Introduction
The PEP4LEP and PEP4LEP 2.0 projects aim to identify the most effective and feasible ways to screen people at risk of developing leprosy and to provide chemoprophylaxis in Ethiopia, Mozambique, and Tanzania.
Why chemoprophylaxis is important
Leprosy develops very slowly. Unlike many bacteria that multiply rapidly, the leprosy bacillus doubles only once every two weeks. As a result, symptoms may take two to five years to appear. Early signs such as skin lesions with reduced sensation are often missed by both people affected by leprosy and health workers. This delay means transmission can continue for years without detection. To interrupt transmission, innovative and proactive approaches are required.
A single dose of rifampicin (SDR-PEP) has been shown to reduce the risk of developing leprosy by nearly 60% when given to contacts of people affected by leprosy. While SDR-PEP was included in the WHO guidelines in 2018, questions remain about how best to implement it in different settings.
What PEP4LEP compares
PEP4LEP and PEP4LEP 2.0 are cluster-randomized implementation trials that compare the effectiveness and feasibility of two intervention approaches:
-
Community-based skin camps
Screening approximately 100 household members and neighbours of an index patient, followed by SDR-PEP administration when eligible. -
Health centre–based screening
Inviting household contacts of an index patient to attend a health facility for screening and SDR-PEP administration.
To reduce stigma, screening is not limited to leprosy but includes other skin diseases, following an evidence-based and WHO-supported dermatological approach.
Effectiveness is assessed by comparing:
-
Case detection rates
-
Delays in diagnosis
-
Cost-effectiveness
-
Acceptability among stakeholders
Use of the NLR SkinApp
Both projects use and evaluate the NLR SkinApp, developed to support community health workers in recognising early signs of leprosy and other skin diseases in contexts with limited access to dermatologists.
By enabling early diagnosis and treatment, the SkinApp helps prevent:
-
Disability
-
Psychological impact
-
Social and economic consequences such as stigma
The NLR SkinApp has since been integrated into the WHO Skin NTD App, marking an important milestone.
Capacity building
As part of the projects, health workers receive training in:
-
Diagnosing leprosy and other skin diseases
-
Administering SDR-PEP
Capacity assessments are conducted throughout the projects to evaluate the impact of training and digital support tools, including the NLR SkinApp.
Timeline and funding
-
PEP4LEP ran from 1 October 2018 to March 2024
-
Project results, publications, and tools are available below
Funding:
-
PEP4LEP: EDCTP2 / EU and the Leprosy Research Initiative (LRI)
-
PEP4LEP 2.0: Global Health EDCTP3 Joint Undertaking (GH EDCTP3 JU) / EU