My son went to visit his grandfather this holiday. they returned yesterday and the person who drove them back home was tested today for covid 19. both my son and his grandfather don't have any symptoms. his grandfather decided for them to self isolat?

COVID 19 concerns: Not sure I understand description. But if driver was COVID 19 positive, both son and grandfather need to quarantine. In South Africa, one contacts a medical provider for eval to decide if COVID 19 testing is indicated. You may contact your own medical provider or consider getting telemedicine consult from an on-line provider. You can use one of the free on-line apps check your risk.

See below: Covid-19: https://www.cdc.gov/coronavirus/2019-ncov/index.html Contact your doctor/local hospital, by phone for evaluation and testing in your area. Wear a mask, stay away from others, practice hand hygiene. If you develop breathing difficulty, go to the nearest hospital, immediately. Get Covid vaccine. Wish you good health.