CMV primary and non-primary infections among daycare workers, and development of strategies to prevent infection (EDUQ-CMV): a mixed-method study protocol.

BACKGROUND: Cytomegalovirus (CMV) is associated with congenital infections that can lead to severe developmental and neurological complications in affected children. Daycare workers, who frequently interact with infants and young children, may be at higher risk of CMV infection. This study aims to investigate the rates of primary infection and reinfection of CMV among female daycare workers in the province of Québec, Canada to better understand the risk of occupational exposure in this population. METHODS: This mixed-method observational study protocol uses quantitative (prospective cohort) and qualitative (semi-structured interviews with daycare workers) components. Female daycare workers (n = 553) are recruited and enrolled in a prospective cohort study, with a non-daycare workers comparison group comprising hospital employees and plasma donors who do not have direct professional contact with children < 36 months of age (low-risk group, n = 1659, 1:3 ratio). Participants are followed for 12 months, with blood for CMV serology, strain-specific antibody profiling with CMV-specific ELISA, CMV quantitative polymerase chain reaction (qPCR) and CMV-Scan assay collected from all participants at the first (V0) and last (V12) study visits. Among daycare workers and hospital employees, saliva samples are collected at these visits and monthly throughout the study for testing via CMV qPCR. Testing enables the identification of primary infections, reinfections, and reactivations, and estimates the association between demographic and occupational factors and CMV infection. Additionally, qualitative data is collected through interviews with daycare workers and daycare managers, focusing on their perceptions of CMV risks and current infection control practices. DISCUSSION: This study is expected to improve the understanding of CMV epidemiology among a high-risk group (i.e. female daycare workers). By estimating the incidence of CMV infections and patterns of viral shedding, the findings may inform occupational health strategies and public health policies. Based on our findings, guidelines aimed at preventing CMV infections could help protect not only daycare workers but also vulnerable populations, including young children and immunocompromised individuals, with whom they interact.