Mobile community-based active case-finding for tuberculosis among older populations in rural Cambodia

OBJECTIVE : To systematically screen older rural populations in Cambodia for tuberculosis (TB) and develop an effective active case-finding (ACF) model for this TB high-risk group. DESIGN: A retrospective study using routinely collected programmatic data on community-based ACF among people aged >= 55 years using TB symptoms and systematic chest radiography (CXR) screening, followed by Xpert (R) MTB/RIF testing for participants with positive screening results and TB culture for certain Xpert-negative specimens. RESULTS : Of 22 101 participants included in the analysis, 7469 (33.8%) were screening-positive and 5960 (27.0%) underwent Xpert testing. Pulmonary TB was identified in 482 (2.2%) individuals: 288 (1.3%) were bacteriologically confirmed (253 using Xpert, 35 using culture) and 194 (0.9%) were clinically diagnosed. Eighty-seven people needed to be screened in order to diagnose one Xpert-positive case. Among the Xpert-positive cases, only 31.6% (80/253) reported cough >= 2 weeks, and 39.9% (101/253) were asymptomatic but had a CXR suggestive of active TB. Treatment uptake was 97.3% (469/482), and treatment success was 88.0% (424/482). CONCLUSIONS : Community-based ACF was effective in detecting and successfully treating older TB patients, most of whom might otherwise have remained undiagnosed. Mobile CXR appears to be crucial in identifying a high number of asymptomatic, bacteriologically confirmed cases.