I second the efficacy of PCR in diagnosing infectious disease, including COVID-19. While more traditional lab tests, like checking someone's temperature or white blood cell count can provide information regarding the possibility of an infection, they do not tell you which infection. While clinical information, such as knowing the prevalence of COVID-19 in a community, sick contacts, and symptoms can point towards COVID-19, this would not be definitive evidence. PCR provides definitive evidence because it is designed to only detect SARS-CoV-2 viral genetic material. As with any test, PCR is not perfect, but it is considered the gold standard, ie the best we have. If you have COVID-19 and have detectable virus, there is very high chance that you have COVID-19. While false positives and negatives can occur with any test, why would you ignore a positive test as a "fluke" on your own, ie without considering the information with a licensed healthcare provider, when such denial could quite easily lead to you causing the death of one of your children, your romantic partner, your parents, or your grandparents? COVID-19 is deadly. It isn't like the common cold, which you could arguably ignore and everyone would still be alright. People can and have died because people ignored this disease. Could any of us live with ourselves knowing that we were responsible for the death of those we care for the most?