Prevalence of <i>Streptococcus pneumoniae</i> serotypes causing pneumococcal diseases in the Chinese Mainland: A systematic review and meta-analysis

Pneumococcal disease (PD) caused by <i>Streptococcus pneumoniae</i> (<i>Sp</i>) continues to be a global public health concern. Monitoring the prevalence and shift of <i>Sp</i> serotypes causing PD is critical for vaccination and local policies for PD management. A systematic review of published work on pneumococcal serotype distribution in the Chinese Mainland from January 1997 to July 2023 was conducted. The literature was searched in Medline, Embase, the Cochrane Library, Web of Science, CNKI, and Wanfang. Distribution of the <i>Sp</i> serogroups/serotypes was presented as count and proportion. Pooled distributions were calculated using a double arcsine transformation. Subgroup analyses were performed according to isolate location, strain source, patient age, period, and clinical manifestation. In total 36,477 <i>Sp</i> isolates in 159 studies were included. In the Chinese Mainland, the highest proportion of <i>Sp</i> in PD was serotype 19F, followed by 19A, 23F, 14 and 6B. Serotype 19F was the most predominant circulating serotype through all time periods. PD cases caused by non-vaccine serotypes showed a significant increase after 2019. In summary, from 1997 to 2023, the top 10 prevalent <i>Sp</i> serotypes causing PD in the Chinese Mainland were 19F, 19A, 6, 23F, 14, 6B, 6A, 3, 15B, and 9 V. Although the distribution of serotypes varied according to the subgroups, the increase in non-vaccine serotypes (e.g. 15A), and diversity distribution of serotypes 6A and 3 in different age groups should not be ignored. <i>Streptococcus pneumoniae</i> is a type of bacteria that commonly causes disease. It is widespread in many areas of the world, including the Chinese Mainland. To effectively control the spread of <i>streptococcus pneumoniae</i>,policy makers and healthcare providers need to know what serotypes of the bacteria are present.This systematic review analyzed the literature from the last 25 years about the serotype distribution of <i>streptococcus pneumoniae</i> in the Chinese Mainland. The review also checked to see if the serotype distribution changed as a list of factors changed.This review found that the serotype distribution of <i>streptococcus pneumoniae</i>changes according to location, strain source, patient age, time period, and clinical manifestation. The changes that happened over time suggest that the serotypes of <i>streptococcus pneumoniae</i>that are not covered by commonly used vaccines have become more common over time. However, even though they became more common, the vaccine types remain covering the predominant serotypes. Policy makers and Healthcare providers should take the results of this review into consideration going forward. <i>Streptococcus pneumoniae</i> is a type of bacteria that commonly causes disease. It is widespread in many areas of the world, including the Chinese Mainland. To effectively control the spread of <i>streptococcus pneumoniae</i>,policy makers and healthcare providers need to know what serotypes of the bacteria are present. This systematic review analyzed the literature from the last 25 years about the serotype distribution of <i>streptococcus pneumoniae</i> in the Chinese Mainland. The review also checked to see if the serotype distribution changed as a list of factors changed. This review found that the serotype distribution of <i>streptococcus pneumoniae</i>changes according to location, strain source, patient age, time period, and clinical manifestation. The changes that happened over time suggest that the serotypes of <i>streptococcus pneumoniae</i>that are not covered by commonly used vaccines have become more common over time. However, even though they became more common, the vaccine types remain covering the predominant serotypes. Policy makers and Healthcare providers should take the results of this review into consideration going forward. <b>Systematic review registration</b>: PROSPERO CRD42020205573

由肺炎链球菌（Streptococcus pneumoniae, Sp）引发的肺炎球菌疾病（Pneumococcal disease, PD）仍是全球公共卫生领域的重点关切问题。监测导致PD的肺炎链球菌血清型的流行态势与变迁，对于疫苗接种策略制定及PD本地防控政策至关重要。本研究针对1997年1月至2023年7月期间发表的、有关中国大陆地区肺炎链球菌血清型分布的文献开展系统综述（systematic review）。检索数据库涵盖Medline、Embase、Cochrane图书馆、Web of Science、中国知网（CNKI）及万方数据。研究以计数与占比形式呈现肺炎链球菌血清群/血清型的分布情况，采用双反正弦变换（double arcsine transformation）计算合并分布率，并根据菌株分离地点、菌株来源、患者年龄、研究时段及临床表现进行亚组分析（subgroup analyses）。最终纳入159项研究的36477株肺炎链球菌分离株。中国大陆地区引发PD的肺炎链球菌中，占比最高的血清型为19F，其次依次为19A、23F、14及6B。19F为所有研究时段内最主要的流行血清型。2019年后，非疫苗覆盖血清型所致PD病例占比显著升高。综上，1997年至2023年，中国大陆地区引发PD的前10位流行肺炎链球菌血清型依次为19F、19A、6、23F、14、6B、6A、3、15B及9V。尽管血清型分布因亚组不同存在差异，但非疫苗覆盖血清型（如15A）的占比上升，以及6A与3型血清型在不同年龄组中的多样化分布均不容忽视。肺炎链球菌是一类常见致病菌，在包括中国大陆在内的全球多数地区广泛传播。为有效控制肺炎链球菌的传播，政策制定者与医疗服务提供者需明确当地流行的细菌血清型。本系统综述分析了近25年以来有关中国大陆地区肺炎链球菌血清型分布的文献，同时探讨了血清型分布是否随一系列影响因素发生变化。研究发现，肺炎链球菌的血清型分布会因菌株分离地点、菌株来源、患者年龄、研究时段及临床表现而有所不同。随时间推移的变化趋势显示，常规疫苗未覆盖的肺炎链球菌血清型占比逐年升高。尽管如此，现有疫苗仍可覆盖绝大多数主要流行血清型。政策制定者与医疗服务提供者在后续工作中应参考本综述的研究结果。肺炎链球菌是一类常见致病菌，在包括中国大陆在内的全球多数地区广泛传播。为有效控制肺炎链球菌的传播，政策制定者与医疗服务提供者需明确当地流行的细菌血清型。本系统综述分析了近25年以来有关中国大陆地区肺炎链球菌血清型分布的文献，同时探讨了血清型分布是否随一系列影响因素发生变化。本研究发现，肺炎链球菌的血清型分布会因菌株分离地点、菌株来源、患者年龄、研究时段及临床表现而有所不同。随时间推移的变化趋势显示，常规疫苗未覆盖的肺炎链球菌血清型占比逐年升高。尽管如此，现有疫苗仍可覆盖绝大多数主要流行血清型。政策制定者与医疗服务提供者在后续工作中应参考本综述的研究结果。系统综述注册编号：PROSPERO CRD42020205573