A randomised controlled trial (RCT) to evaluate a scalable active case finding primary care-based intervention for tuberculosis using a point-of-care
Medical Research Council
University of Cape Town
A startling statistic is that more than 40% of TB cases in endemic countries are "missing" (~4.2 million cases globally remain undiagnosed or unreported)! Most of these undiagnosed cases, which continue to transmit disease, are concentrated in the peri-urban 'slums' and 'shanty towns' of large African cities. Without addressing the 'missing cases' the TB epidemic will never be controlled. However, the lack of suitable diagnostic tools has been a major hurdle in finding the 'missing cases'. However, we have recently shown that community-based screening with molecular diagnostic tools (Gene Xpert) is highly effective in detecting these missing cases (Calligaro & Dheda, Lancet Infect Dis, 2017; XACT I study). This has now been superseded by a new simple to use portable, battery operated, point-of care (POC) version of Xpert (OMNI). For the first time we have a highly sensitive tool that is ideally suited for community-based active case finding (ACF). We have now validated this tool in a NIH-funded RCT in Cape Town (XACT II study; n= 5500 participants). The results show that Xpert is feasible at community-based POC and works much better than POC smear microscopy. However, we now need to validate the methodology and results in different settings to enable uptake and policy recommendations for primary care. Moreover, we now need to optimise the ACF model and determine where Xpert should optimally be located. Thus, we propose conducting a RCT to evaluate the feasibility and impact of primary care-based Xpert performed at POC compared Xpert performed in a centralized laboratory (XACT III). This study will set a new standard of care for ACF and likely revolutionize TB detection, moving it out of clinics and into the community. Furthermore, this project will enable, for the first time, the bio-phenotyping of TB patients in the community who have minimal or no TB symptoms using novel technologies including cough aerosol sampling and whole genome sequencing.
2.5 Research design and methodologies (aetiology) / P&Cs