Congenital cytomegalovirus infection is associated with high maternal socio-economic status and corresponding low maternal cytomegalovirus seropositivity

Aims Human cytomegalovirus (CMV) is the leading infectious cause of congenital infection in developed countries. Globally, CMV seropositivity has been associated with low socio-economic status (SES); however, Australian data are lacking. Therefore, we examined the association between SES and CMV seroprevalence in children and pregnant women. Methods Three groups were examined: 1, a prospective cohort of Australian children aged 0-15 years (n = 220); 2, a clinic-based sample of pregnant women (n = 778); and 3, a case series of infants and children (n = 219) with symptomatic congenital CMV infection. SES was determined using a postcode-based score from the Australian Bureau of Statistics.Group 1 was recruited from endocrinology clinics and follow-up at Prince of Wales Hospital and Children's Hospital at Westmead. Group 2 was recruited at the Royal Hospital for Women. Congenitally infected infants were identified through the Australian Paediatric Surveillance Unit. Results CMV seroprevalence among all children was 20% (95% confidence interval (CI) 15-25%), and there was no association with SES (P = 0.58). Seroprevalence among pregnant women was 57% (53-60%), and higher rates of CMV seropositivity were associated with lower SES (P < 0.001). More congenital CMV cases were reported in the highest socio-economic groups (55%) than the lowest (9%) (P < 0.001). Conclusions A marked socio-economic gradient in CMV seroprevalence is evident in Australian pregnant women and cases of congenital CMV but not in unselected Australian children. These findings highlight the importance of a community-wide approach to CMV awareness and the potential for hygienic measures to reduce the burden of congenital CMV in Australia.