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Virulence Dec 2022Leprosy is caused by (. ) and , an obligate intracellular organism, and over 200,000 new cases occur every year. parasitizes histiocytes (skin macrophages) and Schwann... (Review)
Review
Leprosy is caused by (. ) and , an obligate intracellular organism, and over 200,000 new cases occur every year. parasitizes histiocytes (skin macrophages) and Schwann cells in the peripheral nerves. Although leprosy can be treated by multidrug therapy, some patients relapse or have a prolonged clinical course and/or experience leprosy reaction. These varying outcomes depend on host factors such as immune responses against bacterial components that determine a range of symptoms. To understand these host responses, knowledge of the mechanisms by which parasitizes host cells is important. This article describes the characteristics of leprosy through bacteriology, genetics, epidemiology, immunology, animal models, routes of infection, and clinical findings. It also discusses recent diagnostic methods, treatment, and measures according to the World Health Organization (WHO), including prevention. Recently, the antibacterial activities of anti-hyperlipidaemia agents against other pathogens, such as and have been investigated. Our laboratory has been focused on the metabolism of lipids which constitute the cell wall of . Our findings may be useful for the development of future treatments.
Topics: Animals; Mycobacterium leprae; Virulence; Drug Therapy, Combination; Leprostatic Agents; Leprosy
PubMed: 36326715
DOI: 10.1080/21505594.2022.2141987 -
Anais Brasileiros de Dermatologia 2022Leprosy, a disease caused by Mycobacterium leprae, has polymorphic neurocutaneous manifestations strongly correlated with the host immune response. Peripheral neural... (Review)
Review
Leprosy, a disease caused by Mycobacterium leprae, has polymorphic neurocutaneous manifestations strongly correlated with the host immune response. Peripheral neural damage can lead to sensory and motor losses, as well as deformities of the hands and feet. Both innate and acquired immune responses are involved, but the disease has been classically described along a Th1/Th2 spectrum, where the Th1 pole corresponds to the more limited presentations and the Th2 to the multibacillary ones. The aim of this review is to discuss this dichotomy in light of the current knowledge of the cytokines, T helper subpopulations, and regulatory T cells involved in each presentation of leprosy. The text will also address leprosy reactions related to increased inflammatory activity in both limited and multibacillary presentations, leading to exacerbation of chronic signs and symptoms and/or the development of new ones. Despite the efforts of many research groups around the world, there is no standardized serological test/biological marker for diagnosis so far, even in endemic areas, which could contribute to the eradication of leprosy.
Topics: Cytokines; Humans; Leprosy; Mycobacterium leprae; T-Lymphocytes, Regulatory
PubMed: 35379512
DOI: 10.1016/j.abd.2021.08.006 -
Indian Journal of Dermatology,... 2020With the worldwide implementation of WHO multidrug therapy in the 1980s, the global burden of leprosy has decreased. However, the annual new case detection rate around... (Review)
Review
With the worldwide implementation of WHO multidrug therapy in the 1980s, the global burden of leprosy has decreased. However, the annual new case detection rate around the world has remained nearly static over the past decade with India, Brazil, and Indonesia contributing the majority of these new cases. This has been attributed to the ongoing transmission of Mycobacterium leprae from existing untreated cases and partly to the intensive new case detection programs operative in endemic areas. The WHO has called for a "global interruption of transmission of leprosy by 2020". Targeted chemoprophylaxis of contacts may help bring down the number of new cases. The single-dose rifampicin currently in use for post-exposure prophylaxis (PEP) has limitations and so newer antileprosy drugs and regimens have been trialed for chemoprophylaxis. BCG re-vaccination in combination with chemoprophylaxis for the prevention of leprosy transmission has not been very encouraging. The use of the anti-phenolic glycolipid-1 (PGL-1) antibody test to detect subclinical cases and administer targeted chemoprophylaxis was unsuccessful owing to its low sensitivity and technical difficulties in a field setup. There is a pressing need for newer multidrug chemoprophylactic regimens using second-line antileprosy drugs. The Netherlands Leprosy Relief has proposed an enhanced PEP++ regimen. A simple but highly sensitive and specific serological test to detect subclinical cases at the field level needs to be developed. Although there are a number of challenges in the large-scale implementation of strategies to halt leprosy transmission, it is important to overcome these in order to move towards a "leprosy-free world."
