在非洲出现和传播SARS-CoV-2 omicron (BA.1) 变种:一项观察性研究
Carlo Fischer1, Tongai Gibson Maponga2, Anges Yadouleton3
1Institute of Virology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany.
The Lancet. Global health
|January 31, 2025
概括
2021年底,Omicron BA.1变种在非洲迅速传播,超过了旅行限制. 这凸显了对综合基因组监测和建模的需要,以追踪新出现的SARS-CoV-2变种.
科学领域:
- 病毒学 病毒学
- 流行病学 流行病学
- 公共卫生 公共卫生
背景情况:
- 2021年11月,SARS-CoV-2 Omicron BA.1亚系在非洲南部出现,导致国际旅行限制.
- 在被检测时,关于Omicron BA.1在非洲的地理传播存在有限的数据.
研究的目的:
- 为了调查SARS-CoV-2 Omicron BA.1变种在非洲国家的传播.
- 评估旅行限制在限制Omicron BA.1.传播方面的有效性.
- 评估基于PCR的策略与基因组监测和用于追踪新兴病原体的数学建模相结合的实用性.
主要方法:
- 一项涉及实时RT-PCR测试的观察性研究,对来自24个非洲国家的13,294名SARS-CoV-2患者样本进行了实时RT-PCR测试 (2021年6月至2022年4月).
- 排除在估计BA.1出现之前收集的样本,以确保数据完整性.
- 通过高通量测序验证诊断试验,并将观察到的传播与基于移动性的数学模拟和GISAID数据进行比较.
- 估计有效繁殖数 (Rt) 和植物地理分析.
主要成果:
- 截至2021年11月至12月,Omicron BA.1在所有非洲次区域取代了Delta变种,平均Rt值为2.60,南北传播.
- 基于PCR的BA.1优势的重建与GISAID基因组数据有显著的相关性 (p=0.0002,r=0.78).
- 基于移动性的模拟准确地预测了非洲以外的早期BA.1检测,并表明非洲的SARS-CoV-2感染报告不足,约为十倍.
- 截至2021年12月初,在六个非洲国家发现了BA.1的入境旅行者.
结论:
- 当旅行禁令实施时,Omicron BA.1 已经在非洲广泛传播,从而降低了其有效性.
- 基于PCR的策略,与基因组监测和数学建模相结合,为监测Rt和新兴病原体的地理传播提供了具有成本效益和及时的方法.
- 这些综合方法可以为基于证据的非药物干预提供信息,包括旅行限制和身体距离.
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