The Pan American Health Organization
Promoting Health in the Americas

 Safe Hospitals

Health Surveillance & Disease Prevention & Control — Communicable Diseases: 
Acute Respiratory Infections - Anthrax - Antimicrobial Resistance - Campylobacter - Chagas -
Cholera - Dengue - Diarrheal/Enteric Diseases - Disease Outbreak News -
Emerging/Reemerging Diseases - Filariasis - Hantavirus - InfluenzaAvian |  Pandemic |  Seasonal - International Health Regulations - Leishmaniasis - Leprosy - Malaria -
Neglected Diseases - Parasitic Diseases - Rabies - Research - Salmonella - Shigella - Smallpox -
Tuberculosis - West Nile Virus  - Yellow Fever  -
Health Analysis & Statistics - Chronic Diseases - Veterinary Public Health

Note: The WHO manual was updated and adapted in Brazil for use in their 2003 LEM exercise; for more information, see the Portuguese version or the summary in Spanish.

Full-Text WHO Manual (2000)
(43 pp, PDF, with forms)

Cover and Contents

  Purpose of LEM
  Contents of the Manual

What to Monitor
What to Monitor
Summary Table of Key Indicators
Group I: Elimination Indicators
  1. Case-Finding Activities
  2. Prevalence
  3. Detection
Group II: Integration Indicators
  1. Proportion of Existing Health Facilities Providing MDT
  2. Accessibility to MDT
  3. Availability of MDT Drugs
Group III: Quality of MDT Services
  1. Proportion of Patients Treated with MDT
  2. Case-Holding
  3. Quality of MDT Blister-Packs

How to Monitor
Design of a Monitoring Exercise
  Steps Taken by LEM Monitors
  Qualifications of LEM Monitors
  Inventory of Data Sources
  Defining the Sample Size
  Selecting the Sample Units
Planning and Carrying Out the Study
  Planning the Monitoring
  Selecting Areas to Be Visited
  Preparations of Field Visits
  Data Collection in the Field
Analysis and Reporting

Annexes (forms)

PAHO Leprosy Page
WHO Leprosy Page

Leprosy Elimination Monitoring (LEM):
Guidelines for Monitors (2000)


Multi-Drug Therapy(MDT) is recognised as a major technological improvement in leprosy control. It enables leprosy control to have a tremendous impact on disease prevalence and consequently on disease burden and workload. This impact has led to the concept of eliminating leprosy as a public health problem with the assumption that, below a given level of prevalence, disease transmission will be partially or totally interrupted.

LEM Objective

Assessment of interventions becomes particularly important when considering the leprosy elimination goal. The purpose of monitoring is to assist decision makers and programme managers to assess the progress towards leprosy elimination, to make a plan of action, to implement it and to measure its impact. Monitoring a minimum set of indicators that describes the MDT services will serve the purpose.

The selection of indicators to be monitored needs to be made carefully, in the light of the epidemiological characteristics of leprosy and the large number of grey areas in our understanding of the disease. Incidence is the most relevant but probably the most difficult indicator. Prevalence varies not only with the level of disease burden but also with the operational component of intervention. The uneven distribution of leprosy, as well as the role of various local factors, calls for caution when extrapolating the results from one place to another.

Monitoring methods should be quick and cost-effective. Routine information system is the principal and essential component in monitoring leprosy situation. It needs to be programme oriented, simple and speedy. Too many indicators to be put on the information flow of routine systems will cause paralysis, and therefore some of the indicators among 'a set of minimum indicators' cannot be collected from routine systems. A monitoring exercise that complements routine information systems is needed to measure specific aspects of leprosy elimination programmes and methods for reviewing elimination programmes.

The techniques for collecting indicators are implemented in a standardised way by 'monitors', in collaboration with national programmes and WHO. Monitors collect information which will complement routine leprosy information systems to address specific issues, such as more detailed information on the trend of transmission, cure rates, impact of interventions and changing patterns of leprosy. It is becoming increasingly important to differentiate areas where substantial numbers of backlog cases are included in newly-detected cases from areas where newly-detected cases may be largely made up of single lesion cases. Information on the number of lesions per case, age and sex specific detection, smear positivity, if available and the delay between onset and diagnosis help in better describing indicators used for monitoring leprosy elimination. It is equally important to validate key indicators, such as prevalence and detection, mainly by applying internationally recommended definitions. Wherever possible, trend analysis over the last five years will be used to assess the impact of leprosy elimination activities.

Besides all these technical aspects of LEM, past experiences in LEM have shown that it has had a highly positive effect on field workers and programme managers, who were strongly motivated through discussions on the epidemiological and clinical situations of their areas.


Indicators collected through LEM exercises are well standardised, have been in use for several years in many countries and are well known to programme managers. All the required information has to be collected from existing patient records, leprosy registers, reporting forms and stock bin cards in selected health facilities as well as interviews of patients. The selected health facilities should reflect the situation prevailing in a specific geographical or administrative area at a given point in time and therefore selection of sample and sample size are essential for extrapolating the findings.

The monitoring will have to be repeated in order to assess the impact of interventions and changes over time. These studies are carried out by independent monitors, responsible for visiting selected units to collect information through standardised methods, and for reporting their findings on compiled data to the national programme managers and the WHO. The monitoring should be time-limited and the complete cycle (from design to report) should not exceed four weeks. Selected health facilities should be informed in advance of the monitors' visit so that they have time to prepare to get patients available.

Regional Office for the Americas of the World Health Organization
525 Twenty-third Street, N.W., Washington, D.C. 20037, United States of America
Tel.: +1 (202) 974-3000 Fax: +1 (202) 974-3663

Pan American Health Organization. All rights reserved.