Review of the genus Mansonella Faust, 1929 sensu lato (Nematoda: Onchocercidae), with descriptions of a new subgenus and a new subspecies.

Based on material deposited in museum collections, twelve species within Mansonella sensu lato were examined and their descriptions amended. Based on additional morphological details, the erection of the new monotypic subgenus Filyamagutia Bain & Uni for M. (F.) akitensis (Uni, 1983), and the new combination M. (Pseudolitomosa) musasabi (Yamaguti, 1941) Bain & Uni are proposed. A new subspecies, M. (Tetrapetalonema) atelensis amazonae Bain & Guerrero is described and a key to the seven subgenera of Mansonella is provided. Furthermore, the elevation of Sandnema to full genus rank comprising the two species S. digitatum (Chandler, 1929) n. comb. and S. sunci (Sandground, 1933) n. comb., is proposed. Host and geographic records for the species of Mansonella and Sandnema are included.

Affinities between Cutifilaria (Nematoda: Filarioidea), parasites of deer, and Mansonella as seen in a new onchocercid, M. (C.) perforata n. sp., from Japan.

A new dermal filarioid nematode, collected from Cervus nippon nippon (sika deer) on Kyushu Island, Japan, showed close affinities between the genera Cutifilaria and Mansonella (Onchocercidae: Onchocercinae): no buccal capsule, esophagus reduced to a thin fibrous tube, and female tail with four lappets. We propose Cutifilaria as a subgenus of Mansonella. Cutifilaria was distinguished from the five other subgenera, Mansonella, Tetrapetalonema, Esslingeria, Sandnema, and Tupainema, in having an area rugosa composed of transverse bands with tiny points, 14-16 papillae around the cloacal aperture, two prominent rhomboidal subterminal papillae, and a thick right spicule with spoon-shaped distal extremity. The host range of Mansonella was extended to ungulates by the addition of Cutifilaria, which appears to be derived from Tupainema, parasitic in Tupaioidea (insectivores), because of the similarity in their right spicules; Cutifilaria seems to have an Asiatic origin. M. (C.) perforata n. sp. was distinct from the sole other related species, M. (C.) wenki, a parasite of Cervus elaphus (red deer) in Europe, having a more complex right spicule with a sturdy terminal point and microfilariae with a bifid posterior end. In addition, almost all females had cuticular pores near the vulva, on the ventral line. The prevalence of microfiloriae and adults of M. (C.) perforata in the skin of sika deer was 38% and 21%, respectively.

The morphological discrimination of microfilariae of Onchocerca volvulus from Mansonella ozzardi.

There is no published account which allows the morphological discrimination of microfilariae of Onchocerca volvulus and M. ozzardi from each other. However, they occur together in parts of Brazil and Venezuela, and presumably there is always the possibility that migration could establish new sympatric populations in the future. The objective of this study was to evaluate simple morphological characters that might be used for species-diagnosis of microfilariae. The conclusions were that the location of microfilariae in the blood or skin, the body size and the nucleation of the nerve ring are expected to be useful first indications of species identity, but cannot be used for confident diagnosis. The structure of the cephalic armature (stained with alcian blue) seems to be species specific, but is of limited application because it is often difficult to see. However, the pattern of nucleation of the tail (as expressed by the ratio of the length of the terminal nucleus compared with the length of the tail space) is distinctive and is expected to be diagnostic.

Filariae from a wild gorilla in Gabon with description of a new species of Mansonella.

A search for filariae was performed on a wild male Gorilla g. gorilla from the Lopé Reserve in Gabon, which had died as a result of injuries inflicted by another male gorilla. A female worm of Loa loa and female worms of two species of Mansonella were recovered from the deep tissues of a wounded thigh. In order to analyze these Mansonella, specimens of M. (E.) perstans, M. (E.) vanhoofi and M. (E.) streptocerca from the Collections of the Museum National d'Histoire Naturelle de Paris have been studied and new important discriminative characters characterised, such as the body-swellings in M. (E.) perstans, due to the presence of coelomocytes as in South-american M. (Tetrapetalonema) spp. One of the Mansonella from this gorilla was not identified, but the body-swellings and the microfilarial morphology suggested a possible similarity with M. (Esslingeria) perstans. The other species is new; M. (E.) lopeensis n. sp. is distinguished by its large size, lack of body-swellings, structure of the tegumental sheath, complex vagina, and a tail with a subterminal constriction, a terminal bend and large lappets. Histological sections of organs of this gorilla also showed a microfilaria of M. (E) leopoldi in the blood vessels of the liver, and a male of Mansonella sp., interestingly situated in an afferent lymphatic vessel of an axillary lymph node.(ABSTRACT TRUNCATED AT 250 WORDS)

