Measuring endemicity and burden of leprosy across countries and regions: A systematic review and Delphi survey.

BACKGROUND: Leprosy is a chronic infectious disease caused by Mycobacterium leprae, the annual new case detection in 2019 was 202,189 globally. Measuring endemicity levels and burden in leprosy lacks a uniform approach. As a result, the assessment of leprosy endemicity or burden are not comparable over time and across countries and regions. This can make program planning and evaluation difficult. This study aims to identify relevant metrics and methods for measuring and classifying leprosy endemicity and burden at (sub)national level. METHODS: We used a mixed-method approach combining findings from a systematic literature review and a Delphi survey. The literature search was conducted in seven databases, searching for endemicity, burden and leprosy. We reviewed the available evidence on the usage of indicators, classification levels, and scoring methods to measure and classify endemicity and burden. A two round Delphi survey was conducted to ask experts to rank and weigh indicators, classification levels, and scoring methods. RESULTS: The literature review showed variation of indicators, levels, and cut-off values to measure leprosy endemicity and/or burden. The most used indicators for endemicity include new case detection rate (NCDR), new cases among children and new cases with grade 2 disability. For burden these include NCDR, MB cases, and prevalence. The classification levels 'high' and 'low' were most important. It was considered most relevant to use separate scoring methods for endemicity and burden. The scores would be derived by use of multiple indicators. CONCLUSION: There is great variation in the existing method for measuring endemicity and burden across countries and regions. Our findings contribute to establishing a standardized uniform approach to measure and classify leprosy endemicity and burden at (sub)national level, which would allow effective communication and planning of intervention strategies.

Trends and patterns in leprosy in nine states of the Republic of the Sudan 7 years after the introduction of routine contact screening.

Background: This paper analyzes the trends of key indicators reflecting the epidemiological situation of leprosy in nine different states of the Republic of the Sudan after the introduction of a systematic contact screening in 2010. Methods: The routinely assessed data from the leprosy control program from 2010 to 2016 were analyzed. Results: Despite, intense contact screening, the overall number of new cases detected showed a decreasing trend. The female:male ratio among new cases was constantly low. The overall average number of contacts needed to screen in order to detect a new case among contacts was 64. However, this number varied significantly in the nine states under investigation, with the best yield being observed in the state with the lowest case detection rate. Conclusions: The total number of new cases of leprosy in nine states of the Republic of the Sudan has shown declining tendencies since 2010. Our data are not suggestive of a significant impact of contact screening on the trends of leprosy key indicators. Overall, contact screening proved to be efficient in most states, including those that exhibited very low annual new case detection rates (ANCDRs). Sensitization of personnel undergoing training and measures improving access of females to leprosy services are urgently needed.