The government has asked that all people remain at least six feet away from each other in any public setting. While this may not apply to those who are inside your house at all times, when there is someone new, this rule replies indoors too.
When the plumber visits your house, keep your distance. There should be at least six feet between you and the plumber at all times. You can even wear a mask to help reduce the risk of spreading viruses. The plumber may also be required to wear a mask while providing you with plumbing services. The ideal option would be to remain in a different room while the plumber is busy doing their work.
After the plumber has provided you with the requested services, disinfecting the area where they worked is a good idea. Remember that some people can transmit the coronavirus infection without showing any obvious symptoms. Disinfect all the surfaces with an appropriate cleaning detergent to ensure any viruses or other pathogens left behind are killed.