Department of Intensive Care Services, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia.
Department of Pathology and Laboratory Medicine, Royal Inland Hospital, Kamloops, BC, Canada.
Clin Microbiol Infect. 2021 Dec;27(12):1856.e1-1856.e5. doi: 10.1016/j.cmi.2021.03.006. Epub 2021 Apr 1.
To investigate whether positivity in one or both index sets of blood cultures influences clinical determinants and mortality when diagnosing bloodstream infections (BSI).
Retrospective population-based surveillance of all mono-microbial BSI was conducted among residents of the western interior of British Columbia. Clinical details were obtained by chart review and all-cause case-fatality was established at 30 days. Index cultures were defined as the first two sets of cultures initially drawn to diagnose incident BSI.
A total of 2500 incident BSI were identified of which 945 (37.8%) and 1555 (62.2%) were based on one and two positive index cultures, respectively. There was an overall difference in the distribution of pathogens, with both Staphylococcus aureus and Streptococcus pneumoniae more likely to have two positive index cultures. Different foci of infection were associated with one versus two positive index cultures. Overall, 409 patients died within 30 days of index BSI for an all-cause case-fatality of 16.4%; with no difference between two positive (250/1555; 16.1%) and one positive (159/945; 16.8%; p 0.3) index blood culture. The number of positive index blood cultures was not associated with 30-day case-fatality after adjustment for confounding variables using logistic regression analysis.
Although approximately one-third of BSI are diagnosed on the basis of a single positive blood culture and are associated with different clinical determinants, whether one or both index blood cultures are positive is not associated with lethal outcome.
探究在诊断血流感染（BSI）时，血液培养物的一套或两套阳性指标是否会影响临床指标和死亡率。
对不列颠哥伦比亚省西部内陆地区的居民进行了所有单一致病菌性 BSI 的回顾性基于人群的监测。通过病历回顾获取临床详细信息，并在 30 天内确定全因病死率。索引培养物被定义为最初用于诊断新发 BSI 的前两套培养物。
共确定了 2500 例新发 BSI，其中 945 例（37.8%）和 1555 例（62.2%）分别基于一套和两套阳性索引培养物。病原体的分布总体上存在差异，金黄色葡萄球菌和肺炎链球菌更有可能有两套阳性索引培养物。不同的感染病灶与一套或两套阳性索引培养物有关。总体而言，2500 例新发 BSI 中有 409 例在索引 BSI 后 30 天内死亡，全因病死率为 16.4%；两套阳性（1555 例中的 250 例；16.1%）和一套阳性（945 例中的 159 例；16.8%；p 0.3）的索引血培养之间无差异。在校正了混杂变量后，使用逻辑回归分析，阳性指数血培养的数量与 30 天病死率无关。
尽管约三分之一的 BSI 基于单一阳性血培养物诊断，并且与不同的临床指标有关，但一套或两套索引血培养物的阳性与否与致命结局无关。
