The long-term impact of the Leprosy Post-Exposure Prophylaxis (LPEP) program on leprosy incidence: A modelling study.

• Main Authors: David J Blok (Author), Peter Steinmann (Author), Anuj Tiwari (Author), Tanja Barth-Jaeggi (Author), Mohammad A Arif (Author), Nand Lal Banstola (Author), Rabindra Baskota (Author), David Blaney (Author), Marc Bonenberger (Author), Teky Budiawan (Author), Arielle Cavaliero (Author), Zaahira Gani (Author), Helena Greter (Author), Eliane Ignotti (Author), Deusdedit V Kamara (Author), Christa Kasang (Author), Pratap R Manglani (Author), Liesbeth Mieras (Author), Blasdus F Njako (Author), Tiara Pakasi (Author), Unnati R Saha (Author), Paul Saunderson (Author), W Cairns S Smith (Author), René Stäheli (Author), Nayani D Suriyarachchi (Author), Aye Tin Maung (Author), Tin Shwe (Author), Jan van Berkel (Author), Wim H van Brakel (Author), Bart Vander Plaetse (Author), Marcos Virmond (Author), Millawage S D Wijesinghe (Author), Ann Aerts (Author), Jan Hendrik Richardus (Author)
• Format: Book
• Published: Public Library of Science (PLoS), 2021-03-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 1935-2727; 1935-2735; 10.1371/journal.pntd.0009279
• Keywords: Arctic medicine. Tropical medicine; RC955-962; Public aspects of medicine; RA1-1270
• Source: PLoS Neglected Tropical Diseases, Vol 15, Iss 3, p e0009279 (2021)

<h4>Background</h4>The Leprosy Post-Exposure Prophylaxis (LPEP) program explored the feasibility and impact of contact tracing and the provision of single dose rifampicin (SDR) to eligible contacts of newly diagnosed leprosy patients in Brazil, India, Indonesia, Myanmar, Nepal, Sri Lanka and Tanzania. As the impact of the programme is difficult to establish in the short term, we apply mathematical modelling to predict its long-term impact on the leprosy incidence.<h4>Methodology</h4>The individual-based model SIMCOLEP was calibrated and validated to the historic leprosy incidence data in the study areas. For each area, we assessed two scenarios: 1) continuation of existing routine activities as in 2014; and 2) routine activities combined with LPEP starting in 2015. The number of contacts per index patient screened varied from 1 to 36 between areas. Projections were made until 2040.<h4>Principal findings</h4>In all areas, the LPEP program increased the number of detected cases in the first year(s) of the programme as compared to the routine programme, followed by a faster reduction afterwards with increasing benefit over time. LPEP could accelerate the reduction of the leprosy incidence by up to six years as compared to the routine programme. The impact of LPEP varied by area due to differences in the number of contacts per index patient included and differences in leprosy epidemiology and routine control programme.<h4>Conclusions</h4>The LPEP program contributes significantly to the reduction of the leprosy incidence and could potentially accelerate the interruption of transmission. It would be advisable to include contact tracing/screening and SDR in routine leprosy programmes.