Why are we still seeing so many new cases of Covid?

[Oblahdeeoblahdoe]

This is a serious question. Why is it after almost 5 weeks of lockdown are we seeing 4000+ new cases in hospital every day and that's not including care homes. Who are these people? Are they people going to work , using public transport etc? My DH and I have stuck to the guidance from the Government and we're avoiding going to the shops so not mixing with anyone. This applies to everyone in my extended family too. I know it might be speculation but does anyone know we're still getting this many cases every day?

People with symptoms are told to 'self isolate' with the rest of their household and for just 7 days. So, dump a large viral load onto everyone they live with and then go back out while highly likely to still be infectious.

Most infections don't show up as cases so we never have a true picture of the number of cases, the more we test the more infections we will be able to identify as cases

DH and I are getting tested today, at the Manchester airport hub, he is a key worker and has symptoms, he works on the opposite shift to someone who came back to work a week ago after self isolating for 14 days, all he did was sit in a room with him for less than 10 mins, the only other place he’s been was to the hospital (cancer centre) with his Dad and he wore a provided surgical mask the whole time.
I am coughing but have been for weeks with what I assume is post nasal drip as I’m phlegmy in a morning. I go out once a week shopping, for us and for my Sister who is shielding, I had to go into her flat on Friday as she couldn’t carry the shopping inside.
I’m hoping we’ll be one of the 70% of tests that are negative.
There is obviously something else going around causing similar symptoms if only 30% of all tests are positive? Unless the tests are not very accurate, which would be a disaster.

Thank you for your thoughts. It was a genuine and probably a naive question. I wasn't being judgemental. All my family are either furloughed or WFH except for my daughter who works in a school. As a long time regular customer she has an Ocado delivery every 10 days so she tags ours on, as Ocado encouraged her to do. As I said, I very much appreciate all the key workers who are keeping the country going. It's awful if it is in fact these people who are still catching the virus.

My husband has just had a phone call with his mother. She lives several hundred miles away, as does his brother and ex-sister-in-law.
Transpires that brother, his grown up children and ex-wife are ALL regularly visiting other family members homes, shopping together etc etc. Total disregard of the advice of not mixing with other households.
No surprise why the rate is rising.

@redwoodmazza. It isn't rising it's falling.