OR07

1:University of Pretoria; 2:University of the Free State; 3:Utrecht University

Food-producing animals are a source of non-tuberculous mycobacteria (NTM) and, most importantly, of Mycobacterium bovis (M. bovis), known to cause bovine tuberculosis in cattle and zoonotic TB in humans. The routine approach used by medical laboratories in South Africa to diagnose tuberculosis (TB) in patients is based on the GeneXpert technology, which is unable to speciate M. bovis. We implemented an integrated investigation of TB transmission between cattle and humans in a rural setting with a high human TB incidence and endemic M. bovis infection in communal cattle herds in northern KwaZulu-Natal, South Africa.

Sputum samples from GeneXpert-positive patients and aspirates from cases with possible extrapulmonary TB were cultured for Mycobacteria using the Bactec MGIT 320 system and Löwenstein-Jensen medium. The TB status of cattle herds owned by TB patients was determined using the Bovigam® assay and culture of milk and nasal swabs.

To date, M. tuberculosis was isolated from 28 out of 227 (12.3%) TB patients and NTM from 11 patients (4.8%). M. bovis was not isolated. A total of 64 cattle herds owned by TB-confirmed farmers were tested for bovine tuberculosis, revealing a herd prevalence of 10.9%. M. bovis was isolated from 5/37 (13.5%) and NTM was isolated from 14 of the 37 (38%) milk samples collected. The preliminary findings corroborate the risk of zoonotic transmission of M. bovis and NTM via raw milk, although the analyses to date could not confirm M. bovis infection in TB patients in this ongoing study.