Barletta William A
Department of Physics Massachusetts Institute of Technology Cambridge, MA United States.
JMIRx Med. 2022 May 24;3(2):e32935. doi: 10.2196/32935. eCollection 2022 Apr-Jun.
In 2021, new variants of the SARS-CoV-2 virus appeared with increased transmissibility and virulence as compared with the original wild variant. The first variants of concern (VoCs), Alpha (B1.1.7) and Gamma (P.1), first appeared in the United Kingdom and Brazil, respectively. The Delta (B.1.617.2) variant, seen in India in October 2020, dominated COVID-19 infections across all regions through the second half of 2021.
This research explores the degree to which SARS-CoV-2 VoCs generate waves of fluctuations in case-fatality rates (CFRs) across countries in several regions, increase the risk of mortality to persons with certain comorbidities, and decrease the risk of mortality as the percentage of fully vaccinated populations increases.
This analysis introduces a measure of the temporal dynamics of COVID-19 infections in the form of a proxy CFR (pCFR), which can be compared among countries. It uses economic and demographic data reported by the World Bank and International Monetary Fund, plus publicly available epidemiological and medical statistics reported to the relevant national and international public health authorities. From these ecological data, pandemic average and daily COVID-19 CFRs and their correlations with potential cofactors were computed for 2021, a year dominated by the spread of World Health Organization-designated VoCs. The study does not investigate disease pathology; rather, it compares the daily case rates and pCFRs to reveal underlying contributing factors that vary from country to country and region to region.
The in-depth global regression analysis of cofactors found that the strongest single correlation with COVID-19 fatality was 0.36 (SD 0.02) with <.001 for chronic kidney disease. No other single physiological cofactors display positive correlations exceeding 0.26 (SD 0.26), with =.008 (asthma) and =.01 (coronary disease). The study confirms that the pCFR is a valuable metric for tracking waves of infection due to different VoCs within countries.
The influence of social, economic, and medical cofactors on the CFR due to VoCs remains qualitatively similar, albeit strengthened, to the levels found for the wild strain. The strong regional variations of the influence of all cofactors observed for the wild strain persists in infections for all VoCs with very strong correlation coefficients seen in the Middle East for asthma (0.76), coronary heart disease (0.60), lung disease (0.70), and chronic kidney disease (0.52). Strong regional variations emphasize the influence on COVID-19 mortality due to regional differences in national economics, patterns of health care policies, and variations in cultural practices and environment. The pCFR-based analysis reveals clear patterns of the spread of VoCs across regions, but there is little evidence for the spread of the Lambda and Mu (B.1.621) variants of interest outside of South America.
2021年，严重急性呼吸综合征冠状病毒2（SARS-CoV-2）病毒出现了新变种，与原始野生变种相比，其传播性和致病性有所增加。首批受关注变种（VoC），即阿尔法（B1.1.7）和伽马（P.1），分别首次出现在英国和巴西。2020年10月在印度发现的德尔塔（B.1.617.2）变种，在2021年下半年主导了所有地区的新冠病毒感染。
本研究探讨SARS-CoV-2 VoC在几个地区的不同国家中导致病死率（CFR）波动的程度，增加某些合并症患者死亡风险的情况，以及随着完全接种疫苗人群比例增加死亡风险降低的情况。
本分析引入了一种以替代CFR（pCFR）形式衡量新冠病毒感染时间动态的指标，可在不同国家之间进行比较。它使用了世界银行和国际货币基金组织报告的经济和人口数据，以及向相关国家和国际公共卫生当局报告的公开可用的流行病学和医学统计数据。根据这些生态数据，计算了2021年大流行期间的平均和每日新冠病毒CFR及其与潜在辅助因素的相关性，2021年是世界卫生组织指定的VoC传播主导的一年。该研究不调查疾病病理；相反，它比较每日病例率和pCFR，以揭示因国家和地区而异的潜在促成因素。
对辅助因素的深入全球回归分析发现，与新冠病毒死亡最强的单一相关性为0.36（标准差0.02），慢性肾病的相关性<0.001。没有其他单一生理辅助因素显示正相关性超过0.26（标准差0.26），哮喘的相关性为=0.008，冠心病的相关性为=0.01。该研究证实，pCFR是追踪不同国家内不同VoC引起的感染浪潮的有价值指标。
社会、经济和医学辅助因素对VoC导致的CFR的影响在性质上仍然相似，尽管有所增强，与野生毒株的影响水平相当。在野生毒株中观察到的所有辅助因素影响的强烈区域差异在所有VoC感染中仍然存在，在中东地区，哮喘（0.76）、冠心病（0.60）、肺病（0.70）和慢性肾病（0.52）的相关系数非常高。强烈的区域差异强调了由于国家经济、医疗保健政策模式以及文化习俗和环境差异对新冠病毒死亡率的影响。基于pCFR的分析揭示了VoC在各地区传播的清晰模式，但几乎没有证据表明南美以外地区有感兴趣的拉姆达和缪（B.1.621）变种传播。
