Abstract:
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.
摘要:
麻风病是由麻风分枝杆菌(M.麻风病)和最近发现的麻木病分枝杆菌(M.麻风病)。两种麻风杆菌引起相似的病理状况。它们主要针对皮肤和周围神经系统。目前它被认为是一种被忽视的热带病,在美洲国家的特定地点流行,亚洲,非洲,而在欧洲,它很少被报道。在一个国家内所谓的地方病地区,麻风病流行的空间不平等的原因在很大程度上仍然无法解释。针对麻风病传播研究数据进行了系统综述,使用PubMed和Scopus作为来源。包括1945年1月1日至2019年7月1日的出版物。麻风分枝杆菌的传播途径尚未完全了解。确凿的证据表明,与麻风病人密切接触的人的风险增加,很可能是通过感染性气溶胶,咳嗽和打喷嚏造成的,但也可能通过直接接触。然而,本系统综述强调,人与人之间的传播并不是麻风病获得的唯一途径.这种疾病的传播可能比以前想象的要复杂得多。在美洲,九带状Armadillo(Dasypusnovemcinctus)已被确立为麻风分枝杆菌的另一种自然宿主和水库。已提出将人畜共患和人畜共患传播作为感染该疾病的方式,基于显示人类和Armadillos共享相同的麻风分枝杆菌菌株的数据。最近,在不列颠群岛的麻风病样病变的红松鼠(Sciurusvulgaris)中,检测到麻风分枝杆菌和麻风病分枝杆菌的DNA。这个发现是出乎意料的,因为麻风病被认为是人类的一种疾病(除了Armadillo),因为人们认为麻风病(和麻风分枝杆菌)已经从英国消失了。此外,动物可能会受到其他麻风病样疾病的影响,由与麻风分枝杆菌密切相关的病原体引起。已提出将这些分枝杆菌归类为麻风分枝杆菌复合物。我们认为,麻风分枝杆菌复合体成员的传播和水库的见解可能与麻风病研究有关。需要更好地了解可能的动物或环境水库,因为从这些水库传播可能部分解释了麻风病的稳定的全球发病率,尽管有效和广泛的多药治疗。不能期望仅通过人类医疗保健领域的行动或干预来减少传播,因为所涉及的机制很复杂。因此,为了增加我们对麻风病传播的复杂图景的理解,我们提出了一个健康的跨学科研究方法。