Selangor’s SELangkah Hits Scientific Threshold As Effective Contact Tracing App

Businesses that take part in e-tracing become Covid-19 surveillance spots, says SELangkah app creator.

KUALA LUMPUR, July 14 — The Selangor government’s SELangkah Covid-19 contact tracing app is scientifically considered effective as it is used by 95 per cent of the state’s population, the app’s creator said.

Dr Helmi Zakariah cited a study conducted by Oxford University that stated that an e-tracing ecosystem is considered effective when 60 per cent of the population uses it.

“From this perspective, the population of Selangor is about 6.2 million, to compare with 5.9 million uptakes, we can satisfyingly say that at least in Selangor, SELangkah has reached a scientific threshold for it to be a useful e-tracing ecosystem,” Dr Helmi told CodeBlue in an interview.

Besides that, according to Dr Helmi, the utilisation of the app is another key metric to measure the performance of the digital contact tracing process.

He pointed out that a contact tracing app should not be treated as a scoreboard by focusing solely on the number of users.

“While I don’t have the full contact, as contact tracing in SELangkah SOP (standard operating procedure) is rightly conducted only by health professionals, I can share some anecdotal numbers.

“From 225 patients, 1,208 contacts have been generated while 321 business premises have been alerted for them to conduct in-house sanitisation, whenever SELangkah flags an exposure,” he added.

Dr Helmi also mentioned that three factors — agent, host, and environment — differ for each infectious disease, and changes in these three factors cause different challenges in tracing various infectious diseases.

According to the US Centers for Disease Control and Prevention (CDC), the epidemiological triad or triangle — the traditional model for infectious disease — comprises an external agent, a susceptible host, and an environment that brings the agent and host together. The three factors interrelate to produce disease. Agent originally refers to a pathogen, like a virus or bacteria. Host refers to the person who can get the disease, with individual risk factors like age, sex, and hygiene influencing his or her susceptibility to the agent. Environment refers to extrinsic factors that affect the agent and opportunity for exposure, including physical factors like climate and socioeconomic factors like crowding and sanitation.

In such a scenario, Covid-19 is entirely different from other diseases like Ebola and SARS because the novel coronavirus has different characteristics compared to the other diseases, Dr Helmi said. Unlike Ebola or SARS that are only transmitted by infected people after they fall sick, Covid-19 can be spread by people without symptoms, also known as pre-symptomatic or asymptomatic transmission.

He highlighted that digital tracing methods become essential as asymptomatic patients, or those who do not display symptoms, tend to spread the virus at a much faster rate, especially in areas with a denser population.

SELangkah is used at business premises to record visits by customers, who only need to fill in their name and mobile number after scanning the QR code. 

Dr Helmi stated that business premises are playing a role as a surveillance spot for public health professionals by taking part in the e-tracing initiative.

“By having the SELangkah poster, we turned business premises into a sentinel site or into a surveillance mechanism.

“In a way actually, these business premises become the eye or additional eye for the public health people. Public health people cannot trace people everywhere, so they voluntarily use their premise as a surveillance site.

“Business is not contradictory to public health — they are actually part of this initiative too,” he further explained.

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