Futile Covid-19 tests for mild cases are crippling healthcare, warn Cape doctors

Pointless Covid-19 testing has become a public health threat as the Omicron variant continues to deliver a wave of mild cases, a group of Western Cape doctors said on Tuesday.

Calling for monitoring to be switched “away from cases towards hospitalisations”, the medics said attempts to meet the demand for tests as SA’s fourth wave of infections surges are “deeply damaging to all other primary healthcare services”.

“Limited resources are diverted from usual operations towards assessing and testing the abundance of mild cases,” the seven provincial health department doctors wrote in a SA Medical Journal editorial.

“Wave four is disproportionately affecting primary healthcare services, given that it is so far dominated by milder disease. As a result, fewer staff are available to attend to patients acutely ill with non-Covid-19 disease.

“Tuberculosis diagnosis is down by a third. Chronic HIV and non-communicable disease patients’ prescriptions are being rewritten, often without patient assessment, so limited clinical staff can attend to the glut of mild Covid-19 patients.

“Anecdotally, after 18 months of health service challenges, many chronic disease patients are presenting with severe morbidity that could have been prevented — late-diagnosed metastatic cancers, uncontrolled blood glucose resulting in end-organ damage, opportunistic infections from advanced HIV.”

The doctors, most of whom also work in the health sciences faculty at the University of Cape Town, said testing people with symptoms came at a cost to other health services during previous waves “when severe Covid-19 threatened to overwhelm acute hospital services”.

However, it was questionable now that only 6% of patients were requiring admission — about a third of the number in the first wave.

“To preserve the integrity of primary healthcare services during Covid-19 surges, testing strategies must change,” said Andrea Mendelsohn, Angela de Sá, Erna Morden, Benjamin Botha, Andrew Boulle, Masudah Paleker and Mary-Ann Davies.

“Options could include ramping up testing stations that are delinked from primary healthcare facilities in which public sector patients with mild disease could obtain a Covid-19 test, affordable home-based self-testing, or, if neither of these are feasible, restricted testing to severe Covid-19 patients requiring hospital admission.”

The doctors said only 6% of Covid-19 patients admitted to Western Cape hospitals during the fourth wave had been tested at primary healthcare facilities.

The rest were tested on admission, “suggesting those with severe Covid-19 are seeking care only when they are very ill”.

The doctors said: “Essentially, primary healthcare services risk being swamped with the assessment and diagnosis of mild Covid-19 disease for arguably very little benefit to the patient or the public.

“No antiviral treatment is available in SA for mild Covid-19 disease. Likewise, severe Covid-19 patients are not presenting prior to admission, thereby negating any potential case management benefits of early diagnosis.

“Furthermore, case finding is not blunting community transmission rates. Testing is biased towards symptomatic cases but a high proportion of Covid-19 cases are asymptomatic, and even in symptomatic cases, infectiousness starts before symptom onset.”

All of this was compounded by poor test sensitivity, leading to many false negative results, and it was thought that as few as one in 10 cases are diagnosed.

“While individual knowledge of one’s diagnosis may enable one to isolate and protect others, since most Covid-19 cases go undetected and most Covid-19 contacts occur in the context of a case that has not been identified in the first place, the public health impact of testing what is effectively a minority of total cases is negligible,” said the doctors.

“Outpatient Covid-19 testing does not decrease community transmission, nor does it offer any benefit to individual clinical management, aside from a definitive diagnosis.”

The pressure on the health system was being worsened by Omicron’s greater transmissibility, the doctors said. It was likely about one in 10 Western Cape health workers were either sick, in quarantine or isolating, and “healthcare for all patients will inevitably be compromised in the face of such extreme staff shortages”.

The doctors supported recommendations from the Covid-19 ministerial advisory committee that quarantine and contact tracing should be scrapped, and that the isolation period should be reduced from 10 days to seven to keep emergency services operational.

“Given that most Covid-19 cases go undiagnosed, during a surge exposure to asymptomatic cases is inevitable. Therefore, vaccination, ventilation and masking are our primary prevention tools,” they said.

“Isolating a small proportion of Covid-19 cases and quarantining their contacts does not protect individuals and may create a false sense of security if the public assumes all Covid-19 cases and contacts are effectively in isolation or quarantine,” they said.

The doctors acknowledged changing strategies after “repeated waves of illness and mortality over the past two years” would cause anxiety.

However, “we cannot continue to cripple the healthcare system and the economy with what does not work. People must stay at home if they are mildly ill and only go to hospital if they are unwell and in need of treatment.

“Indoor masking, avoiding large indoor crowds, socialising outdoors, ventilation and, most importantly, vaccination are the best defence against future seasons of endemic Covid-19, and the best way of ensuring our health services are able to provide optimal management of all health conditions.”

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