Primer caso de Microfilariasis de ocurrencia fatal en Santa Cruz-Bolivia / The first of case microfilariasis probably fatal in Santa Cruz-Bolivia

Se presenta el primer caso de Microfilariasis patogena probable Mansonella Ozzardi, diagnosticado por estudio Histopalogico, en un nino de 12 anos de edad, procedente de la ciudad de Santa Cruz, con un cuadro clinico atipico y desenlace fatal

Nodules in the conjunctiva, bung-eye, and bulge-eye in Africa caused by Mansonella perstans.

Eight patients from Uganda, Sudan, Nigeria, and Zaire presented with swelling of the eyelids, proptosis, or conjunctival granulomas. In 5 patients the cause was Mansonella perstans; in 1, it was a Wuchereria bancrofti-like worm; and in 2, an unidentifiable worm. The morphologic features and histopathologic changes in the conjunctiva and periorbital fat are described and illustrated.

Adult Mansonella perstans in the abdominal cavity in nine Africans.

Adult Mansonella perstans infected the abdominal cavity of nine patients seen at Karawa Hospital in the Ubangi territory of Zaire. In four patients the worms were removed at laparotomy, and in the other five they were removed at autopsy. Twelve adult worms were identified in the nine patients. None of the worms caused symptoms or contributed to the patient's death. Worms were in the hernial sac in three patients, and one each was in connective tissue beside a reactive mesenteric lymph node, in peripancreatic connective tissue, in perirenal connective tissue, in hepatic portal connective tissue, on the serosal surface of the small intestine, and in connective tissue adjacent to rectum. The diameter of male worms was 45 microns to 60 microns and of female worms, 80 microns to 125 microns. One female worm was removed intact. It was 6 cm long and had a bifurcated tail characteristic of M. perstans.

En face view of Mansonella (Mansonella) akitensis (Uni, 1983) by scanning electron microscopy.

The en face view of the head of M. (M.) akitensis was examined by scanning electron microscopy (SEM). The cephalic extremity with major axis dorsoventral confirmed the taxonomical position of the species.

The genus Mansonella (syn. Tetrapetalonema): a new classification.

Mansonella has been established as a valid genus, and Tetrapetalonema synonymized with it. Comparative morphological studies have resulted in the restructuring of the Mansonella group. The genus is characterized by the following features: cuticular pre-esophageal ring absent; esophagus slender, poorly differentiated; female tail with four terminal papillae; caudal papillae in male typically clustered around cloaca; and, microfilariae without sheath. Twenty-four species are assigned to the genus Mansonella. Five subgenera are proposed to accommodate these species. The subgeneric groups are distinguished principally on morphological criteria, although host range and geographical distribution are considered. The following systematic classification is proposed: Mansonella (Mansonella) subgen. n., to accommodate those species which have the following morphological features: cephalic extremity with dorsoventral orientation; male tail with tip flattened dorsoventrally; vulva in midesophageal region; and microfilariae without nuclei extending to tip of tail. Type species is M. (M.) ozzardi. Mansonella (Tupainema) subgen. n., to accommodate the single species M. dunni with the following characters: cephalic extremity with lateral orientation and body constricted to form cephalic extremity in shape of hemisphere narrower than body behind it; tip of male tail not flattened dorsoventrally; vulva at or posterior to base of esophagus; and, microfilariae without nuclei to tip of tail. Mansonella (Esslingeria) comb. n., to accommodate those species with the following characters: cephalic extremity with lateral orientation; male tail flattened dorsoventrally at tip or not; vulva in midesophageal region; and, microfilariae with nuclei to tip of tail. Type species is M. (E.) perstans. Mansonella (Tetrapetalonema) comb. n., to accommodate those species with the following characters: cephalic extremity with dorsoventral orientation or with body constricted to form cephalic extremity in shape of hemisphere narrower than body behind it; male tail not flattened at tip; vulva in midesophageal region; and, microfilariae with nuclei to tip of tail. Type species is M. (T.) marmosetae. Mansonella (Sandnema) comb. n., to accommodate those species with the following characters: cephalic extremity rounded, not oriented along lateral or median axis; tip of male tail not flattened; caudal papillae on male tail not clustered around cloaca; vulva near base of esophagus; and, microfilariae with nuclei to tip of tail. Type species is M. (S.) digitata.

