A total of 49 road-killed red foxes were used for the detection of Mycobacterium tuberculosis complex (MTC) in Portugal. MTC infection was detected by PCR in 10 red foxes (20.4%; 95% confidence interval [CI] 8.8-31.2%) and confirmed in three (6.1%; 95% CI 0.0-7.9%) of them by microbiological culture. The complex was detected in 20 tissues out of 441 by PCR techniques (4.5%; 95% CI 16.3-23.7%) and in seven tissues out of 441 (1.6%; 95% CI 4.6-9.4%) by culture. MTC was most frequently detected in the brain (8.2%) and in the mediastinal lymph nodes (8.2%). The seven cultures obtained were positive for M. bovis by PCR-based genotyping of the MTC targeting genomic deletions. This study confirms the presence of disseminated M. bovis in red foxes in Portugal, and it is the first report in the world of the natural infection in the animals' brains.
Keywords: Epidemiology; Mycobacterium tuberculosis complex; Red foxes.