# 3078
Over the next few days, possibly even weeks, the news is going to be filled with reports of suspected swine flu cases popping up in cities, towns, and countries all over the world.
It is likely there will be school closings and other public health measures taken in an attempt to curtail the spread of this virus. It will be disruptive, both to people’s lives, and to the economies of the world.
Right now it is big news when a new case is discovered, mostly because the numbers confirmed to date are so small. As an example, there are only eleven cases confirmed so far in California, a state of 33 million people.
As of today, there are only 64 confirmed cases in the US.
Of course, the expectation is there are a lot more cases than that. Those are just the ones that have been identified as probable, tested, and found to have the virus.
And that takes time and resources.
We really have very little idea how many other's are out there.
Sure, hospitals and doctor’s offices are actively looking for cases, and forwarding suspect case samples to testing laboratories.
But for many people, seeing a doctor for anything less than a life threatening illness is out of the question. In some remote areas of the world, it isn’t even an option.
There may also be asymptomatic cases walking around, shedding the virus, but not showing clinical symptoms.
Right now, we are probably doing a better job than normal picking up suspect cases, simply because this new flu has everyone’s attention.
But we most certainly aren’t finding every case.
And even if every probable case were being found, and samples taken and sent to a lab, some percentage of those may test negative when in fact the patient has the virus.
Lab tests and collection methods aren’t perfect.
This graphic, which comes from the CDC, shows how laboratory confirmed cases of a disease may reflect only a percentage of the actual cases in a community.
As scientists and doctors study this virus, and collect data on those sickened by it and those in contact with the infected, we’ll get a much better idea of the incidence level of sub-clinical or asymptomatic cases.
We may find a lot of them, or we may find very few.
The numbers we are seeing reflect a trend, not the whole picture. Epidemiologists know that, of course.
They take it into account, realizing that when you see a few hundred cases, it probably is just the tip of the iceberg.
Or in this case, the pyramid.
