Application of interferon gamma and urine lipoarabinomannan (LAM) assays in the evaluation of tuberculosis infection in cattle with low body conditions score in Sembabule District, Uganda

Abstract

Bovine tuberculosis (bTB) is a neglected contagious zoonotic disease, imprinting major economic loses in agriculture and public health, yet the diagnosis still pose a serious challenge. WOAH approved BoviGam assay as a proficient test to be used during eradication programs because of its specificity and sensitivity However, it’s not yet applied widely across the globe. Lipoarabinomannan (LAM) assays have proven efficient in humans with advanced TB and could be applicable in cattle for rapid and early diagnosis of bTB. This research aimed to estimate the prevalence of bovine tuberculosis in low body conditioned cattle in the Sembabule using BoviGam, and to determine the diagnostic capability of a new rapid point-of care assay. Interferon gamma assay is a good test of choice and can be recommended for screening bTB in cattle, however, this can be accompanied by autopsy and microbiology since BoviGam positivity may not necessarily mean active tuberculosis. 14/369 (3.79%) were BoviGam positive and seven of the fourteen BoviGam positives (7/14) were lactating. Majority of the BoviGam positives were Friesians at 42.84% (6/14). Of the 310 animals tested with urine LAM, 59/310 (19.03%) were positive. LAM positive samples; of which one (1/59; 1.7%) was GeneXpert positive. This study revealed that bTB exists in low body conditioned cattle. Bovine Tuberculosis being a neglected reemerging infectious disease threatening lives of humans and animals. Access to rapid diagnostic kits to field veterinarians should be improved to facilitate early detection and safeguard diagnostic integrity. Low body conditioned cattle have the potential of being bTB positive even before clinical signs manifest. BoviGam® detects bTB infected cattle and it’s a good test for ruling out disease in control programs due to its high specificity. LAM Determine kits can further be improved to suit application in animal diagnostics. Further research should be conducted using BoviGam and microbiology on all domestic species in different parts of Uganda and to validate LAM assay so as to qualify it as a test in animals. Farmers should also be sensitized on the risk factors that expose their animals to M. bovis infection.