کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2456049 | 1110528 | 2010 | 6 صفحه PDF | دانلود رایگان |
The protective efficacy of Mycobacterium bovis BCG (1 × 106 single dose) was evaluated under field conditions. A total of 140 male Holstein Friesian calves, one to two week-old were selected. Two groups of 70 each were formed, one group was vaccinated and the other was injected with a placebo during their second week of age and followed until 12 months of age. The study considered a positive case of tuberculosis to be an animal that had a positive reaction to the three following tests in a row: tuberculin, IFNγ PPD-B and IFNγ ESAT6-CFP10 during the 12 months of exposure. The results showed a 59.4% efficacy (IC95%: 47.64–71.16). The non-vaccinated calves were 2.4 times more at risk of becoming infected (IC95%: 1.07–5.68) compared to vaccinated animals. As a complementary test a PCR test was performed using nasal exudates in some animals from both groups using a Mycobacterium complex detection kit. All the positive PCR reactions (5/44) were found in the non-vaccinated animals. These findings suggest that the use of the BCG vaccine, even though it is not capable of protecting 100%, does prevent TB vaccinated animals from excreting bacilli in their nasal secretions at their first year of age.
Journal: Research in Veterinary Science - Volume 88, Issue 1, February 2010, Pages 44–49