von Mollendorf Claire, Tempia Stefano, von Gottberg Anne, Meiring Susan, Quan Vanessa, Feldman Charles, Cloete Jeane, Madhi Shabir A, O'Brien Katherine L, Klugman Keith P, Whitney Cynthia G, Cohen Cheryl
Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, a division of the National Health Laboratory Service, Johannesburg, South Africa.
School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
PLoS One. 2017 Jul 3;12(7):e0179905. doi: 10.1371/journal.pone.0179905. eCollection 2017.
Streptococcus pneumoniae is a leading cause of severe bacterial infections globally. A full understanding of the impact of pneumococcal conjugate vaccine (PCV) on pneumococcal disease burden, following its introduction in 2009 in South Africa, can support national policy on PCV use and assist with policy decisions elsewhere.
We developed a model to estimate the national burden of severe pneumococcal disease, i.e. disease requiring hospitalisation, pre- (2005-2008) and post-PCV introduction (2012-2013) in children aged 0-59 months in South Africa. We estimated case numbers for invasive pneumococcal disease using data from the national laboratory-based surveillance, adjusted for specimen-taking practices. We estimated non-bacteraemic pneumococcal pneumonia case numbers using vaccine probe study data. To estimate pneumococcal deaths, we applied observed case fatality ratios to estimated case numbers. Estimates were stratified by HIV status to account for the impact of PCV and HIV-related interventions. We assessed how different assumptions affected estimates using a sensitivity analysis. Bootstrapping created confidence intervals.
In the pre-vaccine era, a total of approximately 107,600 (95% confidence interval [CI] 83,000-140,000) cases of severe hospitalised pneumococcal disease were estimated to have occurred annually. Following PCV introduction and the improvement in HIV interventions, 41,800 (95% CI 28,000-50,000) severe pneumococcal disease cases were estimated in 2012-2013, a rate reduction of 1,277 cases per 100,000 child-years. Approximately 5000 (95% CI 3000-6000) pneumococcal-related annual deaths were estimated in the pre-vaccine period and 1,900 (95% CI 1000-2500) in 2012-2013, a mortality rate difference of 61 per 100,000 child-years.
While a large number of hospitalisations and deaths due to pneumococcal disease still occur among children 0-59 months in South Africa, we found a large reduction in this estimate that is temporally associated with PCV introduction. In HIV-infected individuals the scale-up of other interventions, such as improvements in HIV care, may have also contributed to the declines in pneumococcal burden.
肺炎链球菌是全球严重细菌感染的主要病因。全面了解肺炎球菌结合疫苗（PCV）自2009年在南非引入后对肺炎球菌疾病负担的影响，有助于支持该国关于PCV使用的政策，并为其他地区的政策决策提供参考。
我们建立了一个模型，以估算南非0至59个月儿童在PCV引入前（2005 - 2008年）和引入后（2012 - 2013年）严重肺炎球菌疾病的全国负担，即需要住院治疗的疾病负担。我们利用基于国家实验室监测的数据，并根据样本采集情况进行调整，估算侵袭性肺炎球菌疾病的病例数。我们利用疫苗探针研究数据估算非菌血症性肺炎球菌肺炎的病例数。为了估算肺炎球菌死亡人数，我们将观察到的病死率应用于估算的病例数。估算按艾滋病毒感染状况分层，以考虑PCV和与艾滋病毒相关干预措施的影响。我们通过敏感性分析评估了不同假设对估算结果的影响。通过自抽样法创建置信区间。
在疫苗接种前的时代，估计每年发生约107,600例（95%置信区间[CI] 83,000 - 140,000）严重住院的肺炎球菌疾病病例。在引入PCV和改善艾滋病毒干预措施后，2012 - 2013年估计有41,800例（95% CI 28,000 - 50,000）严重肺炎球菌疾病病例，每10万个儿童年的发病率降低了1,277例。在疫苗接种前时期，估计每年有大约5000例（95% CI 3000 - 6000）与肺炎球菌相关的死亡，2012 - 2013年为1900例（95% CI 1000 - 2500），每10万个儿童年的死亡率差异为61例。
虽然南非0至59个月儿童中仍有大量因肺炎球菌疾病住院和死亡的情况，但我们发现这一估算值大幅下降，且在时间上与引入PCV相关。在艾滋病毒感染个体中，扩大其他干预措施，如改善艾滋病毒护理，可能也有助于肺炎球菌负担的下降。
