Number of people requiring post-exposure prophylaxis to end leprosy: A modeling study

Abstract

Background Worldwide, around 210,000 new cases of leprosy are detected annually. To end leprosy, i.e. zero new leprosy cases, preventive interventions such as contact tracing and post-exposure prophylaxis (PEP) are required. This study aims to estimate the number of people requiring PEP to reduce leprosy new case detection (NCD) at national and global level by 50% and 90%. Methodology/Principal findings The individual-based model SIMCOLEP was fitted to seven leprosy settings defined by NCD and MB proportion. Using data of all 110 countries with known leprosy patients in 2016, we assigned each country to one of these settings. We predicted the impact of administering PEP to about 25 contacts of leprosy patients on the annual NCD for 25 years and estimated the number of contacts requiring PEP per country for each year. The NCD trends show an increase in NCD in the first year (i.e. backlog cases) followed by a significant decrease thereafter. A reduction of 50% and 90% of new cases would be achieved in most countries in 5 and 22 years if 20.6 and 40.2 million people are treated with PEP over that period, respectively. For India, Brazil, and Indonesia together, a total of 32.9 million people requiring PEP to achieve a 90% reduction in 22 years. Conclusion/Significance The leprosy problem is far greater than the 210,000 new cases reported annually. Our model estimates of the number of people requiring PEP to achieve significant reduction of new leprosy cases can be used by policymakers and program managers to develop long-term strategies to end leprosy.

Delayed detection of leprosy cases: A systematic review of healthcare-related factors

“…An effective and feasible intervention recommended by the WHO for reducing leprosy cases is to follow a contact survey by providing post-exposure prophylaxis to eligible contacts with single-dose rifampicin (SDR). This intervention can prevent delay effectively due to the leprosy control program must contact the community directly to increase the awareness of the community through health promotion efforts and do active case finding [53][54][55].…”

Modulation of the Response to Mycobacterium leprae and Pathogenesis of Leprosy

“…After the introduction of multi-drug therapy (MDT) for leprosy the prevalence of this disease had a major initial reduction, but the number of new cases remains stable around 200,000 cases/year, including children, demonstrating that transmission is not interrupted in leprosy endemic countries ( Taal et al, 2021 ). Another important problem is underdiagnosis of this disease.…”

“…A model for changes in Treg/Teff ratios with increase in bacillary load is shown in Figure 3 . The likely requirement of M. leprae for this inhibition of effector response suggests that improvement of effector response against M. leprae is a likely benefit for post-exposure prophylaxis of leprosy ( Taal et al, 2021 ).…”

Atualizações Em Doenças Tropicais Negligenciadas

“…Com isso, em áreas com um nível mais alto de endemicidade, mais contatos são selecionados e, portanto, são elegíveis para o programa, o que, como resultado, evitará mais casos em termos absolutos, em comparação com uma área com um nível de endemicidade mais baixo. Além disso, o impacto é maior se o programa de hanseníase de rotina for mais eficiente, o que implica em menos pacientes clínicos com hanseníase não diagnosticados na população (TAAL., et al 2021).…”