Rifapentine effective in preventing leprosy in household contacts

1. In this randomized controlled trial, rifapentine was associated with a reduced incidence of leprosy in household contacts compared to rifampin and no intervention.

2. No severe adverse events were associated with rifapentine or rifampin.

Evidence Rating Level: 1 (Excellent)

Study Rundown: Leprosy is a chronic infection caused by Mycobacterium leprae, mainly affecting low-resource areas. Despite its treatability with anti-mycobacterial drugs, its high transmissibility continues to pose a challenge in reducing its incidence. Household contacts of a patient with leprosy are at an especially elevated risk of contracting the infection. Single-dose rifampin has shown moderate effectiveness in reducing this risk. Rifapentine, a derivative of rifampin with a longer half-life and higher activity against Mycobacterium leprae, has emerged as a potential novel prophylactic. The current study was a randomized trial to assess the effectiveness of single-dose rifapentine against rifampin and no intervention in preventing leprosy in household contacts. At four years, the rifapentine group was associated with a significantly lower incidence of leprosy than the rifampin and control groups. Notably, the rifampin and control groups did not differ significantly in incidence rates of leprosy. No serious adverse events were observed across the groups. The study was limited by the low endemic level of leprosy in China. However, these results demonstrated that rifapentine could be a potential prophylactic for household contacts of patients with leprosy.

Click here to read the study in NEJM

Relevant Reading: Four-Month Rifapentine Regimens with or without Moxifloxacin for Tuberculosis

In-Depth [randomized controlled trial]: This cluster-randomized controlled trial assessed the effectiveness of single-dose rifapentine compared to single-dose rifampin and no intervention in preventing infections among household contacts of patients with leprosy. Overall, 207 leprosy clusters consisting of 7,450 household contacts were randomized to receive a single dose of rifapentine, a single dose of rifampin, or no intervention. The primary outcome was the cumulative incidence rate of leprosy among household contacts by four years. Secondary outcomes included cumulative incidence at two years and safety outcomes. By four years, the cumulative incidence rate was 0.09% among participants who received rifapentine, 0.33% in those who received rifampin, and 0.55% in those who got no intervention. Per intention-to-treat analysis, the cumulative incidence of leprosy for the rifapentine group was 84% lower than that for the control group (incidence ratio, 0.16; 95% confidence interval [CI] 0.03 to 0.87, p=0.02). However, there was no significant difference in cumulative incidence between the rifampin and the control group (incidence ratio, 0.59; 95% CI, 0.22 to 1.57; p=0.23). There was no significant difference between these groups at the two-year follow-up. No severe adverse events were noted among any of the groups. There were very few relapse cases of episodes among the index patients across all groups, all of whom were subsequently treated and followed. These results demonstrated rifapentine as a potential leprosy post-exposure prophylaxis for household contacts.

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