Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK; Maternal, Adolescent, Reproductive & Child Health Centre, London School of Hygiene & Tropical Medicine, London, UK.
Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK; Maternal, Adolescent, Reproductive & Child Health Centre, London School of Hygiene & Tropical Medicine, London, UK.
Lancet Glob Health. 2022 Jun;10(6):e807-e819. doi: 10.1016/S2214-109X(22)00093-6. Epub 2022 Apr 28.
Group B streptococcus (GBS) colonisation during pregnancy can lead to invasive GBS disease (iGBS) in infants, including meningitis or sepsis, with a high mortality risk. Other outcomes include stillbirths, maternal infections, and prematurity. There are data gaps, notably regarding neurodevelopmental impairment (NDI), especially after iGBS sepsis, which have limited previous global estimates. In this study, we aimed to address this gap using newly available multicountry datasets.
We collated and meta-analysed summary data, primarily identified in a series of systematic reviews published in 2017 but also from recent studies on NDI and stillbirths, using Bayesian hierarchical models, and estimated the burden for 183 countries in 2020 regarding: maternal GBS colonisation, iGBS cases and deaths in infants younger than 3 months, children surviving iGBS affected by NDI, and maternal iGBS cases. We analysed the proportion of stillbirths with GBS and applied this to the UN-estimated stillbirth risk per country. Excess preterm births associated with maternal GBS colonisation were calculated using meta-analysis and national preterm birth rates.
Data from the seven systematic reviews, published in 2017, that informed the previous burden estimation (a total of 515 data points) were combined with new data (17 data points) from large multicountry studies on neurodevelopmental impairment (two studies) and stillbirths (one study). A posterior median of 19·7 million (95% posterior interval 17·9-21·9) pregnant women were estimated to have rectovaginal colonisation with GBS in 2020. 231 800 (114 100-455 000) early-onset and 162 200 (70 200-394 400) late-onset infant iGBS cases were estimated to have occurred. In an analysis assuming a higher case fatality rate in the absence of a skilled birth attendant, 91 900 (44 800-187 800) iGBS infant deaths were estimated; in an analysis without this assumption, 58 300 (26 500-125 800) infant deaths from iGBS were estimated. 37 100 children who recovered from iGBS (14 600-96 200) were predicted to develop moderate or severe NDI. 40 500 (21 500-66 200) maternal iGBS cases and 46 200 (20 300-111 300) GBS stillbirths were predicted in 2020. GBS colonisation was also estimated to be potentially associated with considerable numbers of preterm births.
Our analysis provides a comprehensive assessment of the pregnancy-related GBS burden. The Bayesian approach enabled coherent propagation of uncertainty, which is considerable, notably regarding GBS-associated preterm births. Our findings on both the acute and long-term consequences of iGBS have public health implications for understanding the value of investment in maternal GBS immunisation and other preventive strategies.
Bill & Melinda Gates Foundation.
怀孕期间 B 组链球菌（GBS）定植可导致婴儿侵袭性 GBS 病（iGBS），包括脑膜炎或败血症，具有高死亡率风险。其他后果包括死产、产妇感染和早产。存在数据空白，特别是关于神经发育障碍（NDI）的空白，尤其是在 iGBS 败血症之后，这限制了之前的全球估计。在这项研究中，我们旨在使用新获得的多国家数据集来解决这一空白。
我们汇集并使用贝叶斯分层模型对元分析摘要数据进行了分析，这些数据主要在 2017 年发表的一系列系统评价中确定，但也来自最近关于 NDI 和死产的研究，用于估计 2020 年 183 个国家的以下情况的负担：产妇 GBS 定植、3 个月以下婴儿的 iGBS 病例和死亡、幸存 iGBS 感染的儿童患有 NDI 以及产妇 iGBS 病例。我们分析了 GBS 死产的比例，并将其应用于联合国估计的每个国家的死产风险。使用荟萃分析和国家早产率计算与产妇 GBS 定植相关的早产。
来自 2017 年发表的七项系统评价的信息（共有 515 个数据点）与来自神经发育障碍（两项研究）和死产（一项研究）的大型多国家研究的新数据（17 个数据点）相结合。据估计，2020 年有 1970 万（95%置信区间 1790 万至 2190 万）孕妇存在直肠阴道 GBS 定植。据估计，有 231800（114100-455000）例早发性和 162200（70200-394400）例晚发性婴儿 iGBS 病例。在没有熟练接生员的情况下假设更高的病死率分析中，估计有 91900（44800-187800）例 iGBS 婴儿死亡；在没有这一假设的分析中，估计有 58300（26500-125800）例 iGBS 婴儿死亡。预计有 37100 名从 iGBS 中康复的儿童（14600-96200）患有中度或重度 NDI。预计 2020 年将有 40500（21500-66200）例产妇 iGBS 病例和 46200（20300-111300）例 GBS 死产。GBS 定植也被认为与大量早产有关。
我们的分析提供了对与妊娠相关的 GBS 负担的全面评估。贝叶斯方法能够一致地传播不确定性，这是相当大的，特别是关于 GBS 相关的早产。我们关于 iGBS 的急性和长期后果的发现对理解投资于产妇 GBS 免疫接种和其他预防策略的价值具有公共卫生意义。
比尔和梅琳达·盖茨基金会。
