Leprosy Mailing List – December 4th, 2011
Ref.: Why Brazil is doing this?
From: S. Noto, Genoa, Italy
From: S. Noto, Genoa, Italy
In 1991 the World Health Assembly (WHA) approved the resolution “Elimination of leprosy as public health problem by the year 2000”. Elimination was defined as a prevalence rate of less than one case per 10,000 population. That was a sad experience of how Ministries of Health can be misled and, strategies without sound scientific basis can be approved.
For years leprosy workers were asking how that happened? In 2004 Dr Sansarricq, ex head of the leprosy division at WHO gave the explanation. In his publication (Multidrug therapy against leprosy: development and implementation over the past 25 years / [editor]: H Sansarricq) he explained that the authors of the “elimination” strategy (no names are given) “felt” that the strategy had no scientific basis and instead of correcting it, they decided to bypass the requested procedures.
Herewith are reported Sansarricq’ s words: << “ … Noteworthy, too, is that the elimination initiative was recommended by the WHO Executive Board and the World Health Assembly without a WHO Expert Committee meeting, Study Group, or other preparatory step. It may have been felt that a technical meeting was likely to express some reservations about the elimination concept …”> >
The major points of the “Elimination” resolution are wrong. The Table 1. shows the components, namely: the goal, “elimination”; the indicator, “ register prevalence rate” and; the benchmark, “one in 10,000” and, alternatives are suggested.
The word “elimination” is inappropriate. It signifies elimination of the disease (i.e. the disappearance of that disease from a region). Even when the so-called elimination goal is reached we are still left with enormous numbers of patients. For example in countries like India and Brazil the numbers would still be about 120,000 and 20,000 cases per year respectively. How such numbers of cases of a serious and complex disease like leprosy can be called “elimination”?
Prevalence in an area consists of the known prevalence, those patients on register, and the patients not yet diagnosed. The real prevalence is often more than twice the known prevalence. For the elimination strategy only the known prevalence, defined as the number of patients on multi-drug therapy treatment, was taken into account. Apparently the patients not yet diagnosed and living in the community were not considered to take part in the transmission of the infection.
There is a mathematic formula that correlates prevalence and incidence. Prevalence is equal to incidence times duration of the disease. If treatment shortens the duration of disease, the prevalence goes down but, this does not necessarily influences incidence and the persistence of the transmission in the community.
The Figure 1. shows the global trend of the registered point prevalence (in red) and new case detection (in blue) of leprosy from 1985 to 2010. The source of the data is the Weekly Epidemiologically Record (WER). The red line is misleading. In the studied period the duration of the treatment of leprosy has changed and consequently the prevalence too but, is the blue line that is nearer to core of the problem.
An indicator related to incidence, like new case detection is more appropriate to monitor the trend of leprosy and gives better information about the risk of contracting the infection in a given community.
The benchmark used, “one in 10,000 population” has no meaning. The biology and the epidemiology of the disease have no relation with it. The endemic foci of leprosy will continue to produce new cases above and below this benchmark. Nobody knows who “invented” it.
Many colleagues have reported these and, other problems of the so called “elimination” strategy. Dr Sansarricq from WHO has honestly explained what happened. The new WHO strategies (2006-2010) have adopted the necessary changes.
Some days ago, on November 23rd, 2011 at the national congress of the Brazilian Society of Hansenology and regional congress of the International Leprosy Association, in Maceio’, Brazil, the Brazilian Ministry of Health announced, via video-message, that his country will adopt the so called “Elimination” strategy. As discussed above such a policy would not have any scientific significance.