West Hunter: The Coming Plague

Laurie Garret has an article out in the Washington Post. She say that there’s no point in trying to block the spread of Ebola by travel bans.

The problem is, she’s full of crap. Look, there are two possible scenarios. In both of them, r, the number of new cases generated by each case, is greater than 1 in parts of West Africa – which is why you get exponential growth, why you have an epidemic. If r < 1.0, the series converges – a case generates a few extra cases before dying out. Everything we know so far suggests that even though it is greater than 1.0, r in West Africa is not all that big (maybe around 2), mostly because of unfortunate local burial customs and incompetent medical personnel. It seems highly likely that r in US conditions is well under 1.0 which means you can’t get an epidemic. However, r is probably not zero. It doesn’t mean that you can’t get a few cases per imported case, from immediate contact and hospital mistakes…