Adolpho Lutz and controversies over the transmission of leprosy by mosquitoes

Abstract

During his years of study in Switzerland and Germany, Adolpho Lutz published his first articles on zoology, clinical practice, and therapeutics. In Limeira, São Paulo, he began studies on animal and human diseases caused by germs and parasites. In 1885-86, Lutz traveled to Hamburg to study the morphology of germs related to skin diseases, in conjunction with Paul Gerson Unna, one of Germany's foremost dermatologists. He proposed the inclusion of Hansen's and Koch's bacilli in a new genus. In 1889, Unna nominated his student as physician-in-chief of the Leper Settlement on Molokai Island, Hawaii. From then on, Lutz sustained the theory that the disease was transmitted by mosquitoes. He conducted research to prove this theory when he was head of the Instituto Bacteriológico de São Paulo (1893-1908) and, later, after he moved to the Instituto Oswaldo Cruz (1908-1940). Although this research was not successful, on commissions and at congresses in which he participated until his death in October 1940, he still held to his conviction that leprosy was transmitted by mosquitoes.

Triatomines: Trypanosomatids, Bacteria, and Viruses Potential Vectors?

“…Moreover, it is important to highlight that a study reported wild armadillos as well as patients with leprosy infected with the same strain of M. leprae (Truman et al, 2011 ). In this context, it is a topic of concern the overlapping geographic distribution of Triatominae species and the endemicity of leprosy in some regions, as triatomines that are transitioning from wild environments to the domiciliary ones may be a potential source of M. leprae transmission to humans (Neumann Ada et al, 2016 ), supporting that old hypothesis that leprosy can be vector-borne transmitted through the insect feces containing the bacteria when in contact with host wound or mucosa (Kirchheimer, 1976 ; Benchimol and Romero Sa, 2003 ; Neumann Ada et al, 2016 ).…”

“…McFadzean and Macdonald evaluated the possible role of mosquitoes and bed bugs in leprosy transmission by allowing infected and control insects to take a blood meal on volunteers and found no difference in transmission (McFadzean and Macdonald, 1961 ). Almost two decades later, the presence of M. leprae was reported in the proboscis, cuticle and blood smears from mosquitoes and ticks (de Souza-Araujo, 1942 ; Banerjee et al, 1991 ), suggesting arthropods could act as biological or mechanical vectors to these bacilli (Kirchheimer, 1976 ; Benchimol and Romero Sa, 2003 ).…”

Aquatic Insects and Mycobacterium ulcerans: An Association Relevant to Buruli Ulcer Control?

“…The hypothesis that arthropods were involved in the transmission of M. leprae to humans was originally put forward at the end of the 19th century [8]. This hypothesis was intermittently considered and tested until the early 1990s, but it was never consistently demonstrated.…”

Experimental Infection of Rhodnius prolixus (Hemiptera, Triatominae) with Mycobacterium leprae Indicates Potential for Leprosy Transmission

“…Leprosy transmission by insects is an old hypothesis [ 14 , 15 ], which could explain how the bacteria circulate from armadillos to humans in US and Brazil, where the disease is highly prevalent at the agricultural frontier regions of the most depopulated states in the amazon region with an average of 6 cases / 10,000 habitants, and regarding the big cities large poverty populations at south east of 1 case / 10,000 habitant [ 16 ]. Some authors described experimentally leprosy transmission by Aedes aegypti , Culex fatigans and flies [ 14 , 17 – 22 ].…”