contact with body fluids from infected individuals. Transmission of CMV in households, particularly those with young children, contributes significantly to CMV infection in the general population. However, little is known about the contribution of occupational healthcare or childcare exposure to risk of CMV infection.

OBJECTIVES

To determine CMV seroprevalence, incidence of primary infection, and associated risk factors in healthcare and childcare workers.

METHODS

Six electronic databases were searched systematically for publications on CMV infection in healthcare and childcare workers until March 7, 2022. Two authors independently evaluated the literature for quality and inclusion in our analyses. The pooled results for seroprevalence, incidence, and relative risk (RR) were determined using a random effects model. Heterogeneity among studies was quantified and further investigated in subgroup analysis and meta-regression. Publication bias was assessed using funnel plot. Statistical analyses were preformed using R version 4.05.

RESULTS

Forty-eight articles were included in this meta-analysis (quality assessment: 18 good, 14 fair, and 16 poor). Pooled CMV seroprevalence was 59.3% (95% CI: 49.8-68.6) among childcare workers and 49.5% (95% CI: 40.3-58.7) among healthcare workers, and pooled incidences of primary CMV infection per 100 person-years were respectively 7.4 (95% CI: 3.9-11.8) and 3.1 (95% CI: 1.3-5.6). RR for primary infection compared to controls were 3.4 (95% CI: 1.3-8.8) and 1.3 (95% CI: 0.6-2.7) for healthcare and childcare workers, respectively. The odds of CMV seropositivity were 1.6 (95% CI: 1.2-2.3) times higher for childcare workers compared to controls, but not significantly different between healthcare workers and controls (0.9; 95% CI: 0.6-1.2). CMV seropositivity in both groups was significantly associated with having one or more children residing at home, marital status, ethnicity, and age.

CONCLUSIONS

Childcare workers, but not healthcare workers, have an increased risk of prevalent and incident CMV infection, a risk that is further increased with the presence of at least one child living at home. These findings suggest that enforcing simple, conventional hygienic measures in childcare settings could help reduce transmission of CMV, and that special precautionary measures for preventing CMV infection may not be required for pregnant healthcare workers.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020139756.

The risk of cytomegalovirus infection in daycare workers: a systematic review and meta-analysis

PURPOSE

The primary aim of this review was to summarize the evidence on the relationship between being a daycare worker working with children and the possible increased risk of cytomegalovirus infection.

METHODS

We searched the Medline and Embase databases using search strings defined according to the population, exposure, comparison, and outcomes (PECO) applicable to our research questions in order to find studies published since 2000. Two independent reviewers evaluated the search hits using predefined inclusion and exclusion criteria. A manual search was performed to identify additional relevant literature. We extracted the resulting studies and assessed them in eight domains of bias. The pooled CMV seroprevalence for daycare workers compared to the general population was calculated.

RESULTS

After evaluating the 6879 records, six methodologically adequate studies were identified: five cross-sectional studies and one cohort study. The pooled seroprevalence of daycare workers was 59.3% (95% CI 47.6-70.9). The four studies investigating risk of infection indicated an increased seroprevalence for daycare workers compared to a reference population (prevalence ratio, PR = 1.54, 95% CI 1.33-1.77). No study evaluated CMV seroconversions for daycare workers.

CONCLUSIONS

Our findings suggest a higher CMV seroprevalence for daycare workers compared to the general population. Notwithstanding the need for longitudinal and intervention studies, preventative efforts are needed. A pooled PR of 1.54 is compatible with a doubled seroconversion risk corresponding to a vocational probability of 50% if the substantial underestimation of the actual occupational seroconversion risk by prevalence-based estimators is considered.

