Nationwide Cross-Sectional Study on Bovine Tuberculosis by Intra Vitam Testing in Germany, 2013-2014

Germany was declared officially free from bovine tuberculosis (bTB) effective from 1 July 1996. After the occurrence of several Mycobacterium (M.) bovis outbreaks in north-western Germany in recent years with high intraherd prevalence at the time of detection, the reliability of abattoir surveillance as the principal component of the national bTB control programme was debated by veterinary public health officials. Rising numbers of wildlife-associated outbreaks caused by M. caprae in southern Germany eventually prompted a nationwide cross-sectional study on bTB. A total of 51 999 cattle, that is 0.41% of the national herd kept on 1.73% of German cattle farms, were tested. Despite 4 positive and 152 inconclusive single intradermal comparative cervical test results, none of the animals was confirmed as bTB-positive by a subsequent interferon-release assay or by post-mortem PCR testing. The estimated prevalence of bTB in Germany was thus calculated as 0.0% (CI 0.0000-0.0064%) affirming that Germany still qualifies as an officially tuberculosis-free (OTF) country. Occasional randomized nationwide testing can be an appropriate tool to reassure the OTF status and may also help to maintain an appropriate training level for the diagnostic procedures and for supporting sustained disease awareness among stakeholders.