Unsolved matters in leprosy: a descriptive review and call for further research.

Leprosy, a chronic mycobacterial infection caused by Mycobacterium leprae, is an infectious disease that has ravaged human societies throughout millennia. This ancestral pathogen causes disfiguring cutaneous lesions, peripheral nerve injury, ostearticular deformity, limb loss and dysfunction, blindness and stigma. Despite ongoing efforts in interrupting leprosy transmission, large numbers of new cases are persistently identified in many endemic areas. Moreover, at the time of diagnosis, most newly identified cases have considerable neurologic disability. Many challenges remain in our understanding of the epidemiology of leprosy including: (a) the precise mode and route of transmission; (b) the socioeconomic, environmental, and behavioral factors that promote its transmission; and

Patterns of ocular morbidity and blindness in leprosy--a three centre study in Eastern India.

BACKGROUND: Eye disease and visual impairment due to leprosy are not uncommon, but their prevalence and the risk factors for such pathology have yet to be fully characterized. METHODS: An observational study of leprosy-affected individuals in the community, in three districts in Eastern India was performed to determine the prevalence of ocular morbidity and blindness. The subjects were chosen by stratified random sampling, according to stage of treatment, or stage of post-treatment surveillance. Each subject underwent ophthalmic examination according to a standard pro-forma. RESULTS: Thirty-three out of 1137 (2.9%) subjects were blind according to the WHO classification, and 232/1137 (20.7%) had moderate visual impairment. The prevalence of blindness and visual impairment was greatest in one centre, Jhalda. Multivariate Logistic Regression analysis showed that longer duration of disease, more advanced treatment stage and older age were independently associated with blindness. One hundred and forty-one cases (28%) in Muzaffarpur, 95 cases (63%) in Saldoha and 378 cases (78%) in Jhalda had active or treated multibacillary leprosy. DISCUSSION: The prevalence of blindness in leprosy varies in different population groups, with differing patterns of leprosy-related ocular morbidity, blindness and disease type evident even in different areas of the same region. Leprosy screening and surveillance programmes should include ocular examination as part of routine screening, particularly in individuals with a history of multi-bacillary disease. Individuals with known sight- threatening pathology should undergo continued active follow up. Local epidemiological studies would enable appropriate programme planning and efficient allocation of resources.

Leprosy in a trachomatous population.

In an Egyptian leprosy hospital, 17% of 133 patients had a visual acuity of less than 3/60. Corneal opacity, phthisis bulbi, and cataract accounted for 85% of blindness. Leprosy and trachoma together produce blinding corneal opacity by exposure, leprous keratitis, and trichiasis and entropion. Inturned lids, a late result of conjunctival scarring due to childhood trachoma, were less frequent in patients with lepromatous leprosy than in patients with tuberculoid leprosy; because conjunctival scarring from trachoma depends on cell-mediated immunity, patients with lepromatous leprosy may not have had severe trachomatous scarring develop due to their lifelong abnormality in cellular immunity. In patients with leprosy, even when complicated by trachoma, simple measures to prevent or restore vision include medical treatment of leprosy, surgical correction of lid deformities, sector iridectomy for constricted pupils or central corneal opacities, and cataract extraction.