To mass test or not to mass test


  • Focus
  • Sunday, 03 May 2020

Malaysia has generally done well with containing and treating Covid-19 patients of known clusters. Next, should it carry out mass testings to detect and contain sporadic and asymptomatic cases before it lifts the movement control order (MCO)?

MALAYSIANS are feeling more at ease now that the daily number of Covid-19 cases in known clusters appears to have gone down.

But, despite the movement control order (MCO) and enhanced MCO, sporadic Covid-19 cases are still being detected while the actual number of asymptomatic cases in the population is not known.

The Health Ministry's Covid-19 statistics revealed that as of April 28, an accumulative 152 Covid-19 sporadic cases had been detected among severe acute respiratory infections (SARI) and influenza-like illness (ILI) patients in its health facilities.

Sporadic cases are cases where the source cannot be pinpointed. They indicate that the disease has spread into the community.

This poses a concern as these patients may cause a spike in cases when the MCO is lifted in the future, and now that the conditional MCO is due to start on May 4 with almost all sectors of the economy allowed to re-open under specific conditions and strict guidelines.

Given the scenario, and the need to be extra vigilant for at least a year, should mass testings be carried out to detect, isolate and treat the patients?

Currently, the Health Ministry screens all from high risk groups such as from known Covid-19 clusters and enhanced MCO areas by asking a list of questions to narrow down those who need to be tested.

The health officers will then take throat swabs from those who need to be tested. They are those who meet the criteria of close contacts of confirm cases, those with symptoms or those suspected to have Covid-19.

The throat swabs are then sent for laboratory testing.

Covid-19 testing is also done on SARI and ILI patients.

(However, Malaysians who returned from overseas will be quarantined, screened, and tested only if needed.)

Some health experts have advocated mass testing or large-scale testing for Covid-19 infection where as many people as possible are tested with the use of a rapid antigen test kit. The World Health Organization (WHO) has recommended that countries find, isolate, test and treat every case to break the chains of transmission.

On April 22, Health director-general Datuk Dr Noor Hisham Abdullah maintained that the Health Ministry will continue with its targeted approach - which is based on locations and high-risk groups - for screening and testing Covid-19 cases. Raising the issue of whether mass screening for 32 million population was feasible or necessary, he pointed out that even South Korea did not screen everyone but only high-risk groups.

While health experts concur with Dr Noor Hisham that it is not possible to test all the 32 million population in Malaysia, opinions vary on the extent the testings should be carried out.

Universiti Malaya virologist Prof Dr Sazaly Abu Bakar says large numbers of random testings should be done before the MCO is lifted.

"Treat patients early to reduce the number of those needing intensive care and to directly reduce the risk of mortality," he says.

The country could start testing 1% of the population randomly and migrant workers should be fully screened, especially those not documented, Dr Sazaly says.

States with very low positives for 21 days should not have to go through the full MCO.

He adds,"Even after the MCO is lifted, people should still stay within their zones and not leave home unnecessarily."

While the Health Ministry is looking into a rapid test kit from South Korea to complement its reverse transcription-polymerase chain reaction (RT-PCR) to expedite Covid-19 results, Dr Sazaly says a big number of testings can be done by liberalising testing.

(RT-PCR is a method used for detecting the presence of specific genetic material from a pathogen.)

"The government should explore some of the test kits that are locally manufactured as this not only give jobs to locals but could even serve as a form of health diplomacy if they were to be donated to less fortunate countries," he says.

See also: Getting back to business

Former deputy Health director-general Datuk Dr Lokman Hakim Sulaiman believes a cost-benefit analysis should be carried out to determine if Malaysia should invest on testing the entire population or selected samples or not test at all but continue with the MCO for a longer period.

"We need to be reminded that people do not only suffer and die from Covid-19 but also from the socio-economic impact of a prolonged MCO," he says.

He adds seroprevalence tests should be undertaken to see the level of exposure of Malaysians to Covid-19 infection as this will help assess the need for testing and the intensity required to detect new cases.

