1. In the early 1900s, 2,500 people died each year from bovine TB (bTB) and a further 50,000 were infected. This is why a control programme was instigated.
2. Trials of cattle vaccination in the 1950s (involving 6,000 calves over ten years, with a booster dose at six months) failed to remove the disease, so the government introduced a test and cull policy to eradicate the disease in cattle and to reduce the risk to human health.
3. Using the same TB skin test for cattle as we do today, by the mid 1970s – when UK cattle numbers were at an all-time high – the number of cases of bTB had been cut to just 400 a year. Since then, cattle numbers have fallen by 32% but bTB cases in cattle have risen to well over 30,000 a year. This is despite far more intensive controls (such as premovement testing and whole-herd restrictions following inconclusive reactor disclosure).
4. The graph below the relationship between the number of TB reactors in cattle and various badger culling programs. There is clearly a direct link: when badgers were gassed on farms from the late 1970s, we saw the lowest bTB figures ever. From that point on, the clean ring and reactive programs took place and were less effective at removing badgers. Badgers became protected in 1981 but it was not until 1997 that all badger culling ceased. Note the huge increase in bTB cases in the years after this.
5. There is no doubt that bTB has decreased in Wales recently. However, as the current vaccination program is being conducted only in 1% of the country it is difficult to see how this has led to a 25% decrease in bTB overall. Other factors must be at play.
6. There have been no field trials involving the vaccination of badgers. Experimentally, badger vaccination has no effect in animals already infected and, when challenged with infection, all uninfected vaccinated badgers eventually succumb to bTB, although the vaccine does slow down the onset and progression of the disease.
7. On the Killerton Estate in North Devon, where the National Trust has vaccinated badgers over the past four years at an annual cost of £45,000, there have recently been a significant number of herd breakdowns.
8. It is true that Randomised Badger Culling Trial (RBCT) (‘Krebs’) concluded that culling badgers in small areas would make ‘no meaningful contribution’ to bTB control. However, a subsequent committee chaired by Professor John King, the Chief Scientist at the time, recalculated the same data and showed that in the four years after the 2000 cull had ended, bTB decreased considerably in culled areas, and it was his opinion that removing the wildlife reservoir would decrease cattle cases by at least 40%.
9. According to the Krebs report, the number of badgers culled in the Gloucester proactive triplet varied from 93 to 219 per annum, despite intensive Defra staffing and training. This is a mean of 165 badgers per annum per 100 sq km. Despite huge protester disruption, Gloscon has done much better than that. In 2013, 914 badgers were culled in 330 sq km, which equates to 277 badgers per 100 sq km. Your contractors have done a superb job.
10. The Krebs report also shows that in the Gloucester area total badger density was 2.61 badgers per sq km or 261 per 100 sq km, so in 2013 when Gloscon removed 277 per sq km it removed more than the total number present at the time of Krebs. Numbers culled in 2014 therefore will be much lower than in 2013.
11. The rates of bTB infection in badgers killed on the road tested during the Krebs trial (2002–05) varied from 19% to 26% infected year on year. Of these, 38% of adult badgers and 55% of cubs showed visible lesions, and 10% of adults and 23% of cubs showed severe lesions.
12. More recent data (2006–09) from the Gloucestershire Badger Vaccine Deployment Project, where blood tests were used to confirm infection in badgers, demonstrated an infection rate varying from 28% to 54% year on year. Therefore, in our opinion the evidence for badgers being a reservoir of infection is incontrovertible.
13. Cheshire is defined by Defra as an ‘edge area’ with a comparatively low incidence of bTB, deemed to be suitable for control by badger vaccination only. However, a recent survey in the county showed that 24% of badgers killed on the road were bTB positive. This means that vaccination will not be effective in at least 24% of the animals vaccinated here.
14. The effect of perturbation was studied during the Krebs trial, where there was evidence of the effect only in a 2 km wide band around the outside of the proactive cull areas. Even in these areas, for four years after the Krebs trial ended the level of bTB in these bands was actually lower than before the trial started.
If anyone would like further information on the subject, please visit the NFU TB Free England website at http://www.tbfreeengland.co.uk.
With many thanks to Roger Blowey FRCVS for the above document