Sequencing of the HD genome and discoveries of genetic material in human skeletal material from previous centuries also give us more information about the movement of the disease as well as about human migration.
Although the worldwide prevalence of this disease has significantly decreased, HD is still a poorly understood illness, and often, the statistics do not capture the disability and dysfunction that remain after MDT is complete.
Among susceptible individuals, there is great variety in terms of the individual immune response to the bacilli in the body, such that physicians who work with the disease for many years see the value in looking at each person's disease as unique. Many NTDs cause chronic illness and disability; while interruption of transmission will help future generations, new ways to reduce the suffering of those already infected should also be promoted.
Leprosy research: future targets and priorities Future Targets In addition to ofloxacin, two more drugs - minocycline a tetracycline and clarithromycin a macrolide - have shown very promising anti-leprosy activity in experimental animals and short-term clinical trials.
Tuberculosis infection later spread to dairy animals as a result of human transmission during their domestication and involving a mechanism of transmission either through direct contact or through an unrecognized vector [ 44 ].
The highest priority, however, will remain with research studies in areas which would be directly beneficial for the patients in the community.
Whats new in leprosy
Because leprosy cannot be grown in vitro, the exact dynamics of transmission are not known, but they are gradually becoming clearer through strain typing, which has shown, for example, that leprosy in armadillos in Louisiana and Texas USA is the same strain as that found in people in the same areas. Many patients worldwide complete MDT, which consists of a combination of the medications rifampin, clofazimine, and dapsone, in a year or less. Gupta et al. Some population groups exhibit higher prevalence rates of HD than others. There is also evidence that M. In Japan, mandatory confinement continued until the mids. The impact of HIV infection on the individual patient and the epidemiology of the disease will also need close monitoring. Studies addressing the significant issue of nerve and tissue damage need further support. Additionally, M. Disability prevention has been an important area of research in leprosy and other conditions for many years, but there has been little cross-fertilization of ideas across diseases until recently. Development of PCR-based technology as a tool for epidemiological and clinical studies. For several NTDs this can be done through annual mass drug administration MDA ; in leprosy, there are encouraging new developments in the prevention of transmission through chemoprophylaxis, 1 which need further research, as outlined below.
Free-living amoebas as environmental sanctuaries of M. In many but not all parts of the world, the deformities and disabilities caused by HD, as well as religious and social meanings associated with the disease or the physical changes that might result from it, have resulted in and continue to generate stigmatizing attitudes toward and negative beliefs about people affected by the disease.
Epidemiology of leprosy
In this sense, the degenerative changes associated with infection of the peripheral sensory nerves are considered a crucial event in the natural history of HD 7 , 8. Under the current WHO-recommended treatment scheme, many people complete the treatment in less than a year, so the global prevalence of leprosy is often lower than the incidence; the total number of registered cases at the beginning of was , New cases continue to be reported in children in over countries and this has led many to see the need for a new approach to interrupting transmission. In fact, there are several biting arthropods residing in highly endemic areas of leprosy that theoretically might act as a vector of M. Early identification of leprosy cases remains a central priority in controlling this disease. Confirmation of this as a new species that could cause HD requires further research, as defined by Gillis et al. Early detection and treatment of neuropathy in leprosy has important preventive potential. All Rights Reserved. Similarly, survival of M leprae in environmental niches may also involve natural reservoirs e. Studies with skin test antigens, their application and evaluation in the field. We need to expand our understanding of factors that predispose individuals to develop leprosy reactions and the mechanisms that trigger their occurrence. Peripheral nerve sensorimotor dysfunction in patients with leprosy is frequently exacerbated by episodes of leprosy reactions [ 8 , 9 ]. HD results from infection with the Mycobacterium leprae bacillus, which produces a chronic infection in humans that affects mainly peripheral nerves and skin but may also affect sites such as the eyes, mucous membranes, bones, and testes and produces a spectrum of clinical phenotypes 1 , — 3. While leprosy bacilli are present in the nasopharynx of individuals with multibacillary leprosy [ 51 ] and from cutaneous lesions [ 52 ], and that these bacilli are able to infect other susceptible human hosts [ 18 , 19 ], the precise mechanism and route of transmission remain to be completely elucidated.
All Rights Reserved. Conclusion New approaches to NTD control have stimulated new thinking about leprosy—particular challenges relate to innovative ways to interrupt the transmission of leprosy and, secondly, the need for an integrated approach to morbidity management across several diseases.
Mycobacterium ulcerans transmission cycle involves aquatic insect vectors, aquatic plants, and aquatic animals [ 4547 — 50 ]. In some studies, the distribution of single lesions of tuberculoid leprosy correlated with exposed skin areas [ 6061 ].
Upgrading reactions are associated with increased cell-mediated immune responses which tend to occur when patients are receiving MDT , while downgrading reactions take place when patients develop lesions in the lepromatous pole of the spectrum after beginning with borderline forms usually prior to initiation of MDT 1 , 8 , In this article, we discuss recent findings related to genetics, susceptibility, and disease reservoirs and the implications of these findings for Hansen's disease control and health outcomes for patients. Moet et al. In the skin, M. The spillover of M. However, most of the clinical phenotypes may be due to genetic variability determined by different biological pathways modulated by M. Gupta et al. Some of the preliminary results from a and b are expected to be available by early All Rights Reserved. There is a great need, however, to simplify the basic principles and then decentralize the skills to affected communities. India and Brazil account for the majority of these cases. This could be combined with simple instructions about how to suspect and refer new cases.
In the last few decades, particularly with the advent of multidrug therapy MDT and the use of anti-inflammatory therapies, there have been substantial improvements in long-term health outcomes for individuals diagnosed with HD.
Further evidence has demonstrated that M.
Leprosy research paper
This transformation creates a suitable environment for the bacteria to proliferate 7. In addition studies to monitor post-treatment relapses and development of resistance to existing and new drugs will be important. Nevertheless, it is possible that there are other unidentified environmental reservoirs or vectors influencing the occurrence of new human infections in highly endemic areas. Evaluation of the immunoprophylactic efficacy of candidate anti-leprosy vaccines in field studies, and assessment of possibilities for immunotherapy will be continued. In this sense, the degenerative changes associated with infection of the peripheral sensory nerves are considered a crucial event in the natural history of HD 7 , 8. These programs have the greatest potential for reducing transmission by early instituting of treatment early in the course of the disease; and by identifying household contacts and household cases. One important consideration is the potential role of the microbiome in modulating the inflammatory response, particularly of herpes viruses [ 2 ]. It remains to be tested if M. All Rights Reserved. Similarly, survival of M leprae in environmental niches may also involve natural reservoirs e. In fact, there are several biting arthropods residing in highly endemic areas of leprosy that theoretically might act as a vector of M. Under the current WHO-recommended treatment scheme, many people complete the treatment in less than a year, so the global prevalence of leprosy is often lower than the incidence; the total number of registered cases at the beginning of was , Because leprosy cannot be grown in vitro, the exact dynamics of transmission are not known, but they are gradually becoming clearer through strain typing, which has shown, for example, that leprosy in armadillos in Louisiana and Texas USA is the same strain as that found in people in the same areas. The challenge now is to apply the lessons learned to a whole range of diseases in an integrated manner, and to disseminate this knowledge and expertise at the community level.
based on 83 review