Wang Lin, Fu Jinjian, Liang Zhuoxin, Chen Jichang
Department of Science and Education, Liuzhou Municipal Maternity and Child Healthcare Hospital, Liuzhou, Guangxi, China.
Department of Laboratory, Liuzhou Municipal Maternity and Child Healthcare Hospital, Liuzhou, Guangxi, China.
BMC Infect Dis. 2017 Dec 13;17(1):765. doi: 10.1186/s12879-017-2816-8.
To explore the overall prevalence and serotype distribution of nasopharyngeal carriage of Streptococcus pneumoniae(S. pneumoniae) among healthy children.
A search for pneumococcal nasopharyngeal carriage studies including children published up to July 31th, 2016 was conducted to describe carriage in China. The review also describes antibiotic resistance in and serotypes of S. pneumoniae and assesses the impact of vaccination on carriage in this region. Summary measures for overall prevalence, antibiotic resistance, and serotype distributions extracted from the analyzed data were determined with 95% confidence intervals (CIs) using random-effects models. Heterogeneity was assessed using I test statistics.
Thirty-seven studies were included in this review, and the majority of studies (64.9%) were located in the pre-introduction period of 7-valent pneumococcal conjugate vaccine (PCV7) in China. The pooled prevalence of S. pneumoniae nasopharyngeal carriage was 21.4% (95% CI: 18.3-24.4%). Carriage was highest in children attending kindergartens [24.5%, (19.7-29.3%)] and decreased with increasing age. Before the introduction of PCV7 into China, the prevalence of S. pneumoniae nasopharyngeal carriage was 25.8% (20.7-30.9%), the pooled carriage of S. pneumoniae sharply dropped into the 14.1% (11.3-16.9%) by PCV7 vaccination period (P < 0.001). Before the pneumococcal conjugate vaccine (PCV) was introduced in China, the penicillin resistance rate in S. pneumoniae isolated from healthy children was 31.9% (21.2-42.6%); however, this rate sharply decreased after the introduction of PCV7 in China [21.6%, (7.4-35.9%)], and the difference between the rates during these two time periods was statistically significant (P value <0.05). Serotypes 19F, 6A and 23F were the most commonly isolated. Meta-analysis of data from young children showed a pooled rate estimate of 46.6% (38.8-54.4%) for PCV7 vaccine coverage and 66.2% (58.6-73.8%) for PCV13 vaccine coverage.
The prevalence of nasopharyngeal carriage among children was high in China. PCV7 immunization was found to be associated with reduction of nasopharyngeal colonization of S. pneumoniae. Conjugate vaccination coverage was slightly affected by the introduction of PCV7 into China because of low vaccination rate. The government should implement timely adjusted conjugate vaccination strategies based on our findings.
探讨健康儿童鼻咽部肺炎链球菌（S. pneumoniae）携带情况的总体流行率及血清型分布。
检索截至2016年7月31日发表的包括儿童在内的肺炎链球菌鼻咽部携带情况的研究，以描述中国的携带情况。该综述还描述了肺炎链球菌的抗生素耐药性及血清型，并评估疫苗接种对该地区携带情况的影响。采用随机效应模型，从分析数据中提取总体流行率、抗生素耐药性及血清型分布的汇总指标，并确定其95%置信区间（CIs）。使用I²检验统计量评估异质性。
本综述纳入了37项研究，大多数研究（64.9%）位于中国7价肺炎球菌结合疫苗（PCV7）引入前的时期。肺炎链球菌鼻咽部携带的合并流行率为21.4%（95%CI：18.3 - 24.4%）。在幼儿园儿童中携带率最高[24.5%，（19.7 - 29.3%）]，且随年龄增长而降低。在PCV7引入中国之前，肺炎链球菌鼻咽部携带率为25.8%（20.7 - 30.9%），到PCV7疫苗接种时期，肺炎链球菌的合并携带率急剧降至14.1%（11.3 - 16.9%）（P < 0.001）。在中国引入肺炎球菌结合疫苗（PCV）之前，从健康儿童中分离出的肺炎链球菌对青霉素的耐药率为31.9%（21.2 - 42.6%）；然而，在中国引入PCV7后，该耐药率急剧下降[21.6%，（7.4 - 35.9%）]，这两个时期的耐药率差异具有统计学意义（P值<0.05）。19F、6A和23F血清型是最常分离出的。对幼儿数据的荟萃分析显示，PCV7疫苗接种覆盖率的合并率估计为46.6%（38.8 - 54.4%），PCV13疫苗接种覆盖率为66.2%（58.6 - 73.8%）。
中国儿童鼻咽部携带率较高。发现PCV7免疫接种与肺炎链球菌鼻咽部定植的减少有关。由于疫苗接种率低，PCV7引入中国后结合疫苗接种覆盖率受到轻微影响。政府应根据我们的研究结果及时实施调整后的结合疫苗接种策略。