(Seroprevalence test is to gauge the number of people in a population - as a percentage or as a proportion per 100,000 persons- tested for a specific disease based on serology or blood serum specimens. It is usually based upon the presence of antibodies for the disease.)

While an antigen test is used to determine if someone is currently infected, an antibody test will tell if one has had a previous infection.

Dr Lokman says all testing initiatives should be linked with the ministry's post-MCO plan of action.

He suggests lifting of the MCO in stages and testings be carried out based on the estimated prevalence of the infection.

The Health Ministry needs to define its "operational" or "implementation unit" (IU) which could be a mukim (sub-district) in rural areas and a zone/section in urban areas, a geographical area that is practical for disease control activities, surveillance and border-control.

The disease transmission level within the IU is then defined into: white – no new cases for more than 28 days (two incubation periods); green – no new cases for more than 14 days; yellow – no new cases for more than seven days; and red – a persistent weekly new case.

"If it is a white area, lift the MCO. There is no need for tests to be done but put in strict border control and continue with preventive measures such as social distancing and crowd control.

"For the yellow and red zones, continue with the MCO, while green, considered a grey area, continue with the MCO for another two weeks and if possible, do testings too," he says.

Post-MCO, early detection is critical and GPs and primary care clinics can serve as the first line of care and play an important role in detecting cases early, Dr Lokman stresses.

"The ministry should come out with a guideline on diagnosis, testing and patient management (referral), the clinical signs and symptoms, the rapid diagnostic test to use and its interpretation, and measures to be taken if a case is positive or negative, including home quarantine and repeat testing," he says.

Test kits must be made affordable at GP clinics (free in health clinics) and the government should also negotiate with the supplier the price for GPs and subsequently make it a controlled price item to ensure accessibility, he says.

Asia-Pacific Academic Consortium of Public Health (KL) president Datuk Prof Awang Bulgiba Awang Mahmud opines that mass testing is not a pre-condition for the lifting of MCO and it has not been the strategy used by Malaysia for Covid-19 due to the lack of RT-PCR testing capacity.

He feels it is not possible to test the whole population but proposes for mass testing for early detection to be targeted at high-risk populations including migrant workers, if Malaysia could get a sensitive rapid antigen test kit.

However, this needs to be accompanied by an isolation strategy even if they may be asymptomatic or it will not be able to stop the infection from spreading, he says.

"Relying on self-isolation for asymptomatic cases is dangerous and is not likely to work," he says.

According to Dr Awang, there are many gazetted quarantine centres and a temporary make-shift hospital (MAEPS) for such cases to be isolated if they have symptoms but the Health Ministry's guideline currently is to use hospital beds for positive asymptomatic patients.

"This is fine if there are not many positive asymptomatic patients, but if there are too many, then quarantine centres should be an option for such cases," he says, emphasising that access to a centralised online database for rapid analysis of events and use of big data analytics for contact tracing are equally important.

Asked how the country could identify sporadic and asymptomatic cases since mass testing is not viable, Dr Awang says the current sentinel clinic testing for SARI and ILI cases helps identify sporadic cases.

However, SARI and ILI identify symptomatic cases only.

In a press conference on April 21, Dr Noor Hisham said that Covid-19 patients with symptoms such as SARI and ILI have been proven to spread the disease but there are no conclusive findings thus far on whether asymptomatic patients can transmit Covid-19 and it still needs to be studied.

In view of employers' concern that infected workers may spread it to others when they return to work, MCO is lifted, Dr Awang says companies need to put in stringent SOPs and guidelines to ensure physical distancing and that good hygiene are practised at the workplace.

"The management should also split teams up to reduce risks, work from home for non-essential workers and reduce non-essential work-related travel," he says, noting that employers should pay for workers' screening using affordable rapid antigen tests.

Any purchase of mass test kits by the government should be negotiated for the entire country to ensure the best price, he adds.

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