Adapting Covid-19 infection prevention policies based on community transmission

There has been an increase in the number of daily Covid-19 cases over the past week (July . This has led to increased anxiety among members of the public. The vacuum of knowledge we have of the virus is soon filled with fear of the unknown. Our fear of the next big wave of infections and its consequences gets further amplified through social media echo chambers and the 24-hour news cycle.

I believe the resurgence in daily cases is likely due to the importation of cases from overseas and local transmission. However, the daily reported Covid-19 cases are a heterogeneous mix of three types: imported cases, cases arising from known local clusters, and cases with no epidemiological link (community transmission).

When local transmission is very low and managed well, the biggest threat of a large outbreak is imported cases. With good border control and strict entry restrictions, all incoming cases should be identified and isolated. This will prevent the resurgence of new clusters via imported cases.

There are also new cases that arise from known clusters secondary to effective contact tracing and testing. These cases from previous clusters have a higher likelihood of being successfully controlled by contact tracing, testing, and isolation.

New cases that cannot be traced to a known previous case or cluster is more of an issue and is a marker of community transmission. Another important marker of community transmission is the percentage of serious acute respiratory illness and influenza-like illnessness that are diagnosed as Covid-19.

Decisions about movement control order (MCO) intensity should account for the magnitude of community transmission rather than just the total number of cases. Nationwide preventive policies aimed at known and scattered clusters will not be very efficient. At this stage of the outbreak in Malaysia, our prevention strategies should be dynamic and reactive to community transmission in smaller geographical areas (village/district), ie, enhanced MCO.

The decision about when next to impose a lockdown should consider the country’s healthcare capacity. A too low threshold may result in high economic cost for little health benefits whereas too high a threshold may result in the number of cases overwhelming our healthcare capacity, which would lead to higher morbidity and mortality.

Based on a few assumptions, the numbers suggest that the country’s healthcare system currently has sufficient capacity to handle 20,000 active cases.

If we are really concerned about reducing Covid-19 cases rather than movement restriction, should we focus on expanding our testing strategy? Perhaps test all patients who have fever and are symptomatic?

It is interesting that most of those with higher temperatures detected during standard operating procedure screenings are not tested for Covid-19 if they have no prior contact history with a case. A good screening marker is one that will significantly increase the likelihood of being tested and correctly being diagnosed.

An opinion piece by Prof Dr Sanjay Rampal published in the Star Newspaper on 27 July 2020.

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