Higher contagion rate

With the recent rise of clusters in Kedah and Sabah, Malaysia’s Covid-19 infectivity rate has gone up since early this month. But experts say how fast the disease is spreading still depends on public health measures and how well we comply with them.

PETALING JAYA: Malaysia had the highest Covid-19 reproduction number (Rt) of 1.57 on Sept 15 among six other countries in the region, according to a disease modelling centre based in Britain.

The Centre for Mathematical Modelling of Infectious Diseases on its “Epiforecasts” website estimated that Malaysia’s Covid-19 reproduction number on Sept 15 was at 1.57, followed by Singapore at 1.15, Thailand at 1.1, Indonesia at 1.06 and Philippines at 1.0.

Two countries which recorded a Covid-19 reproduction rate of below 1.0 were Vietnam at 0.61 and Cambodia at 0.49.

However, data for Myanmar, Brunei and Laos were not available.

The R, or reproduction number, is the rate of infectivity and estimates the average number of people that one positive Covid-19 patient can infect.

“Our modelling framework, based on open source tooling, accounts for uncertain reporting delays so that the reproduction number is estimated based on underlying latent infections and not reported cases or deaths,” said its website.

The centre, which is located at the London School of Hygiene and Tropical Medicine, claims to be a

multidisciplinary grouping of epidemiologists, mathematicians, economists, statisticians and clinicians.

While the centre’s estimation at 1.57 on Sept 15 for Malaysia was close to the Health Ministry’s figure of 1.58 on Sept 13, it did not explain why this was higher than the infectivity rates in Indonesia, Singapore and the Philippines which have far higher number of cases.

Other countries badly hit by the pandemic such as Britain – which has a total of 390,358 cases – also had a slightly lower reading than Malaysia.

Malaysia’s Rt peaked at 2.34 on Sept 8 and at 2.30 on Sept 11.

Health director-general Tan Sri Dr Noor Hisham Abdullah previously cautioned that it was crucial to keep the Rt to below 1.60 to avoid a new wave of Covid-19 infections in the country.

On Sept 18, the British government stated on its official website that the R number in the country was estimated to be between 1.1 and 1.4, with the number of new infections growing by 2% to 7% every day.

“An R number of between 1.1 and 1.4 means that on an average, every 10 people infected will infect between 11 and 14 other people,” it said, pointing out that there was widespread growth of the epidemic across the country.

According to the Daily Mail ,theR value for Britain estimated by the

Imperial College Covid-19 Response Team was at 2.4 before lockdown started.

“But some experts analysing outbreaks across the world have estimated that this could be closer to the 6.6 mark.

“Estimates of the R number vary because the true size of the pandemic remains a mystery, and how fast the virus spreads depends on the environment,” it said.

The virus will spread faster in densely populated cities with public transportation as a main method of commuting.

Asked why Malaysia recorded a higher Rt compared to other countries that recorded much higher cases in the region, Medical Practitioners Coalition Association of Malaysia president Dr M. Raj Kumar said the number was not fixed.

“Instead, it changes as our behaviour changes or as immunity develops.

“Rt does not depend on the number of cases in the country but how many other people can get infected from one infected case,” he said.