Topics: Clinical Trials as Topic; Drug Therapy, Combination; Humans; Immunotherapy; Leprostatic Agents; Leprosy; Mycobacterium leprae
PubMed: 31975697
DOI: 10.4103/ijdvl.IJDVL_326_19 -
PLoS Neglected Tropical Diseases Apr 2020Leprosy is a chronic infectious disease caused by Mycobacterium leprae (M. leprae) and the more recently discovered Mycobacterium lepromatosis (M. lepromatosis). The two...
Leprosy is a chronic infectious disease caused by Mycobacterium leprae (M. leprae) and the more recently discovered Mycobacterium lepromatosis (M. lepromatosis). The two leprosy bacilli cause similar pathologic conditions. They primarily target the skin and the peripheral nervous system. Currently it is considered a Neglected Tropical Disease, being endemic in specific locations within countries of the Americas, Asia, and Africa, while in Europe it is only rarely reported. The reason for a spatial inequality in the prevalence of leprosy in so-called endemic pockets within a country is still largely unexplained. A systematic review was conducted targeting leprosy transmission research data, using PubMed and Scopus as sources. Publications between January 1, 1945 and July 1, 2019 were included. The transmission pathways of M. leprae are not fully understood. Solid evidence exists of an increased risk for individuals living in close contact with leprosy patients, most likely through infectious aerosols, created by coughing and sneezing, but possibly also through direct contact. However, this systematic review underscores that human-to-human transmission is not the only way leprosy can be acquired. The transmission of this disease is probably much more complicated than was thought before. In the Americas, the nine-banded armadillo (Dasypus novemcinctus) has been established as another natural host and reservoir of M. leprae. Anthroponotic and zoonotic transmission have both been proposed as modes of contracting the disease, based on data showing identical M. leprae strains shared between humans and armadillos. More recently, in red squirrels (Sciurus vulgaris) with leprosy-like lesions in the British Isles M. leprae and M. lepromatosis DNA was detected. This finding was unexpected, because leprosy is considered a disease of humans (with the exception of the armadillo), and because it was thought that leprosy (and M. leprae) had disappeared from the United Kingdom. Furthermore, animals can be affected by other leprosy-like diseases, caused by pathogens phylogenetically closely related to M. leprae. These mycobacteria have been proposed to be grouped as a M. leprae-complex. We argue that insights from the transmission and reservoirs of members of the M. leprae-complex might be relevant for leprosy research. A better understanding of possible animal or environmental reservoirs is needed, because transmission from such reservoirs may partly explain the steady global incidence of leprosy despite effective and widespread multidrug therapy. A reduction in transmission cannot be expected to be accomplished by actions or interventions from the human healthcare domain alone, as the mechanisms involved are complex. Therefore, to increase our understanding of the intricate picture of leprosy transmission, we propose a One Health transdisciplinary research approach.
