At present when health care staff are testing people who might have Covid2019, only 2% are actually getting positive test results. This shows that suspicion or anxiety may be quite high and that it is very difficult to tell Covid 2019 infection apart from numerous other infections and problems. This means it may be equally difficult for you to spot a potentially infected or infective person. Of course, if or when the infection spreads to much more of the population, that 2% figure will increase significantly.
People who have been confirmed as having Covid19 have typically reported Cough 81%, Fever (feeling hot, shivering, temperature raised to 38C or higher) 77%, Phlegm 56%, Achy Muscles/Fatigue 52%, Diarrhoea 8%. Sneezing, runny nose, shortness of breath have also been reported. Obviously, these are incredibly common symptoms and signs so you will encounter them in lots of people who do not have Covid19. However, at present, anyone falling into this group should not be at a DZ as staff, customer or spectator. The aim should be to prevent such people attending your DZ in the first place, as prevention of contact is important in preventing or at least slowing spread (and important in allowing your DZ to stay open). An isolated cough, sneeze, drip on the end of the nose or transient ache is so common as to be unremarkable but persistent/recurrent symptoms should cause a response.