Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Italian National Workers' Compensation Authority (INAIL), Rome, Italy.
Front Public Health. 2022 Nov 1;10:986743. doi: 10.3389/fpubh.2022.986743. eCollection 2022.
The novel coronavirus disease 2019 (COVID-19) is an ongoing pandemic that was first recognized in China in December 2019. This paper aims to provide a detailed overview of the first 2 years of the pandemic in Italy.
Using the negative binomial distribution, the daily incidence of infections was estimated through the virus's lethality and the moving-averaged deaths. The lethality of the original strain (estimated through national sero-surveys) was adjusted daily for age of infections, hazard ratios of virus variants, and the cumulative distribution of vaccinated individuals.
From February 24, 2020, to February 28, 2022, there were 20,833,018 (20,728,924-20,937,375) cases distributed over five waves. The overall lethality rate was 0.73%, but daily it ranged from 2.78% (in the first wave) to 0.15% (in the last wave). The first two waves had the highest number of daily deaths (about 710) and the last wave showed the highest peak of daily infections (220,487). Restriction measures of population mobility strongly slowed the viral spread. During the 2nd year of the pandemic, vaccines prevented 10,000,000 infections and 115,000 deaths.
Almost 40% of COVID-19 infections have gone undetected and they were mostly concentrated in the first year of the pandemic. From the second year, a massive test campaign made it possible to detect more asymptomatic cases, especially among the youngest. Mobility restriction measures were an effective suppression strategy while distance learning and smart working were effective mitigation strategies. Despite the variants of concern, vaccines strongly reduced the pandemic impact on the healthcare system avoiding strong restriction measures.
2019 年新型冠状病毒病（COVID-19）是一场正在进行的大流行，于 2019 年 12 月在中国首次被发现。本文旨在提供意大利大流行前 2 年的详细概述。
使用负二项分布，通过病毒的致死率和移动平均死亡人数来估计每日感染率。通过全国血清学调查，对原始毒株的致死率进行了每日调整，以适应感染年龄、病毒变异的危害比以及接种个体的累积分布。
从 2020 年 2 月 24 日至 2022 年 2 月 28 日，共发生 20833018 例（20728924-20937375）病例，分为 5 波。总体致死率为 0.73%，但每日波动范围为 2.78%（第一波）至 0.15%（第五波）。前两波每日死亡人数最多（约 710 人），第五波每日感染人数最多（220487 人）。人口流动性限制措施大大减缓了病毒传播。在大流行的第二年，疫苗预防了 1000 万例感染和 11.5 万例死亡。
COVID-19 感染中有近 40%未被发现，而且大部分集中在大流行的第一年。第二年，大规模的检测运动使得更多的无症状病例能够被发现，尤其是在最年轻的人群中。限制人口流动的措施是一种有效的抑制策略，而远程学习和远程办公则是有效的缓解策略。尽管出现了令人担忧的变异株，但疫苗大大减轻了大流行对医疗系统的影响，避免了采取强有力的限制措施。
