Factors Influencing Leprosy Incidence: A Comprehensive Analysis of Observations in Wenshan of China, Nepal, and Other Global Epidemic Areas

Abstract

Leprosy remains endemic in some regions and is a global health concern. However, the possible causes and risk factors of the disease remain unclear. Data in Wenshan, China were collected from the Wenshan Institute of Dermatology (1986–2015); data in Nepal were obtained from the Leprosy Control Division, Department of Health Services, Nepal (2011 to 2015); and data from Indonesia, India, and Brazil were collected from WHO records. We assessed the epidemiological trends of leprosy in Wenshan and compared the features of possible causes and risk factors with those of other countries. We then performed a descriptive and statistical analysis to make our study more purposeful and definitive. A total of 3,376 cases were detected in Wenshan from 1986 to 2015. The overall prevalence rate (PR) of leprosy presented a decreasing trend with a peak (4.9/10,000 population) in 1986. The detection of new leprosy cases was higher in males than in females. Visible deformity increased every year since 2005 with a disability of 34.8% in 2015 among new cases. In Nepal, 2,461 leprosy patients received multi-drug therapy (MDT) in 2015 which corresponded to the PR of 0.89/10,000 population. Geographic latitude and socio-economic situations appeared to be the main causes of leprosy, and the healthcare condition was an important factor associated with leprosy incidence. The introduction of MDT effectively reduced leprosy prevalence worldwide. Wenshan (China), Nepal, and other countries share similarities in various aspects with respect to socio-cultural features, geographical distribution, environmental factors, and economic situation, which may contribute to leprosy being endemic in these areas.

Comportamiento epidemiológico de la lepra en varios países de América Latina, 2011-2020

“…Aunado a esto, se debe tomar en cuenta la gran extensión territorial brasileña y las desigualdades socioeconómicas entre sus regiones, de hecho, las regiones más pobres del país son las más endémicas ( 19 ). Un mayor número de contactos domésticos entre los miembros de la familia es otra de las razones de una mayor transmisión y una mayor prevalencia de lepra en Brasil ( 20 ). No obstante, existen muchas lagunas en la notificación de nuevos casos para los países de todas las regiones.…”

Advances in the Diagnosis of Leprosy

“…Endemic areas of leprosy are often lacking specialized labs that highlight the need for low-complexity diagnostics (97)(98)(99). A test was developed and field-assessed known as the lateral flow test (100).…”

Leprosy Epidemiology According to Leprosy Type in 13 Teaching Hospitals in Indonesia between 2018 and 2020

“…Leprosy has been classified by the World Health Organization (WHO) as paucibacillary type (PB) and multibacillary type (MB) depending on the number of lesions. Ridley-Jopling's classification divides leprosy into five groups: Tuberculoid leprosy (TT), borderline tuberculoid (BT), mid-borderline (BB), borderline lepromatous (BL), and lepromatous lepromatosy (LL) [1], [2], [3] Transmission of leprosy can occur through inhalation of droplets containing pathogenic M. leprae bacteria and through prolonged skin contact with the patient. Infection from M. leprae causes anesthetic skin lesions, enlargement of peripheral nerves accompanied by impaired nerve function and the discovery of acidresistant bacilli on skin smear are the characteristic clinical findings in leprosy.…”

“…Delayed diagnosis can cause nerve damage, leading to loss of motoric function or paralysis, even permanent defects. Hence, early diagnosis is very important, especially in individuals below the age of 15 years old [2], [3], [4], [5], [6] Leprosy is a disease that persistently causes health problems in several countries including Indonesia. A significant reduction in new cases of leprosy after the regiment of multidrug therapy (MDT) was used as a treatment in the 1980s.…”