División de Análisis en Salud. Coordinación de Vigilancia Epidemiológica, Mexican Social Security Institute, Mexico City, Mexico.
División de Vigilancia Epidemiológica de Enfermedades Transmisibles. Coordinación de Vigilancia Epidemiológica, Mexican Social Security Insitute, Mexico City, Mexico.
BMC Infect Dis. 2022 Oct 31;22(1):813. doi: 10.1186/s12879-022-07800-w.
The Mexican Institute of Social Security (IMSS) is the largest health care provider in Mexico, covering about 48% of the Mexican population. In this report, we describe the epidemiological patterns related to confirmed cases, hospitalizations, intubations, and in-hospital mortality due to COVID-19 and associated factors, during five epidemic waves recorded in the IMSS surveillance system.
We analyzed COVID-19 laboratory-confirmed cases from the Online Epidemiological Surveillance System (SINOLAVE) from March 29th, 2020, to August 27th, 2022. We constructed weekly epidemic curves describing temporal patterns of confirmed cases and hospitalizations by age, gender, and wave. We also estimated hospitalization, intubation, and hospital case fatality rates. The mean days of in-hospital stay and hospital admission delay were calculated across five pandemic waves. Logistic regression models were employed to assess the association between demographic factors, comorbidities, wave, and vaccination and the risk of severe disease and in-hospital death.
A total of 3,396,375 laboratory-confirmed COVID-19 cases were recorded across the five waves. The introduction of rapid antigen testing at the end of 2020 increased detection and modified epidemiological estimates. Overall, 11% (95% CI 10.9, 11.1) of confirmed cases were hospitalized, 20.6% (95% CI 20.5, 20.7) of the hospitalized cases were intubated, and the hospital case fatality rate was 45.1% (95% CI 44.9, 45.3). The mean in-hospital stay was 9.11 days, and patients were admitted on average 5.07 days after symptoms onset. The most recent waves dominated by the Omicron variant had the highest incidence. Hospitalization, intubation, and mean hospitalization days decreased during subsequent waves. The in-hospital case fatality rate fluctuated across waves, reaching its highest value during the second wave in winter 2020. A notable decrease in hospitalization was observed primarily among individuals ≥ 60 years. The risk of severe disease and death was positively associated with comorbidities, age, and male gender; and declined with later waves and vaccination status.
During the five pandemic waves, we observed an increase in the number of cases and a reduction in severity metrics. During the first three waves, the high in-hospital fatality rate was associated with hospitalization practices for critical patients with comorbidities.
墨西哥社会保障研究所（IMSS）是墨西哥最大的医疗保健提供者，覆盖了约 48%的墨西哥人口。在本报告中，我们描述了在 IMSS 监测系统记录的五次流行波中，与 COVID-19 确诊病例、住院、插管和院内死亡相关的流行病学模式以及相关因素。
我们分析了 2020 年 3 月 29 日至 2022 年 8 月 27 日在线流行病学监测系统（SINOLAVE）的 COVID-19 实验室确诊病例。我们构建了每周流行曲线，描述了按年龄、性别和波次划分的确诊病例和住院的时间模式。我们还估计了住院、插管和医院病死率。在五个大流行波次中，计算了平均住院天数和住院延迟天数。使用逻辑回归模型评估了人口统计学因素、合并症、波次和疫苗接种与严重疾病和院内死亡风险之间的关联。
共记录了五次流行波次中的 3396375 例实验室确诊 COVID-19 病例。2020 年底快速抗原检测的引入增加了检测数量，并修改了流行病学估计。总体而言，11%（95%CI 10.9，11.1）的确诊病例住院，20.6%（95%CI 20.5，20.7）的住院病例插管，医院病死率为 45.1%（95%CI 44.9，45.3）。平均住院天数为 9.11 天，患者平均在症状出现后 5.07 天入院。以奥密克戎变异株为主的最近几波疫情发病率最高。随着后续波次的推进，住院、插管和平均住院天数均呈下降趋势。院内病死率在波次间波动，在 2020 年冬季的第二次波次达到最高值。主要观察到≥60 岁人群的住院人数显著下降。严重疾病和死亡的风险与合并症、年龄和性别呈正相关，与后续波次和疫苗接种状况呈负相关。
在五次大流行波次中，我们观察到病例数量增加，严重程度指标下降。在前三个波次中，高院内病死率与患有合并症的重症患者的住院治疗实践有关。
