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Tuesday, 7 April 2020 01:59 - - {{hitsCtrl.values.hits}}
The Sri Lanka Medical Association, Ceylon College of Physicians and Sri Lanka College of Microbiologists have suggested to the Government to increase the RT-PCR testing capacity for COVID-19 to 1,500 tests per day.
In a joint press release, the Presidents of the three institutes also recommended the conduct of community surveillance in hotspots.
“According to the Epidemiology Unit, currently there are 2,000 first level contacts in Sri Lanka. If these first level contacts can be covered through risk-stratified/pooled sampling, it will provide the evidence base on how the next level of contacts should be screened and address current concerns and uncertainty regarding the number of asymptomatic patients,” the press release on ‘Diagnostic and Screening Tests for COVID-19’ said.
The Presidents of the three institutes said the World Health Organisation (WHO) recommended confirmation of cases of COVID-19 by Nucleic Acid Amplification Tests (NAAT), such as Reverse-Transcription Polymerase Chain Reaction (RT-PCR), while many in-house and commercially available assays are used in different laboratories across the world.
“The primary strength of molecular tests is that they directly detect the gene sequences of the virus in the early stages of infection when the patient is infectious. Thus, detection of COVID-19 by RT-PCR can be done from five days prior to the onset of symptoms to several days after symptoms have waned off,” the press release said.
It however added that no laboratory test was perfect. “Although the test carries an almost a 100% specificity, these molecular tests can miss COVID-19 infections depending on the sample collected or if the patient carries a low viral load. The sensitivity is improved by repeating the RT-PCR tests,” it said.
The specialists also said that even though the introduction of a rapid test to detect COVID-19 had been discussed, this test could not replace the value of the RT-PCR tests in the acute diagnosis of the coronavirus.
“Detection of IgM/IgG antibodies to diagnose COVID-19 infection has been discussed at length at many meetings at local and national level.
Advantages such as ease of testing, availability of results within a shorter time, and possibility of using as a point of care (PoC) test have been cited by the proponents. However, this test cannot replace the value of RT-PCR test in the acute diagnosis of COVID-19,” the specialists pointed out.
They added that the IgG/IgM rapid tests relied on the detection of antibodies made by the patient in response to COVID-19 infection and patients may take up to seven to 12 days to produce antibodies to COVID-19 infection and therefore patients in the early stages of the disease will be missed if rapid serological tests were used for diagnosis and could lead to more spreading within the community due to false assurance depending on a negative IgG/IgM test result.
The doctors said introducing a widespread screening test that was not sensitive and would become positive late in the course of the disease was not compatible with the unique pre-emptive policy of Sri Lanka, which had been proven to be successful so far, adding that, for example, if such a method was adopted, it may convey a misleading message to the public, hindering the current efforts of the Government to curtail the spread of the virus and community participation.
“We would like to emphasise that any shift of the current policy of testing for COVID-19 be considered within the broader framework of the present successful public health response and not as an isolated technical matter,” the press release said.
The press release was jointly sent by Ceylon College of Physicians President Dr. Ananda Wijewickrama, Sri Lanka College of Microbiologists President Dr. Shirani Chandrasiri and Sri Lanka Medical Association President Professor Indika Karunathilake.
