The problem facing world governments isn't lack of precedent, exactly. People point to the 1918 flu, or even the 1968-69 season. More recently, South Korea faced a threat from MERS, which is a similar, more deadly although mercifully less infectious, virus. Part of the reason South Korea has been so lightly affected, in comparison to other countries, is that they had seen the importance of rapid and widespread testing and isolation programmes and were ready to roll these out within maybe a couple of weeks of the first cases being reported. South Korea's reported death toll so far, despite being among the first countries reached by the virus, is 1,378, which the UK surpassed in a single day yesterday.
There *was* precedent, but a combination of factors has led to most Governments choosing to ignore it.