Faculty of Medicine, University of Peradeniya, Kandy, Sri Lanka.
Department of Health Metrics Sciences, School of Medicine, Institute for Health Metrics and Evaluation, University of Washington, WA, Seattle, USA.
Virol J. 2020 Oct 7;17(1):144. doi: 10.1186/s12985-020-01411-0.
The basic reproduction number (R0) is the number of cases directly caused by an infected individual throughout his infectious period. R0 is used to determine the ability of a disease to spread within a given population. The reproduction number (R) represents the transmissibility of a disease.
We aimed to calculate the R0 of Coronavirus disease-2019 (COVID-19) in Sri Lanka and to describe the variation of R, with its implications to the prevention and control of the disease.
Data was obtained from daily situation reports of the Epidemiology Unit, Sri Lanka and a compartmental model was used to calculate the R0 using estimated model parameters. This value was corroborated by using two more methods, the exponential growth rate method and maximum likelihood method to obtain a better estimate for R0. The variation of R was illustrated using a Bayesian statistical inference-based method.
The R0 calculated by the first model was 1.02 [confidence interval (CI) of 0.75-1.29] with a root mean squared error of 7.72. The exponential growth rate method and the maximum likelihood estimation method yielded an R0 of 0.93 (CI of 0.77-1.10) and a R0 of 1.23 (CI of 0.94-1.57) respectively. The variation of R ranged from 0.69 to 2.20.
The estimated R0 for COVID-19 in Sri Lanka, calculated by three different methods, falls between 0.93 and 1.23, and the transmissibility R has reduced, indicating that measures implemented have achieved a good control of disease.
基本繁殖数（R0）是指感染者在整个传染期内直接引起的病例数。R0 用于确定疾病在特定人群中的传播能力。繁殖数（R）代表疾病的传染性。
我们旨在计算 2019 年冠状病毒病（COVID-19）在斯里兰卡的 R0，并描述 R 的变化，及其对疾病预防和控制的影响。
数据来自斯里兰卡流行病学部门的每日情况报告，使用估算的模型参数使用 compartmental 模型计算 R0。使用两种方法（指数增长率法和最大似然法）来验证该值，以获得 R0 的更好估计值。使用贝叶斯统计推断方法来说明 R 的变化。
第一个模型计算的 R0 为 1.02（置信区间 0.75-1.29），均方根误差为 7.72。指数增长率法和最大似然估计法分别得出 R0 为 0.93（置信区间 0.77-1.10）和 R0 为 1.23（置信区间 0.94-1.57）。R 的变化范围从 0.69 到 2.20。
三种不同方法计算的 COVID-19 在斯里兰卡的估计 R0 在 0.93 到 1.23 之间，传染性 R 已降低，表明实施的措施已实现对疾病的良好控制。
