BBC News Reality Check

There have been warnings in the UK that family reunions over the Christmas holiday period will lead to a spike in coronavirus infections.

The example of the Thanksgiving holiday last month in America has been pointed to, with claims that it led to a surge in infections.

In Parliament today, the shadow health secretary, Jonathan Ashworth said: “We saw in Canada and the US huge spikes in infections after Thanksgiving. We will see a spike here.”

But does the data support this assertion of “huge spikes” in the US?

The Thanksgiving holiday weekend was between Thursday 26 and Sunday 29 November.

BBCCopyright: BBC

Prior to Thanksgiving, infection rates were already increasing across the US and this upward trend has continued following Thanksgiving.

There were reporting delays around the holiday period (indicated by the flattening of the curve followed by a catch up period) but overall, cases in the two weeks following Thanksgiving rose by around 20% - about the same increase as in the two weeks prior to 26 November.

BBCCopyright: BBC

So there is no clear indication yet from the data that infection rates have accelerated following the Thanksgiving holiday. The rate of growth of infections has remained about the same as in the weeks before the holiday.

As for hospital admissions, the two weeks prior to Thanksgiving actually saw more people admitted to hospital with coronavirus, than the two weeks after – but you would expect any increase in hospital admissions to take longer to show up in the data.

It’s also too early to assess the impact on deaths as they can occur several weeks after infection. Experts say we may still be a week or so away from seeing the true impact – if any – of the Thanksgiving holiday.

The Covid Tracking Project, which monitors coronavirus statistics in the US, urged caution over drawing any conclusions from the recent data, saying: “Given the high rates of pre-holiday disease transmission, it'll be tricky to perfectly distinguish which events cause the spikes.”

At Prime Minister’s Questions, Labour leader Keir Starmer said that “In three out of four tier two areas, infections are going up. In over half of the tier three areas, infections are going up.”

When England exited its second national lockdown on December 2, 119 of the country’s 316 local authorities were placed into tier three areas.

Of these areas, rolling weekly case rates have increased in 61 of them (although the latest day the government has released these numbers for is December 10) – or just over a half.

And case rates are increasing in an even higher proportion of tier two areas – 159 out of 195 local authorities placed in tier two areas have cases growing.

So Mr Starmer is correct in both of his claims.

Case rates are increasing in a higher proportion of local authorities in the South of England than those in the North or Midlands.

Case rates show the proportion of the population who have tested positive for coronavirus in any given week. This can though be influenced by the amount of tests done in an area.

However, weekly admissions to hospital, which can be a metric of serious coronavirus cases, have also started increasing again.

Labour leader Sir Keir Starmer asked the prime minister: "Why does he think that Britain, the sixth richest country in the world, with all our brilliant scientists and amazing NHS end the year with one of the highest numbers of Covid deaths in Europe?"

You can compare coronavirus figures from across the World in this piece from BBC News.

It shows the UK second in Europe behind Italy in the number of Covid deaths.

In deaths per 100,000 people, the UK comes ninth in Europe, behind countries such as Belgium, Italy and Spain.