Scale up of rifapentine-isoniazid (3HP) for tuberculosis prevention amongst household contacts in two urban centers: An effectiveness assessment

Scaling up a shorter preventive regimen such as weekly isoniazid-rifapentine (3HP) for three months is a priority for tuberculosis (TB) prevention treatment (TPT). However, there are limited data on 3HP acceptability and completion from high-burden TB countries. We scaled up 3HP from 2018-2021 in two cities in Pakistan. Eligible participants were household contacts of persons diagnosed with TB disease. Participants were prescribed 3HP after ruling out TB disease. Treatment was self-administered. We analyzed the proportion who completed 3HP. In Karachi, we verbally screened 22,054 household contacts of all ages. Of these, 83% were clinically evaluated and 3% were diagnosed with TB. Of household contacts without TB disease, 59% initiated the 3HP regimen, of which 69% completed treatment. In Peshawar, we verbally screened 6,389 household contacts of all ages. We evaluated 95% of household contacts, of whom 2% were diagnosed with TB disease. Among those without TB disease, 65% initiated 3HP, of which 93% completed. Factors associated with higher 3HP completion included residence in Peshawar (RR: 1·35; 95%CI: 1·32-1·37), index patient being a male (RR:1·03, 95%CI: 1·01-1·05), and index patient with extrapulmonary TB (EPTB) compared to bacteriologically-positive pulmonary TB (RR: 1·10, 95%CI: 1·06-1·14). The age of the index patient was inversely associated with completion. We observed a high level of acceptance and completion of 3HP in programs implemented in two cities in Pakistan, with differences observed across the cities. These findings suggest that 3HP can be effectively scaled in urban settings to improve the reach and impact of TPT.