When it comes to reaching the contacts off.

Those infected in the community tracing team only reached 58% of contacts.

Of those testing positive in the week ending the seventh of October, our health editor, Hugh Pym, has been looking at wider system is still struggling to deliver.

Could this be the future for mass testing of the population?

Children arriving at school in Southampton drop off saliva samples, which are tested for coronavirus.

It's easy for them to do with quick results and is now part of a trial to assess the potential way.

No, we can turn around those results within 24 to 48 hours.

So it's a great opportunity not just to keep Children and teachers within school settings, but also more broadly to other businesses and settings to that's the aim.

But right now, the system for testing using swabs on following up contacts in England is under strain.

Ministers say capacity is being increased up 10% in a week, but some say it's not working efficiently on a lot of the calls were essentially repeat calls.

Martin's family are self isolating after two tested positive, but they were surprised to get dozens of calls from test and trace staff.

We probably need to four or five phone calls to tell us what our end date was and how we were doing, but that's it.

And so the other 32 phone calls could have been given to other families in the first week in October, the number of results back in 24 hours for people going to testing centers in England was 32.6% slightly better than the week before, but much lower than in June.

Just 57.6% of close contacts of those testing positive in the community were reached and asked to self isolate, down from 62.5% the previous week.

Senior health officials say testing and tracing gets more and more difficult as case numbers accelerate across the population, and it's really most effective when infection rates are lower than they are now on.

Local outbreaks could be quickly identified on tackled sorts of restrictions that we're seeing coming in off course.

They are to save lives, but They're also to reduce the number of cases and circulation so that it comes down to a manageable level so that the test and trade system is ableto work so effectively that it will be able to find a much higher proportion off the people who are at risk.

In Spain.

The testing system may be working, but tracing said to be very patchy.

In Berlin, long queues have built up outside testing centers.

Test and trace problems are not just limited to parts of the UK Hugh Pym, BBC News People who've been working at one coronavirus testing laboratory have told a joint investigation by the BBC on the on line newspaper The Independent off their concerns about safety standards.

One scientist who worked at the Milton Keynes Lighthouse Lab claimed that staff were being put at risk.

The Health and Safety executive has found breaches in safety following the claims.

The company, which runs the laboratory, says it does have strict safety measures in place on the government said tonight it regularly reviews on dim spect the labs that it uses.

Our health correspondent Sophie Hutchinson has the story.

The lighthouse labs, sometimes called mega labs, mass processing centers for coronavirus swab tests.

The government had them set up in order to dramatically increased testing during the pandemic.

One of the first open was this lab in Milton Keane's, where hundreds of staff process around 40,000 tests a day.

But some of those who have worked here have told us of safety concerns, which they fear are putting staff a risk.

It's just chaotic.

It's dangerous.

Julian Harris, a virologist, worked at the lab this summer.

He believes cracks in the system began to show when the caliber of staff changed when the lab started in March.

Then they had furloughed academics, biologists, biologists, all these people.

So they had the experience right.

But in towards the middle of June onwards, they started to go back and then you got an influx of these really young people with absolutely no experience, he alleges.

The training for new recruits was completely inadequate.

Thes people know lab induction for a biosafety level two and then they're just launched into this facility on it.

It freaked me out.

The work is carried out in protective cabinets like this, which remove infected air.

But Dr Harris claims, in order to get a many tests Dunas possible cabinets designed for one person were being used by to a practice.

Other scientists have told us is at best, poor on at worst, dangerous aunt, he says the cabinets were being overloaded with piles of plastic bags from swab tests.

The whole dynamics off the air flow in the Cabinet is corrupted on what you get.

You get turbulence.

You might as well be working on an open bench.

These young people don't realize that they're being put at risk.

Another scientist who wanted to remain anonymous told us he resigned from the Milton Keynes lab because of safety concerns.

We had disposable visitors lab coats with gloves taped to the sleeves with brown parcel tape to reach into cabinets.

I know it could be permissible in developing world labs, but operating that way, and Mills and Keane's was just inviting litigation and ridicule.

The UK Bio Center, which runs the lab, said safety was their number one priority, it said.

We have strict safety measures in place to protect staff who were operating in a confined laboratory space.

It said training was robust.

Recruits have lab experience.

Cabinets were operated by just one person with a second person observing and that there was a choice of PPE, including cotton lab coats.

We believe everyone has the right to come home safe and well from their job, but the health and safety executive has visited the lab.

It told us it found five material breaches.

We understand they relate to social distancing cleaning regimes on site safety training.

The lab said it had already reinforced its processes based on the HFCs recommendations.

The government's target is to increase testing capacity by a third by the end of the month in an attempt to get a handle on the pandemic.

Ensuring it can scale up safely has never been more important.