Most of the people with the flu don't get a confirmatory test while those that are tested are usually sick enough to go to the PCP or be admitted to the hospital. And not all PCPs and hospitals routinely test for the flu. I think the most telling data points are the number of hospital admissions, ICU admissions and deaths in the small clusters where the virus is clearly in the population. You just don't see this with the flu every year. It's much more likely a new phenomenon or virus that caused the Italy scene. There is no other reasonable explanation.