woman wearing mask at Grand Central Station, New YorkAlthough most deaths from the virus have been in Mexico, it's the United States which has been th

If you ask most people where you are most likely to catch H1N1 swine flu, my guess is they would answer, Mexico. That was the case initially, but has not been for some time.

The Centers for Disease Control and Prevention (CDC) CDC H1N1 Flu website has reported 10,053 probable or confirmed cases of swine flu, up from nearly 9,000 on Friday and 17 deaths. Furthermore, the virus has spread to all 50 states.

The CDC has estimated that perhaps only one in 20 cases ever gets recorded. If that is the case then it would suggest there could be 200,000 people in the US who have contracted the virus.

In one sense that would be worrying, as it would indicate that H1N1 is well and truly here to stay and that a pandemic is almost certain. But it would also confirm that the virus is causing mostly very mild illness, and mean that the death toll from a pandemic might be no worse than with seasonal flu.

Remember though that scientists are still learning about the virus and are unsure how any pandemic might

The World Health Organisation says the global number of confirmed cases of H1N1 is 17,410 in 62 countries, including 115 deaths. Since then, Bulgaria and Luxembourg have confirmed their first cases of the disease.