Background
The issue of “Missing TB Cases” (cases that go undiagnosed, untreated, or unreported) is a major public health challenge in Nigeria, which ranks as the country with the highest TB burden in Africa and one of the top high-burden countries globally. Institute of Human Virology of Nigeria (IHVN), therefore, deployed an innovative, mobile Portable Digital Chest X-ray (PDX) machine integrated with qXR artificial intelligence and real-time AI-assisted interpretation to determine the extent to which the PDX machine will increase case identification among household contacts of TB patients through contact tracing in Nigeria.
Methods
This was an intervention study, a quasi-experimental design between two groups, namely the experimental (Osun and Oyo States) and control (Ogun State). The target population for this study are household contacts of bacteriologically diagnosed index TB cases, where the experimental and control groups were screened with the PDX machine and symptomatic screening, respectively. Data was subjected to a t-test analysis.
Results
In the experimental group, 682 individuals were screened, identifying 77 presumptive cases (11.29%), all of which were evaluated. In contrast, the control group screened 692 individuals, identifying 108 presumptive cases (15.6%), with 89 of these cases evaluated (82.41%). TB diagnosis rates were significantly higher in the experimental group, with 24 TB cases diagnosed (31.12% of presumptive cases) compared to just 4 cases (4.49%) in the control group (p<0.05). Of the diagnosed cases, 91.67% in the experimental group and 100.0% in the control group began treatment. Efficiency metrics reveal that the experimental group had a Number Needed to be Screened (NNS) of 28.4 and a Number Needed to be Treated (NNT) of 3.2, compared to an NNS of 173 and an NNT of 27 in the Control group (p<0.05). Similarly, the TB Yield (No. Diagnosed/No. Evaluated × 100) was significantly higher in the experimental (31.1%) than in the control group (4.49%) (p<0.05).
Conclusions
The findings showed that the PDX machine resulted in a significantly higher and more efficient diagnosis of tuberculosis compared to symptomatic screening. While the Control group had a slightly higher proportion of presumptive cases identified (15.6% vs. 11.29%), the Exp. group had a higher number of tuberculosis cases. It is therefore recommended to adopt PDX machine-based screening to replace or supplement existing symptomatic screening in high-burden settings.