Don’t put Oldham into lockdown

The Manchester Evening News reports that political tensions are simmering as Oldham battles to avoid lockdown. Manchester itself could break through the 50 cases per 100,000 level by the end of the week – placing the city in the ‘red alert’ bracket. Andy Burnham, Mayor of Greater Manchester, is opposed to Oldham going into lockdown, saying he would like no new restrictions on Oldham beyond those already in place. He sent out a tweet last night with data showing that cases are coming down. In the week ending the 8th of August, there were 109.7 per 100,000 in Oldham: in the week ending the 15th cases were down to 83.1 per 100,000.

Data from the Digital.nhs.uk ‘Progression dashboard’ is more up to date. It shows Oldham at the top of the dashboard with 70.5 cases per 100k for the week of the 11th to the 17th August. Looking at it another way, the numbers mean that 0.0007 of the Oldham population has had SARs-CoV-2 RNA detected from a swab in the last week – a tiny fraction.

This represents a further reduction compared with Andy Burnham’s data – a 37 per cent drop over the week.

But lockdown measures should be predicated on the impact of the disease. NHS England’s Covid-19 data provides information on the number of people admitted and in a Pennine Acute or Pennine Care Hospital with Covid (these hospitals cover Oldham, Rochdale and North Manchester). The data shows that 1,252 beds are occupied across the Pennine Hospitals of which just nine were occupied by Covid patients as the 9th of August – down from 290 beds at the peak of the virus. And how about local hospital admissions? The data also shows they also remain low: a seven-day moving average of three to four patients per day. Again, a downwards trend.

This takes us to a big question: how do you gauge local risk? On what criteria should local lockdowns be implemented? If you do more testing you will, of course, see more positive cases (especially as so many Covid cases are asymptomatic). The current criteria for somewhere to be put in the ‘red alert’ bracket is 50 cases for every 100,000 people (That is to say: people with PCR-detected RNA for SARs-CoV-2.) But this does not support a sustainable long term strategy – and is not based on sound evidence.

The main driver should not simply be the number of Covid-positive tests but disease measures such as:

• Covid hospital admissions
• Beds occupied in those with active Covid infection (i.e. in the last 28 days)
• Symptomatic cases detected. This data is, now, available. And it should be used a lot more than it is when deciding the severity of a local outbreak and whether to impose local lockdown.