In response to increasing numbers of confirmed or suspected cases of swine flu in the US, plus a still relatively unknown number of cases and at least 81 deaths in Mexico, the US government has declared a public health emergency.

This H1N1 swine influenza virus has many of the hallmarks of a virus with pandemic potential. It is of animal origin but has a unique combination of gene sequences that has not been found previously in swine or human influenza strains. People don’t have pre-existing antibodies because they have not been exposed to it before, which leads to the chance for widespread disease. A big concern is that it seems to spread at least somewhat efficiently between people (unlike the H5N1 avian flu virus which is not efficiently transmitted between people). Fortunately, while it can cause death, this swine flu virus does not seem to be as deadly as avian flu, which kills approximately 50% of the people it infects. Therefore, while swine flu appears to be much more transmissible, it’s probably not as fatal. (However, the large number of reported deaths in Mexico and early stage of the outbreak at this point means we need to be cautious making such statements).

It is clear that this swine flu strain is spreading in the US. It’s been found in multiple US states and it is probably going to be found throughout the country.  Mild cases have already been confirmed in Canada, and there are suspected cases in other countries. The number of cases in different regions and the amount of international travel makes containment of a reasonably-transmissible virus very difficult.

Some tips to reduce the risk of catching (or spreading) swine flu:

  • Wash your hands regularly, particularly after contact with other people or common-contact sites (e.g. public door handles, public transit).
  • If you are sick, STAY AT HOME. The era of "sucking it up" and going to work when you are sick should be over. All you’re doing is putting others at risk.

More information about swine influenza can be found on the CDC’s swine influenza website.

Image from