title: Within herd transmission and evaluation of the performance of clinical and serological diagnosis of foot-and-mouth disease in partially immune cattle herds.
abstract: The control of foot-and-mouth disease (FMD) in vaccinated populations relies upon surveillance activities such as clinical inspections (CI) and serological monitoring. New evidence to refine current surveillance guidelines has been provided by evaluating (1) the diagnostic performance of CI and serological tests for detection of FMD virus (FMDV) non-structural proteins (NSP), and (2) the within-herd transmission of the virus in partially immune cattle. Data came from 23 affected herds during an epidemic of FMDV type O in Bolivia, in 2007. All cattle (n=957) in these herds were clinically inspected and serum samples were collected one month after the last animal with clinical signs was detected. Samples were tested for the presence of antibodies against NSP using the PANAFTOSA 3ABC-ELISA test and a subset of samples were tested using the enzyme-linked immunoelectrotransfer blot assay (EITB). Data from clinical and serological diagnoses were analysed using a Bayesian model. The sensitivity Se and specificity Sp of the tests, as well as the prevalence and the within-herd reproduction ratio R of FMDV were estimated. In addition, risk factors for infection were identified. The Se of CI, the 3ABC-ELISA and the EITB tests were estimated to be 0.30, 0.88 and 0.96 respectively. The estimated Sp, in the same order, were 0.88, 0.93 and 0.97. The within-herd prevalence of infected animals ranged from 0.04 to 0.91 and R ranged from 1.02 to 2.68. It was observed that cattle coming from areas with high vaccination coverage had a lower risk of becoming infected than home-bred cattle from the affected herds, where vaccination coverage was thought to be low. Although these estimates come from herds kept under specific conditions, they provide a reference for future surveillance design and can inform simulation models for surveillance and control of FMD in similar cattle populations.
authors.affiliation: Unidad Nacional de Sanidad Animal, Servicion Nacional de Sanidad Animal y Ganaderia "SENASAG", Calle Natush Bush S/N, Trinidad, Bolivia; The Pirbright Institute, Ash road, GU24 0NF, Pirbright, Woking, UK. Electronic address: jose.gonzales@pirbright.ac.uk.
authors.forename: J L
authors.initials: JL
authors.lastname: Gonzales
authors.affiliation: Unidad Nacional de Sanidad Animal, Servicion Nacional de Sanidad Animal y Ganaderia "SENASAG", Calle Natush Bush S/N, Trinidad, Bolivia.
authors.forename: M A
authors.initials: MA
authors.lastname: Barrientos
authors.affiliation: Laboratorio de Investigacion y Diagnostico Veterinario LIDIVET, Av. Ejercito Nacional No 153, Santa Cruz, Bolivia.
authors.forename: J L
authors.initials: JL
authors.lastname: Quiroga
authors.affiliation: Laboratorio de Investigacion y Diagnostico Veterinario LIDIVET, Av. Ejercito Nacional No 153, Santa Cruz, Bolivia.
authors.forename: D
authors.initials: D
authors.lastname: Ardaya
authors.affiliation: Unidad Nacional de Sanidad Animal, Servicion Nacional de Sanidad Animal y Ganaderia "SENASAG", Calle Natush Bush S/N, Trinidad, Bolivia.
authors.forename: O
authors.initials: O
authors.lastname: Daza
authors.affiliation: Unidad Nacional de Sanidad Animal, Servicion Nacional de Sanidad Animal y Ganaderia "SENASAG", Calle Natush Bush S/N, Trinidad, Bolivia.
authors.forename: C
authors.initials: C
authors.lastname: Martinez
authors.affiliation: APHIS-USDA, Bolivia.
authors.forename: C
authors.initials: C
authors.lastname: Orozco
authors.affiliation: FAO/IAEA Joint Division, Vienna.
authors.forename: J
authors.initials: J
authors.lastname: Crowther
authors.affiliation: The Pirbright Institute, Ash road, GU24 0NF, Pirbright, Woking, UK.
authors.forename: D J
authors.initials: DJ
authors.lastname: Paton
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D001499:Bayes Theorem; D001838:Bolivia / Q000453:epidemiology; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis* / Q000453:epidemiology / Q000635:transmission; D004196:Disease Outbreaks / Q000662:veterinary; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D062665:Epidemiological Monitoring / Q000662:veterinary; D005260:Female; D005536:Foot-and-Mouth Disease / Q000175:diagnosis* / Q000453:epidemiology / Q000635:transmission; D029544:Foot-and-Mouth Disease Virus; D008297:Male; D015995:Prevalence; D012680:Sensitivity and Specificity; D014611:Vaccination / Q000662:veterinary*
chemical_list: D000914:Antibodies, Viral
keywords: DIVA tests; Foot-and-mouth disease; Reproduction ratio; Sensitivity; Specificity; Transmission