The following is a summary of “Long-term protective effect of tuberculosis preventive therapy in a medium/high TB incidence setting,” published in the February 2024 issue of Infectious Disease by Teixeira et al.
Researchers conducted a retrospective study investigating tuberculosis preventive therapy (TPT) long-term effectiveness in preventing tuberculosis (TB) disease.
They assessed the IR of new TB disease over 12 years post-randomization into either four months of rifampin or nine months of isoniazid among 991 participants from Brazil in a TPT trial conducted in Rio de Janeiro, where the incidence was 68.6 cases per 100,000 population (2022), aHR for independent variables associated with incident TB were computed.
The results showed an overall TB IR of 1.7 per 1,000 person-years (PY). TB IR was notably higher among those who didn’t complete TPT compared to completers [2.9/1000 PY (95% CI: 1.3; 5.6) versus 1.1/1000 PY (95% CI: 0.4; 2.3), with an IR ratio (IRR) of 2.7 (95% CI: 1.0; 7.2)]. TB IR peaked within 28 months post-randomization [IR: 3.5/1000 PY (1.6; 6.6) PY, compared to 1.1/1000 PY (95% CI: 0.5; 2.1) between 28 and 143 months, with an IRR of 3.1, 95% CI: 1.2-8.2]. Treatment non-completion was the sole variable linked to incident TB [aHR= 3.2 (1.1; 9.7)].
They concluded a completed course of TPT offered lasting defense against TB in a population with low HIV prevalence.
Source: academic.oup.com/cid/advance-article-abstract/doi/10.1093/cid/ciae101/7614117