Reacoes inespecíficas no diagnóstico alérgico da tuberculose bovina :
The tuberculin test was performed on 3124 cattle from 24 tuberculosis-free herds from an area between the cities of Río de Janeiro, Sao Paulo and Belo Horizonte, using bovine tuberculin PPD containing 5000 IU per dose and avian PPD containing 2500 IU per dose applied intradermically. An increase in the thickness of the skin fold equal to or greater than 3mm, independent of local clinical changes were considered positive. The results showed that 305 (9.7 per cent) animals developed non-specific allergic reactions, whose prevalence ranged from 1.1 to 30.4 per cent on all farms tested. The mean increase in the thickness of the skin folds was 4mm, while the mean of the strongest reaction from every farm was 5.9mm. Tuberculin testing was also performed on 1945 cattle from 13 herds with tuberculosis, revealing 368 (18.9 per cent) reactors and a prevalence range of 6.8 to 89.6 per cent. The mean skin fold increase was 7.5mm, while the mean of the strongest reactions was 19.9mm. Furthermore, it was observed that 79 per cent of the non-specific reactions showed skin fold increases of 3-4mm, which required the modification of the key for interpreting tuberculin reactions. Increase of up to 1.9mm were considered negative, between 2.0 and 3.9mm suspect, and 4.0mm and above positive, independent of local changes. Increases of 3mm or greater, if accompanied by pain, edema, exudate or local necrosis were considered positive. Simultaneous tuberculin testing is recommended in doubtful cases to rule out or confirm non-specific allergic reactions. When the modified key was applied to the positive reactors from the 24 tuberculosis-free herds, the number was reduced to 64 (2 per cent)
| Main Authors: | , , , |
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| Format: | biblioteca |
| Language: | eng |
| Published: |
Oct-
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| Subjects: | DIAGNOSTICO DE LABORATORIO, MYCOBACTERIUM, BACTERIOSIS, TUBERCULOSIS BOVINA, TUBERCULINA, PRUEBA TUBERCULINICA, DERIVADO PROTEICO PURIFICADO, REACCIONES ALERGICAS, INCIDENCIA DE LA ENFERMEDAD, GANADO DE LECHE, RIO DE JANEIRO, SAO PAULO, BELO HORIZONTE, BRASIL, |
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| Summary: | The tuberculin test was performed on 3124 cattle from 24 tuberculosis-free herds from an area between the cities of Río de Janeiro, Sao Paulo and Belo Horizonte, using bovine tuberculin PPD containing 5000 IU per dose and avian PPD containing 2500 IU per dose applied intradermically. An increase in the thickness of the skin fold equal to or greater than 3mm, independent of local clinical changes were considered positive. The results showed that 305 (9.7 per cent) animals developed non-specific allergic reactions, whose prevalence ranged from 1.1 to 30.4 per cent on all farms tested. The mean increase in the thickness of the skin folds was 4mm, while the mean of the strongest reaction from every farm was 5.9mm. Tuberculin testing was also performed on 1945 cattle from 13 herds with tuberculosis, revealing 368 (18.9 per cent) reactors and a prevalence range of 6.8 to 89.6 per cent. The mean skin fold increase was 7.5mm, while the mean of the strongest reactions was 19.9mm. Furthermore, it was observed that 79 per cent of the non-specific reactions showed skin fold increases of 3-4mm, which required the modification of the key for interpreting tuberculin reactions. Increase of up to 1.9mm were considered negative, between 2.0 and 3.9mm suspect, and 4.0mm and above positive, independent of local changes. Increases of 3mm or greater, if accompanied by pain, edema, exudate or local necrosis were considered positive. Simultaneous tuberculin testing is recommended in doubtful cases to rule out or confirm non-specific allergic reactions. When the modified key was applied to the positive reactors from the 24 tuberculosis-free herds, the number was reduced to 64 (2 per cent) |
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