On June 11, the World Health Organization upgraded the H1N1 flu outbreak to phase 6, the highest level. This does not mean that the H1N1 (swine) influenza virus has become more deadly, rather that “the virus has caused sustained community level outbreaks in at least one other country in another WHO region“.

To date, the virus has spread to 74 countries with almost 30,000 confirmed cases world-wide and with 145 deaths. A dear friend in Australia feels that there is much hullaballo about a fairly mild course of illness. This thinking belies the potential consequences of a novel virus that to date, shows significant differences between the annual flu outbreaks and the novel H1N1 outbreak.

These differences are:

• 1/3 to 1/2 of severe cases and deaths have occurred in previously healthy young and middle aged people rather than frail elders who traditionally are affected during normal influenza outbreaks
• Majority of people infected have been under 25 years of age

It is true that the majority of cases are also mild but the fact remains that this is a novel virus, meaning that (except for a few exceptions) humans do not have any immunity to the virus. It also has the potential to mutate into a much more virulent strain, just as the infamous flu pandemic of the 1918s did in which an estimated 20-40 million people died world-wide.

Any virus that humans have no immunity to is something we need to be particularly cautious of – anything less is foolish.