In today s Probably Obvious entry, a group from McMaster University in Ontario tells you something that you probably already know, but still ignore.
The group, led by David Earn, Ph.D., a professor of infectious disease and mathematics, reports that when you are sick with a fever from a cold or flu and take medications that lower the fever and make you feel better, you will go to work too soon and infect others.
While this may sound intuitively obvious, the magnitude of the problem is surprisingly large. The researchers estimate that this practice is causing 1,000 (!) extra deaths in North America each year. This effect arises almost entirely from flu a far more serious disease than the common cold. According to the CDC, influenza kills between 3,000 and 50,000 people per year in the US, depending on a host of factors, such as immunization rates, effectiveness of the vaccine and the virulence of the predominant strain of flu.
Ben Bolker, Ph.D., a co-author of the study, explains the methodology that was used: "We put together a chain how many people have influenza, how many of them take these anti-fever drugs, how much does that increase the amount of virus they give off, how much does that increase the chance that they re going to affect somebody else, how much does that increase the overall size of the seasonal flu epidemic. When you put all those numbers together, the answer you get is it increases the size of the annual influenza epidemic by about five per cent."
Paradoxically, since fever is one way that the immune system fights infections, lowering the fever will actually increase the replication and transmission of the virus. The better you feel, the more likely it is that you will go to work and you will be more contagious when you are there.
What to do? The authors don t give advice on taking aspirin, Tylenol, or ibuprofen (which most people do anyhow when they have the flu), but they do suggest that ill people stay home longer.
But, says ACSH s Dr. Josh Bloom, Companies and businesses talk out of both side of their mouths when it come to this. On one hand they may officially encourage sick people to stay home, but many employees worried about limited numbers of sick days or simply keeping their jobs still come to work sick. Not an easy problem.
Bless you.
