Technical Bulletin 16

1. INTRODUCTION

The International Leprosy Association (ILA) convened a Technical Forum in Paris in February 2002, which brought together a group of experts to examine in detail the scientific basis for current guidelines and recommendations in the field of leprosy. A number of important issues were discussed at length during the 4-day meeting. In preparation for the Forum, a comprehensive review of published and ‘grey’ literature from 1966 onwards was carried out, enabling conclusions to be reached and recommendations to be made based on evidence. Where evidence is lacking, recommendations for best practice were made. Matters requiring further research were also identified.

The Report of the Technical Forum was published simultaneously as a supplement to the International Journal of Leprosy (1), Leprosy Review (2), the Indian Journal of Leprosy (3), and the Bulletin de l’ALLF (4). The Report was extensively discussed during the International Leprosy Congress held in Salvador, Brazil, 5-9 August 2002. At the end of the Congress the ILA adopted the following resolution:

“The ILA General Meeting of Members thanks the ILA Technical Forum for the excellent work done and endorses the Report (as published in the International Journal of Leprosy and other Mycobacterial Diseases, Volume 70, number 1 (supplement), dated March 2002).

The ILA General Meeting of Members wishes to make it clear that the available evidence strongly suggests that a significant leprosy problem will continue to exist for many years to come and that services to detect and to manage cases of leprosy must therefore be sustained.

The ILA General Meeting of Members calls on all stakeholders (including national governments, international organizations and non-governmental organizations) to review their recommendations and guidelines for leprosy-related activities in the light of the Report.”

The ILEP Medico-Social Commission fully endorses this resolution. Through this Technical Bulletin, the Commission wishes to ensure that all those involved in leprosy control and leprosy elimination programmes around the world, in particular those responsible for planning and managing such programmes, are aware of the current ‘State-of-the-Art’ and have enough information to make appropriate decisions about their own programmes. In this context, the Commission wants to make it clear that ILEP supported projects should adhere to the national guidelines of the country in which they are working.

2. EPIDEMIOLOGY AND ORGANISATION OF LEPROSY SERVICES

MDT rapidly reduces the infectivity of patients, but it has not yet demonstrated that it is able to prevent new cases occurring in the community. The Forum Report concludes: “There is no consistent evidence that the introduction of MDT has accelerated the decline of the incidence of leprosy” adding that “there is no evidence that, once a predefined level of prevalence rate is reached, leprosy will necessarily die out”. In fact, the prevalence of registered cases is largely determined by operational factors, such as the duration of treatment and the updating of registers, so that the declining trend in recent years does not reflect the true epidemiological situation. The Forum Report states that “the new case detection rate may be a better indication; this rate should be analysed in conjunction with other indicators.”

Implications: The evidence strongly suggests that leprosy will not disappear by the year 2005. It is expected that numbers of new cases will continue to occur at or near to current levels for the foreseeable future and that new disabilities will continue to appear in a significant proportion of them. Continuing service provision will be required in endemic areas, as well as in areas that have recently reached the ‘elimination goal’. Such services will be best provided and sustained as an integral part of general health services. It is clear that the number of newly detected cases may well decline if case-finding efforts diminish or a significant proportion of cases go unrecognised, so it is important that political commitment, case-finding efforts and diagnostic skills are appropriately maintained.

For monitoring and planning purposes, programme managers should rely mainly on the case detection rate (CDR), as an indicator of the leprosy situation in their area. The CDR is made more meaningful by examining trends over the years and by examining the trends in the disability rate for the same period. By examining this information together, it is possible to see where operational factors, such as special case-finding activities, may have influenced certain figures.

3. DIAGNOSIS AND CLASSIFICATION

Most cases of leprosy can be diagnosed on the basis of clinical signs alone, yet clinical examination should not be restricted to searching for patches with sensory loss. Skin smears are still a useful way of diagnosing true MB cases, and particularly for confirming early lepromatous leprosy. The Forum Report notes: “Approximately 70% of leprosy patients can be diagnosed by the single sign of skin patches with sensory loss, and this sign of leprosy should be taught as widely as possible. However, 30% of patients, including many multibacillary (MB) patients, do not present with this sign. Enlargement of one or more nerves is an important additional sign, to be supplemented by skin-smears, if these are available and of assured quality.”

