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Stop random Covid-19 testing and sort out the backlog

- Marc Mendelson, Shabir Madhi, Jeremy Nel and Francois Venter

The testing backlog and proposed testing strategies outside hospital settings are threatening patient management and compromising health care workers’ safety.

The Covid-19 pandemic has created a national crisis in South Africa, requiring a State of Disaster to be enforced. As frontline clinicians and public health specialists at the forefront of this crisis, we signal an urgent need for a course correction of our testing strategy to focus it on saving lives and the integrity of the country’s health system. Acceleration of change must occur, and unnecessary testing for reasons outside of these goals must be stopped.

A medical test should only ever be performed if it will change management of an individual patient or inform a public health response. Early in South Africa’s SARS-CoV-2 epidemic, which has now resulted in 29,240 cases of Covid-19 (as of 29 May), testing for the virus served two main purposes – to triage patients and to trigger the contact tracing, quarantine and isolation cascade.

Recently, different ministries have announced generalised testing of employees returning to work (e.g. in the mines), and screening and testing of sportsmen before non-contact sporting events are allowed to restart under Level 3 restrictions. Unfortunately, these “regulations” are seemingly oblivious to realities of the national crisis facing South Africa’s capabilities to undertake Covid-19 testing.

The testing crisis in South Africa is due to internal planning issues by private and public laboratories, and a consequence of global shortage of testing kits. The number of testing kits available in South Africa within the National Health Laboratory Services (NHLS) is reportedly running dangerously low, and risk being exhausted within a matter of weeks if indiscriminate testing is not halted immediately.

Furthermore, the turnaround time (TAT) of getting results from the time of sampling is already exceeding 24 hours. Dr Kamy Chetty, CEO of the NHLS, indicated during the minister of health’s press conference on 29 May that a backlog of over 80,000 tests had built up nationwide. This is despite the valiant efforts of NHLS laboratory staff on the frontline. This translates into a TAT for a test of up to two weeks. In many instances, this renders testing a futile exercise, since by the time suspected cases tested in the community receive their results, they are less likely (if at all) to be infectious than when they presented for testing, and would have in the interim inadvertently continued spreading the virus. Consequently, a more pragmatic strategy would be the adoption of apps or web-based platforms that are widely and freely available, and that are able to screen for symptoms of Covid-19 and provide advice to the user. The same strategy was implemented in high-resource settings such as the UK at the time of the peak of the outbreak, when they too faced constraints with PCR testing.

The focus of the limited resources for Covid-19 testing available in South Africa – which is unlikely to change over the next few months – needs to be unconditionally reserved for where needs are the greatest, and that’s in our healthcare facilities.

In the hospital setting, the delayed TAT is impairing decision-making on the triage of patients and consequently negatively affecting the management of seriously ill Covid-19 and non-Covid patients and patient flow within the hospital. Consequently, more dedicated wards for suspected cases awaiting tests need to be opened.

Compounding this is the shortage of adequate personal protective equipment (PPE) for healthcare workers (HCWs), with higher levels of PPE (e.g. N95 respirators) being reserved for when managing suspected and confirmed Covid-19 cases and doing aerosol-generating procedures such as intubation. Consequently, not knowing the Covid-19 status of hospitalised patients within the shortest possible time likewise risks jeopardising the wellbeing of HCWs in these facilities.

Also, missing from rationality in the regulations for Covid-19 testing of returning employees or in the sporting environment, is the apparent failure to understand that for such a strategy to be of any use, it would require repeat testing every three to four days, as the risk for acquisition of the virus continues within and outside of workplaces as the outbreak continues its upward trajectory across the country.

This is compounded by the majority (50-80%) of individuals who are infected by SARS-CoV-2 being completely asymptomatic; hence, subsequent testing cannot be reserved for individuals with clinical symptoms of Covid-19 illness. Rather, the only pragmatic strategy available to workplaces and the return of sporting events is one that focuses on ensuring rigorous enforcement and adherence to non-pharmaceutical interventions; i.e. physical distancing, rigorous attention to hand hygiene, use of cloth masks in public, and a ban on mass gatherings (including within the social areas of workplaces).

