Kumar Ashutosh, Asghar Adil, Raza Khursheed, Narayan Ravi K, Jha Rakesh K, Satyam Abhigyan, Kumar Gopichand, Dwivedi Prakhar, Sahni Chetan, Kumari Chiman, Kulandhasamy Maheswari, Motwani Rohini, Kaur Gurjot, Krishna Hare, Kumar Sujeet, Sesham Kishore, Pandey Sada N, Parashar Rakesh, Kant Kamla
Department of Anatomy, All India Institute of Medical Sciences-Patna, Patna, India.
Department of Anatomy, All India Institute of Medical Sciences-Deoghar, Deoghar, Jharkhand, India.
Interact J Med Res. 2024 Oct 8;13:e44492. doi: 10.2196/44492.
The Delta variant (B.1.617.2) was considered the most dangerous SARS-CoV-2 strain; however, in-depth studies on its impact based on demographic and clinical characteristics of COVID-19 are scarce.
We aimed to investigate the shift in demographic and clinical characteristics of the COVID-19 pandemic with the emergence of the SARS-CoV-2 Delta variant compared with the wild-type (WT) strain (B.1).
A cross-sectional study of COVID-19 cases in the Indian population caused by the WT strain (B.1) and Delta variant of SARS-CoV-2 was performed. The viral genomic sequence metadata containing demographic, vaccination, and patient status details (N=9500, N=6238, N=3262) were statistically analyzed.
With the Delta variant, in comparison with the WT strain, a higher proportion of young individuals (<20 years) were infected (0-9 years: Delta: 281/6238, 4.5% vs B.1: 75/3262, 2.3%; 10-19 years: Delta: 562/6238, 9% vs B.1: 229/3262, 7%; P<.001). The proportion of women contracting infection increased (Delta: 2557/6238, 41% vs B.1: 1174/3262, 36%; P<.001). However, it decreased for men (Delta: 3681/6238, 59% vs B.1: 2088/3262, 64%; P<.001). An increased proportion of the young population developed symptomatic illness and were hospitalized (Delta: 27/262, 10.3% vs B.1: 5/130, 3.8%; P=.02). Moreover, an increased proportion of the women (albeit not men) from the young (Delta: 37/262, 14.1% vs B.1: 4/130, 3.1%; P<.001) and adult (Delta: 197/262, 75.2% vs B.1: 72/130, 55.4%; P<.001) groups developed symptomatic illness and were hospitalized. The mean age of men and women who contracted infection (Delta: men=37.9, SD 17.2 years; women=36.6, SD 17.6 years; P<.001; B.1: men=39.6, SD 16.9 years; women=40.1, SD 17.4 years; P<.001) as well as developing symptoms or being hospitalized (Delta: men=39.6, SD 17.4 years; women=35.6, SD 16.9 years, P<.001; B.1: men=47, SD 18 years; women=49.5, SD 20.9 years, P<.001) were considerably lower with the Delta variant than the B.1 strain. The total mortality was about 1.8 times higher with the Delta variant than with the WT strain. With the Delta variant, compared with B.1, mortality decreased for men (Delta: 58/85, 68% vs B.1: 15/20, 75%; P<.001); in contrast, it increased for women (Delta: 27/85, 32% vs B.1: 5/20, 25%; P<.001). The odds of death increased with age, irrespective of sex (odds ratio 3.034, 95% CI 1.7-5.2, P<.001). Frequent postvaccination infections (24/6238) occurred with the Delta variant following complete doses.
The increased involvement of young people and women, the lower mean age for illness, higher mortality, and frequent postvaccination infections were significant epidemiological concerns with the Delta variant.
德尔塔变异株（B.1.617.2）曾被认为是最危险的严重急性呼吸综合征冠状病毒2（SARS-CoV-2）毒株；然而，基于新冠病毒病（COVID-19）的人口统计学和临床特征对其影响进行的深入研究却很匮乏。
我们旨在研究与野生型（WT）毒株（B.1）相比，随着SARS-CoV-2德尔塔变异株的出现，COVID-19大流行在人口统计学和临床特征方面的变化。
对印度人群中由WT毒株（B.1）和SARS-CoV-2德尔塔变异株引起的COVID-19病例进行了一项横断面研究。对包含人口统计学、疫苗接种和患者状态详细信息的病毒基因组序列元数据（N = 9500、N = 6238、N = 3262）进行了统计分析。
与WT毒株相比，德尔塔变异株感染的年轻人（<20岁）比例更高（0 - 9岁：德尔塔变异株：281/6238，4.5% 对比B.1：75/3262，2.3%；10 - 19岁：德尔塔变异株：562/6238，9% 对比B.1：229/3262，7%；P <.001）。感染的女性比例增加（德尔塔变异株：2557/6238，41% 对比B.1：1174/3262，36%；P <.001）。然而，男性的感染比例下降（德尔塔变异株：3681/6238，59% 对比B.1：2088/3262，64%；P <.001）。年轻人群中出现症状性疾病并住院的比例增加（德尔塔变异株：27/262，10.3% 对比B.1：5/130，3.8%；P =.02）。此外，年轻（德尔塔变异株：37/262，14.1% 对比B.1：4/130，3.1%；P <.001）和成年（德尔塔变异株：197/262，75.2% 对比B.1：72/130，55.4%；P <.001）组中出现症状性疾病并住院的女性比例增加（男性未增加）。感染（德尔塔变异株：男性 = 37.9，标准差17.2岁；女性 = 36.6，标准差17.6岁；P <.001；B.1：男性 = 39.6，标准差16.9岁；女性 = 40.1，标准差17.4岁；P <.001）以及出现症状或住院（德尔塔变异株：男性 = 39.6，标准差17.4岁；女性 = 35.6，标准差16.9岁，P <.001；B.1：男性 = 47，标准差18岁；女性 = 49.5，标准差20.9岁，P <.001）的男性和女性的平均年龄，德尔塔变异株比B.1毒株低得多。德尔塔变异株的总死亡率比WT毒株高约1.8倍。与B.1相比，德尔塔变异株感染的男性死亡率下降（德尔塔变异株：58/85，68% 对比B.1：15/20，75%；P <.001）；相反，女性死亡率增加（德尔塔变异株：27/85，32% 对比B.1：5/20，25%；P <.001）。无论性别，死亡几率均随年龄增加（优势比3.034，95% 置信区间1.7 - 5.2，P <.001）。完全接种疫苗后，德尔塔变异株出现了频繁的疫苗接种后感染（24/6238）。
年轻人和女性感染增加、患病平均年龄降低、死亡率升高以及疫苗接种后频繁感染是德尔塔变异株显著的流行病学问题。
