G7 Summit: was the gathering of world leaders a Covid superspreader event for Cornwall? The key figures explained

“Britain’s recent G7 summit of world leaders was a superspreader event that has led to a sharp increase in Covid-19 infections in the surrounding communities.”

So reads a story in the i newspaper yesterday (18 June).

The article reflects commentary on social media in recent days which has questioned the wisdom in hosting an international event that attracted thousands of security officers, delegates, media and support staff to Cornwall during a pandemic.

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But it has also prompted some backlash, with readers pointing out that it takes time for infections to show up in Covid data.

So what is the evidence for the claim, and do the figures stack up?

What did the i say?

The i has analysed data that it says shows infections rose by more than 2,000% in one area close to the G7 summit in the week to the end of the event on 13 June, with cases spiking in a number of other nearby communities too.

One concerned local told the paper “it looks like a superspreader event to me”.

Dr Connor Bamford, a research fellow in virology and antiviral immunity at Queen’s University Belfast told the paper there looks like there could be a link between the rise in cases, but that “more in-depth epidemiological investigations would be needed to prove it conclusively”.

There had previously been criticism of attendees at the summit appearing not to social distance, including during a BBQ on the beach.

What do the figures show?

The i story purportedly uses figures at a council ward level. However council ward data is not publicly available on the UK Covid dashboard, which is run by Public Health England.

All three areas cited by the i are actually the names of Middle Layer Super Output Areas (MSOAs), which are small areas containing around 7,000 people on average.

The area with the highest rate of increase in the week to 13 June, according to the i, was St Ives and Halsetown, where cases have risen by 2,450% to 733.2 per 100,000 people.

The Covid dashboard shows there were 51 cases in the week to 13 June in this area, which is a rate of 733.2 per 100,000.

The figure in the previous week to 6 June however is not available. That is because when there are between 0 and two cases the figure is suppressed and appears blank to protect the anonymity of individuals.

But going by the rate of increase of 2,450% given by the i, that means there must have been two cases in the week to 6 June.

Falmouth East, where the i says cases have risen by 2,000%, had 42 cases, or 600 per 100,000 people, in the week ending 13 June.

There was also no data for the previous week, but there likewise must have been two to give an increase of 2,000%.

The third area cited by the i was St Ives East, Lelant & Carbis Bay. That is not an MSOA although Towednack, Lelant and Carbis Bay is.

There were 18 cases or 294.9 per 100,000 there in the week to 13 June. That matches the figure the i gives.

Going by the rate of increase of 800% given by the paper there were two cases the previous week.

There were 15 MSOAs in England that saw an increase of 500% or more in the same period, including in London, Blackpool, Bristol, Liverpool and Brighton.

How long after infections does it take to get a positive test?

The figures show us the number of positive cases among people who took a test between 7-13 June.

The G7 summit took place from 11-13 June.

But Covid may not show up on a test straight after a person has been infected.

Tests are most accurate once someone has started displaying symptoms – assuming they do show any symptoms at all – which is typically after about five days, but could be anywhere from two to 14 days.

Some studies have shown that false negative results may occur if a test is taken too early. It is often recommended that a test should be taken no earlier than five days after exposure to the virus for the most accurate results.

Going by this five-day incubation period, that would mean positive tests between 7-13 June may be showing infections that occurred no later than between 2-8 June – and possibly even earlier than this.

Many staff did indeed arrive in Cornwall several days before the start of the summit – but the half term holidays in most of England were during 31 May - 4 June, also.

Where else in Cornwall has seen a spike?

In the latest data available from the coronavirus dashboard, there are only three MSOA areas in Cornwall in which it is possible to calculate a percentage increase for the latest seven-day period.

That is because only these three areas had three or more cases in both the seven days to 6 June and the seven days to 13 June.

These areas were Newquay West (324.2 cases per 100,000, up 700%), Posanooth, Mabe Burnthouse and Constantine (530.7 cases per 100,000, up 917%) and St Columb Major and St Mawgan (122.5 per 100,000, up 180%).

None of these three areas are particularly near the G7 hubs of activity, but show the rate of infection was spiking prior to the summit.

How did the county prepare for the G7?

Cornwall County Council had promised residents that “their health and safety will always be at the forefront of all planning around the event”.

Safety measures included testing everyone involved in the summit daily, but there was also a “big push” to make sure residents and visitors not involved in the summit took up rapid lateral flow tests on offer.

Positive results from a lateral flow test are then confirmed by the more accurate PCR tests.

Government figures show there was a spike in people receiving PCR tests in Cornwall in the run up to the G7 summit.

The number of people tested in the seven days to 7 June rose by 10% compared to the seven days to 1 June, from 13,243 to 14,549.

The same figures show the positivity rate – the proportion of people tested who get a positive result – was rising before the summit.

In the seven days to 7 June it was at 0.4%. That rose to 0.7% on 8 June, 1.2% on 9 June and 1.5% on 10 June.

As of 13 June it was at 2.6%.

People who arrived to set up for the summit may very well be captured in these figures.

But data from Cornwall County Council shows a big increase in tests carried out by their mobile testing units, which go out into communities, from 5 June.

There were 90 tests carried out on 4 June, 125 on 5 June, 121 on 6 June, 248 on 7 June and a high of 361 on 8 June.

Who else has been travelling to Cornwall?

Cornwall is a popular UK tourist destination, with the official tourist board reporting a surge in visitors in recent weeks.

There are also more than 13,600 second homes in the county, according to the latest Council Tax Base data from the Ministry of Housing, Communities and Local Government.

That is one in 20 (5%) of all homes in the area.

With international travel largely off the cards for Brits at the moment, many people will be flocking to the county’s beauty spots for domestic holidays.

One man, who works at a major Cornish tourist attraction, told NationalWorld that to blame G7 is “disingenuous” as visitor numbers at non-G7 venues rocketed prior to the summit.

“My take is that the opening up for holidays in the first place was responsible with many different accents becoming evident immediately after that,” he said.

So was the G7 a superspreader event?

It may very well have been. But the answer is we cannot know now – and it is certainly not for journalists to label an event a “superspreader” based on the opinion of one anonymous resident.

There is no denying that when thousands of people descend on an area the potential for infection being spread is there.

But we will need to wait a bit longer for the data to show us the effects of the summit.

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