Testing glitches threaten Level 3
SKEWED RESULTS: CURRENT METHOD YIELDS UNRELIABLE DETECTION RATE
The ‘flawed’ and ‘fallible’ testing strategy for the coronavirus in SA is too random, with a backlog of 15 000 in Cape Town and Johannesburg alone, casting doubt over the accuracy of government’s infection figures, says an expert.
‘Backlogs and delays result in figures that are no longer relevant.’
As the rest of South Africa gears up for lockdown easing to Level 3, a leading medical expert has called on government to refine its flawed testing strategy.
She said the current one yielded an unreliable detection rate – amid a massive more than two weeks backlog of about 15 000 cases in Cape Town and Johannesburg testing laboratories.
While conceding that the 54day government-imposed lockdown “certainly bought us time to prepare our public health facilities”, Dr Kerrin Begg yesterday sketched a picture of “an inefficient, ineffective, inaccurate and fallible testing strategy” she said should be abandoned.
In appraising the Covid-19 testing strategy, Begg, who is University of Cape Town (UCT) public health specialist and a member the College of Public Health Medicine Guidance Task Team, revealed that:
Despite the Western Cape presenting the highest coronavirus-positive cases in South Africa, the province had a high detection rate of 15% out of 100 individuals tested, compared to a 1.72% decline in the rest of SA.
Mass under-counting and inaccuracy in the number of people tested or found to be positive, gave an incorrect picture.
Government relied on historical data in its reporting, leading to decisions on inaccurate and incorrect information.
Begg explained: “While we expected community transmission of the virus much earlier, it only ramped up four weeks ago and is now in full swing, meaning that lockdown has bought us time.
“The Western Cape has emerged as a good model, looking at the numbers of testing done and the detection rate, compared to Gauteng. Looking at the number of cases tested, versus those detected, you find an anomaly.
“Like the rest of the country, the Western Cape earlier stood at 3% detection and now it is on about 15%.”
Elaborating on testing numbers, Begg said: “Highly problematic is under-counting. Until the number of cases of those tested become more accurate, we have a serious issue, because numbers depended on are fallible. What we have been seeing is random and not targeted testing.
“What we have been doing has been looking for a needle in a haystack, but being all over the haystack because of not being targeted, something not helpful.
“Because of massive delays at laboratories to timeously release results of those tested due to a backlog, we get figures that are no longer relevant for reporting and we do not even know the people we tested.
“What we need to do is focus on the position of the haystack by mapping out cases – focusing on community clusters where there is a concentration of cases. There is no point in looking at historical data, which should be thrown away.”
Asked about what South Africans should do to avoid regressing to Level 5, Begg said: “People should get used to the new normal, making it a way of life.
“This includes physical distancing, adhering to hygiene and washing our hands regularly with soap.”
On this week’s disturbing posting by a colleague – senior research scientist Zaer Shameem Jaumdally from the UCT Lung Institute, who commented in a Facebook post about the dire situation at Groote Schuur Hospital, saying that “funeral parlour vehicles were queueing up to collect the bodies of the deceased...”, Begg responded: “Groote Schuur is about the appropriate preparation put in place and not about things being bad.
“As healthcare staff at the hospital saw the Covid-19 ward getting fuller and numbers of cases increasing, they prepared for additional cases, including mortuary space.”