Leprosy Mailing List – January 9, 2017
Ref.: (LML) Rebuilding leprosy services
From: Joel Almeida, London and Bombay
Dear Pieter,
There are many matters in leprosy on which we still need to shed light. But some things are known. We needn't shed darkness on them. For example:
1) Currently untreated lepromatous leprosy patients are responsible for 99.999% or more of the bacteria which spread leprosy. These include not only previously untreated lepromatous patients but also those re-infected after release from MDT.
They all deserve protection against the leprosy bacteria. It is not their fault that we leave them exposed.
2) Silent neuritis is responsible for as much as 85% of the permanent nerve damage in South Asian populations.
3) Leprosy bacteria are highly susceptible to sunlight. In the shade, however, they remain viable and infective for several months or more.
Deforestation and loss of shade may be partly or wholly responsible for the fall in incidence rate attributed to one or other intervention. By contrast, urbanization boosts artificial shade. This, along with migration of lepromatous leprosy patients prematurely released from MDT, may be contributing to the relatively high incidence rate of leprosy in some Indian cities.
This hypothesis about shade is consistent with the dramatic geographical gradients in the distribution of leprosy between arid and forested areas (in India, Egypt, Brazil, among others.)
4) Most newly occurring cases of leprosy are self-limiting and transient. The case detection rate can be doubled or halved at will: simply by reducing or increasing the interval between surveys. Therefore mathematical models or predictions which rely on trends in the crude case detection rate are unreliable.
In these circumstances we can unintentionally deceive ourselves into complacency with unreliable mathematical models. This leads to destruction of leprosy services.
5) The WHO NTD report of 2013 clearly defined elimination as the reduction to zero of the incidence rate of infection in a geographical area as the result of deliberate efforts. That is clear, rational and objective.
Leprosy is an infectious disease, and it is either eliminated or not. Just as a fire is put out or not. No fire brigade is worth anything if it starts saying that the fire has been eliminated from a house, even though it is present in a room of the house. That fire brigade would be sacked.
What does all this mean for leprosy control?
Since the year 2000 we have been neglecting 99.999% or more of the bacteria which keep spreading leprosy. And we have been neglecting 85% of the avoidable nerve damage.
Yet we expect leprosy to be controlled. And we expect people to be protected from the disfigurements of leprosy. This verges on superstition.
Even socio-economic development has not sufficed to control leprosy in India. Instead, the incidence rate of newly detected cases with visible deformity at diagnosis has doubled in the past 10 years.
Superstition and fiction worked for a short while, there was a boost of funds and political support. That support evaporated as our past errors became obvious. Human limbs and eyes are at stake. Let's return to fact and science. That's how we will succeed.
Fortunately we are turning away from the errors and fictions of the past 16 years. Let's now keep rebuilding and staffing expert leprosy services. These are needed promptly to recognize and treat lepromatous leprosy and silent neuritis.
Let's become builders once again, so that we can resume the protection of human limbs and eyes.
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
