Epidemiological Analysis of Congenital Cytomegalovirus (cCMV) Disease in New Zealand using the National Minimum Dataset (NMDS)

Abstract

Congenital cytomegalovirus (cCMV) disease affects about 1 in 200 babies born in the United States. cCMV infection during foetal development can be a significant cause of congenital abnormalities, with sensorineural hearing loss and neurodevelopmental impairments being the most characterised disabilities. Infants with symptomatic cCMV infection are affected by high mortality rates and severe lifelong symptoms. Infants with asymptomatic cCMV infection, although they may have minimal symptoms at birth, have an elevated risk of developing delayed-onset neurodevelopmental sequelae in early childhood. Given the substantial lifelong impact of cCMV infection on affected children, there is an urgent need for approaches to better diagnose, manage, and prevent the disease. However, there is a lack of epidemiological information that could help us understand cCMV disease and its impact in New Zealand. Therefore, this study aims to examine the epidemiology of cCMV infection in New Zealand, using the National Minimum Dataset (NMDS) and, in the process, evaluate the feasibility of using the NMDS as a tool for studying the disease. Demographic and clinical data for all individuals registered on the National Health Index between January 1st, 2000, and April 30th, 2021, were extracted from the NMDS to estimate the prevalence, natural history, and epidemiological risk factors of cCMV disease. The analysis revealed an estimated prevalence of approximately 0.014%, a value well below that predicted from the literature, with an overall increasing trend of cCMV diagnosis over the study period. Individuals with cCMV disease were considerably more likely to develop comorbid conditions such as perinatal complications, hepatitis, hearing loss, cerebral palsy, and congenital central nervous system malformations than those without the disease. Māori and Pacific ethnicity (cCMV disease rate of 0.025% and 0.022%, respectively, with p= < 0.001), as well as higher deprivation scores, were associated with a higher incidence of cCMV infection (p= < 0.001). The mortality rate was 7-fold higher in the cCMV-positive cohort, and this association was statistically significant (p= < 0.001). Although the analysis of currently available data in the NMDS has limitations, including the low identification rate of cCMV disease, it can still be useful in understanding the characteristics of identified cCMV cases. As the NMDS database is an administrative tool that is capable of providing timely data with broad coverage, it can be combined with further research with complementary methodology to gain a more comprehensive understanding of the prevalence and health burden posed by cCMV disease in New Zealand.