A bug that strikes in the first week of life
Group B Streptococcus is a common bacterium. Many adults carry it without ever knowing. But when it passes from a mother to her baby during birth, it can cause severe, sometimes fatal infection within the newborn's first days of life.
The condition is one of the leading causes of newborn death globally. A new analysis shows just how much progress has been made — and how unevenly that progress has been distributed.
In high-income countries, screening pregnant women for Group B Strep and giving antibiotics during labor has dramatically reduced infections in newborns. The result has been one of the quiet success stories of obstetric care.
In many low- and middle-income countries, screening and antibiotic protocols are inconsistent or unavailable. Newborn deaths from this infection remain stubbornly common.
A clear global picture — region by region — helps focus where the next investments need to go.
The old way versus the new way
Before widespread screening, Group B Strep was a major cause of newborn sepsis everywhere. Hospitals had no reliable way to identify which mothers were carriers, and antibiotics were not routinely given during labor.
Modern protocols changed that. Pregnant women are screened in the third trimester. Carriers receive antibiotics during labor. Newborns of high-risk mothers are watched carefully in the first days.
This study uses 30 years of global health data to measure how well that approach has spread — and where it hasn't.
Imagine asking a single question — how often does a disease kill — and being told the answer for hundreds of countries over three decades. That's what the Global Burden of Disease project does.
The project pulls together vital statistics, hospital data, surveys, and other sources to estimate how often each disease causes death in each country, year by year. For diseases like Group B Strep, it allows researchers to track not just total numbers but trends, regional differences, and links to broader social factors like income, healthcare access, and inequality.
This analysis adds a layer of equity assessment — looking not just at average improvements but at how progress is distributed across countries with different resources.
The study snapshot
The team used data from the Global Burden of Disease Study 2021 along with a measure of how broadly each country's universal health coverage extends. They analyzed early-onset Group B Strep mortality globally, by sex, by world region, and by socioeconomic level. They tracked changes over time and explored whether progress was concentrated in specific groups.
Global mortality from early-onset Group B Strep nearly halved between 1990 and 2021 — from about 693 per 100,000 to about 349 per 100,000 newborns.
But the decline was sharply uneven. High-middle income regions saw mortality drop the fastest. Low-income regions saw the slowest decline.
Male newborns accounted for more deaths than female newborns, particularly in higher-income regions.
The clinical picture varied geographically too. Lower respiratory tract infections were more common in Asia and Oceania, while meningitis was more prominent in Europe.
Inequality analysis revealed what the researchers called "absolute convergence but relative differentiation." In raw numbers, the gap between richest and poorest countries narrowed. But proportionally, the burden became increasingly concentrated among the world's poorest populations.
Even with significant overall progress, the disease is becoming a marker of inequality.
Where this fits in the bigger picture
Newborn mortality is one of the headline measures of global health progress. Reductions in deaths from infectious causes — including Group B Strep — have driven much of the improvement seen since 1990.
But the gains have not been distributed equally. The countries with the fewest resources continue to bear a disproportionate burden of preventable newborn deaths. International maternal and child health programs increasingly focus on closing this gap, including through expanded antenatal screening, improved labor care, and better access to antibiotics.
A maternal Group B Strep vaccine is also in late-stage development. If approved, it could particularly benefit settings where prenatal screening and labor antibiotics aren't feasible.
If you're pregnant or planning a pregnancy, ask your prenatal team whether Group B Strep screening is part of your standard care. In most high- and middle-income countries, it is. In some settings, you may need to specifically request it.
If you're a carrier, antibiotics during labor have a strong track record of preventing the infection in your newborn. The treatment is short, safe for both mother and baby, and one of the most effective preventive interventions in obstetrics.
For broader health policy, this study underlines why supporting maternal health programs in low-income countries matters globally. The tools to prevent these newborn deaths exist. The challenge is getting them to the people who need them.
The Global Burden of Disease estimates rely on data of varying quality across different countries. Some low-income regions have limited surveillance, which means estimates can be less precise. Bibliometric and burden analyses can miss subtleties of local clinical practice. The timing and scope of universal health coverage data also affect the inequality analysis.
Continued investment in maternal health programs in low-income countries should narrow the inequality gap. The maternal Group B Strep vaccine, if approved, could transform prevention in settings where current strategies aren't workable. Continued surveillance and tracking will be essential to ensure that progress accelerates rather than stalls.
