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.