背景:这项研究比较了跨波的入院发生率风险,以及OmicronBA.4/BA.5波的死亡风险,到OmicronBA.1/BA.2和Delta波。
方法:来自南非国家医院监测系统的数据,对SARS-CoV-2病例名单和电子疫苗数据系统进行了链接和分析。当该国每周发生30例/100,000人时,定义了波浪期。三角洲地区的住院病死率(CFR),采用插补后随机效应多变量Logistic回归模型比较了OmicronBA.1/BA.2和OmicronBA.4/BA.5波周期。
结果:CFR为25.9%(N=37,538/144,778),三角洲地区的10.9%(N=6,123/56,384)和8.2%(N=1,212/14,879),OmicronBA.1/BA.2和OmicronBA.4/BA.5波分别。在调整了年龄之后,性别,种族,合并症,卫生部门和省,与OmicronBA.4/BA.5波相比,在OmicronBA.1/BA.2波(校正比值比[aOR]1.3;95%置信区间[CI]1.2~1.4)和Delta波(aOR3.0;95%CI2.8~3.2)中,患者的死亡风险较高.部分接种疫苗(aOR0.9,CI0.9-0.9),完全接种(aOR0.6,CI0.6-0.7)和加强(aOR0.4,CI0.4-0.5);和先前实验室确认的感染(aOR0.4,CI0.3-0.4)与死亡率风险降低相关。
结论:总体而言,入院风险和住院死亡率,在南非的前三波浪潮中逐渐增加,在第四次O微米BA.1/BA.2波中下降,在第五次O微米BA.4/BA.5波中进一步下降。自然感染和疫苗接种者的死亡风险较低,随着疫苗剂量的增加,进一步下降。
In this study, we compared admission incidence risk and the risk of mortality in the Omicron BA.4/BA.5 wave to previous waves.
Data from South Africa\'s SARS-CoV-2 case linelist, national COVID-19 hospital surveillance system, and Electronic Vaccine Data System were linked and analyzed. Wave periods were defined when the country passed a weekly incidence of 30 cases/100 000 population. In-hospital case fatality ratios (CFRs) during the Delta, Omicron BA.1/BA.2, and Omicron BA.4/BA.5 waves were compared using post-imputation random effect multivariable logistic regression models.
The CFR was 25.9% (N = 37 538 of 144 778), 10.9% (N = 6123 of 56 384), and 8.2% (N = 1212 of 14 879) in the Delta, Omicron BA.1/BA.2, and Omicron BA.4/BA.5 waves, respectively. After adjusting for age, sex, race, comorbidities, health sector, and province, compared with the Omicron BA.4/BA.5 wave, patients had higher risk of mortality in the Omicron BA.1/BA.2 wave (adjusted odds ratio [aOR], 1.3; 95% confidence interval [CI]: 1.2-1.4) and Delta wave (aOR, 3.0; 95% CI: 2.8-3.2). Being partially vaccinated (aOR, 0.9; 95% CI: .9-.9), fully vaccinated (aOR, 0.6; 95% CI: .6-.7), and boosted (aOR, 0.4; 95% CI: .4-.5) and having prior laboratory-confirmed infection (aOR, 0.4; 95% CI: .3-.4) were associated with reduced risks of mortality.
Overall, admission incidence risk and in-hospital mortality, which had increased progressively in South Africa\'s first 3 waves, decreased in the fourth Omicron BA.1/BA.2 wave and declined even further in the fifth Omicron BA.4/BA.5 wave. Mortality risk was lower in those with natural infection and vaccination, declining further as the number of vaccine doses increased.