Whole this is a correct application of Bayes Rule, a risk adjusted perspective still indicates that you should act as if you do have the virus. This is because

Whole this is a correct application of Bayes Rule, a risk adjusted perspective still indicates that you should act as if you do have the virus. This is because the probability of having the virus multiplied by the damage of an infected person spreading the disease is much higher than the false positive probability times the personal impact of self-quarantine.