Improving tuberculosis management in prisons: Impact of a rapid molecular point-of-care test

To improve tuberculosis (TB) diagnosis in prison, we evaluate the value of the Xpert^ⓇMTB/RIF Ultra assay (Xpert) as point-of-care (POC) in a French prison hospital.

We first validated Xpert use on raw sputum at the referent laboratory. Secondly, trained physicians at the prison hospital performed Xpert tests for each patient presenting TB symptoms. The results were compared with Xpert, microscopic examination, culture and drug susceptibility testing on the corresponding decontaminated specimens.

76 inmates were included in 15 months and 21 were diagnosed with TB. The overall sensitivity, specificity, positive and negative predictive values of Xpert were respectively: 92.3%, 100%, 100% and 98.7% on raw sputum. The efficiency of the molecular POC was confirmed by a concordance of 97% between Xpert findings from the prison hospital and culture results. Delay of microbiological diagnosis was reduced by about 18 days for 13 inmates with smear-negative sputum that avoid the mobilization of major means (escort, transport) to perform fibroscopic samples. Repeated Xpert negative results helped to speed the lifting of inmate isolation.

The implementation of Xpert in prison could optimize the management of incarcerated patients and thus limit the spread of TB among inmates, carers and other staff.