(LML) The so called "elimination" strategy; opinion and questions.

 

Leprosy Mailing List – July 17^th, 2012

 

Ref.:   The so called "elimination" strategy; opinion and questions.

From: Annick Mondjo, Libreville, Gabon

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Dear Dr Noto,

I hope that you will allow me this third message and, I do not overcharge the patience of our colleagues of the leprosy mailing list (LML).

As a regular reader of the LML, I know that there are different points of view about the so called "elimination" strategy.  As an epidemiologist, I have my own opinion and, many questions. Why in Gabon did we drop the "elimination" strategy? 

a)         Is it correct monitoring the "elimination" of a curable infectious disease using the prevalence rate rather than the detection rate?

b)         Is it correct to speak of "elimination" if the new cases (NC) are decreasing while/or because financial inputs and control activities are neglected? 

At the end of the 1980's, in order to confirm the control of the disease and before generalization of the multi-drug therapy (MDT), a multi-centric survey was performed among adults with the help of the "Organisation de la Coordination de la lutte contre les Endémies en Afrique Centrale" (OCEAC) in six partner countries (Ref. 1-5).

In Gabon, the survey took place in April 1988.  According to this survey, the real calculated prevalence was 94,75 +/- 26,91 per 10.000 adults (Ref. 6,7).  The main conclusion was that only half people affected by leprosy was registered by the vertical programme (Ref. 8) and, a number of 3.000 untreated patients was estimated.  According to a retrospective work I performed in 2000, it could have ranged from 1.199 to 3.239 while the cumulative number of new cases notified between 1988 and 2000 was only 1.166. 

Meanwhile, the global project of elimination had replaced the initial national objective of revival detection (1992) but, logistic and human resources decreased further (1993-1995).  So, up to what point can the difference between those figures give an idea of the nowadays remaining problem of undetected cases?

c)         Is elimination a reality as less than 50% of the 2.256 new cases notified between 1983 and 2000 have been cured, (i.e. have achieved a treatment by MDT according to the actual regimen duration)?

d)         Is elimination in Gabon not the main result of the 1997 application of the new (shorter) duration of multibacillary MDT (MB-MDT) treatment and of the former 1991/1992 and 1995/1997 regional registers "updating" too, with no possibility to control the defaulters?

Difficult questions; well, << "Seuls ceux qui posent des questions s'instruisent" >> [in order to learn we should ask questions].

To remain politically correct. "Leprosy was "eliminated" in Gabon by the year 1999" but, this "elimination" remains "fragile".  Having said that, I would ask just one more theoretical question:

"Let's suppose, that in your country, you detect all the NC in the first two weeks of January and cure them by using MDT (even a MB-MDT), by the 31st of December of the same year; what would be the prevalence in your country, if you have detected  1? or 10? or 1.000  new cases?  Would there be any difference in the prevalence?  If you answer "zero" (0), zero, zero and none, I would agree with you, the answer is: no difference.

Therefore, nowadays, prevalence is no longer a good indicator to compare the different countries nor different years in a particular country.  Even more, with such an indicator, how to convince the leaders and the general health workers to sustain your fight against leprosy?

On the other hand, even for WHO/Afro, prevalence rate seemed not to be recommended in areas where the population is less than 10.000 inhabitants, isn't it?. That is generally the case in most of districts of Gabon.

Prevalence cannot help us any more to convince the leaders and the general health workers to sustain a fight against leprosy in Gabon.  Nevertheless, if our national programme carries on with using the prevalence, it is rather:- 

a) as an absolute number, to appreciate our needs in MDT supply;

b) or at the national level to calculate the prevalence/detection rate, as a useful and simple indicator to monitor the quality of services/activities (able to cure, not too many readmitted for treatment, etc.). 

Best regards,

Annick Mondjo

Dr Annick MONDJO, MD
Programme de Lutte contre les Maladies Infectieuses
Ministère de la Santé
BP 50 Libreville, Gabon
E-mail: <<  mondjoannick@yahoo.fr  >>

 

References:-

[1] Sundaresan TK, Sansarricq H, Noordeen SK. Les sondages dans la lutte contre la lèpre – manuel préparatoire. (Document OMS non publié WHO/CDS/LEP 86.1) : 30. [French]

2 Merlin M, Drevet D, Josseran  R, Josse R, Kouka Bemba D. Enquête par sondage sur la prévalence de la lèpre : note de présentation. Bull OCEAC 1985 ; 69 (mai-juin ) : 117-2. [French]

3 Merlin M, Drevet D,  Josse R, Josseran  R, Cottenot F. Les enquêtes par sondage : une méthode objective d'évaluation de la prévalence de la lèpre en zone d'endémie. Acta leprol 1989 ; 5 , 3 (juil-sept) : 163-14. [French]

4 Louis JP, Trebucq A, Merlin M, Josse R, Cottenot F. Etat d'avancement de la fiche programme n°17/84 OCEAC – résultats préliminaires de l'évaluation de la prévalence de l'endémie lépreuse dans les trois états-membres de l'OCEAC. Bull liais doc OCEAC 1989 ; 89-90 (juil-déc) : 49-6.  [French]

5 Louis JP, Trebucq A, Hengy  C et al. Epidémiologie de l'endémie lépreuse en République populaire du Congo – facteurs et marqueurs de risque. Méd trop 1991 ; 1 (janv-mars) : 65-6.  [French]

6 Louis JP, Merlin M, Josse R et al. Prévalence de l'endémie lépreuse en Afrique centrale – méthodologie d'enquête et résultats (1985-1989). Cahiers santé 1991 ; 1 : 9-6.  [French]

7 Louis JP, Merlin M, Josse R et al. Evaluation de l'endémie lépreuse dans cinq états-membres de l'OCEAC – données, méthodologie, analyse comportementale in Spécial 16ème Conf Tech OCEAC 12-16 nov 90 [communications présentées]. Bull liais doc OCEAC 1991 ; 97 (oct) : 5-5. [French]

8 Josse R, Trebucq A, Drevet D et al. Rapport préliminaire de l'enquête d'évaluation par sondage de la prévalence de l'endémie en République du Gabon. Doc technique 663/OCEAC/SG/SES. : 4.  [French]

 

 

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Dr Salvatore Noto
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