[EvaH (OP)]

Chrissie says:

We know that the coronavirus is mainly spread in homes, but how are people bringing it into homes? Is research being done when people receive a positive result to ask where they have been previously? The data could be analysed to look for common patterns to see which settings are the most dangerous.

Can you help?

[alancalverd]

It would be very difficult to trace the prior source, who could be any one person you actually met, worked with, sat within 2m in a cafe, office or a bus or train,  or whose sputum you touched, in the last 5 days.

Forward tracing in a household or workplace is feasible to some extent but again if you moved through a random crowd (as distinct from spending several hours with a limited number of named people in a plane)  nobody will be able to warn your contacts.

[Bored chemist]

Is research being done when people receive a positive result to ask where they have been previously?

Yes

he data could be analysed to look for common patterns to see which settings are the most dangerous.

Schools.

The government has decided to reopen them in spite of this.
Boris is not trying to save the people.

[evan_au]

how are people bringing it into homes?

The process you are describing is called "contract tracing". It is extremely important in controlling disease outbreaks.
https://en.wikipedia.org/wiki/Contact_tracing

It would be very difficult to trace the prior source

Yes, it is difficult. But essential.

If you can't identify the source of infection, it is likely that there are other chains of transmission spreading through your community that you don't know about (yet).

They will come back to bite you, big time!

Some states in Australia have set a benchmark - if you can't identify the source of infection within 48 hours, we will close our border to your state. (That's how my summer holiday this week got cancelled... )

In my state, that means you must register with an app when you arrive & leave work, restaurants, shops, gym, church, etc....
- That way the contact tracers have half a chance to determine everywhere you have been, and everyone who was there at roughly the same time. Then they contact all those people, and they get tested...
- If they find that some of these locations/events are frequent sources of spread, they will shut them down or restrict operations as a precautionary measure (eg restricting pub opening hours, restricting restaurants to take-away meals, limiting schools to children of essential workers only, etc)
- They haven't yet got to the point of automatically pulling a copy of your credit card transactions and mobile phone tower handovers (but those would be useful memory joggers)...

After you have controlled local spread, the main source of infection is people coming in from areas with active cases - so shutting borders and quarantine of people crossing borders is also essential.