Weber M A, Hartley J C, Klein N J, Risdon R A, Malone M, Sebire N J
Department of Paediatric Histopathology, Great Ormond Street Hospital for Children and UCL Institute of Child Health, London, UK.
Forensic Sci Med Pathol. 2011 Jun;7(2):141-7. doi: 10.1007/s12024-010-9199-0. Epub 2010 Nov 10.
Around two thirds of sudden unexpected deaths in infancy (SUDI) remain unexplained following post-mortem examination. It has been postulated that a subset of unexplained SUDI may be caused by toxigenic Staphylococcus aureus. The aim of this study was to compare the prevalence of toxigenic S aureus strains in unexplained and explained SUDI (those in whom a cause of death is determined at autopsy). A retrospective review was performed of 546 SUDI autopsies as part of a larger review of >1,500 pediatric autopsies over a 10-year period, 1996-2005 inclusive. SUDI was defined as the sudden and unexpected death of an infant aged 7-365 days, and categorized into unexplained, explained with histological evidence of infection (bacterial infection group) or explained due to non-infective causes. Toxin gene profiling was carried out by PCR in cases in whom S aureus was isolated as part of clinical investigation. Of the 507 SUDI included in this analysis, bacteriological investigations were performed in 470, and S aureus was isolated on post-mortem culture from at least one site in 173 (37%). There were significantly more cases with S aureus isolated in unexplained SUDI (40%) compared to non-infective SUDI (21%; difference 19.0%, 95% CI 5.4% to 29.3%, P = 0.006). 46% of all cases with S aureus isolated underwent routine testing for a panel of staphylococcal toxin genes (including SEA to SEE, SEG to SEJ, TSST-1, and exfoliative toxins A and B). There were more cases with at least one toxigenic strain of S aureus in the unexplained SUDI (81%) and bacterial infection groups (77%) than in the non-infection group (63%), but these differences were not statistically significant (Fisher exact test, P = 0.44). Toxin gene-carrying S aureus is commonly detected at autopsy in SUDI, accounting for 78% of S aureus isolates submitted for toxin gene profiling in this series. There is a significantly higher prevalence of S aureus in unexplained SUDI compared to non-infective SUDI, but no significant difference in the proportion with toxigenic S aureus strains isolated between the groups. These data are consistent with the hypothesis that a subset of otherwise unexplained SUDI may be related to the presence of S aureus colonization/infection, but do not indicate routine testing for toxin-associated genotypes.
在婴儿猝死综合征（SUDI）中，约三分之二的病例在尸检后仍无法解释死因。据推测，一部分无法解释的SUDI可能由产毒素金黄色葡萄球菌引起。本研究的目的是比较产毒素金黄色葡萄球菌菌株在无法解释死因和可解释死因的SUDI（即在尸检时确定死亡原因的病例）中的患病率。作为对1996年至2005年这10年期间超过1500例儿科尸检进行的一项更大规模回顾的一部分，对546例SUDI尸检进行了回顾性分析。SUDI定义为年龄在7至365天的婴儿突然意外死亡，并分为无法解释死因、有感染组织学证据可解释死因（细菌感染组）或由非感染性原因可解释死因。对于作为临床调查一部分分离出金黄色葡萄球菌的病例，通过聚合酶链反应（PCR）进行毒素基因分析。在纳入本分析的507例SUDI中，对470例进行了细菌学调查，在173例（37%）的尸检培养中至少从一个部位分离出了金黄色葡萄球菌。与非感染性SUDI（21%；差异19.0%，95%可信区间5.4%至29.3%，P = 0.006）相比，无法解释死因的SUDI中分离出金黄色葡萄球菌的病例明显更多（40%）。所有分离出金黄色葡萄球菌的病例中有46%对一组葡萄球菌毒素基因（包括SEA至SEE、SEG至SEJ、TSST - 1以及剥脱毒素A和B）进行了常规检测。无法解释死因的SUDI组（81%）和细菌感染组（77%）中至少有一种产毒素金黄色葡萄球菌菌株的病例比非感染组（63%）更多，但这些差异无统计学意义（Fisher精确检验，P = 0.44）。在SUDI尸检中通常可检测到携带毒素基因的金黄色葡萄球菌，在本系列中提交进行毒素基因分析的金黄色葡萄球菌分离株中占78%。与非感染性SUDI相比，无法解释死因的SUDI中金黄色葡萄球菌的患病率明显更高，但两组之间分离出产毒素金黄色葡萄球菌菌株的比例无显著差异。这些数据与以下假设一致，即一部分原本无法解释死因的SUDI可能与金黄色葡萄球菌定植/感染的存在有关，但并不表明需要对毒素相关基因型进行常规检测。
