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At least 19 recordsLinked to original sources
PubMed1983

Filariasis in Colombia: prevalence and distribution of Mansonella ozzardi and Mansonella (=Dipetalonema) perstans infections in the Comisaría del Guainía.

A survey was conducted to determine the prevalence and distribution of filarial infections among the inhabitants of Comisaría. Approximately 25% of the 604 individuals bled (Knott's sample) harbored microfilariae; more men (29.7%) were infected than women (23.7%); approximately 6% were infected with Mansonella (=Dipetalonema) perstans, 13% with Mansonella ozzardi, and 7% with both filariae. Mansonella ozzardi was more common in men than in women, and its prevalence increased with age in both sex groups; it was detected in most of the resident ethnic groups but was most common in the Puinave and the Curripaco Indians, and appeared to be distributed throughout the Comisaría. The prevalence of M. perstans was essentially the same in men as in women, and in age-groups from the 2nd to 4th decade, although its tendency to increase with age was not as marked as in M. ozzardi infections. Mansonella perstans appeared to be limited to the central and southern regions of the Comisaría, was found principally in the Curripaco Indians, and was detected in settlements situated within the drainage of both the Río Orinoco and the upper Río Negro. Approximately 9% of the white settlers (colonos) harbored M. ozzardi, and 5% M. perstans. These results indicate that both M. perstans and M. ozzardi are endemic in the Comisaría del Guainía, and suggest that the focus of M. perstans may extend further into the South American continent along the Río Negro and its tributaries.

Adolescent↗
PubMed1984

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.

Animals↗
PubMed1990

Filariasis focus due to Mansonella ozzardi and Mansonella perstans in the Amazon Federal Territory of Venezuela.

The presence of filariasis was investigated through Knott's method in 40 Curripaco Indians from communities located on the Casiquiare and Guainia Rivers in the Amazon Federal Territory of Venezuela. The results gave an 82.5% prevalence for infections with Mansonella perstans and 30% for infections with M. ozzardi (mixed infections with M. perstans). In almost all the patients the parasite load was greater for M. perstans and varied between 1 and 327 microfilariae per ml. This paper presents for the first time the presence of a transmission focus of M. perstans in the Amazon Federal Territory and confirms the finding of M. ozzardi in the region.

Adolescent↗
PubMed1984

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.

Animals↗
PubMed1995

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)

Animals↗
PubMed1982

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.

Animals↗
PubMed2001

Molecular identification of Wolbachia from the filarial nematode Mansonella ozzardi.

Mansonella ozzardi, a filarial parasite of humans in Latin America, has been shown to harbour intracellular bacteria not yet identified. Here we show that these bacteria, like those of other filarial nematodes, belong to the genus Wolbachia (alpha 2 Proteobacteria; Rickettsiales). Their unambiguous placement in the Wolbachia group was shown by 16S rDNA sequence analysis. However, the exact position of the Wolbachia from M. ozzardi relative to the other wolbachiae is not clear. Indeed, 16S rDNA sequence analysis places this bacterium at a deep branch in Wolbachia evolution. It is interesting that analysis of the 5S rDNA gene spacer of the nematode host also suggests that the genus Mansonella, together with the genus Loa, could represent a deep-branching lineage in filarial evolution.

Animals↗
PubMed1990

Development of Mansonella perstans in the surrogate vector Aedes aegypti.

The biology of the human filaria Mansonella perstans has been poorly studied due in part to the lack of experimental animal models in which its life-cycle could be reproduced. In nature Culicodes spp. (and probably simuliids) are the vectors involved in disease transmission. In the present work Aedes aegypti black-eyed strain was experimentally infected with M. perstans microfilariae by intrathoracic inoculation of 8 to 15 parasites contained in 0.4-0.6 microliters of RPMI 1640. Concentration of microfilariae was achieved by means of a ficoll separation technique. A. aegypti were maintained at 26 degrees C and 80% relative humidity with a sugar-water diet, except on day 4 post-infection on which they received an uninfected blood meal. Larval development was slow, taking no less than 4 days to reach the sausage stage, which measured 95-100 microns in length. Molt to the second stage took place on the 6th day; the differentiation into a long muscular and glandular esophagus, and short intestine measuring approximately one fourth of the total larval length were the most significant changes. At the end of this period 4 small but well demarcated tail papillae were observed. The first third-stage larvae appeared at the 8th day post-infection, measuring 650 to 680 microns in length. Beyond the 10th day larvae with an average length of 750 microns were found in the thorax, head, and mouthparts. Four conspicuous tail papillae characteristic of the genus Mansonella were seen in all third-stage larvae.(ABSTRACT TRUNCATED AT 250 WORDS)

Aedes↗
PubMed1986

Mansonella ozzardi in Haiti. IV. Evaluation of antibody reactivity to heterologous antigens.

