The Veterinary Record
HOME CURRENT ISSUE TABLE OF CONTENTS ARCHIVE SEARCH SUBSCRIPTIONS JOBS FEEDBACK HELP
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowRequest Permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Lopez-Valencia, G.
Right arrow Articles by Medina-Basulto, G.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Lopez-Valencia, G.
Right arrow Articles by Medina-Basulto, G.
The Veterinary Record 166:118 (2010)
© 2010 British Veterinary Association

Research Digest

Evaluating protective efficacy of a BCG vaccine against TB in a field trial in cattle

G. Lopez-Valencia, T. Renteria-Evangelista, J. de Jesús Williams, A. Licea-Navarro, A. De la Mora-Valle and G. Medina-Basulto

VACCINATION of cattle against Mycobacterium bovis is being considered as one possible tool in the control of bovine tuberculosis (TB). The BCG vaccine has been shown to provide some protection against M bovis infection, but further research is needed on its efficacy under natural conditions. This study evaluated the protective efficacy of a BCG vaccine against M bovis in a commercial dairy herd, in a field trial in Tijuana, Mexico.

A total of 140 Holstein-Friesian male calves, aged less than two weeks, and shown to be negative for TB, were selected for the study. They originated from a herd, comprising 600 breeding cattle, which was determined to have an overall TB prevalence of 40 per cent. Calves were separated into two equal groups of control and vaccinated animals; vaccinated calves were inoculated subcutaneously with 1 ml (1 x 106 cfu) BCG Tokyo strain. Following weaning, both groups were exposed to TB-positive cattle by allocation to neighbouring pens sharing common water troughs. The animals were studied until they reached 12 months of age.

An animal was considered to be TB-positive if it reacted to three consecutive tests: tuberculin skin test, and IFN-{gamma} tests with antigens PPD-B and ESAT6-CFP10. At 12 months, nasal secretion samples were taken from a subsample of animals and analysed by PCR.

In the non-vaccinated group, the first TB-positive animal was detected at three months, compared with nine months in the vaccinated group. Vaccine efficacy was shown to be 59.4 per cent, with non-vaccinated calves being 2.4-times more at risk of M bovis infection than vaccinated animals. All positive PCR reactions (five/44) were in samples from non-vaccinated calves. The findings suggested that although BCG does not afford total protection against TB, it could be capable of preventing vaccinated animals from excreting nasal bacilli.

Research in Veterinary Science (2010) 88, 44-49 (doi: 10.1016/j.rvsc.2009.05.022)





This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowRequest Permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Lopez-Valencia, G.
Right arrow Articles by Medina-Basulto, G.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Lopez-Valencia, G.
Right arrow Articles by Medina-Basulto, G.

HOME CURRENT ISSUE TABLE OF CONTENTS ARCHIVE SEARCH SUBSCRIPTIONS JOBS FEEDBACK HELP