Test, Test, Test

By Dr Milton Lum | 25 March 2020

The data reported daily by the authorities do not reflect the actual situation as about 80% of the infected have no or mild symptoms, which may be non-specific.

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The Covid-19 outbreak is causing havoc globally and Malaysia is no exception. It is spreading exponentially taking 67 days from the first report to reach 100,000 cases, 11 days to reach 200,000, and four days to reach 300,000 globally.

Whilst there is no single measure to rein it in, one has to go back to basics to deal with it, which this article seeks to address.

Serious situation

At the outset, it is vital that everyone comprehend the seriousness of the outbreak and the extraordinary threat to life, notwithstanding seemingly optimistic reports by some analysts.

According to the World Health Organization (WHO) report on the China outbreak, which is the largest published series, about 80 per cent of laboratory confirmed patients had mild to moderate disease, which includes non-pneumonia and pneumonia cases, 13.8 per cent had severe disease and 6.1 per cent were critically ill.

The crude fatality rate (CFR) for China was 3.8 per cent (5.8 per cent in Wuhan and 0.7 per cent in the rest of China).

The numbers in the Malaysian population who will die from the illness depends on the percentage infected and the CFR, bearing in mind that there is, as yet, no published data on the percentage of the population that is infected. The table below provides some estimates to ponder over.

The current data is that well prepared health systems like Hong Kong, Taiwan, Singapore, Japan and South Korea, who all had the benefit of the experience of managing SARS in 2002-2003, have lower fatality rates than that of health systems which are less well prepared or with less experience.

The Johns Hopkins University Coronavirus Resource Centre (Accessed 1300 hours 24 March 2020) tracks Covid-19 globally. The CFR, as at 24 March 2020, of Hong Kong (4/356), Taiwan (2/195), Singapore (2/509), Japan (42/1140) and South Korea (120/9037) were 1.12 per cent, 1.03 per cent, 0.39 per cent, 3.68 per cent and 1.33 per cent respectively.

The CFR for Italy (6077/63927) was 9.51 per cent in contrast with 0.42 per cent of Germany (123/29056). Malaysia’s CFR was 0.98 per cent (15/1518).

It is important to bear in mind that the CFR changes with time, context and mutation of the virus, the information of which is yet to be elucidated.

The number of patients in the intensive care units is of concern, particularly to anaesthesiologists and nursing staff, having been on an upward trend since 15 March 2020, with an increase of more than seven-fold in 10 days.

Reproduction number

The basic reproduction number (Ro) measures the potential of spread of an infectious disease. It is the average number of secondary infections produced by a typical case of the infection in a population where everyone is susceptible, which would be the case with Covid-19, a novel infection.

For example, if the Ro of a disease in a population is 10, then each new case of the disease will produce 10 new secondary cases, assuming everyone around the case was susceptible. Ro does not include new cases produced by the secondary cases.

The basic Ro depends on the rate of contacts in the population, the duration of infectiousness and the probability of infection spread during a contact.

If the Ro is 1, each infection will cause one other infection, which means the infection remains stable but controllable. If the Ro is >1.0, each infection causes more than one infection, which means the disease will spread. If the Ro is <1, it means the disease can eventually die out.

The WHO estimated that the Ro for Covid-19 is 2.0-2.5. However, others have estimated the Ro between 3.6-4; 2.24-3.58 and 1.5-3.5.

By comparison, the Ro for SARS was 2.0 and the common flu is 1.3.

In short, the SARS-COV-2 virus which causes Covid-19 is more infectious and contagious than SARS and the common flu.

Testing

The data reported daily by the authorities do not reflect the actual situation as about 80 per cent of the infected have no or mild symptoms, which may be non-specific.

This means that undetected infected people continue to spread the infection unknowingly.

The more tests are done, the more cases will be detected and the greater the likelihood that the reported data reflects the actual situation on the ground.

The tests done per million of Malaysia’s population as at 20 March 2020 was 422.2 (Accessed 1300 hours 24 March 2020). By comparison, the tests done per million population in Hong Kong was 698.4, Taiwan 898.9, South Korea 6148, Italy 3498.7 and Germany 2023.3. The tests done by Singapore were reported to be more than that of South Korea.

The criteria for testing in the Ministry of Health facilities are limited by its testing capacity. Its daily testing capacity of 3,500 will be doubled to 7,000 by the end of this week and 16,500 by the first week of April.

With the increase in testing capacity together with aggressive testing and contact tracing, numbers that are more reflective of the actual situation will emerge.

Social distancing

The objective of the Movement Control Order (MCO) is social distancing, which is the deliberate absence of contact with another person unless there is an absolute need and involves an increase in the physical space between people.

This is because the virus spreads when an infected person coughs or sneezes out droplets, containing large amounts of viruses, into the air which is breathed in by another person. An infection can also result if one comes into contact with droplets which have landed onto a surface and then touches one’s eyes, nose or mouth.

The less time people spend together and/or maintain a distance of 2 metres from another person, the less likely the virus can spread.

The reasons for the criticism of the MCO by a former Deputy Director General of Health are obvious. The exodus from the major urban areas after the announcement of the MCO, on 16 March 2020, did not promote social distancing at all. Instead, it increased the chances of spreading through crowding at transportation centres and police stations.

It also led to the dispersal of those with undiagnosed infection across the country, with its attendant consequences, including delay in the emergence of a trend.

The value of testing vis-à-vis social distancing was stated by Dr Michael Ryan, Director of WHO Health Emergencies Programme “Social distancing is based on a principle that you don’t know who’s infected and you’re separating, putting social distance between, everyone. We’ve said again and again, many countries are not in that situation yet.

“Many countries are in a situation where the disease is recognisable, cases can be detected, contacts can be identified, quarantined. And it is a more cost-effective intervention to separate some individuals from society than separate everybody in society from each other.”

Social distancing, carried out properly, slows the spread of the disease thereby reducing the burden on the health system. This is termed as “flattening of the curve” by public health specialists. It only buys time for the health system to re-strategise and improve capacity and capabilities.

Test, test, test

Covid-19 is caused by a virus. If every infected person is identified, monitored and treated, if necessary, then the infection can be controlled. This requires testing, contact tracing and testing repeatedly until tests on all contacts are negative ideally but minimal practically.

If not, spread will continue at a lower level and resurge once social distancing measures are lifted.

The need for testing is well summarised by the WHO Director General who stated “You cannot fight a fire blindfolded. And we cannot stop this pandemic if we don’t know who is infected…We have not seen an urgent enough escalation in testing, isolation and contact tracing, which is the backbone of the response. We have a simple message for all countries: Test, test, test.”

In an interview with the British Broadcasting Corporation (BBC) on 15 March 2020, the South Korean Foreign Minister informed that extensive testing has been the key to its low mortality rate and stating “Testing is central because that leads to early detection, it minimises further spread and quickly treats those found with the virus.”

It’s early days in the epidemic in Malaysia. Until a clear trend emerges, it would be prudent not to make claims that would be difficult to retract.

The battle against Covid-19 has just begun and the signs of the end of the war will be when a vaccine is available.

Dr Milton Lum is a past President of the Federation of Private Medical Practitioners Associations, Malaysia and the Malaysian Medical Association. This article is not intended to replace, dictate or define evaluation by a qualified doctor. The views expressed do not represent that of any organization the writer is associated with.

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