ALVES, J. R. A.; http://lattes.cnpq.br/3808284544729695; ALVES, José Romero Alexandre.
Resumo:
This thesis consists of three articles. In Chapter I, seroprevalence of C. pseudotuberculosis
infection in sheep in Northeastern Brazil was determined by indirect enzyme linked
immunosorbent assay (i-ELISA). Samples were collected from 2,638 sheep from 223 farms of
five states (Ceara, Paraiba, Piaui, Rio Grande do Norte, and Sergipe). From 2,638 sheep tested,
996 (37.76%; 95% CI = 35.93 - 39.62%) were seroreactives and from 223 properties evaluated,
210 (94.17%; 95% CI = 90.28 - 96, 56%) were positive. The i-ELISA test showed sensitivity
and specificity of 91.84% e 97.01%, repectively, proving to be useful in diagnosis of caseous
lymphadenitis (CLA) in sheep. In Chapter II, factors associated with seroreactivity for C.
pseudotuberculosis in the Northeast region were evaluated. Samples were collected from 2,312
sheep from 196 farms studied in Chapter I. It was identified 93.88% (184/196) of the properties
and 37.46% (866/2312) animals with positive serological result for C. pseudotuberculosis.
Purebred animals (PR = 1.189; p = 0.017), source of exposure breeder (PR = 1.192; p = 0.020),
separate lambs from ewes (PR = 1.132; p = 0.048), lakes water source ( PR = 1.65; p = 0.002)
and eliminating infected animals as a control measure (PR = 1.263; p = 0.027) were identified
with factors associated with seropositivity. Measures to increase disease control are
recommended in purebred animals that participate in agglomerations of animals, to reduce
environmental contamination by the agent, stress in handling weaning, proper disposal of the
infected and isolation with inspection on recently acquired animals before introducing them to
herds, as well as to encourage the use of early diagnosis and vaccination to reduce the
occurrence of the disease. In Chapter III a seroprevalence study of caseous lymphadenitis was
conducted in goats sold in animals fair on northeastern semiarid. Samples were collected from
233 goats and the diagnostic was performed by the i-ELISA. Eighty-seven (37.34%; 95% CI =
31.38 - 43.71%) seroreacitive goats were identified. C. pseudotuberculosis infection is present
in marketed goat herds. Policies to encourage early access to disease diagnosis by producers
and the implementation of a CLA control program are recommended to reduce the high
prevalence observed in farms and animals.