Brenna Hughes, MD, MSc, was recently awarded an investigator-initiated R21 grant by the NIH National Institute of Child & Human Development (NICHD) to continue her research in cytomegalovirus (CMV), the most common congenital viral infection in pregnancy. Affecting approximately 0.4-1% of live born infants, congenital CMV can cause stillbirth and newborn death, or severe morbidity in the form of cognitive and motor delay, and most commonly, significant, progressive hearing loss. While classically teaching has been that primary maternal CMV infection is associated with congenital infection, a relatively large proportion of congenital infections result from maternal reinfection or re-activation in highly seropositive populations. There is a gap in knowledge regarding the clinical and viral factors that contribute to viral activity among seropositive women in the US. Under the working hypothesis that re-infection with a new viral strain is responsible for more frequent shedding and higher mucosal viral loads than viral re-activation, the project goal is to characterize the clinical and viral factors associated with ongoing CMV infection among 240 seropositive women. Project aims include 1) defining the frequency, magnitude, and risk factors for maternal CMV viral shedding across gestation and 2) profiling shed viral populations and serologic response using next generation sequencing to characterize re-infection versus re-activation. The working hypothesis is that low socioeconomic status, crowding in the home, exposure to young children, and hygienic risk factors will be associated with maternal viral shedding, which may indicate maternal re-infection. This work will allow development of a paradigm shift from the use of serology to a more accurate measure of disease activity and advance the field to identify a potential therapeutic target for prevention of congenital CMV.