Highet A R, Berry A M, Goldwater P N
Department of Microbiology and Infectious Diseases, SA Pathology, Women's and Children's Hospital, North Adelaide, South Australia, Australia.
Arch Dis Child. 2009 Nov;94(11):841-3. doi: 10.1136/adc.2009.158352. Epub 2009 May 3.
Two recent retrospective studies independently reported typically pathogenic bacteria in normally sterile sites of infants succumbing to sudden unexpected death in infancy (SUDI). These findings suggested a proportion of unexplained SUDI might be triggered by bacteraemia. The objective was to assess these observations in the context of the pathology and epidemiology of sudden infant death syndrome (SIDS) in relation to the role of infection and inflammation as triggers of these deaths.
A review of the literature to identify potential risk factors for unexplained infant deaths and proposal of a theoretical model for SUDI.
Pathologic and epidemiological evidence suggests a hypothesis based on three factors: bacterial translocation, pathogen pattern recognition insufficiency and prenatal exposure to infection.
We propose that sterile site infections in which common toxigenic bacteria are identified indicate a brief bacteraemic episode prior to death. This might reflect an ineffective innate response to invasive pathogens that results in reduced clearance of the bacteria. Thymomegaly observed consistently among infants diagnosed under the category of SIDS might have its origins in prenatal life, perhaps generated via in utero infection or exposure to microbial antigens which results in thymocyte priming. There is consistent evidence for an infectious aetiology in many unexplained SUDI. Future directions for research are suggested.
两项近期的回顾性研究独立报告了在死于婴儿猝死综合征（SUDI）的婴儿通常无菌的部位发现典型的致病细菌。这些发现表明，一部分不明原因的SUDI可能由菌血症引发。目的是在婴儿猝死综合征（SIDS）的病理学和流行病学背景下评估这些观察结果，以探讨感染和炎症作为这些死亡触发因素的作用。
对文献进行综述，以确定不明原因婴儿死亡的潜在风险因素，并提出SUDI的理论模型。
病理和流行病学证据提示了一个基于三个因素的假说：细菌易位、病原体模式识别不足以及产前感染暴露。
我们提出，在无菌部位发现常见产毒细菌的感染表明死亡前有短暂的菌血症发作。这可能反映了对侵入性病原体的先天性反应无效，导致细菌清除减少。在被诊断为SIDS的婴儿中始终观察到的胸腺肿大可能起源于产前生活，或许是通过宫内感染或接触微生物抗原导致胸腺细胞致敏而产生的。在许多不明原因的SUDI中，有一致的证据支持感染病因学。文中还提出了未来的研究方向。
