Programmatic Evaluation of an Algorithm for Intensified TB Case Finding and Isoniazid Preventive Therapy for People Living with HIV in Thailand and Vietnam

BACKGROUND.Tuberculosis (TB) screening affords clinicians opportunities to diagnose or exclude TB disease and initiate Isoniazid Preventive Therapy (IPT) for people living with HIV (PLHIV). METHODS.We implemented an algorithm to diagnose or rule out TB among PLHIV in eleven HIV clinics in Thailand and Vietnam. We assessed algorithm yield and uptake of IPT and factors associated with TB disease among PLHIV. RESULTS.A total of 1,448 PLHIV not yet on antiretroviral therapy (ART) were enrolled and screened for TB. Overall, 634 (44%) screened positive and 119 (8%) were diagnosed with TB; of these, 40% (48/119) were diagnosed by a positive culture following a negative sputum smear microscopy. In total, 55% of those eligible (263/477) started on IPT and of those, 75% (196/263) completed therapy. The prevalence of TB disease we observed in this study was 8.2% (8,218 per 100,000 persons)46 and 25 times the prevalence of TB in the general population in Thailand and Vietnam, respectively. Several factors were independently associated with TB disease including being underweight (aOR [95% CI]2.3 [1.2, 2.6]) and using injection drugs (aOR [95% CI]2.9 [1.3, 6.3]). CONCLUSIONS.The high yield of TB disease diagnosed among PLHIV screened with the algorithm, and higher burden among PLHIV who inject drugs, underscores the need for innovative, tailored approaches to TB screening and prevention. As countries adopt Test-and-Start for ART, TB screening, sensitive TB diagnostics, and IPT should be included in differentiated-care models for HIV to improve diagnosis and prevention of TB among PLHIV.