Measuring antigen-specific responses in Mycobacterium bovis-infected warthogs (Phacochoerus africanus) using the intradermal tuberculin test
Date
2018
Journal Title
Journal ISSN
Volume Title
Publisher
BMC (part of Springer Nature)
Abstract
Background: Bovine tuberculosis (bTB) caused by Mycobacterium bovis has previously been diagnosed in warthogs
and infection can be highly prevalent (> 30%) in endemic areas. Thus, warthogs could potentially be an important
species to consider as sentinels for disease surveillance. However, disease surveillance is dependent on availability
of accurate diagnostic assays and only a few diagnostic tests have been investigated for warthogs. Furthermore, the
tests that have been used in this species require laboratory equipment and trained personnel to obtain results.
Therefore, this study investigated the use of the intradermal tuberculin test (ITT) to screen warthogs for bTB, which
can be done with minimal equipment and under field conditions by most veterinarians and other qualified
professionals. Changes in skin fold thickness measurements at the bovine purified protein derivative (PPD)
administration site, between 0 and 72 h, were compared with differential changes between the bovine and avian
PPD sites, for 34 warthogs, to evaluate the performance when different interpretation criteria for the ITT was used.
Results: Using an increase of 1.8 mm or more at the bovine PPD site as a cut-off for positive responders, 69% of
16 M. bovis culture-positive warthogs had a positive test result, with 100% of the 18 culture-negative warthogs
considered as test negative. When a differential of 1.2 mm or more in skin fold thickness at the bovine PPD
compared to the avian PPD site was used as a cut-off for the comparative ITT, 81% of culture-positive warthogs
were considered as test positive, with 100% of culture-negative warthogs considered as test negative.
Conclusion: The findings in this study suggest that the ITT is a promising tool to use when screening warthogs for
M. bovis infection.
Description
CITATION: Roos, E. O., et al. 2018. Measuring antigen-specific responses in Mycobacterium bovis-infected warthogs (Phacochoerus africanus) using the intradermal tuberculin test. BMC Veterinary Research, 14:360, doi:10.1186/s12917-018-1685-8.
The original publication is available at https://bmcvetres.biomedcentral.com
Publication of this article was funded by the Stellenbosch University Open Access Fund.
The original publication is available at https://bmcvetres.biomedcentral.com
Publication of this article was funded by the Stellenbosch University Open Access Fund.
Keywords
Bovine tuberculosis, Warthogs (Phacochoerus africanus) -- Diseases, Tuberculin test -- South Africa, Antigenic determinants
Citation
Roos, E. O., et al. 2018. Measuring antigen-specific responses in Mycobacterium bovis-infected warthogs (Phacochoerus africanus) using the intradermal tuberculin test. BMC Veterinary Research, 14:360, doi:10.1186/s12917-018-1685-8