AN ANALYSIS OF FOOT-AND-MOUTH-DISEASE EPIDEMICS IN THE UK

There was a major epidemic of the foot-and-mouth-disease virus among c attle herds in the UK in 1967-68 which showed a very rapid early sprea d, a much slower later spread, and eventually infected 12% of herds in the core epidemic area. A simple discrete-time version of a susceptib le-latent-infectious-removed epidemiological model is used to generate a set of estimates of the transmission rate. This parameter has high values over the first few days, then the values are lower and they sub sequently decline. The early high values are consistent with the view that unusual meteorological conditions produced exceptionally good con ditions for wind-borne spread of the virus over the first few days. Th e corresponding basic reproduction number, R(0), is estimated as 38.4. Subsequent low values of the transmission rate correspond to a value of R(0) of 2.0; this is within the range of estimates made from the ob served ratio of secondary to primary outbreaks for 25 other epidemics. Prophylactic control measures, such as vaccination, would have to be extremely effective to prevent epidemics with the higher R(0) value.