title: Eradication of bovine tuberculosis at a herd-level in Madrid, Spain: study of within-herd transmission dynamics over a 12 year period.
abstract: BACKGROUND
  Eradication of bovine tuberculosis (bTB) through the application of test-and-cull programs is a declared goal of developed countries in which the disease is still endemic. Here, longitudinal data from more than 1,700 cattle herds tested during a 12 year-period in the eradication program in the region of Madrid, Spain, were analyzed to quantify the within-herd transmission coefficient (β) depending on the herd-type (beef/dairy/bullfighting). In addition, the probability to recover the officially bTB free (OTF) status in infected herds depending on the type of herd and the diagnostic strategy implemented was assessed using Cox proportional hazard models.
  
  
  RESULTS
  Overall, dairy herds showed higher β (median 4.7) than beef or bullfighting herds (2.3 and 2.2 respectively). Introduction of interferon-gamma (IFN-γ) as an ancillary test produced an apparent increase in the β coefficient regardless of production type, likely due to an increase in diagnostic sensitivity. Time to recover OTF status was also significantly lower in dairy herds, and length of bTB episodes was significantly reduced when the IFN-γ was implemented to manage the outbreak.
  
  
  CONCLUSIONS
  Our results suggest that bTB spreads more rapidly in dairy herds compared to other herd types, a likely cause being management and demographic-related factors. However, outbreaks in dairy herds can be controlled more rapidly than in typically extensive herd types. Finally, IFN-γ proved its usefulness to rapidly eradicate bTB at a herd-level.
authors: Instituto de Investigación en Recursos Cinegéticos IREC (CSIC-UCLM-JCCM), Ronda de Toledo s/n, 13071, Ciudad Real, Spain.
authors: Julio
authors: J
authors: Alvarez
authors: Andres M
authors: AM
authors: Perez
authors: Javier
authors: J
authors: Bezos
authors: Carmen
authors: C
authors: Casal
authors: Beatriz
authors: B
authors: Romero
authors: Sabrina
authors: S
authors: Rodriguez-Campos
authors: Jose L
authors: JL
authors: Saez-Llorente
authors: Rosa
authors: R
authors: Diaz
authors: Jesus
authors: J
authors: Carpintero
authors: Lucia
authors: L
authors: de Juan
authors: Lucas
authors: L
authors: Domínguez
mesh_terms: D000818:Animals; D002417:Cattle; D003612:Dairying; D004196:Disease Outbreaks / Q000662:veterinary; D013030:Spain / Q000453:epidemiology; D013997:Time Factors; D014380:Tuberculosis, Bovine / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission