Department of Infection, Royal Free London NHS Trust, London, UK.
Department of Pharmacy, Royal Free London NHS Trust, London, UK.
J Antimicrob Chemother. 2021 Apr 13;76(5):1323-1331. doi: 10.1093/jac/dkaa563.
COVID-19 is infrequently complicated by bacterial co-infection, but antibiotic prescriptions are common. We used community-acquired pneumonia (CAP) as a benchmark to define the processes that occur in bacterial pulmonary infections, testing the hypothesis that baseline inflammatory markers and their response to antibiotic therapy could distinguish bacterial co-infection from COVID-19.
Retrospective cohort study of CAP (lobar consolidation on chest radiograph) and COVID-19 (PCR detection of SARS-CoV-2) patients admitted to Royal Free Hospital (RFH) and Barnet Hospital (BH), serving as independent discovery and validation cohorts. All CAP and >90% COVID-19 patients received antibiotics on hospital admission.
We identified 106 CAP and 619 COVID-19 patients at RFH. Compared with COVID-19, CAP was characterized by elevated baseline white cell count (WCC) [median 12.48 (IQR 8.2-15.3) versus 6.78 (IQR 5.2-9.5) ×106 cells/mL, P < 0.0001], C-reactive protein (CRP) [median 133.5 (IQR 65-221) versus 86.0 (IQR 42-160) mg/L, P < 0.0001], and greater reduction in CRP 48-72 h into admission [median ΔCRP -33 (IQR -112 to +3.5) versus +14 (IQR -15.5 to +70.5) mg/L, P < 0.0001]. These observations were recapitulated in the independent validation cohort at BH (169 CAP and 181 COVID-19 patients). A multivariate logistic regression model incorporating WCC and ΔCRP discriminated CAP from COVID-19 with AUC 0.88 (95% CI 0.83-0.94). Baseline WCC >8.2 × 106 cells/mL or falling CRP identified 94% of CAP cases, and excluded bacterial co-infection in 46% of COVID-19 patients.
We propose that in COVID-19, absence of both elevated baseline WCC and antibiotic-related decrease in CRP can exclude bacterial co-infection and facilitate antibiotic stewardship efforts.
COVID-19 很少并发细菌合并感染，但抗生素处方却很常见。我们使用社区获得性肺炎（CAP）作为基准来定义细菌性肺部感染过程，检验以下假设，即基线炎症标志物及其对抗生素治疗的反应可区分细菌合并感染和 COVID-19。
对皇家自由医院（RFH）和巴尼特医院（BH）收治的 CAP（胸片上的肺叶实变）和 COVID-19（SARS-CoV-2 的 PCR 检测）患者进行回顾性队列研究，作为独立的发现和验证队列。所有 CAP 和 >90% COVID-19 患者在入院时接受抗生素治疗。
我们在 RFH 识别了 106 例 CAP 和 619 例 COVID-19 患者。与 COVID-19 相比，CAP 的特征为基线白细胞计数（WCC）升高[中位数 12.48（IQR 8.2-15.3）与 6.78（IQR 5.2-9.5）×106 细胞/ml，P<0.0001]、C 反应蛋白（CRP）升高[中位数 133.5（IQR 65-221）与 86.0（IQR 42-160）mg/L，P<0.0001]，以及入院后 48-72 小时 CRP 下降更大[中位数 ΔCRP-33（IQR-112 至 +3.5）与 +14（IQR-15.5 至 +70.5）mg/L，P<0.0001]。在 BH 的独立验证队列中也重现了这些观察结果（169 例 CAP 和 181 例 COVID-19 患者）。纳入 WCC 和 ΔCRP 的多变量逻辑回归模型可区分 CAP 和 COVID-19，AUC 为 0.88（95%CI 0.83-0.94）。基线 WCC>8.2×106 细胞/ml 或 CRP 下降提示 94%的 CAP 病例，并排除了 46%COVID-19 患者的细菌合并感染。
我们提出，在 COVID-19 中，不存在基线 WCC 升高和抗生素相关 CRP 下降可以排除细菌合并感染，并有助于抗生素管理。
