Nearly a year since the country first went into lockdown because of the covid-19 pandemic, frontline staff at Croydon Council are to be part of a six-week rapid testing programme for coronavirus, starting from Monday.
In an email to staff this afternoon, Katherine Kerswell,the interim chief executive, wrote, “This testing offer will play an important role in boosting our defences against the virus and protect people on the frontline, their families, loved ones, and our residents.”
Kerswell explained that staff eligible for the testing have already been contacted directly.
The council will be using lateral flow covid-19 tests which, according to a report last week in the British Medical Journal, may be of questionable reliability.
These are the sort of test kits that have been used in the government’s much-criticised test and trace programme. The government has spent £1.3billion on buying up 384 million kits, most being bought from the American manufactureer, Innova Group. “Lateral flow tests have become a lucrative business in the covid-19 pandemic,” the BMJ notes.
“The World Health Organization points out that the accuracy of lateral flow tests depends on several factors, including the time from onset of infection, the concentration of virus in the specimen, the quality and processing of the specimen collected from a person, and the precise formulation of the reagents in the test kits,” said the report.
WHO says that lateral flow tests are more likely to detect positive cases when viral loads are highest and patients are most infectious — typically, one to three days before the onset of symptoms and during the first five to seven days after the onset of symptoms. And WHO says that just because someone tests negative, the result “should never be used as a basis of decision making”.
The BMJ reports, “Lack of a central registration process and of comparative data means that Public Health England’s Porton Down laboratory and the University of Oxford have been tasked with evaluating the sensitivity, specificity, and kit failure rate of lateral flow tests.
“Only three of 40 test kits evaluated made it through the first assessments. And only one of these has been evaluated in field studies; it is still unknown how the others work in the real world.”
The tests’ reliability usually depends on the expertise of the person conducting the test, the medical journal report suggests. Research suggests that testers get better with practice.
“Public Health England’s evaluation of the Innova test showed that its sensitivity was 79.2 per cent when used by trained laboratory scientists, 73 per cent when used by trained healthcare staff, but only 57.5 per cent when used by track and trace centre staff employed by the pharmacy chain Boots.”
Kerswell’s email to council staff didn’t state whether those chosen for testing would be expected to traipse over to the chemists’ shop in the Whitgift Centre. Let’s hope not…
Meanwhile, there has been some encouraging figures come through this week, as the number of people in Croydon testing positive for the virus has fallen below 100 per day for four consecutive days.
While this is a long way short of showing that the virus has been beaten in Croydon, it does show that the post-Christmas lockdown is having an effect, with just 63 positive tests on Monday and Wednesday this week, well below the peak of 837 positive cases registered on January 8.
- You can support Inside Croydon’s news-breaking independent local journalism. Sign up today as a subscriber. Click here
- If you have a news story about life in or around Croydon, or want to publicise your residents’ association or business, or if you have a local event to promote, please email us with full details at firstname.lastname@example.org
- Inside Croydon is a member of the Independent Community News Network
- Inside Croydon works together with the Bureau of Investigative Journalism and BBC London News
- ROTTEN BOROUGH AWARDS: Croydon was named the country’s rottenest borough in 2020 in the annual round-up of civic cock-ups in Private Eye magazine – the fourth successive year that Inside Croydon has been the source for such award-winning nominations
- Inside Croydon: 3million page views in 2020. Seen by 1.4million unique visitors