Leprosy Mailing List – December 10, 2015
Ref.: (LML) Ways forward
From: Joel Almeida, Mumbai and London
Dear Pieter,
A. Monitoring for nerve damage
1. Delayed detection
Detecting nerve damage too late is like detecting cardiac fibrillation too late. If a defibrillator is used several hours after the fibrillation, it will be useless. The patient will be dead forever. The same applies to a nerve which is neglected for months (or even weeks).
According to the literature, as many as 90% of patients regain nerve function with anti-inflammatory treatment: if, and only if, nerve damage is detected promptly. Infrequent or absent monitoring of nerves is responsible for the damage which is sometimes wrongly attributed to the limitations of anti-inflammatory treatment. If defibrillators were tested on corpses, we might conclude (wrongly) that they, too, are no better than placebo.
The solution:
Skilled leprosy workers to monitor the nerves of MB patients every month, and keep records. The more prompt the start of anti-inflammatory treatment, the greater the chance of reversing nerve function impairment.
2. Silent neuropathy
According to the literature, about 85% of nerve function impairment (NFI) in South Asian patients is silent: without signs of inflammation. Further, about 65% of patients developing NFI do so within the first year after starting MDT. Another 30% do so within the second year after starting MDT.
The solution:
Monthly monitoring of the nerves of MB patients should begin with the start of MDT and continue for at least 2 years. Leprosy workers should be taught that 85% of nerve function impairment is silent: without “reaction” or signs of inflammation.
3. Poverty and distance
The poorer leprosy patients in India cannot afford to take public transport to the nearest government health post. They suffer silent neuropathy, and consequent disfigurement, in silence. This steadily increases the burden of leprosy (the prevalence and weight of disabling sequelae).
The solution:
Skilled leprosy workers should be mobile, so that they can travel to near the homes of MB patients. They could also cover the population of more than one health centre, in India.
These skilled leprosy workers would not only examine nerve function and keep records, but also be a valuable resource for educating the public about skin conditions. They would boost attendance at skin camps (for early, non-stigmatising case-finding of leprosy).
The Indian government, ILEP in India and the people of India all deserve congratulations. This is because they are pressing for skilled leprosy workers to be appointed. ILEP can make a real difference in the lives of poor people through these workers.
B. Skin smears
A significant subset of MB patients requires prolonged MDT. Otherwise they are likely to suffer from proliferating M. leprae after MDT, and type 2 reactions, while constituting sources of infection for others.
A significant subset of the most infectious MB patients shows few or no signs of infection. Positive skin smears might be the only objective sign of disease. Without skin smears, they infect many others before they are finally detected.
The solution: Skin smears should be reintroduced for diagnosis and classification of leprosy. This helps not only the patient but also the population at risk.
The staining technique for skin smear slides needs to use methods appropriate for M. leprae. M. Tb staining methods can be misleading when applied to M. leprae!
C. Mathematical models, definitions and assumptions
Mathematical models are only as good as the assumptions and definitions they adopt.
For example, a model may ignore the increasing proportion and number of newly detected Indian cases diagnosed with visible deformity. This increasing proportion indicates delay in diagnosis, with accompanying self-healing. Models which overlook this are liable to make misleadingly optimistic projections, and even mistake the direction of the trend in incidence rate.
Further, a model may fail to use the WHO’s clear 2013 definition of elimination: zero incidence.
The solution: Mathematical models should be disregarded if they disregard the proportion with visible deformity at diagnosis, and rely entirely on the crude new case detection rate. It seems prudent too to insist on mainstream scientific definitions. These are objective and rational rather than arbitrary.
D. Promises or demonstration
In the 1980s rifampicin caused a great stir in the TB world. However, it was to be confined to affluent countries, since it might be carelessly used in poorer countries. Then Dr. Karel Styblo went to Tanzania and demonstrated that rifampicin-containing regimens could be used to cure patients in poorer countries too. He did not promise, he merely demonstrated: by setting up a system in the field. That was the precursor of the DOTS strategy now used around the world.
It may be that we can reduce the incidence rate to zero by earlier detection of infectious cases, prompt MDT, or even mass chemoprophylaxis and various other measures. However, it would be more responsible to demonstrate than to claim. We need to set up a system in the field, and demonstrate exactly how zero incidence can be achieved.
Repeated mass chemoprophylaxis was tried and found wanting in the Federated States of Micronesia. However, that should not stop us from attempting to reduce the incidence rate to zero on those same islands. A small island allows us to rapidly demonstrate or refute our claims. We need to do one or the other, quickly. Otherwise promises of zero incidence can be like pie in the sky: causing people to become careless and complacent about low-hanging fruit (such as the monitoring of nerves and prompt anti-inflammatory treatment where required).
The solution:
Our fervent hopes need to be put to the test in a whole-hearted, “no effort spared” demonstration project. We need to go “all out” to achieve zero incidence on a small island: the quicker the better. If we succeed, the key elements can be scaled up and adopted elsewhere. Otherwise we need to know where the gaps are. Instead of making untested promises, we need to remember Dr. Styblo’s approach. Demonstrate, demonstrate, demonstrate.
Regards,
Joel Almeida
LML - S Deepak, B Naafs, S Noto and P Schreuder
LML blog link: http://leprosymailinglist.blogspot.it/
Contact: Dr Pieter Schreuder << editorlml@gmail.com
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