Re: Hong Kong vs Mainland China cases
Clearly, the small numbers of mainland China may be due to under reporting or poor surveillance in remote regions of the Nation.
But it is not possible to state that flu is widespread in the Mainland.
If was the case, as the population is more than 1 billion, we should have tens of millions of cases and excess mortality in rural areas where the health care system is derelict or at least not existent.
So, the picture could be more complex than one may suspect at first instance.
I mean that as pigs population in China is above the billion some swine influenza viruses may have circulated well before actual crisis, and human infections may have happened in a number well higher than in western countries.
Cross-immunity may be present in a portion of Chinese mainland population even we have no proof to state that this is the case.