Infeccion natural de Speothos venaticus (Carnivora: Canidae) por estadios adultos de Lagochilascaris sp. Natural infection of Speothos venaticus (Carnívora: Canidae) by adult Lagochilascaris sp.

Un ejemplar adulto macho de Speothos venaticus Lund, 1842 fue muerto accidentalmente en una vía de penetración rural, situada en la región Noroeste del Estado Bolívar, Venezuela, en el Municipio donde desde hace 16 años vive una paciente con lagochilascariasis. El animal conservado durante un mes por congelación y desprovisto de su piel y cabeza fue autopsiado, hallándose en la tráquea dos especímenes adultos hembras y grávidos de Lagochilascaris sp., los cuales presentaban algunas características morfológicas de sus partes blandas diferentes a Lagochilascaris minor Leiper, 1909; entretanto, distintivos estables como son la forma de los interlabios, la localización de la vulva y particularmente el tamaño y número de las depresiones de la cáscara de los huevos, inclinan a pensar que se trata de aquel parásito, a pesar de no haberse hallado vermes machos que permitiesen el estudio de las espículas y su ducto eyaculador. Fueron localizadas en cortes histológicos de laringe y tráquea profundamente situadas, secciones de formas degeneradas con características atribuíbles a Lagochilascaris sp.<br>An adult male Speothos venaticus Lund (bush dog) was found killed on a rural road in the Northeast of Bolívar State, in a locality where a patient with lagochilascariasis has lived for the past 16 years. The animal was frozen for 1 month, and after removal of the head and skin, was autopsied. Two adult gravid females of Lagochilascaris sp. were found in the trachea. Certain morphological characteristics of the soft parts differed from the description given for Lagochilascaris minor Leiper, 1909; however, stable characters, such as the form of the interlabials, the location of the vulva, and particulary the size and number of depressions of the egg shell appear to indicate that the worms are of the above mentioned species. Unfortunately, no males were found for study of the spicules and ejaculatory duct. In histological sections of the larynx and the trachea from the deep tissues, parts of degenerated worms were found, with characteristics attributable to Lagochilascaris sp

Lagoquilascaríase humana: sobre três casos encontrados nos Distrito Federal, Brasil Human lagochilascariasis: about three cases found in the Federal District, Brazil

Três novos casos humanos de infecção por Lagochilascaris minor são apresentados. Todos os pacientes eram oriundos do Estado do Pará, Brasil, e viviam em zona rural ou próximo à mata. As lesões, no momento da consulta, localizavam-se no pescoço, mastóide e ouvido, estando já fistulizadas; em dois casos havia também envolvimento do sistema nervoso central. Amostras de tecidos, retiradas das lesões, revelaram, ao exame histológico, ovos e vermes em vários estádios de sua evolução. A identificação da espécie foi confirmada através do estudo de larvas e adultos eliminados, pelas fístulas cutâneas, de mistura com pus. O tratamento consistiu em excisão cirúrgica das tumorações e administração de antihelmínticos, com bons resultados. Em dois pacientes, no entanto, houve recidiva das lesões, após cura aparente, indicando que as drogas utilizadas não destroem os ovos do parasito.<br>Three new cases of human infection with Lagochilascaris minor are reported. All the patients were from the State of Pará (Brazil), living in rural areas or close to the forest. They were admitted to hospitals in the Federal District due to the presence of abscesses in the region of the neck, ear, mastoid process and, in two of them, to the involvement also of the central nervous system. Microscopic examination of tissue samples taken from the lesions showed sections of eggs and worms - in different evolutive stages - identified as Lagochilascaris minor. Larvae and adult worms obtained from existing fistulae proved also to be of the same species. The three patients were treated with autihelmintic drugs and surgical excision of the lesions, with good clinical results. In two of them, however, relapsing occurred, suggesting that the drugs do not destroy the worm eggs, in spite of the apparent healing of the lesions

Experimental life cycle of Lagochilascaris minor Leiper, 1909 Ciclo evolutivo experimental de Lagochilascaris minor, Leiper 1909

The life cycle of Lagochilascaris minor was studied using material collected from human lesion and applying the experimental model: rodents (mice, hamsters), and carnivorae (cats, dogs). In mice given infective eggs, orally, hatch of the third stage larvae was noted in the gut wall, with migration to liver, lungs, skeletal musculature and subcutaneous tissue becoming, soon after, encysted. In cats infected with skinned carcasses of mice (60 to 235 days of infection) it was observed: hatch of third stage larvae from the nodules (cysts) in the stomach, migration through the oesophagus, pharynx, trachea, related tissues (rhino-oropharynx), and cervical lymphonodes developing to the mature stage in any of these sites on days 9-20 post inoculation (P.I.). There was no parasite development up to the mature stage in cats inoculated orally with infective eggs, which indicates that the life cycle of this parasite includes an obligatory intermediate host. In one of the cats (fed carcass of infected mice) necropsied on day 43 P.I., it was observed the occurence of the self-infective cycle of L. minor in the lung tissues and in the cervical region which was characterized by the finding of eggs in different stages of development, third stage larvae and mature worms. It's believed that some component of the carnivorae gastrointestinal tracts may preclude the development of third stage larvae from L. minor eggs what explains the interruption of the life cycle in animals fed infective eggs. It's also pointed out the role of the intermediate host in the first stages of the life cycle of this helminth.<br>A partir de material colhido de lesões humanas estudou-se o ciclo evolutivo de Lagochilascaris minor empregando-se o modelo experimental: roedores (camundongos, hamster) e carnívoros (gatos, cão). Em camundongos inoculados com ovos infectantes, por via oral, observou-se eclosão de larvas de 3º estágio na parede do intestino, migração das mesmas para o fígado, pulmão, musculatura esquelética e tecido subcutâneo tornando-se em seguida encistadas. Em gatos alimentados com carcaças de camundongos infectados (60-235 dias de infecção) observou-se: eclosão de larvas de 3º estágio do interior dos nódulos (cistos) no estômago, migração através do esôfago, faringe, traquéia, e tecidos vizinhos (rino-orofaringe), linfonodos cervicais alcançando a fase adulta, em qualquer uma destas localizações, 9-20 dias pós inoculação. Não houve evolução do parasito até a fase adulta em gatos inoculados com ovos infectantes, por via oral, dado que reforça a necessidade do hospedeiro intermediário neste ciclo evolutivo. Em um dos gatos (alimentados com carcaças de camundongos infectados) necropsiado 43 dias pós inoculação, observou-se a ocorrência do ciclo auto-infectante de L. minor o que foi caracterizado pelo encontro de ovos em várias fases de evolução, larvas de 3º estágio e vermes adultos em tecidos do pulmão e região cervical. Acredita-se que algum componente do trato digestivo de carnívoros possa inviabilizar larvas de 3º estágio do interior de ovos L. minor, justificando a interrupção do ciclo evolutivo quando tais animais são inoculados com ovos infectantes. Ressalta-se o papel do hospedeiro intermediário nas primeiras fases do ciclo evolutivo deste helminto

Nematóides do Brasil. Parte V: nematóides de mamíferos Brazillan nematodes. Part V: nematodes of mammals

<abstract language="eng">A survey of nematode species parasitizing Brazilian mammals is presented, with enough data to provide their specific identification. The tirst section refers to the survey ofthe species, related to 21 superfamilies, 45 families, 160 genera and 495 species that are illustrated and measurement tables are given. The second section is concerned to the catalogue ofhost mammals which includes 34 families, 176 species and their respective parasite nematodes. The identification of these helminths is achieved by means of keys to the superfamilies, families and genera. Specific determination is induced through the figures and tables as above mentioned