Date Published: February 28, 2017
Author(s): Innocent Uwimana, Nestor Bizimungu, Fabrice Ingabire, Elyse Mukamukwiye, Odette Sharangabo, Semuto C. Ngabonziza, Elaine Kamanzi.
Leprosy, or Hansen’s disease, is a chronic, infectious disease caused by Mycobacterium leprae. It remains one of the leading causes of deformity and physical disability.
We analysed laboratory records to assess trends in prevalence rates and case detection rates (CDRs) in Rwanda.
A retrospective review of detected leprosy cases from the records of the Rwanda National Reference Laboratory over a 17-year period (1995–2011) was conducted. Skin biopsy samples were analysed microscopically using Ziehl-Neelsen staining technique to identify M. leprae.
Cumulatively, 266 suspected cases were reported between 1995 and 2011. Of the suspected cases, 77 (28.9%) were laboratory confirmed as having leprosy. Among detected cases, 59 (76.6%) were men and 18 (23.4%) women. The male:female ratio was 3:1. There were 77 registered leprosy cases over the 17-year period of the study, and the prevalence rate was 0.005 per 10 000 population. A gradual decrease in the prevalence rate was observed from 0.015 per 10 000 population in 2003 to 0.003 per 10 000 population in 2010. From 1995 to 2011, the CDR did not exceed one per 10 000 population.
This laboratory review demonstrates a declining trend in prevalence rates and CDR during the period of the study. Early case detection and a sustainable leprosy control programme remain the cornerstones of reducing the physical and socio-economic burden of leprosy in Rwanda.
Despite the availability of powerful, multi-drug therapies, leprosy remains one of the world’s most infectious diseases and is a leading cause of deformity and physical disability. Leprosy, or Hansen’s disease, is a chronic infection caused by Mycobacterium leprae. For affected patients, leprosy carries a significant stigma and contributes to their isolation from the rest of the world. The global burden of leprosy in 1993 was estimated at 2.4 million of leprosy cases worldwide against 10 to 12 million in 1980, and 5.4 million in 1985.1 In 2010, the registered prevalence of leprosy worldwide was 211 903 cases, with the World Health Organization (WHO) reporting 244 796 new cases detected during 2009.2 The WHO reported that the highest number of cases occurred in South East Asia (n = 166 115 new cases), followed by the African Region (n = 28 934 new cases).2
A total of 266 suspected cases were reported between 1995 and 2011 (Figure 1). Of the suspected cases, 77 (28.9%) were laboratory confirmed as being infected with M. leprae. The remaining cases (n = 189; 71.1%) were microscopically negative for acid alcohol-resistant bacilli or leprosy bacilli. Among the detected cases, 76.6% (n = 59) were men and 23.4% (n = 18) women. The male:female ratio was 3:1. The most affected age group was the group of patients over age 45 years. Multibacillary patients with a bacteriological index ranging from 1+ to 4+ were detected in 73.0% of men and 21.0% of women. Paucibacillary cases were less common, at 3.9% in men and 2.6% in women (Figure 1).
The present study shows that over a period of 17 years, the prevalence of leprosy in Rwanda has decreased and remained below the WHO’s elimination target of less than 1 case per 10 000 population. This might be due to increased awareness amongst community health workers, as well as a community sensitisation effort for case detection and treatment.