Invasive pneumococcal disease (IPD) is a vaccine-preventable disease characterized by the presence of Streptococcus pneumoniae in normally sterile sites. Since 2007, Italy has implemented an IPD national surveillance system (IPD-NSS). This system suffers from high rates of underreporting. To estimate the level of underreporting of IPD in 2016–2017 in Tuscany (Italy), we integrated data from IPD-NSS and two other regional data sources, i.e., Tuscany regional microbiological surveillance (Microbiological Surveillance and Antibiotic Resistance in Tuscany, SMART) and hospitalization discharge records (HDRs). We collected (1) notifications to IPD-NSS, (2) SMART records positive for S. pneumoniae from normally sterile sites, and (3) hospitalization records with IPD-related International Classification of Diseases, Ninth Revision, Clinical Modification (ICD9) codes in discharge diagnoses. We performed data linkage of the three sources to obtain a combined surveillance system (CSS). Using the CSS, we calculated the completeness of the three sources and performed a three-source log-linear capture–recapture analysis to estimate total IPD underreporting. In total, 127 IPD cases were identified from IPD-NSS, 320 were identified from SMART, and 658 were identified from HDRs. After data linkage, a total of 904 unique cases were detected. The average yearly CSS notification rate was 12.1/100,000 inhabitants. Completeness was 14.0% for IPD-NSS, 35.4% for SMART, and 72.8% for HDRs. The capture–recapture analysis suggested a total estimate of 3419 cases of IPD (95% confidence interval (CI): 1364–5474), corresponding to an underreporting rate of 73.7% (95% CI: 34.0–83.6) for CSS. This study shows substantial underreporting in the Tuscany IPD surveillance system. Integration of available data sources may be a useful approach to complement notification-based surveillance and provide decision-makers with better information to plan effective control strategies against IPD.

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2016-2017年，意大利托斯卡纳地区的侵袭性肺炎球菌病：整合多个数据源以调查漏报事件

侵袭性肺炎球菌疾病（IPD）是一种疫苗可预防的疾病，其特征在于在正常无菌场所存在肺炎链球菌。自2007年以来，意大利实施了IPD国家监控系统（IPD-NSS）。该系统的报告率很高。为了估算2016-2017年托斯卡纳（意大利）IPD漏报的程度，我们整合了来自IPD-NSS的数据和其他两个区域数据源，即托斯卡纳区域微生物监测（托斯卡纳的微生物监测和抗生素耐药性，SMART）和住院出院记录（HDR）。我们收集了（1）向IPD-NSS发出的通知，（2）SMART记录为肺炎链球菌阳性（3）出院诊断中IPD相关国际疾病分类，第九修订版，临床修改（ICD9）代码的住院记录。我们执行了三个来源的数据链接，以获得一个组合的监视系统（CSS）。使用CSS，我们计算了三个来源的完整性，并执行了三个来源的对数线性捕获-捕获分析，以估算IPD报告不足的总数。从IPD-NSS总共鉴定出127例IPD病例，从SMART鉴定出320例，从HDR鉴定出658例。数据链接后，共检测到904个独特案例。CSS的年平均通知率为12.1 / 100,000居民。IPD-NSS的完整性为14.0％，SMART的完整性为35.4％，HDR的完整性为72.8％。捕获-再捕获分析表明，总共估计有3419例IPD（95％置信区间（CI）：1364-5474），与CSS的漏报率73.7％（95％CI：34.0-83.6）相对应。这项研究表明，托斯卡纳IPD监视系统的报告严重不足。可用数据源的集成可能是补充基于通知的监视并为决策者提供更好的信息以计划针对IPD的有效控制策略的有用方法。