Sera from individuals in an area of Haiti endemic for Mansonella ozzardi were analyzed for reactivity to antigens of Brugia pahangi, Dirofilaria immitis, Mansonella llewellyni or Ascaris lumbricoides using either an enzyme-linked immunosorbent assay or an indirect immunofluorescent antibody test. IgM and IgG reactivity to all antigens was observed with sera from both microfilaremic and amicrofilaremic individuals when compared to reactivity of sera from individuals from nonendemic areas. Antibody reactivity to B. pahangi was greater than that to other antigens. IgG reactivity of sera from endemic patients to filarial antigens was consistently greater than that of IgM. Antibody reactivity was not correlated with age or microfilarial density.

Animals↗
PubMedDate not supplied

Loa loa and Mansonella perstans filariasis in the Chaillu mountains, Congo: parasitological prevalence.

1934 Bantus and 379 Pygmies were investigated for Loa loa and Mansonella perstans filariasis in 7 villages in the Chaillu forest of the Congo. Bantus were more frequently infected with L. loa than Pygmies (18.9% of microfilariae carriers compared with 10.6%). In individuals over 30 years of age, males were more frequently infected than females. Microfilarial densities increased until the age of 20 years and then remained stable. Parasite load was not significantly different in the two ethnic groups. For mansonelliasis, the microfilarial rate was higher in the Pygmies (67.5% compared with 22.0%) and males of the 2 groups were more frequently infected than females. Microfilarial load was also higher in Pygmies than in Bantus (mean microfilarial densities (MfD 50) 13 and 2 respectively). In the Pygmy group, MfD 50 for M. perstans increased with age whereas it remained stable in the Bantus. 53.8% of the 249 questioned persons had experienced worm migration under the conjunctiva. Both ethnic groups were equally exposed to the vectors of L. loa and reasons for the difference in prevalence of microfilaria carriers are discussed. For mansonelliasis increased contact with vectors may explain the higher degree of infestation observed in Pygmies. Other filariases were infrequent in (Mansonella streptocerca), or absent from (Onchocerca volvulus and Wuchereria bancrofti), the study area.

Adolescent↗
PubMed1992

Mansonella perstans filariasis: failure of albendazole treatment.

Infections with Mansonella perstans are common in certain parts of Africa and South America. There is no standard treatment at present. We evaluated the effect of albendazole on microfilaremia in ten consecutive patients. No decrease in microfilarial counts could be demonstrated after a median follow-up period of 45 days. Albendazole was not shown to be useful for treatment of Mansonella perstans filariasis.

Adult↗
PubMed2003

Epidemiology of concomitant infections due to Loa loa, Mansonella perstans, and Onchocerca volvulus in rain forest villages of Cameroon.

An epidemiological survey was conducted in 16 remote villages of the rain forest of southern Cameroon to ascertain the prevalence and intensity of three species of filariae: Loa loa, Onchocerca volvulus, and Mansonella perstans. We examined 1458 individuals for blood-dwelling microfilariae and 1255 of these were also for the presence of palpable nodules. All the villages surveyed were found highly endemic for onchocerciasis and mansonellosis with prevalence ranging from 28.44% to 87.17% for O. volvulus and 52.48% to 100% for M. perstans. The intensities of infection were also found high for M. perstans with arithmetic means of microfilaremia ranging from 280.94 to 4947.57 mf/ml. The loiasis prevalence was relatively low with value from 2.22% to 19.23%. Males were found more infected than females for the three species of filariae, and the prevalence and intensities of microfilaremia vary differently in males and females at different ages. The three species of filariae displayed different degrees of association in the inhabitants with a low prevalence of co-occurrence between L. loa/O. volvulus and between L. loa/M. perstans. In contrast, there was a high prevalence of co-occurrence between M. perstans and O. volvulus. The implications of the co-occurrence of the three species of filariae in the populations of these remote villages on the intervention programs based on mass treatment with mectizan are discussed.

Adolescent↗
PubMed2003

No evidence of Wolbachia endosymbiosis with Loa loa and Mansonella perstans.

