Treatment with MDT is not the end of the story for many cured of leprosy.
|Practicing self-care in India|
I often have the privilege of talking about leprosy to audiences in the U.K., based on my 25 years’ experience working for The Leprosy Mission in India, Nepal and Bangladesh. One of the points I stress is that leprosy is a cruel disease: your troubles are not necessarily over once you have completed your course of treatment with multidrug therapy (MDT). In fact, they may even seem worse because you are disappointed not to be “back to normal.”
A bacterial infection that mainly affects the skin and peripheral nerves, leprosy can result in permanent disability if left untreated. Some people, before they are diagnosed, already have developed irreversible nerve damage, causing muscle weakness or numbness. Perhaps the doctor they first saw did not recognize the disease; or perhaps these individuals genuinely did not notice any problems until impairment set in.
Nowadays, however, many people come early for treatment when they just have changes in their skin. They hope to be cured with no residual problems. Unfortunately, however, this is not always possible.
It seems very unfair — and to some, inexplicable — but the disability associated with leprosy can develop during treatment and escalate after the patient has finished conscientiously taking MDT.
The main cause of this disability is nerve damage caused by leprosy reactions, when the body responds to the infection itself or to the presence of dead bacteria by becoming inflamed.
Take a patient with a single numb patch on his leg who has been diagnosed with paucibacillary (PB) leprosy. Over a six-month course of MDT, any leprosy bacteria he had in his body will certainly die, but debris left from the bacterial cell walls may precipitate an immune response that damages nerves in the leg.
As a result, before completing his MDT, he develops a condition known as foot-drop and his sole becomes numb. He may then develop an ulcer on his toe where it keeps hitting the ground when he walks. Over time, his foot becomes more scarred and walking more difficult.
If the new muscle weakness and sensory loss are recognized early, treatment with suitable drugs and physiotherapy may reverse the impairment. If the patient is trained and supported in care of the limb, he may be able to prevent ulceration. If muscle weakness does not recover with medication, reconstructive surgery can often restore good function.
Or take a patient whose skin is shiny and thickened or lumpy because it is packed with leprosy bacteria. He may feel well and have no disability at time of diagnosis. Following a 12-month course of MDT for multibacillary (MB) leprosy, he is declared cured of leprosy and released from treatment.
Subsequently, however, he suffers a fierce immune response to the residual bacterial debris. This may last several years and require months in hospital, where strong drugs are administered to suppress his “lepra reaction.” Without proper treatment, this immune response may result in blindness, nerve damage and even infertility, all of which are permanent. With expert medical care, however, the outlook is better.
Polio is a disease accompanied by pain and fever while the virus circulates in the body. It may cause paralysis, which is devastating and life-long. Decades after the last polio virus in your body has died and you are no longer infectious, you remain lame. Somehow, people understand this more easily than they understand that a person affected by leprosy may be disabled long after his infection is cured.
Pulmonary tuberculosis may scar the lungs, leaving a “shadow” visible on a chest X-ray and perhaps some shortness of breath. But because of all the anti-TB medicine a patient swallows to kill the bacteria, he is no longer infectious and need not worry about passing on the disease to family and friends. Generally, the public accept this.
Sadly, it can be more difficult to convince them that leprosy is cured after a course of MDT, especially if they see that a person has more disability than he had at the time of starting treatment.
|Example of a self-care kit|
Does MDT work? Yes. We need to exercise faith and believe the evidence produced by scientists and epidemiologists. MDT does kill leprosy bacteria. It does interrupt transmission of the disease. What it cannot do is stop the body’s immune system from overreacting to left-over bits of dead bacteria. For that, different medicine is needed.
MDT cannot protect unfeeling limbs from injury. For that, teaching self-care techniques (and constant vigilance) are needed. MDT will not restore power to paralyzed muscles, but reconstructive surgery can restore function in appropriate cases.
As well as supplying MDT, every leprosy program must offer these other services. Only then will people obtain the full benefit of their MDT, and the cruel progress of the disease will be fully halted.
Dr. Butlin is medical advisor to the The Leprosy Mission Bangladesh. She can be contacted at firstname.lastname@example.org