Pandemic status has been called because the number of cases of H1N1 has now reached a threshold value. This situation was, and is, expected. Cases of infection will continue to appear throughout the next few weeks or months as the disease spreads. As time progresses, cases are likely to lessen as the natural immunity of the population develops and control measures are implemented.
There are members of the population that are seen as being susceptible. There can be a number of reasons for this, ranging from underlying natural immunity, general health status and so on.
What must be remembered is that despite the increase in cases around the world, and apparently in some countries specifically, the number of deaths is still very low.
Now that Australia is entering winter, cases might rise. This is exactly what we see with influenza infections in winter in the rest of the world.
Dr Mark Fielder is a medical microbiologist at Kingston University