Topics: Animals; Armadillos; Disease Reservoirs; Disease Transmission, Infectious; Global Health; Humans; Incidence; Leprosy; Mycobacterium; Mycobacterium leprae; Prevalence; Sciuridae
PubMed: 32339201
DOI: 10.1371/journal.pntd.0008276 -
Neurotherapeutics : the Journal of the... Oct 2021Neuropathy and related disabilities are the major medical consequences of leprosy, which remains a global medical concern. Despite major advances in understanding the... (Review)
Review
Neuropathy and related disabilities are the major medical consequences of leprosy, which remains a global medical concern. Despite major advances in understanding the mechanisms of M. leprae entry into peripheral nerves, most aspects of the pathogenesis of leprosy neuropathy remain poorly understood. Sensory loss is characteristic of leprosy, but neuropathic pain is sometimes observed. Effective anti-microbial therapy is available, but neuropathy remains a problem especially if diagnosis and treatment are delayed. Currently there is intense interest in post-exposure prophylaxis with single-dose rifampin in endemic areas, as well as with enhanced prophylactic regimens in some situations. Some degree of nerve involvement is seen in all cases and neuritis may occur in the absence of leprosy reactions, but acute neuritis commonly accompanies both Type 1 and Type 2 leprosy reactions and may be difficult to manage. A variety of established as well as new methods for the early diagnosis and assessment of leprosy neuropathy are reviewed. Corticosteroids offer the primary treatment for neuritis and for subclinical neuropathy in leprosy, but success is limited if nerve function impairment is present at the time of diagnosis. A candidate vaccine has shown apparent benefit in preventing nerve injury in the armadillo model. The development of new therapeutics for leprosy neuropathy is greatly needed.
Topics: Animals; Armadillos; Leprosy; Mycobacterium leprae; Neuritis; Peripheral Nervous System Diseases
PubMed: 34799845
DOI: 10.1007/s13311-021-01153-z -
International Journal of Molecular... Oct 2022Dapsone (DDS), Rifampicin (RIF) and Ofloxacin (OFL) are drugs recommended by the World Health Organization (WHO) for the treatment of leprosy. In the context of leprosy,... (Meta-Analysis)
Meta-Analysis Review
Dapsone (DDS), Rifampicin (RIF) and Ofloxacin (OFL) are drugs recommended by the World Health Organization (WHO) for the treatment of leprosy. In the context of leprosy, resistance to these drugs occurs mainly due to mutations in the target genes (Folp1, RpoB and GyrA). It is important to monitor antimicrobial resistance in patients with leprosy. Therefore, we performed a meta-analysis of drug resistance in Mycobacterium leprae and the mutational profile of the target genes. In this paper, we limited the study period to May 2022 and searched PubMed, Web of Science (WOS), Scopus, and Embase databases for identified studies. Two independent reviewers extracted the study data. Mutation and drug-resistance rates were estimated in Stata 16.0. The results demonstrated that the drug-resistance rate was 10.18% (95% CI: 7.85-12.51). Subgroup analysis showed the highest resistance rate was in the Western Pacific region (17.05%, 95% CI:1.80 to 13.78), and it was higher after 2009 than before [(11.39%, 7.46-15.33) vs. 6.59% (3.66-9.53)]. We can conclude that the rate among new cases (7.25%, 95% CI: 4.65-9.84) was lower than the relapsed (14.26%, 95 CI%: 9.82-18.71). Mutation rates of Folp1, RpoB and GyrA were 4.40% (95% CI: 3.02-5.77), 3.66% (95% CI: 2.41-4.90) and 1.28% (95% CI: 0.87-1.71) respectively, while the rate for polygenes mutation was 1.73% (0.83-2.63). For further analysis, we used 368 drug-resistant strains as research subjects and found that codons (Ser, Pro, Ala) on RpoB, Folp1 and GyrA are the most common mutation sites in the determining region (DRDR). In addition, the most common substitution patterns of Folp1, RpoB, and GyrA are Pro→Leu, Ser→Leu, and Ala→Val. This study found that a higher proportion of patients has developed resistance to these drugs, and the rate has increased since 2009, which continue to pose a challenge to clinicians. In addition, the amino acid alterations in the sequence of the DRDR regions and the substitution patterns mentioned in the study also provide new ideas for clinical treatment options.
Topics: Humans; Rifampin; Dapsone; Leprostatic Agents; Ofloxacin; Drug Resistance, Bacterial; Mycobacterium leprae; Leprosy; Mutation; Amino Acids; Microbial Sensitivity Tests
PubMed: 36293307
DOI: 10.3390/ijms232012443 -
Microbiology Spectrum Aug 2016The use of paleomicrobiological techniques in leprosy has the potential to assist paleopathologists in many important aspects of their studies on the bones of victims,... (Review)
Review
The use of paleomicrobiological techniques in leprosy has the potential to assist paleopathologists in many important aspects of their studies on the bones of victims, solving at times diagnostic problems. With Mycobacterium leprae, because of the unique nature of the organism, these techniques can help solve problems of differential diagnosis. In cases of co-infection with Mycobacterium tuberculosis, they can also suggest a cause of death and possibly even trace the migratory patterns of people in antiquity, as well as explain changes in the rates and level of infection within populations in antiquity.
