Follow the money
The CDC states that only a PCR test can distinguish between seasonal flu and H1N1,
PCR tests cost between 100 to 300 dollars and takes about 2 days. ( the costs in India were said to be about 200 dollars.
The PCR machines are expensive; from 50,000 to 100,000 dollars.
They require trained staff
They can only do so many tests ia a day
The WHO talks about "confirmed" cases; but not about the lack of PCR machines in most of the world.
(Hearsay) a distant relative, a nurse in the USA, says that when the results of a "quick" test (that can only indicate flu or not flu,) comes back she is told to always mark it as H1N1.
The CDC stats that treatment should begin within the first 48 hours; i.e the time it takes to get the PCR result.
So the physician assumes the worst and initiates treatment appropriate to H1N1