The focus of the limited resources for Covid-19 testing available in South Africa – which is unlikely to change over the next few months – needs to be unconditionally reserved for where needs are the greatest, and that’s in our healthcare facilities.

We, and others, have repeatedly highlighted this in publications (The Conversation, SAMJ), within the advisory system of government and in public interviews. Despite the department of health taking steps to rectify this, acceleration of change is needed, and other government departments must retract regulations that will not significantly mitigate the risk of people becoming infected, but will only increase demand for testing and worsen the current testing crisis. Here is what needs to happen:

  1. The backlog of tests must be dealt with. For the reasons outlined above, we see little point in testing any of the backlogged samples that were taken more than 48 hours previously. The backlog is such that rapid identification and separation of the mountain of tests is going to be a challenge. Realistically, those tested within 48 hours would get their result back between day 3-5, which may still influence management. As the laboratory test detects the virus’ genetic code, which begins to degrade in the days after the sample is taken, the heightened chance of a false negative result is too great, impairing interpretation. Hence, any test taken more than 48 hours previously – that is from a non-hospitalised person or any test from a hospitalised patient that is unable to be tested immediately – should be discarded. The person who was sampled, and the HCW who took the sample, should be informed with a clearly defined procedure to follow for different scenarios that the person may find themselves in at this new time point. Furthermore, we believe that all tests from the community screening programme (if identifiable) should be discarded, irrespective of sampling time, if from the country’s high prevalence areas where the ability to impact on contact tracing cascade has been lost.
  2. The ‘tap’ regulating the flow of tests to the laboratory must be tightened, and indeed, turned off for certain testing indications. A prioritisation process for determining which persons will benefit from a test at this surge and mitigation stage of the epidemic (and the position we find ourselves in here and now as a country) must be accelerated, and focus on testing only those persons for whom it will change clinical management or protect the integrity of the health service. The process is already nearing completion, but rapid publication and communication to the public is now vital, so that everyone understands the reasons behind the new strategy of our public health response. Testing must focus squarely on hospitalised patients for the reasons given above, and on HCWs to ensure continued running of the health service in South Africa. Linking prioritisation groups to the realistic number of tests that can be performed each day allows us to optimise the testing strategy. Substitution of testing with already formulated screening apps or similar platforms that can impart advice and instruction, should be rapidly rolled out.
  3. Regulations from government ministries outside the department of health that will not impact on mitigating the epidemic or have no scientific rationale, must be rescinded immediately. These include:
  4. Department of Labour – the Minister of Employment and Labour is planning to amend workplace regulations to compel employers to test employees and place them in quarantine if close contacts are infected.  These tests would give a snapshot at one moment in time, but are meaningless as a once-off test, as explained above.
    The current department of labour regulations also state that employees that have been diagnosed with Covid-19 can only return to work once they have tested negative. This is not consistent with national guidelines or advice from the Ministerial Advisory Committee on Covid-19. The only workers for which a recommendation of testing is made to facilitate early return to work are HCWs who have a high-risk exposure to a confirmed Covid-19 patient, but who are asymptomatic themselves. This does not apply to any other worker.
  5. Department of Sport, Arts and Culture. It is pointless to require that athletes and staff of clubs must undergo Covid-19 testing and quarantine pending results of the tests before resumption of activities during Level 3 lockdown. As for employees forced to be tested by the department of labour, these ‘snapshot’ tests will not significantly contribute to mitigating viral transmission or meaningfully address virus acquisition, and will detract from the critical focus of our testing strategy.

Our focus at this stage of the epidemic in South Africa demands that our sole attention must be on saving lives and the integrity of our health service through its workers. This can only be achieved through accelerated course correction of the testing platform, and elimination of unnecessary and wasteful testing countrywide.

Marc Mendelson is Professor of Infectious Diseases and Head of the Division of Infectious Diseases & HIV Medicine at Groote Schuur Hospital, University of Cape Town (UCT). Shabir A. Madhi is Professor of Vaccinology and Director of the MRC Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand. Jeremy Nel is Head of Division of Infectious Diseases, Helen Joseph Hospital, University of the Witwatersrand Francois Venter is Professor of Medicine, Ezintsha, University of the Witwatersrand. This article was first published in Daily Maverick/Maverick Citizen.