Department of Community Medicine, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran.
Department of Emergency Medicine, Alborz University of Medical Sciences, Karaj, Iran.
BMC Infect Dis. 2021 Nov 25;21(1):1185. doi: 10.1186/s12879-021-06870-6.
The first confirmed cases of COVID-19 in Iran were reported in Qom city. Subsequently, the neighboring provinces and gradually all 31 provinces of Iran were involved. This study aimed to investigate the case fatility rate, basic reproductive number in different period of epidemic, projection of daily and cumulative incidence cases and also spatiotemporal mapping of SARS-CoV-2 in Alborz province, Iran.
A confirmed case of COVID-19 infection was defined as a case with a positive result of viral nucleic acid testing in respiratory specimens. Serial interval (SI) was fitted by gamma distribution and considered the likelihood-based R0 using a branching process with Poisson likelihood. Seven days average of cases, deaths, doubling times and CFRs used to draw smooth charts. kernel density tool in Arc GIS (Esri) software has been employed to compute hot spot area of the study site.
The maximum-likelihood value of R0 was 2.88 (95%, CI: 2.57-3.23) in the early 14 days of epidemic. The case fatility rate for Alborz province (Iran) on March 10, was 8.33% (95%, CI:6.3-11), and by April 20, it had an increasing trend and reached 12.9% (95%,CI:11.5-14.4). The doubling time has been increasing from about two days and then reached about 97 days on April 20, 2020, which shows the slowdown in the spread rate of the disease. Also, from March 26 to April 2, 2020 the whole Geographical area of Karj city was almost affected by SARS-CoV-2.
The R0 of COVID-19 in Alborz province was substantially high at the beginning of the epidemic, but with preventive measures and public education and GIS based monitoring of the cases,it has been reduced to 1.19 within two months. This reduction highpoints the attainment of preventive measures in place, however we must be ready for any second epidemic waves during the next months.
伊朗首例 COVID-19 确诊病例报告于库姆市。随后，邻近省份以及伊朗的 31 个省份逐渐受到影响。本研究旨在调查不同时期的病死率、基本繁殖数、每日和累计发病率的预测，以及伊朗阿尔博兹省 SARS-CoV-2 的时空映射。
将 COVID-19 感染的确诊病例定义为呼吸道标本病毒核酸检测阳性的病例。通过伽马分布拟合序列间隔（SI），并使用具有泊松似然的分支过程考虑基于似然的 R0。使用 7 天平均病例数、死亡数、倍增时间和 CFR 绘制平滑图表。ArcGIS（Esri）软件中的核密度工具用于计算研究地点的热点区域。
在疫情早期的 14 天内，R0 的最大似然值为 2.88（95%CI：2.57-3.23）。3 月 10 日，阿尔博兹省（伊朗）的病死率为 8.33%（95%CI：6.3-11），到 4 月 20 日，病死率呈上升趋势，达到 12.9%（95%CI：11.5-14.4）。倍增时间从大约两天增加到 2020 年 4 月 20 日的大约 97 天，这表明疾病传播速度放缓。此外，从 2020 年 3 月 26 日至 4 月 2 日，卡尔杰市的整个地理区域几乎都受到了 SARS-CoV-2 的影响。
在疫情早期，阿尔博兹省 COVID-19 的 R0 相当高，但通过预防措施和公众教育以及基于 GIS 的病例监测，在两个月内已降至 1.19。这一降低突出了已采取的预防措施的效果，但我们必须为未来几个月可能出现的第二波疫情做好准备。