Mansonella (E.) rotundicapita sp.n. and Mansonella (E.) longicapita sp.n. (Filarioidea : Onchocercidae) from Venezuelan capybaras, Hydrochoerus hydrochaeris.

Mansonella (E.) longicapita sp. n. and Mansonella (E.) rotundicapita sp. n., two filarial nematodes from the dermis of Venezuelan capybaras, are described. The two species can be distinguished on the size of the spicules (M. longicapita 327 and 139 micron, ratio of 2.3 : 1 ; M. rotundicapita 405 and 120 micron, ratio of 3.4 : 1), the degree of lateral elongation of the cephalic shield and in the size and configuration of the microfilaria. The microfilaria of M. rotundicapita is large (280 micron long), and in specimens fixed in 2% formalin, the posterior end of the body is bent in a shepherd's crook, while the microfilaria of M. longicapita is short (195 micron long) and when similarly fixed, assumes a gently curved attitude. Within the subgenus M. (Esslingeria), the species M. longicapita and M. rotundicapita are intermediate in size. Morphologically they resemble M. streptocerca and M. rodhaini most closely, but can be distinguished on size, spicule morphology, and microfilarial morphology.

Comparative morphology of Mansonella ozzardi microfilariae from Colombia and Haiti. A light microscope study.

Comparative morphological studies were conducted at the light microscope level to determine whether any difference could be detected in thin smears, thick smears, or Knott samples, between Colombian (simuliid-transmitted) and Haitian (culicoid-transmitted) Mansonella ozzardi microfilaria. Results indicated that the microfilariae from these two geographical areas are essentially identical. The small differences observed in the dimensions of microfilariae in thick and in thin smears can be attributed to different preparative procedures. The consistent morphological differences, noted in PAS-hematoxylin-stained microfilariae, from Knott smears, was that the central body was thinner and stained less intensely with the Schiff reagent in the Haitian than in the Colombian microfilariae. Although these observations suggest a physiological difference between these two forms, additional studies are needed to exclude the possibility that these differences are not indications of the age or a state of physiological activity of the microfilariae.

Mansonella ozzardi: a redescription with comments on its taxonomic relationships.

Mansonella ozzardi is redescribed from adult worms collected from the subcutaneous tissues of patas monkeys (Erythrocebus patas) infected with a Haitian strain of the filaria. The worms are small and very slender; females measure about 49 mm in length by 0.15 mm in diameter and males, 26 by 0.07 mm. Haitian (Caribbean) and Colombian (Amazon) forms of the filaria are morphologically identical, as are their microfilariae. Mansonella is most closely related to Tetrapetalonema. Based on taxonomic priority the latter becomes a synonym of Mansonella. As a consequence, T. perstans and T. streptocerca of man in Africa are designated as M. perstans (Manson, 1891) n. comb. and M. streptocerca (Macfie and Corson, 1922) n. comb. Further, M. ozzardi is most closely related to the species M. llewellyni (Price, 1962) n. comb., a parasite of the raccoon, and M. interstitium (Price, 1962) n. comb. found in squirrels, both in North America.

Development of Mansonella ozzardi in a black fly species of the Simulium sanguineum group from Eastern Vaupés, Colombia.

Development of the microfilaria of Mansonella ozzardi to the infective stage in a species of the Simulium sanguineum group from the Mitú area, Comisaría del Vaupés, Colombia is described. Development was synchronous, and by day 6 third-stage larvae were observed in the head of flies which had fed on two naturally infected volunteers. Simulium biting activity was high from January-March, during the dry season. Only 261 blood-fed Culicoides were collected from an infected volunteer; 40% of 43 dissected on day 0 had ingested microfilariae. However, only one of 129 C. caprilesi specimens dissected after day 2 was positive, containing a second-stage larva thought to be M. ozzardi. It is concluded that Simulium, rather than Culicoides are the principal vectors of mansonelliasis in the Mitú area.

Mansonella ozzardi infections in Indians of the Southwestern part of the state of Bolivar, Venezuela.

Mansonella ozzardi infections were found in 80/139 (58%) of Indians living in the forest of the upper Caura River Basin located in the southwestern part of Bolivar State, Venezuela. In four (3%) of the blood samples a second type of microfilaria which could not be identified was also found.