Implications: Basic diagnostic skills need to be taught widely, but field staff also need to be able to identify and to refer people with suspicious skin lesions that do not have sensory loss. Staff at the referral level must be able to do a more thorough examination (including examination of peripheral nerves), which will enable them to diagnose more than 95% of cases. There are important implications for training and supervision. Skin smear examination is a valuable tool, if the service can be provided in a reliable, accessible and cost effective way. This is feasible especially in areas where the tuberculosis control programme has well-established microscopy services.

4. CHEMOTHERAPY

The practice of giving patients more than one month’s supply of MDT has been used for many years in situations where regular access to clinics was difficult or impossible. In an increasing number of countries ‘Accompanied MDT’ (A-MDT) as it is called, is now becoming the standard policy for MDT delivery. There is, however, resistance to the idea that what may be used under special circumstances, should become the norm for all patients, as if there is no benefit to be gained from regular contact with the health worker.

The Forum Report comments: “The system for delivery of MDT should be patient-friendly. Flexibility is important, but regular contact between the patient and the health worker should be maintained. Only in exceptional cases, in which the patients cannot be seen monthly, should more than a one-month supply of MDT blister packs be provided.” 

Activities aimed at preventing impairment and disability in leprosy patients are important and depend on a good relationship between health worker and patient. Apart from ensuring that patients receive treatment with the right drugs, in the right dosage and at the right interval, such a regular contact increases the likelihood of early detection and treatment of complications (most commonly reactions), which is crucial for the prevention of impairments.

The recommendation made by the WHO Technical Advisory Group of a six-month multibacillary MDT regimen for all leprosy patients, both PB and MB, also raises concern. Since 1998 almost all MB patients have been treated with a twelve-month MDT regimen, but we still do not know the long-term relapse rate after this regimen and there is no obvious justification of further shortening the duration of MDT for MB leprosy to six months. The duration of treatment for MB patients should not be reduced until controlled studies show that such a reduction will not lead to unacceptably high relapse rates. The appropriateness of adding clofazimine to the regimen for PB patients may also be questioned.

The Forum Report concludes: “Although a shorter, common regimen for both PB and MB leprosy is desirable, such a regimen must first be studied in controlled trials, with relapse as the outcome, before it can be implemented.” It was also recommended that nerve function should be included as an outcome measure in trials of leprosy chemotherapy.

Implications: It is important that all health care activities are patient-friendly, but the concept of A-MDT put forward by WHO is applicable only in exceptional and well-defined circumstances; as a routine policy in all leprosy control programmes it is likely to seriously compromise the effectiveness of MDT. Similarly, the six month ‘uniform MDT regimen’ (U-MDT) must be properly researched, with the identification of the relapse rate as the end point, before it can be more widely applied.

5. PREVENTION OF DISABILITY AND REHABILITATION

The Forum noted with concern that nerve function impairment (NFI) has already developed in a significant percentage of leprosy patients at the time of diagnosis. In order to prevent disability, therefore, early detection of cases is a high priority. However, early detection and treatment with MDT will not prevent all nerve function impairment. Therefore patients should be regularly examined, so that reactions and new nerve function impairment can be detected and treated appropriately. MB patients have the highest risk of developing these complications.

No one would wish to recommend the uncontrolled use of prednisolone in the field, but patients presenting with neuritis should be allowed to benefit from it. The Forum Report says: “Steroids are recommended for the treatment of reactions and NFI of recent onset; the expected recovery rate for nerve function is approximately 60%.”

Implications: Reactions are an important reversible cause of disability in people affected by leprosy. The correct treatment of leprosy cases, wherever they occur in the world, includes the recognition and appropriate management of leprosy reactions. Programmes should therefore put in place mechanisms for regularly monitoring nerve function and treating new nerve function  impairment with steroids.

References

1. International Journal of Leprosy, Volume 70 (1) 2002: S1 – S62.
2. Leprosy Review, Volume 73 (2), 2002: S61– 62.
3. Indian Journal of Leprosy Volume 74 Supplement 2002: 1 – 93).
4. Le Bulletin de l’ALLF (l’Association des Léprologues de Langue Française) Volume  11 Supplement, 2002: 1 – 48. Article written in French.

The ILEP Medico-Social Commission.

ILEP is a Federation of autonomous anti-leprosy Associations. The advice contained in this publication is not binding on ILEP Members.

The text of this Technical Bulletin can be freely quoted subject to acknowledgement of its source.