Leprosy, or leprosy, is a chronic infectious disease caused by the mycobacterium Mycobacterium leprae, which primarily affects the skin, peripheral nerves, upper respiratory tract and eyes. The pathogenesis of the disease is characterized by granulomatous inflammation with the formation of specific nodular infiltrates in the affected tissues. Neurological complications, leading to irreversible damage to the nervous system and subsequent disability of patients, are especially dangerous. The incubation period can range from several months to 30 years, which significantly complicates early diagnosis.
History of the disease and interesting historical facts
The history of leprosy goes back more than 4,000 years, which is confirmed by archaeological finds in ancient burial sites. The first written mentions of the disease are found in ancient Indian texts of the Vedic culture (around 1400 BC). It is interesting to note that the Egyptian Ebers Papyrus (1550 BC) contains a description of symptoms characteristic of leprosy. In the Middle Ages, leprosy became widespread in Europe, which led to the creation of special leprosariums. A significant contribution to the study of the disease was made by the Norwegian doctor Armauer Hansen, who discovered the causative agent of the disease in 1873.
Epidemiology
According to WHO data for 2022, the global prevalence of leprosy is about 0.2 cases per 10,000 population. The highest incidence rates are recorded in India, Brazil and Indonesia, where more than 80% new cases are concentrated. Statistics show the following distribution:
- India – 56% new cases
- Brazil – 16% new cases
- Indonesia – 8% new cases
It is important to note the significant reduction in incidence over the past 30 years due to elimination programs and timely therapy.
Genetic predisposition to this disease
Research shows a significant role of genetic factors in the development of leprosy. Key genes that influence susceptibility to the disease are:
- Major histocompatibility complex (HLA) genes: HLA-DR2, HLA-DR3
- PARK2 gene associated with parkinsonism
- LTA gene encoding tumor necrosis factor
Mutations in these genes can increase the risk of developing the disease up to five times compared to the general population. “Genetic studies confirm that about 20% of the variability in susceptibility to leprosy is explained by genetic factors,” notes a study in Nature Genetics, 2019.
Risk factors for the development of this disease
The main risk factors for developing leprosy include:
- Constant contact with infected persons
- Unfavorable socio-economic conditions
- Immunodeficiency states of various etiologies
- Chronic stress and fatigue
- Long-term exposure to extreme temperatures
According to a study in The Lancet Infectious Diseases, people with immunodeficiency have a 2.5 times higher risk of developing leprosy compared to the general population.
Diagnosis of this disease
Diagnosis of leprosy is based on a comprehensive approach:
- Clinical signs: hypopigmented spots, loss of sensitivity
- Laboratory methods: Ziehl-Neelsen staining, PCR diagnostics
- Histological examination of skin biopsies
- Radiographic examination of the hands and feet
Differential diagnosis is carried out with vitiligo, mycoses, systemic diseases of connective tissue.
Treatment
Treatment for leprosy includes:
- Multidrug therapy (MDT) lasting 6-12 months
- Surgical treatment of complications (neurolysis, arthrolysis)
- Physiotherapy procedures
- Orthopedic correction of deformities
Early initiation of treatment helps prevent the development of disabling complications in 99.5% cases.
List of drugs used to treat this disease
The main drugs for the treatment of leprosy:
- Dapsone
- Rifampicin
- Clofazimine
- Ofloxacin
- minocycline
According to WHO protocols, the combination of these drugs ensures maximum effectiveness of therapy.
Disease monitoring
Monitoring the effectiveness of treatment includes regular examinations every 3 months during the first year and every 6 months for the next 2 years. The prognosis with timely treatment is favorable, but the following complications are possible:
- Deformations of the hands and feet
- Blindness
- Polyneuritis
- Muscle atrophy
Age-related features of the disease
Age-related features of the course of leprosy:
- Children (under 14 years): faster progression, higher risk of developing reactions
- Adults (15-59 years): the predominant age group of patients
- Elderly (60+ years): more often severe forms with multiple lesions develop
According to a study in the Journal of Infection, children account for about 10% of all new cases of leprosy.
Questions and Answers
- How is leprosy transmitted? The main route of transmission is airborne, through prolonged close contact with a sick person.
- Is it possible to cure leprosy completely? Yes, with timely initiation of MDT, a complete cure is possible, however, the consequences of damage to the nervous system may remain.
- What preventive measures are most effective? Regular medical examinations in endemic areas and BCG vaccination are the main preventive measures.
Advice from Dr. Oleg Korzhikov
Patients often ask questions about prevention and the specifics of the disease. Answering the popular question about the contagiousness of leprosy, I would like to note that less than 5% of those who have been in contact with a patient actually get sick. How to protect yourself? Regular use of personal protective equipment and personal hygiene rules significantly reduce the risk of infection. How often should I get checked? If you have constant contact with patients, I recommend an annual examination.
