Leprosy epidemiology and demographics
|
Leprosy Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Leprosy epidemiology and demographics On the Web |
|
American Roentgen Ray Society Images of Leprosy epidemiology and demographics |
|
Risk calculators and risk factors for Leprosy epidemiology and demographics |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: João André Alves Silva, M.D. [2]
Overview
Current prevalence rate of leprosy per 100,000 is 3.7. The disease is more prevalent in endemic areas, which represent a potential source of spread of the disease to the rest of the world.
Epidemiology and Demographics
In 1990, the WHO defined a goal of eliminating leprosy as a public health issue within 10 years. Between the years of 1985 and 2010, the number of registered cases of leprosy fell from 5.4 million to 244,796, with prevalence rate per 100,000 falling from 211 to 3.7. However this prevalence is very variable according to the region, since most reported cases come from developing countries, such as India, Brazil and Indonesia. Efforts have been made to decrease the number of cases in endemic areas and to avoid transmission of the disease to other parts of the world, since international travel represents an important vehicle of the bacteria into other parts of the globe. This transmission has such impact that among the cases reported annually in the United States, 75% occur in emigrants.
Incidence
Due to the long incubation period, delay in diagnosis, and lack of laboratory infrastructures it is difficult to measure the true incidence of leprosy.
Two to three million people are estimated to be permanently disabled due to leprosy. India has the greatest number of cases, followed by Brazil and Myanmar.
In 1999, the world incidence of leprosy was estimated to be 640,000; in 2000, 738,284 cases were identified. In 1999, 108 cases occurred in the United States. In 2000, the World Health Organization (WHO) listed 91 countries in which leprosy was endemic.
According to the WHO, the number of new cases has decreased by approximately 107,000 cases (or 21%) from 2003 to 2004. This decreasing trend has been consistent for the past three years.
Prevalence
Registered prevalence reflects the number of active leprosy cases diagnosed with the disease and retrieving treatment with multi-drug therapy (MDT) at a given point in time. In fact, the global registered prevalence of leprosy at the beginning of 2012 was 181,941; 219,075 new cases were detected during 2011.
As reported to the WHO by 105 countries and territories in 2012 the global registered prevalence of leprosy at the beginning of 2012 was 181,941 cases. [1] New case detection during the previous year (2011) was 219,075. The number of new cases detected annually continues to increase in all regions other than the Americas and African Regions. The significant decline in the African Region reflects the low number of reports submitted, particularly from member states reporting high number of new cases in the past. Increased coverage along with provision of better services in South Sudan and Somalia were the main factors that led to detection of more new cases in the Eastern Mediterranean Region.[1]
The prevalence of Leprosy in the United States is believed to be rising and underreported. There are a rising number of cases worldwide, though pockets of high prevalence continue in certain areas such as Brazil, South Asia (India, Nepal), some parts of Africa (Tanzania, Madagascar, Mozambique) and the western Pacific.
The above image shows an increase in the number of new cases detected from 2010 to 2011, with exception of the Americas and African regions
The above image shows prevalence of leprosy at the beginning of 2012. In 2011, the number of new cases, from 105 countries was 219,075. At the beginning of 2012, the registered prevalence was 181,941
Due to the rising numbers, several support groups exist, the headquarters of which is currently in Lynbrook, NY and headed by Brian Marasco, leprosy survivor.
Endemic countries also report the number of new cases with established disabilities at the time of detection, as an indicator of the backlog prevalence. However, determination of the time of onset of the disease is generally unreliable, is very labour-intensive and is seldom done in recording these statistics.
Elimination of Leprosy as a Public Health Problem
In 1991 WHO's governing body, the World Health Assembly (WHA) passed a resolution to eliminate leprosy by the year 2000. Elimination of leprosy is defined as a prevalence rate of less than 1 case per 10 000 persons. The target was achieved on time and the widespread use of multi drug therapy reduced the disease burden dramatically.
- Over the past 20 years, more than 14 million leprosy patients have been cured, about 4 million since 2000.
- The prevalence rate of the disease has dropped by 90% – from 21.1 per 10 000 inhabitants to less than 1 per 10 000 inhabitants in 2000.
- Dramatic decrease in the global disease burden: from 5.2 million in 1985 to 805 000 in 1995 to 753 000 at the end of 1999 to 181 941 cases at the end of 2011.
- Leprosy has been eliminated from 119 countries out of 122 countries where the disease was considered as a public health problem in 1985.
- So far, there has been no resistance to antileprosy treatment when used as multi drug therapy.
- Efforts currently focus on eliminating leprosy at a national level in the remaining endemic countries and at a sub-national level from the others.
References
- ↑ 1.0 1.1 "global leprosy situation, 2012" (PDF).