Chances are >99% of cases are so mild they were never tested. It's pretty surprising this one was detected at all. It's only the second confirmed case in the US despite tons of confirmed animal cases in poultry and migratory birds.
[1] https://www.cdc.gov/flu/avianflu/chart-epi-curve-ah5n1.html
> It's only the second confirmed case
We know it doesn't transmit very well in humans. Luckily people have been working on that:
https://www.scientificamerican.com/blog/observations/controv...
> The patient reported eye redness (consistent with conjunctivitis), as their only symptom, and is recovering.
This is not a disease with a double digit mortality rate, no matter how many times people try to do math with a three digit sample size of poor people in developing countries.
The CDC only caught this case because it's literally testing anyone with symptoms at the cattle farm.
You make it sound as though they're working on making it transmit well in humans. Oh wait, they are! What's wrong with them?!