免疫抑制儿童感染新型冠状病毒Omicron变异株病毒清除时间的回顾性队列研究

背景：儿童新型冠状（新冠）病毒Omicron变异株流行期间，免疫抑制状态儿童新冠病毒清除时间定量分析研究较少。 目的：探讨新冠病毒Omicron株感染后免疫抑制和非免疫抑制儿童病毒清除的时间差别，为公共卫生政策制定和精准疫情防控措施提供临床数据。 设计：回顾性队列研究。 方法：以新冠病毒Omicron变异株感染住院患儿为队列人群，分为免疫抑制组和非免疫抑制组，免疫抑制分为绝对免疫抑制、相对免疫抑制和实施免疫抑制疗法，以免疫抑制组病例的性别、年龄和新冠病毒感染的分型与非免疫抑制组行1∶3匹配。以鼻咽拭子新冠病毒PCR检测拷贝数阈（Ct）值≥35为队列终点。 主要结局指标：新冠病毒清除时间。 结果：2022年4月12日至2022年5月12日在上海市新冠病毒感染定点收治医院符合本文共同纳入和排除标准的连续病例728例。免疫抑制组33例，其中绝对免疫抑制8例，相对免疫抑制23例，接受免疫抑制疗法2例（不包括绝对和相对免疫抑制患儿）。非免疫抑制组匹配后99例。2组临床症状、新冠病毒感染治疗和疫苗接种次数差异均无统计学意义。免疫抑制组和非免疫抑制组新冠病毒清除时间分别为（16.5±6.8）和（10.3±4.4）d，差异有统计学意义。免疫抑制组和非免疫抑制组新冠病毒感染轻型病例病毒清除时间分别为（14.0 ± 8.3）和（9.7 ± 3.1）d，普通型病例病毒清除时间分别为（18.3 ± 4.9）和（11.2 ± 5.9）d，差异均有统计学意义。2组单日病毒清除率在第9~14天时差异有统计学意义（P为0.005~0.039）。2组普通型病例单日病毒清除率在第10~15天时差异有统计学意义。免疫抑制组新冠病毒感染2周后核酸检测再次呈阳性3例（9%），临床分型均较前轻，3例均未接种新冠疫苗。 结论：Omicron株感染的免疫抑制患儿病毒清除时间较非免疫抑制患儿显著延长，主要反映在第9~14天，免疫抑制患儿病毒复阳风险高，提示需要更长的隔离时间和转阴后严格的病毒监测。

Virus shedding of immunocompromised children infected with SARS-CoV-19 Omicron variant: A retrospective cohort study

Background：The quantitative analysis focused on virus shedding duration of immunocompromised (IC) children infected with SARS CoV 2 during the Omicron wave is rare. Objective：To investigate the differences in virus shedding duration between IC and non IC patients infected with Omicron and to provide first line information for public health policy making and precise epidemic prevention strategy. Design：Retrospective cohort study. Methods：The study population was Omicron infected in hospital pediatric patients. According to their immune condition, these patients were divided into IC and non IC groups. The immunocompromised state was divided into complete immunocompromised condition, relative immunocompromised condition, and immunosuppressive therapy. The non IC group was matched with gender, age, type of SARS CoV 2 infection, and 1:3 ratio in the IC group. The SARS CoV 2 genome PCR test detected nasal swab samples. Cycle threshold (Ct) value ≥35 was the endpoint. Main outcome measures：SARS CoV 2 virus shedding time. Results：From April 12 to May 12, 2022, we enrolled 728 patients hospitalized in Renji Hospital, School of Medicine, Shanghai Jiao Tong University, the dedicated hospital in Shanghai. Among them, 33 patients were in the IC group, including 8 cases in complete immunocompromised state and 23 cases in a relative immunocompromised state. Two patients without complete or relative immunocompromised state received immunosuppressive therapy. Ninety nine patients were included in the non IC group. No significant differences were detected in clinical phenotypes, treatment, and vaccination between the two groups. The virus shedding time between IC and non IC groups had a significant difference (16.5±6.8 vs. 10.3±4.4 days). The virus shedding duration of mild type was (14.0±8.3) and (9.7±3.1) days, (18.3±4.9) and (11.2±5.9) days in moderate type. Significant differences were detected. The virus shedding duration of the two groups had significant differences during the 9th 14th days (P=0.005 0.039). The virus shedding duration of moderate type in two groups had significant differences during the 10th 15th days. Three patients (9%) in the IC group had positive PCR test results again after two weeks. The disease type of these three patients were milder than the previous infection. All three patients were unvaccinated. Conclusion：Virus shedding duration of IC patients was significantly longer than that of non IC patients in Omicron wave. The prolonged virus shedding duration in IC patients was mainly in the 9th 14th days. The IC patients had a higher risk of recurrent positive PCR results, which indicated longer isolation time and a strict nucleic acid test strategy after negative PCR test results.