Reasons to chill and reasons not to chill

Okay, I ' m not an epidemiologist or a virologist. But I do know something about those subjects, I ' m a public health professor, and I am an expert in clinical communication and risk communication. So I ' m going to offer some observations that I hope will help people keep this public health scare in proper perspective and maybe be of practical use.There are two important parameters we need to understand the risk caused by any communicable disease. I ' m going to broadly say transmissibility, and the probability that exposure will lead to serious disease.We often see transmissibility represented as a single number, called R0 or " R naught. " That ' s supposed to mean the average number of people who will catch the disease from a single infectious individual, in an exposure naive population. So, as should be intuitively obvious, if R0 is greater than 1, the disease can spread, and if it ' s less than 1, it should peter out. If R0>1, then the growth in cases will presumably be exponential, although how fast the exponentiation happens obviously depends on how long it take to get to the R0 number. If R0=2 and the person infects those two people in one day, then that person will generate 128 cases in 1 week and more than 16,000 cases in two weeks. If R0=3, then we ' re talking 4.8 million cases in two weeks. Yikes! (In reality, of course, that number is likely to be spread out over a week or two, not a single day, so this is just by way of illustration.)Fortunately, that isn '...
Source: Stayin' Alive - Category: American Health Source Type: blogs