Background
People with HIV (PHIV) have a 30% lifetime risk of developing tuberculosis (TB) disease, which TB preventive therapy (TPT) reduces by 60%. Six-month daily isoniazid (6H) regimens are challenged by non-adherence and suboptimal completion. Shorter regimens such as 3-month weekly rifapentine and isoniazid (3HP) were introduced in Kenya in October 2022. There is a lack of programmatic data comparing the 3HP and 6H cascades.
Methods
We evaluated the TPT cascade among PHIV in western Kenya, January to September 2022, when only 6H was implemented, and October 2022 to September 2023, when 3HP was the preferred regimen. Both regimens were self-administered, with monthly refills. Data were abstracted using standardized report forms for PHIV aged >15 years newly enrolled in HIV care with at least six months of follow-up. We assessed symptom screening, TPT eligibility, initiation, and completion. TPT outcomes by regimen were compared using Chi-square tests. Poisson regression was used to assess correlates of TPT non-completion.
Results
Data was abstracted for 1930 PHIV with median age of 33 years (IQR=27-41). 65.8% were female (n=1269) and 19.5% (n=374) were in WHO stage 3 or 4 (advanced HIV disease [AHD]) at enrolment. Overall, 99.6% (n=1922) underwent TPT eligibility screening, of whom 6.9% (n=132) were diagnosed with TB disease; 97.5% (n=1970) were eligible for TPT. Among 1970 eligible PHIV, 88.1% (n=1577) initiated TPT, 55.4% [n=873] 3HP and 44.6% [n=704] 6H. TPT initiation was significantly higher for 3HP than 6H (89.8% vs. 84.2%; p<0.001). 3HP completion was similar to 6H (89.2% vs. 88.8%, p=0.77). Discontinuation of 3HP due to adverse effects was similar to 6H (3.1% vs. 2.3%, p=0.70). Non-completion of 6H was nearly five-fold higher (adjusted risk ratio [aRR]=4.89; 95%CI 1.91-12.48) among PHIV with AHD than those without AHD. Non-completion of 3HP was over twice higher among PHIV with AHD than those without AHD (aRR=2.36; 95% CI 1.04-5.37) and among PHIV in formal employment (aRR=2.42; 95% 1.12-5.21).
Conclusions
3HP implementation significantly increased TPT initiation. Overall, completion rates were high, adverse events leading to discontinuation were low and similar for both regimens. TPT non-completion was substantially higher among PHIV with AHD. 3HP non-completion was higher among PHIV in formal employment. While 3HP is a promising alternative to 6H, interventions are needed to support treatment completion among PHIV with AHD and those in formal employment.