Leprosy - Unfinished Story

Most people think that leprosy is a thing of the past. Well, not quite. It is still around and still affects lots of people — with as many as 200,000 new cases registered every single year, including up to 100 in the United States. Most cases of leprosy these days happen in the developing world, but even in Europe the disease still occurs. The last remaining leprosorium on the European continent is located in Romania.

It is also known as Hansen’s disease, named after the physician Gerhard A. Hansen who discovered the causative bacterium in 1873. Leprosy is a very ancient disease. It is mentioned in the Bible and Vedas, and was surrounded by various myths. Many believed this disfiguring disease to be a curse from God. It was said to be a punishment people were saddled with for immoral behavior, and it was said to be incurable and so contagious that infected people should be isolated from normal social life. But with the progress of science, all these legends have been disproved.

Biological nature of the disease

The pathogen behind the leprosy infection is the bacterium Mycobacterium leprae. This is an aerobic (oxygen requiring) pathogen that has a slow growth rate with a long incubation time. The bacterium that spreads Hansen's disease gets transmitted through nasal droplets.

Upon infection, the bacteria primarily attack the patient's skin and later the peripheral nervous system, along with the mucosa of the upper respiratory tract.

Manifestations of leprosy

Leprosy takes 3 to 5 years and sometimes even up to 20 years to manifest symptoms post infection. It is a granulomatous disease, a disease in which affected tissues are characterized by inflamed granulation. Therefore, when symptoms start showing, Hansen's disease affects the skin — forming lesions, nodules, lumps and sores commonly known as plaques.

Nerve damage caused by leprosy leads to a loss of sensation and muscle weakness. In many cases, loss of fingers, toes and nose tips are associated with leprosy. This is not the direct result of leprosy, however. Rather, this is caused by secondary infections that occur due to the compromised immune system leprosy also leads to.

Other complications related to this disease include blindness or glaucoma, nosebleeds and a chronic, stuffy nose, face disfiguration that includes lumps, permanent swellings and bumps, erectile dysfunction and infertility in men, and kidney failure.

Leprosy comes with many symptoms and in many forms

According to the World’s Health Organization, leprosy can be subdivided into two major categories, paucibacillary and multibacillary. This classification is based on the proliferation rate of the bacteria.

In its paucibacillary form, the bacteria grow in small numbers as compared to the multibacillary form. Depending on the symptoms, doctors distinguish six types of leprosy. They differ in particular manifestation and severity.

Successful treatments for leprosy are now available

Many people still erroneously believe Hansen's disease to be incurable — but medications are now available to kill the caustive bacteria. Leprosy should always be brought under control as soon as possible; before the disease causes irreversible damage to the patient. If this has not been done in time, the damage caused by infection becomes irreversible and can be very serious.

The drugs used to cure the disease are normally bacteriostatic in nature and are commonly known as leprostatic agents. There many different antibiotics which fall under this broad category. Some commonly used examples include dapsone, rifampicin, clofazimine and thalidomide.

Unfortunately, a single drug treatment often leads to failure due to acquaintance of drug resistance mechanisms by the bacteria. Therefore, Multi-Drug Therapy, or MDT, is preferred nowadays to treat leprosy. Chemotherapeutics that build the backbone of the MDT regimen are dapsone, rifampicin, clofazimine, ofloxacin and minocycline.

Followed by the initial treatment, different treatment course is assigned to different patients according to the severity and type of the disease.

Leprosy vaccines need to be improved

Vaccination against leprosy has limited success. The BCG (Bacillus-Calmette-Guerin) vaccine offers some degree of protection against Mycobacterium. It appears that 40-60% of patients develop immunity with the administration of two subsequent doses of this vaccine. New developments in vaccine design against leprosy are still in progress, with some promising new research offering hope for the future eradication of this disease.

Leprosy tends to affect people in poorer countries

According to the WHO,the number of new leprosy cases worldwide exceeded 200,000 in 2019. Geographically, the majority of patients were located in Africa, South America (mainly Brazil) and Asia (India). In the USA, about 200 leprosy cases are diagnosed every year.

Leprosy can infect people of all ages. Males seem to be easier targets for the pathogen: around 66-75% of infected people are men.

Why leprosy is still not eliminated?

Leprosy still persists around the world at a relatively high rate. One of the reasons behind this is the non-compliance with treatment. The low rate of continuous adhesion to treatment regimens gives rise to potential recurring infection sources, irreversible complications, and resistance to multiple drugs as well as incomplete cure.

Factors that are responsible for these treatment dropout cases are mostly of a socioeconomic nature: improper education and knowledge about the disease, alcoholism, side effects of drugs and lack of interest in being under prolonged treatment. Moreover, stigmatizing and the consequent fear among people about losing their social and economic security also prevent them from approaching medical professionals for proper treatment.

It is said that prevention is always better than cure. Thus, proper knowledge about the disease, especially among people in the areas where it is more common, can help in eliminating Hansen's disease from the population. Patients should be properly informed about each and every aspect of the disease so that they are aware of the risks associated with incomplete treatment. Governments should also take adequate measures to combat the infection. Leprosy can and must be eliminated.