Temporal and geographical distribution of cases of foot‐and‐mouth disease during the early weeks of the 2001 epidemic in Great Britain

Abstract

Estimates of the likely dates of infection of the early cases of the 2001 foot-and-mouth disease (FMD) epidemic indicate that at least 57 premises in 16 counties in Great Britain were infected before the first case was disclosed. Nationwide animal movement controls were imposed within three days of the first case being confirmed on February 20, when FMD was only known to be in two counties, and these controls limited its geographical spread. After the first few cases were confirmed, new cases were rapidly discovered, and the epidemic curve for the daily number of confirmed cases peaked five weeks later, 11 days later than the peak of the curve based on the estimated dates of infection. In the peak week, both curves showed an average daily number of 43 new cases. The estimated dates of infection are believed to be relatively unbiased for the early cases, for which they were derived from a known contact with infection. However, for the later cases they were estimated mainly from the age of the clinical signs of the disease, and were biased by species and other factors, a bias which would probably have made the estimated dates later than was in fact the case.

The foot‐and‐mouth disease epidemic in Dumfries and Galloway, 2001. 1: Characteristics and control

“…On this point, it should be noted that a stricter epidemiological definition of control -the application of any measure intended to interfere with the unrestrained occurrence of disease (Done 1985) -implies that the epidemic was under control as soon as movement restrictions came into force on February 23. The peak of the epidemic in D&G coincided, approximately, with the overall national peak (Gibbens and Wilesmith 2002 …”

Epidemiological analysis of an outbreak of foot-and-mouth disease (serotype SAT2) on a large dairy farm in Kenya using regular vaccination

“…In recent years, outbreaks have been described in several previously FMD-free countries including the UK (Gibbens et al, 2001;Gibbens and Wilesmith, 2002), the Netherlands (Bouma et al, 2003), Japan (Muroga et al, 2012) and South Korea (Park et al, 2013). These descriptions and subsequent risk factor studies have focussed primarily on farm-to-farm level transmission, since control policies have emphasised preventing the virus moving to non-infected holdings (Wilesmith et al, 2003;Ellis-Iversen et al, 2011;Muroga et al, 2013).…”

The foot‐and‐mouth disease epidemic in Dumfries and Galloway, 2001. 2: Serosurveillance, and efficiency and effectiveness of control procedures after the national ban on animal movements

“…It is possible that these IPs were incorrectly identified on clinical grounds because of the difficulty of unequivocal diagnosis of FMD in sheep (Ayres andothers 2001, de la Rua andothers 2001) and the high efficiency of laboratory techniques (Anon 2002a) at all stages of infection, (Snowdon 1966, R. P. Kitching, personal communication). Although animals on contiguous premises could have been incubating infection at the time of slaughter, and some affected sheep on these premises may not have been detected clinically because of the mild infections that can occur (Bolton 1968, Kitching and Hughes 2002, Watson 2002, 50 per cent of these premises were slaughtered out beyond the average incubation period of five days (Gibbens and Wilesmith 2002) (Fig 2, plot 3); and 85 per cent of these premises farmed cattle and were therefore slaughtered out when clinical infection could have been detected, had it been present. (This time was calculated from the date of confirmation of an IP, rather than the estimated date of infection and initial release of virus.…”