Departamento de Pesquisa & Desenvolvimento, Instituto Hermes Pardini, Belo Horizonte 31270-901, Brazil.
Laboratório de Biologia Integrativa, Departamento de Genética, Ecologia e Evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil.
Viruses. 2022 Apr 20;14(5):847. doi: 10.3390/v14050847.
Coronavirus disease 2019 (COVID-19) pandemic has caused immeasurable impacts on the health and socioeconomic system. The real-time identification and characterization of new Variants of Concern (VOCs) are critical to comprehend its emergence and spread worldwide. In this sense, we carried out a national epidemiological surveillance program in Brazil from April to October 2021. Genotyping by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and sequencing were performed to monitor the dynamics and dissemination of VOCs in samples from 15 federative units. Delta VOC was first detected on June 2021 and took sixteen weeks to replace Gamma. To assess the transmissibility potential of Gamma and Delta VOCs, we studied the dynamics of RT-qPCR cycle threshold (Ct) score in the dominance period of each variant. The data suggest that Delta VOC has a higher transmission rate than Gamma VOC. We also compared relevant symptom patterns in individuals infected with both VOCs. The Delta-infected subjects were less likely to have low oxygen saturation or fatigue, altered results on chest computed tomography, and a propensity for altered X-rays. Altogether, we described the replacement of Gamma by Delta, Delta enhanced transmissibility, and differences in symptom presentation.
2019 年冠状病毒病（COVID-19）大流行对健康和社会经济系统造成了无法估量的影响。实时识别和描述新的关注变异株（VOCs）对于了解其在全球的出现和传播至关重要。在这方面，我们于 2021 年 4 月至 10 月在巴西开展了一项全国性的流行病学监测计划。通过逆转录定量聚合酶链反应（RT-qPCR）和测序进行基因分型，以监测 15 个联邦单位样本中 VOCs 的动态和传播。Delta VOC 于 2021 年 6 月首次检测到，并花了十六周时间取代 Gamma。为了评估 Gamma 和 Delta VOC 的传播潜力，我们研究了每个变体主导期间 RT-qPCR 循环阈值（Ct）分数的动态。数据表明，Delta VOC 的传播率高于 Gamma VOC。我们还比较了两种 VOC 感染个体的相关症状模式。Delta 感染患者的低血氧饱和度或疲劳、胸部计算机断层扫描结果改变以及 X 光片改变的倾向较低。总之，我们描述了 Gamma 被 Delta 取代、Delta 增强的传播能力以及症状表现的差异。
