Early-onset group B streptococcal infections in five Nordic countries with different prevention policies, 1995 to...

Area of Science:

• Neonatal infectious diseases
• Public health interventions
• Epidemiology

Background:

• Group B Streptococcus (GBS) neonatal early-onset disease is a significant cause of infant morbidity.
• Intrapartum antibiotic prophylaxis (IAP) is crucial for prevention, but optimal identification strategies for at-risk mothers remain debated.
• Current approaches include risk-based prophylaxis (RBP) and GBS screening-based prophylaxis (SBP).

Purpose of the Study:

• To evaluate the impact of universal GBS screening-based prophylaxis (SBP) on the epidemiology of early-onset GBS infections.
• To compare the effectiveness of SBP against risk-based prophylaxis (RBP) in Nordic countries.

Main Methods:

• An interrupted time series analysis was conducted, using 2012 as the intervention point.
• Data on early- and late-onset GBS infections were collected from national registers for 6,605,564 live births across five Nordic countries (Finland, Denmark, Iceland, Norway, Sweden) from 1995 to 2019.
• Finland implemented universal SBP in 2012, while other countries continued with RBP.

Main Results:

• Following the introduction of SBP in Finland in 2012, a 58% reduction in early-onset GBS disease incidence was observed (IRR 0.42).
• In contrast, the pooled incidence rate ratio for early-onset GBS disease in the RBP countries (Denmark, Iceland, Norway, Sweden) was 0.89.
• Significant reductions were noted in Iceland (IRR 0.34) and Norway (IRR 0.72) within the RBP group.

Conclusions:

• The implementation of universal GBS screening-based prophylaxis (SBP) in Finland was associated with a substantial decrease in early-onset GBS infections.
• The findings suggest SBP is a more effective public health strategy for reducing neonatal GBS disease compared to RBP.
• Early-onset GBS infections were approximately halved in Finland after adopting the SBP approach.