Infections in Healthcare Workers in Germany-22-Year Time Trends

Health workers (HWs) run an increased risk of infection. The standardised data set of an accident insurer was used to analyse the time trends of infection-related claims and confirmed occupational diseases (ODs) in HWs. The numbers of claims and confirmed claims for different infections were analysed for the years 1996 to 2017. The rate of claims and confirmed ODs were calculated per 100,000 full-time workers. The number of claims was relatively stable over time. However, the rate per 100,000 full-time workers decreased from 25.2 to 15.4. The decrease was most pronounced for hepatitis B and hepatitis C infections, which were the most frequent infections for which claims were made at the start of the period. In 2017, tuberculosis (TB)-related claims were more frequent than those related to blood-borne virus infections. However, the growing number of TB claims does not reflect an increased infection risk, but rather improved methods for the diagnosis of latent TB infection (LTBI). Measures to prevent blood-borne virus infections in HWs were successful in the last 22 years, but attention should be paid to newly emerging infections.

Development of a Bead-Based Multiplex Assay for the Analysis of the Serological Response against the Six Pathogens HAV, HBV, HCV, CMV, T. gondii, and H. pylori

The spread of infectious diseases and vaccination history are common subjects of epidemiological and immunological research studies. Multiplexed serological assays are useful tools for assessing both current and previous infections as well as vaccination efficacy. We developed a serological multi-pathogen assay for hepatitis A, B and C virus, cytomegalovirus (CMV), Toxoplasma gondii, and Helicobacter pylori using a bead-based multiplex assay format. The multi-pathogen assay consisting of 15 antigens was utilized for the analysis of the serological response in elderly individuals of an influenza vaccination study (n = 34). The technical assay validation revealed a mean intra-assay precision of coefficient of variation (CV) = 3.2 ± 1.5% and a mean inter-assay precision of CV = 8.2 ± 5.3% across all 15 antigens and all tested samples, indicating a robust test system. Furthermore, the assay shows high sensitivities (ranging between 94% and 100%) and specificities (ranging between 93% and 100%) for the different pathogens. The highest seroprevalence rates in our cohort were observed for hepatitis A virus (HAV; 73.5%), followed by CMV (70.6%), T. gondii (67.6%) and H. pylori (32.4%). Seroprevalences for hepatitis B virus (HBV, 8.8%) and hepatitis C virus (HCV, 0%) were low. The seroprevalences observed in our study were similar to those from other population-based studies in Germany. In summary, we conclude that our multiplex serological assay represents a suitable tool for epidemiological studies.

Prevalence of CMV infection among staff in a metropolitan children's hospital - occupational health screening findings

Background: Staff in children’s hospitals may run an increased risk of cytomegalovirus (CMV) contact infection leading to a congenital CMV fetopathy during pregnancy. The main risk factor is close contact with inapparent carriers of CMV among infants (<3 years). We therefore examined CMV seroprevalence (SP) and possible risk factors for CMV infection among staff at a children’s hospital.

Method: In 2014, staff at a metropolitan children’s hospital were offered a CMV antibody test in the context of occupational health screening. Besides of anti-CMV immunoglobulin G (anti-CMV IgG) gender, age, profession, number of children and migration background were assessed and used as independent variables in multiple logistic regression. Women without a migration background (MIG) were considered as a separate group.

Results: The study included 219 employees. Women showed a significant higher risk than men of being CMV-positive (adjusted odds ratio [aOR] 3.0; 95% CI 1.1–7.8). The risk among age groups of 30 and over was double that of the under-30s (aOR 2.0; 95% CI 1.0–3.9); among those aged 40-plus it was aOR 2.3 (95% CI 1.1–4.7). Staff with an MIG tested more often positive than those without an MIG (95.5% versus 45.7%). CMV SP was 47.7% among women without an MIG. In this subgroup the probability of CMV infection increased with age (p=0.08) as well.

Conclusion: In the staff group as a whole there was a significant correlation between CMV SP, country of origin and age. We found no significant differences between occupational groups; perhaps our random sample was too small. Given the low CMV SP particularly in those without MIG, women who want to have children in particular must be protected from CMV infection. Follow-up studies should be undertaken to test whether good workplace hygiene offers sufficient protection for pregnant women and could be an alternative to prohibiting certain activities.