Epidemiology in southern India By August 2020, India had reported several million cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with cases tending to show a younger age distribution than has been reported in higher-income countries. Laxminarayan et al. analyzed data from the Indian states of Tamil Nadu and Andhra Pradesh, which have developed rigorous contact tracing and testing systems (see the Perspective by John and Kang). Superspreading predominated, with 5% of infected individuals accounting for 80% of cases. Enhanced transmission risk was apparent among children and young adults, who accounted for one-third of cases. Deaths were concentrated in 50- to 64-year-olds. Incidence did not change in older age groups, possibly because of effective stay-at-home orders and social welfare programs or socioeconomic status. As in other settings, however, mortality rates were associated with older age, comorbidities, and being male. Science, this issue p. 691; see also p. 663 The epidemiology of SARS-CoV-2 in southern India shows marked differences from that observed in higher-income countries. Although most cases of coronavirus disease 2019 (COVID-19) have occurred in low-resource countries, little is known about the epidemiology of the disease in such contexts. Data from the Indian states of Tamil Nadu and Andhra Pradesh provide a detailed view into severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission pathways and mortality in a high-incidence setting. Reported cases and deaths have been concentrated in younger cohorts than would be expected from observations in higher-income countries, even after accounting for demographic differences across settings. Among 575,071 individuals exposed to 84,965 confirmed cases, infection probabilities ranged from 4.7 to 10.7% for low-risk and high-risk contact types, respectively. Same-age contacts were associated with the greatest infection risk. Case fatality ratios spanned 0.05% at ages of 5 to 17 years to 16.6% at ages of 85 years or more. Primary data from low-resource countries are urgently needed to guide control measures.

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印度两个邦的 COVID-19 流行病学和传播动态

印度南部的流行病学 截至 2020 年 8 月，印度报告了数百万例严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 病例，与高收入国家报告的病例相比，病例的年龄分布往往更年轻。拉克斯米纳拉扬等人。分析了来自印度泰米尔纳德邦和安得拉邦的数据，这些邦开发了严格的接触者追踪和测试系统（参见约翰和康的观点）。超级传播占主导地位，5% 的感染者占病例的 80%。儿童和年轻人的传播风险明显增加，占病例的三分之一。死亡人数集中在50岁至64岁之间。老年群体的发病率没有变化，可能是因为有效的居家令和社会福利计划或社会经济地位。然而，与其他情况一样，死亡率与年龄较大、合并症和男性有关。科学，本期第 14 页。691; 另见 p. 663 印度南部的 SARS-CoV-2 流行病学与高收入国家的流行病学存在显着差异。尽管大多数 2019 年冠状病毒病 (COVID-19) 病例发生在资源匮乏国家，但人们对该疾病在这种情况下的流行病学知之甚少。来自印度泰米尔纳德邦和安得拉邦的数据详细介绍了严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 在高发环境中的传播途径和死亡率。即使考虑到不同地区的人口差异，报告的病例和死亡仍集中在较年轻的人群中，这比高收入国家的观察结果所预期的要多。在接触过 84,965 例确诊病例的 575,071 人中，低风险和高风险接触类型的感染概率分别为 4.7% 至 10.7%。同龄接触者与最大的感染风险相关。5至17岁的病死率为0.05%，85岁或以上的病死率为16.6%。迫切需要来自资源匮乏国家的原始数据来指导控制措施。