Keegan99 said:
Positivity rate is also hindered by delays in reporting. The statewide figure has been effectively useless for all of August as the state has worked through a background of over a million tests.
Article in the Statesman last night was talking about how Williamson County wanted more people to get tested because the positivity rate was too low. And provided a link to the free testing. Only, to get the free testing, you need exposure or symptoms, which makes sense. But, then falling testing numbers suggest fewer people are qualifying for the free test, that is fewer people have symptoms.
Interestingly, if you look at positivity of the flu test during flu season, it starts out very low ~10%, climbs to ~60%, and then falls again. But I have never seen anyone panic and demand people get more testing because the positivity is ~60%. Since we only test people who have flu like illness, the % is not a direct reflection of how prevalent the flu is in the population, but rather a reflection of how prevalent the flu is compared to everything else that causes flu like illness. That is what percent of the symptomatic patients have flu vs something else.