The impact of COVID-19 non-pharmaceutical interventions (NPIs) in Malaysia

Background: World Health Organisation (WHO) has declared a COVID-19 pandemic on the 11th of March 2020. During the early phase, many countries implement non-pharmaceutical interventions (NPIs) such as movement restriction, physical distancing, and quarantine to control the COVID-19 disease transmission. Malaysia, for example, has introduced various phases of movement control order (MCO) as one of the measures for combating the pandemic. Objectives: To measure the relationship between non-pharmaceutical interventions (NPIs) and confirmed COVID-19 cases transmission in Malaysia. Methodology: This is a time-series analysis study using secondary data from the Ministry of Health (MOH) Malaysia. Daily confirmed COVID-19 incidence data were captured and analysed using R software. We calculated the monthly incidence and incidence rate for Malaysia and all states. The latest population data for Malaysia was taken from the official Department of Statistics Malaysia (DOSM) website. We used the EpiEstim package to estimate the time-varying reproductive number (Rt) and plot the epidemic curves. Finally, we calculated the overall Rt value and analysed the Rt value related to the MCO for Malaysia and the states. Result: Malaysia has recorded 3236 confirmed COVID-19 cases in the middle of March 2020 following a religious gathering in Petaling Jaya, Selangor, followed by other spikes seen in early September 2020 due to another cluster related to State Election in Sabah. On the other hand, we calculated the Rt value and extracted the mean Rt value at Day 1 of each four phases of MCO and compared it. The Rt value showed an overall decrease in trend ranging from 0.542(95% CI: 0.440, 0.656) and 1.443 (95% CI: 1.213, 1.693). Conclusion: In the absence of vaccines, non-pharmaceutical interventions (NPIs) are proven to be the best approach for Malaysia to bring down the time-varying reproductive number (Rt) below the threshold value and to curb the COVID-19 pandemic