Endosymbiotic Wolbachia bacteria from different filarial species, including major pathogens of humans such as Wuchereria bancrofti, Brugia malayi and Onchocerca volvulus, seem to play an important role in the development, viability and fertility of these worms. Wolbachia trigger inflammatory host responses as well as adverse reactions against standard treatment regimens and are therefore under investigation as novel treatment targets. We investigated whether Wolbachia are also endosymbiotic in Loa loa and Mansonella perstans. In both male and female adult L. loa, we found no evidence of bacteria by light or transmission electron microscopy. Furthermore, Wolbachia-specific PCR was negative in both L. loa and M. perstans microfilariae. The absence of Wolbachia in both filarial species therefore discourages the use of antibiotics as an adjunct or alternative approach to current treatment concepts for both loiasis and mansonelliasis perstans.

Animals↗
PubMed1989

Hypogonadism and ecdysteroid production in Loa loa and Mansonella perstans filariasis.

Possible endocrinological repercussions of infection with Loa loa and Mansonella perstans filariae were studied in Gabonese subjects. Microfilaremic males were compared with amicrofilaremic controls. In the infected group 13/105 subjects (12%) presented only abnormally low serum levels of testosterone (less than 4 ng/ml), 25/105 (24%) only abnormally high serum levels of gonadotrophins, FSH (greater than 15 mIU/ml) and LH (greater than 20 mIU/ml), and 22/105 (21%) presented anomalies in both testosterone and gonadotrophin levels. One out of 68 control subjects had 3.6 ng/ml seric testosterone and all had normal levels of gonadotrophins. Ecdysteroids were detected (greater than 0.025 ng/ml) in the serum of 87/97 (90%) microfilaremic subjects (GM 0.123 ng/ml) compared to 12/64 (19%) controls (GM 0.030 ng/ml). Ecdysteroids were detected in the urine of all subjects, infected (GM 8.468 ng/ml) as well as control (GM 1.245 ng/ml). The hormonal perturbations were correlated with the levels of Loa loa microfilaremia but not with those of serum and urinary ecdysteroids. These results demonstrate that microfilaremic subjects often show endocrinal signs of hypogonadism and present appreciable levels of ecdysteroids in serum and urine. A direct role for parasitic ecdysteroids in hypogonadism remains to be demonstrated.

Adult↗
PubMed1979

The prevalence and distribution of Mansonella ozzardi in coastal north Trinidad, W.I.

A day blood smear survey for Mansonella ozzardi in the north coast communities of Trinidad recorded a prevalence of 4.8% in 4,488 persons examined. Prevalence rates were highest in the four western-most communities, where the vector, Culicoides phlebotomus, is a severe nuisance problem. Prevalence rates increased with age and were higher in males than in females. Mean microfilaria densities were low in both sexes up to 50 years of age but in older males the density increased with age. Wuchereria bancrofti infections were detected in five of the ten communities surveyed.

Adolescent↗
PubMed1980

Simulium species of the amazonicum group as vectors of Mansonella ozzardi in the Brazilian Amazon.

Experimental infection with Mansonella ozzardi of common haematophagous Diptera collected at a Ticuna Indian village on the upper reaches of the Solimões river in the Brazilian Amazon, showed that Simulium amazonicum and Simulium n.sp. are capable of supporting full development of the parasite. Natural infections with this filaria were found in both species including infective larvae in Simulium n.sp. No development of M. ozzardi occurred in Mansonia amazonensis, Culicoides insinuatus or Lepiselaga crassipes (Tabanidae). The dimensions of developing larvae of M. ozzardi in both species of black-fly were recorded. Infective larvae of this species may easily be distinguished from those of Onchocerca volvulus, also transmitted in the Amazon by a species closely resembling S. amazonicum, by the presence of a bifid tail and higher anal ratio in M. ozzardi.

Animals↗
PubMed1983

The concentration of Mansonella ozzardi microfilariae in skin capillaries.

The densities of microfilariae of Mansonella ozzardi in different regions of the body of infected individuals were studied. The density in venous blood closely approximated to that found in finger capillaries, but was significantly lower than the densities in capillaries of the scapular region and buttocks. A possible explanation for this concentration of microfilariae is the lack of glomi in these two sites, which consequently have a lower flow of blood than areas where glomi occur and where microfilarial densities are lower. No relationship was found between blood and skin densities in the buttocks and scapular region, probably due to the inadequacy of the skin snip method used for the detection of this species of filaria. It was concluded that the most acceptable detection method for M. ozzardi remains the sampling of finger capillary blood. It could not be decided, due to the paucity of data, whether any relationship exists between skin microfilarial densities and the biting sites of the vectors.

Adolescent↗