THIRTEEN council areas in England have surpassed the safe limit on Covid test positivity rates set by the World Health Organisation (WHO) for governments considering relaxing lockdowns.

Last year WHO recommended that governments should ensure the proportion of coronavirus tests coming back positive remains below 5% for at least two weeks before regions reopen.

The threshold is the maximum limit at which point a pandemic would be considered out of control, although positivity rates would ideally be far lower.

But the latest government data shows 13 councils in England had a positivity rate of more than 5% in the week to 2 June, up from three a week earlier.

That means at least 5% of people tested that week returned at least one positive result, with any duplicates removed, with just two weeks to go until the planned end to England’s lockdown on 21 June.

North West worst affected

All 13 areas were in the North West. One area – Blackburn with Darwen – was more than double the threshold, while Rossendale and Bolton were approaching double.

In Blackburn, the rate increased to 13.6%, up from 8.1% a week earlier. In Rossendale the rate rose from 8.6% to 9.7% and in Bolton it was 9.6%, up from 8.8%.

There were 24 council areas that are now at or above 3% that have seen an increase of at least one percentage point in the latest week – implying many more areas are moving towards the 5% threshold.

TThe situation across England

The positivity rate across the country was 1.5% in the week to 1 June, up from 0.9% a week earlier.

It has almost doubled from 0.8% at the start of May.

But the rate varies significantly across the country, from a low of 0.5% in the South West to 4.3% in the North West.

Areas in the North West that have seen clusters of the Delta variant, first identified in India, have been subject to surge testing, which may have increased the number of positive cases that have been identified.

But more testing would also return a higher number of negative results. The high proportion of tests giving positive results suggests coronavirus is far more widespread in these areas than elsewhere in the country.

Prime Minister Boris Johnson has said there is “no question” that coronavirus infections have increased in England.

“We always knew that was going to happen,” he added.

“What we need to work out is to what extent the vaccination programme has protected enough of us, particularly the elderly and vulnerable, against a new surge.”

What does WHO say?

WHO set out its 5% threshold in May last year, long before effective vaccines had been developed and rolled out.

The positivity rate threshold should be used to supplement estimates of the R-number – the rate of the virus’s transmission in communities – to assess whether the epidemic is under control, it said.

In England, 76.4% of people aged 18 and over had had at least one vaccine dose as of 6 June. Across the UK, the figure is 76.8%.

NationalWorld asked WHO if successful vaccination programmes would affect its guidance on test positivity. It has not yet responded.

What does the Government say?

Not much.

NationalWorld approached the Department of Health and Social Care about the latest data.

We asked if it recognised or took the WHO threshold into account, and whether the situation in the North West was cause for concern.

It passed our query to the Cabinet Office, which simply said before taking each step the Government would review the latest data on the impact of the previous step against four tests.

These are the continued success of the vaccine programme, whether evidence shows vaccines reduce hospitalisations and deaths, whether infection rates risk a surge in hospitalisations that would put unsustainable pressure on the NHS, and whether its assessment of the risks has been fundamentally changed by new variants of concern.

It did not address the 5% threshold directly.