Debate over group B streptococcal recommendations

The Canadian Task Force on Preventive Health Care has made recommendations on 3 strategies to prevent group B streptococcal (GBS) infection in neonates.¹ The recommendations are not consistent with the information provided in the article and are at odds with the existing national guidelines.²

Strategy A is designed to screen all women at 35–37 weeks' gestation for GBS colonization and treat colonized women with risk factors. Strategy B is designed to screen all women and treat all who are colonized. And strategy C is designed to treat on the basis of risk factors alone. The task force's preferred strategy is strategy A. Strategy C is deemed to be the least favoured strategy because there is insufficient evidence to evaluate its effectiveness. However, strategy C would lead to treatment of the same group of infants as strategy A and those whose mothers have risk factors but have a negative screening result. This strategy would also result in treatment when the screen failed to identify colonization of the mother and when the mother was colonized after screening.

Women presenting in preterm labour will be largely unscreened because of the timing of the screen and may require treatment in any case. Those with GBS infection in a previous pregnancy should be treated in any case. Maternal fever in labour would be treated in the interests of both mother and baby. Therefore, strategies A and B would result in all pregnant women being screened at significant cost.

On the basis of the information presented by the task force, strategy C appears to be the most clinically efficient and cost-effective way of preventing GBS infection in neonates.

R.J. Morrow Obstetrician and Gynecologist Oakville, Ont.