Measuring Time-Varying Effective Reproduction Numbers for COVID-19 and Their Relationship with Movement Control Order in Malaysia.

Kamarul Imran Musa,Noor Atinah Ahmad,Mohd Hafiz Mohd,Mohammad Subhi Jamiluddin,Xin Wee Chen,Tengku Muhammad Hanis,Awang Bulgiba,Wan Nor Arifin

doi:10.3390/ijerph18063273

Abstract

To curb the spread of SARS-CoV-2 virus (COVID-19) in Malaysia, the government imposed a nationwide movement control order (MCO) from 18 March 2020 to 3 May 2020. It was enforced in four phases (i.e., MCO 1, MCO 2, MCO 3 and MCO 4). In this paper, we propose an initiative to assess the impact of MCO by using time-varying reproduction number (Rt). We used data from the Johns Hopkins University Centre for Systems Science and Engineering Coronavirus repository. Day 1 was taken from the first assumed local transmission of COVID-19. We estimated Rt by using the EpiEstim package and plotted the epidemic curve and Rt. Then, we extracted the mean Rt at day 1, day 5 and day 10 for all MCO phases and compared the differences. The Rt values peaked around day 43, which was shortly before the start of MCO 1. The means for Rt at day 1, day 5, and day 10 for all MCOs ranged between 0.665 and 1.147. The average Rt gradually decreased in MCO 1 and MCO 2. Although spikes in the number of confirmed cases were observed when restrictions were gradually relaxed in the later MCO phases, the situation remained under control with Rt values being stabilised to below unity level (Rt value less than one).

Highlights

The incidence data reported by the Ministry of Health (MOH), Malaysia refer to the day when a patient was detected positive by the RT-PCR test
From day 40 to day 60, the growth peaked. This observation agrees with the number of reported active COVID-19 cases in Malaysia, which peaked around 5–8 April 2020, with the highest
The overall trend of reproduction number (Rt) values do correspond with the timeline of the pandemic and the level of strict measures imposed during each phase of the movement control order (MCO)

Summary

Introduction

To combat the coronavirus disease 2019 (COVID-19) pandemic, the Malaysian government initiated MCOs, effective on 18 March 2020, with the aim to aggressively contain the outbreak and slow down the transmission rate. This strategy was proclaimed under the Prevention and Control of Infectious Diseases Act 1988 (Act 342) and the Police Act. 1967. Offenders violating MCO directives could face a maximum of RM 1000 fine and/or six months in jail or both if convicted [1]. The imposition of different MCO levels was decided by the Malaysian government, considering the livelihoods in communities and the economic stability

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Conclusion