A newly published study in the Irish Medical Journal provides persuasive evidence for the inclusion of HCV testing with routine antenatal screening and highlights the need for on-going review of selective screening criteria. This large single centre study by Lambert el al has enabled an accurate assessment of HCV antibody prevalence in the Irish antenatal population and calculated a seroprevalence rate of 0.9%.

The aims of this study were to pilot universal antenatal HCV screening and to determine the true seroprevalence of HCV infection in an antenatal population and the associated risk factors. A risk assessment questionnaire for HCV infection was applied to all women booking for antenatal care over a 1-year period in the Rotunda Hospital.

At the Rotunda Hospital, selective screening for HCV is carried out on perceived “high risk” women and as such true seroprevalence rates in the antenatal population aren’t known. The universal screening applied in this study and the high uptake of testing has allowed the prevalence of anti-HCV among this antenatal study population to be calculated at 0.9%. Studies elsewhere have shown that selective screening fails to identify all HCV women. The authors state that “this information will underpin future screening strategies for HCV in antenatal and other Irish populations.”

A significant proportion (27%) of anti-HCV positive women in this study reported no epidemiological risk factors at the time of booking and this was identified only as a result of universal screening. Of the 78 (0.9%) women that were diagnosed as anti-HCV positive, the majority were Irish (60.3%) or from Eastern Europe (24.4%).

At present the Rotunda hospital like many other maternity hospitals, operates a selective screening policy based on disclosed risk factors; however the data presented in the study reveal the shortcomings of this policy. Currently universal screening is recommended in populations where the prevalence rate is 1%. Relying on self-reported risk behaviours and the underestimation of the importance of other risk factors such as heterosexual transmission and nosocomial transmission in high prevalence countries, means a significant proportion of cases will invariably remain undiagnosed under the current guidelines. “This could have potential health implications for both mother and child” say Lambert et al.

The authors suggest that “early referral of mothers to treatment programmes could potentially eradicate their HCV so that future unborn children are not at risk of this infection.” The provision of antenatal care can represent a unique opportunity to test women who otherwise may not have sought testing.

All references and author names are contained in the full article in this month’s IMJ, p.136
Title: Universal Antenatal Screening for Hepatitis C

www.imj.ie