Evaluation in white mice of the infectivity of eggs of Lagochilascaris minor (Nematoda: Ascarididae), incubated by decortication with sodium hypochlorite (NaOCl)

White mice were used to study the infectivity of the eggs of Lagochilascaris minor Leiper, 1909 after incubation in liquid media, with or without preservative substances. Potassium bichromate (K2Cr2O7) at 1 restrict hatching, while 1 formalin gave a greater larval yield. Incubation of eggs in distilled water, in Roux or Falcon flasks gave a good yield, whether the eggs were obtained from human feces or from experimentally infected cats. Treatment of eggs with Sodium hypochlorite (NaOCl) at 5.25 for 2 min prior to inoculation, produced a notable increment of the larval yield in the infections.

Experimental heteroxenous cycle of Lagochilascaris minor Leiper, 1909 (Nematoda: Ascarididae) in white mice and in cats

Reports of natural infections of sylvatic carnivores by adult worms of species similar to Lagochilascaris minor in the Neotropical region led to attempts to estabilish experimental cycles in laboratory mice and in cats. Also, larval development was seen in the skeletal muscle of an agouti (Dasyprocta leporina) infected per os with incubated eggs of the parasite obtained from a human case. In cats, adult worms develop and fertile eggs are expelled in the feces: in mice, larval stages of the parasite develop, and are encapsulate in the skeletal muscle, and in the adipose and subcutaneous connective tissue. From our observations, we conclude that the larva infective for the mouse is the early 3rd stage, while for the final host the infective form is the later 3rd stage. A single moult was seen in the mouse, giving rise to a small population of 4th stage larvae, long after the initial infection

Mansonelosis en el area Sur-oriental de la Orinoquia Venezolana / Mansonelliasis in the southeast Venezuelan Orinoquia region

Physical exam and skin biopsy were performed and peripheral blood samples drawn from 10 of the inhabitants of 26 jungle villages of the State of Bolívar, Venezuela. One hundred and fifty three Indians and an inhabitant of mixed blood from 13 different communities were found to be infected with mansonelliasis representing a global index of 36.40 in the endemic area. The parasitosis was found to be concentrated in three areas. The largest, located in the southwest of the country and forming part of an extent infected area embarking neighboring parts of Venezuela and Brazil, contains villages with a parasite index of 80.76 and 94.44. A second focus is located in the southeast, its carriers, as those of the first, are infected with Mansonella ozzardi. In a third, central eastern focus infections with Mansonella pertans were found. The patients infected with M. ozzardi were apparently asymptomatic and their physical exam was normal, even though individual parasite densities up to 30,000 microfilariae/ml blood and 22,000/gr skin were found.

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

Un ejemplar adulto macho de Speothos venaticus Lund, 1842 fue muerto accidentalmente en una via de penetracion rural, situada en la region Noroeste del Estado Bolivar, Venezuela, en el Municipio donde desde hace 16 años vive una paciente con lagochilascariasis. El animal conservado durante un mes por congelacion y desprovisto de su piel y cabeza fue autopsiado, hallandose en la traquea dos especimenes adultos hembras y gravidos de Lagochilascaris sp., los cuales presentaban algumas caracteristicas morfologicas de sus partes blandas diferentes a Lagochilascaris minor Leiper, 1909; entretanto, distintivos estables como son la forma de los interlabios, la localizacion de la vulva y particularmente el tamano y numero de las depresiones la cascara de los huevos, inclinan a pensar que se trata de aquel parasito, a pesar de no haberse hallado vermes machos que permitiesen el estudio de las espiculas y su ducto eyaculador. Fueron localizadas en cortes histologicos de laringe y traquea profundamente situadas, secciones de formas degeneradas con caracteristicas atribuibles a Lagochilascaris sp.