When institutional transitions interrupt prevention: 3HP tuberculosis preventive treatment continuity in a Paraguayan prison cohort.

OBJECTIVES

To evaluate continuity of once-weekly isoniazid plus rifapentine for 12 weeks (3HP) tuberculosis preventive treatment in a Paraguayan prison cohort, focusing on adherence, strict completion, safety and institutional transitions as drivers of non-completion.

METHODS

We conducted a longitudinal implementation cohort study at Coronel Oviedo Penitentiary Center, Paraguay, during July-October 2025. Persons with QuantiFERON-TB Gold Plus-confirmed tuberculosis infection and active tuberculosis excluded by the program algorithm were offered 3HP under directly observed therapy. Weekly dose administration, missed-dose reasons and self-reported adverse reactions were recorded.

RESULTS

Of 1846 people incarcerated in the facility, 240 accessed QuantiFERON testing and 170 tested positive. Among QFT-positive individuals, 50 did not initiate 3HP because of transfer, release or refusal. A total of 120 initiated 3HP; 90 achieved acceptable adherence, defined as receipt of at least 11 of 12 doses (75.0%), and 82 completed all 12 doses (68.3%). Medication was administered in 1195 of 1440 scheduled person-weeks (83.0%). Non-completion occurred in 30 participants; 28 cases (93.3%) were attributable to release or transfer. Fifty-seven participants (47.5%) reported at least one adverse reaction, mostly mild or moderate.

CONCLUSION

High adherence was achieved with 3HP, but institutional transitions interrupted completion, highlighting the need for prison-to-community continuity mechanisms after incarceration.