Lack of Covid testing in UK highlights supply chain pressures as demand rises

British Health Minister Sajid Javid has admitted that the government will “need to limit” the supply of rapid Covid-19 tests over the next fourteen days to respond to “unprecedented demand” driven by the rise of the Omicron variant.

“The arrival of the Omicron variant has caused record high case numbers and unprecedented demand for both PCR and Lateral Flow Device [LFD] test, ”Javid wrote in a letter to lawmakers Wednesday night. “This has inevitably put pressure on the test system despite the impressive upscaling of supply, logistics and laboratory capacity.

“We expect to have to limit the system at certain times over the next two weeks to manage supply during each day, with new supply tranches being released regularly during each day.”

The letter follows several weeks in which the government’s booking platforms for PCR tests, which require laboratory treatment but are more accurate, and rapid LFD tests have been ruined by irregular availability.

The UK reported a record 189213 Covid-19 cases on Thursday, up 58 per cent from the same day last week.

A further 332 deaths within 28 days of a positive test were recorded, the highest daily figure since early March.

But both daily totals are likely to be inflated by reporting backlogs during the Christmas period.

Does the supply of lateral flow tests keep pace with demand?

The rapid spread of the Omicron variant has put more pressure on the test system than any previous Covid wave.

This is largely due to the fact that double-vaccinated close contacts in a Covid case in England can avoid self-isolation by taking daily lateral flow tests for a week, while infected people who are vaccinated can leave isolation after taking an LFD on day six and seven.

“We can not have enough tests right now,” said Irene Petersen, professor of epidemiology and health informatics at University College London.

In his letter to MPs, Javid promised to triple the supply of 100 million LFDs a month before Omicron.

Diagram showing that lateral currents now make up a large majority of tests in England, and a fifth of new cases

According to the latest figures quoted by Prime Minister Boris Johnson, 200 million tests will be sent directly to UK households over the next month, alongside 42 million being delivered through pharmacies. This corresponds to just over one package with seven tests per. household.

But Petersen said the government had been “very vague” about how LFDs were prioritized, adding that this had created “panic” over the lack of availability on the booking platform.

“We need to perform smart tests by making sure supplies get through to key employees who want to avoid or end their self-isolation period,” she said, repeating calls from doctors and nurse representatives. “Only after that can we think about getting tested out to as many households as possible.”

Prof Azeem Majeed, head of the Department of Primary Care and Public Health at Imperial College London, said some of his patients “tested their whole family every day” due to the “lack of clear guidance”.

Is there a global shortage of lateral flow tests?

On Wednesday, Tory MP Sir Roger Gale tweeted that the health minister had informed him that “lateral flow and PCR test blocking” in his Kent constituency was the result of a “world shortage”.

Two people familiar with the public procurement process told FT that the UK faced “much tougher competition” for sideline power supplies compared to earlier in the pandemic because more countries were now implementing the technology.

They also said Britain’s small pool of approved suppliers limited its options. Only four biotech companies have exceptional use permits to deliver fast test kits for self-use through the NHS Test and Trace program.

“No domestic suppliers can scale up, so the government has to rely on the best international producers out there… Mainly from China,” the source said.

“These companies are getting demands from France, Germany, Poland, Spain, Italy… All over the world, lateral flow tests are seen as the answer to Omicron,” they added.

How stretched is the PCR test capacity?

At a meeting on 20 December, the Government’s Scientific Advisory Group on Emergencies warned that “capacity limits [for testing] can already affect case data ”.

The burden on the PCR testing service has led some experts to call for a change in government strategy.

Majeed said health authorities in the UK should stop asking people to take a PCR test to confirm a positive LFD result to ease the pressure on the “already squeaky” system.

Between January and March this year, the UK Public Health Agency suspended confirmatory PCR tests due to high prevalence. A similar step was taken by the Danish health authorities earlier this month.

Professor Alan McNally, a microbiologist at the University of Birmingham, on Thursday in a series of tweets urged the health minister to “move to socially symptomatic LFD testing” in the UK instead of using more time-consuming PCR tests.

“You can’t possibly run a community PCR test program with a quarter of a million cases a day,” he said.

But a person close to England’s test program said laboratory capacity “was only part of the chain” and supplies of PCR test kits and reagents could also “come under pressure as test volume increases”.

“We are not the only ones doing this, and all nations – in both the private and public sectors – draw on the same inventories of everything from plastic tips and tubes to cotton swabs and PCR reagents,” the source said.

How will lateral flow tests affect the transmission on New Year’s Eve?

Iain Buchan, a professor of public health at Liverpool University, said LFDs “broke transmission chains” over Christmas, resulting in people “staying home when they were positive instead of going to grandma”.

He predicted that the same benefits would come from testing over New Year’s Eve if sufficient supplies were available. “Societal behavior around risk mitigation and testing has completely changed,” he said.

But Petersen said she expected LFD consumption to have been higher over Christmas due to younger groups feeling “a greater sense of responsibility towards older people in their families”.

“Lateral flow tests work when you have everyone to do them,” she said. “If you go to a big party where only 50 percent of people have done it, it will reduce the spread, but it’s less of a guarantee.”

However, John Drury, a professor of social psychology at the University of Sussex, said he was concerned about the “excessive security” that a negative outcome offers.

“How many know that [LFDs] should be taken as late as possible, otherwise they are much less effective ?, ”Drury asked. “They can help people make an informed assessment of how to interact with others, but they can provide false reassurance.”

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