Topics: Bacteriological Techniques; Bone and Bones; Coinfection; Fossils; History, 15th Century; History, 16th Century; History, 17th Century; History, 18th Century; History, 19th Century; History, 20th Century; History, 21st Century; History, Ancient; History, Medieval; Humans; Leprosy; Mycobacterium leprae; Mycobacterium tuberculosis; Paleopathology
PubMed: 27726813
DOI: 10.1128/microbiolspec.PoH-0009-2015 -
Frontiers in Immunology 2018Leprosy is an infectious disease that may present different clinical forms depending on host immune response to . Several studies have clarified the role of various T... (Review)
Review
Leprosy is an infectious disease that may present different clinical forms depending on host immune response to . Several studies have clarified the role of various T cell populations in leprosy; however, recent evidences suggest that local innate immune mechanisms are key determinants in driving the disease to its different clinical manifestations. Leprosy is an ideal model to study the immunoregulatory role of innate immune molecules and its interaction with nervous system, which can affect homeostasis and contribute to the development of inflammatory episodes during the course of the disease. Macrophages, dendritic cells, neutrophils, and keratinocytes are the major cell populations studied and the comprehension of the complex networking created by cytokine release, lipid and iron metabolism, as well as antimicrobial effector pathways might provide data that will help in the development of new strategies for leprosy management.
Topics: Animals; Humans; Immunity, Innate; Leprosy; Mycobacterium leprae
PubMed: 29643852
DOI: 10.3389/fimmu.2018.00518 -
Nature Oct 2021Humans are considered as the main host for Mycobacterium leprae, the aetiological agent of leprosy, but spillover has occurred to other mammals that are now maintenance...
Humans are considered as the main host for Mycobacterium leprae, the aetiological agent of leprosy, but spillover has occurred to other mammals that are now maintenance hosts, such as nine-banded armadillos and red squirrels. Although naturally acquired leprosy has also been described in captive nonhuman primates, the exact origins of infection remain unclear. Here we describe leprosy-like lesions in two wild populations of western chimpanzees (Pan troglodytes verus) in Cantanhez National Park, Guinea-Bissau and Taï National Park, Côte d'Ivoire, West Africa. Longitudinal monitoring of both populations revealed the progression of disease symptoms compatible with advanced leprosy. Screening of faecal and necropsy samples confirmed the presence of M. leprae as the causative agent at each site and phylogenomic comparisons with other strains from humans and other animals show that the chimpanzee strains belong to different and rare genotypes (4N/O and 2F). These findings suggest that M. leprae may be circulating in more wild animals than suspected, either as a result of exposure to humans or other unknown environmental sources.
Topics: Animals; Autopsy; Cote d'Ivoire; Feces; Genotype; Guinea-Bissau; Humans; Leprosy; Mycobacterium leprae; Pan troglodytes; Phylogeny
PubMed: 34646009
DOI: 10.1038/s41586-021-03968-4 -
Emerging Infectious Diseases Mar 2022The treatment of leprosy is long and complex, benefiting from the development of sterilizing, rapidly-acting drugs. Reductive evolution made Mycobacterium leprae...
The treatment of leprosy is long and complex, benefiting from the development of sterilizing, rapidly-acting drugs. Reductive evolution made Mycobacterium leprae exquisitely sensitive to Telacebec, a phase 2 drug candidate for tuberculosis The unprecedented potency of Telacebec against M. leprae warrants further validation in clinical trials.
Topics: Imidazoles; Mycobacterium leprae; Piperidines; Pyridines
PubMed: 35202539
DOI: 10.3201/eid2803.210394