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F Le Pont

Publications and source records attributed to F Le Pont.

At least 37 records · Page 2Linked to original sources
PubMed1995

Description of Lutzomyia (Pifanomyia) robusta n. sp. (Diptera, Psychodidae, Phlebotominae) from Peruvian Equadorean interandean areas.

Description of Lutzomyia robusta, n. sp. (Diptera, Psychodidae, Phlebotominae) from interandean areas of Peru and Equador. Lutzomyia robusta, n. sp., probable vector of human bartonellosis and cutaneous leishmaniasis, is described and illustrated. This species presents strong affinity with L. serrana (Damasceno & Arouck, 1949) but they can be distinguished by variance analysis of four male characteristics and only one female characteristic. In the variance analysis, populations of L. serrana, of Amazonian areas of Brazil, Peru and Bolivia, the coast of Equador and other areas of Brazil were studied. The synonymy of Lutzomyia guayasi (Rodriguez) and L. serrana was corroborated.

Analysis of Variance↗
PubMed1995

Sexual behaviour and HIV epidemiology: comparative analysis in France and Britain. The ACSF Group.

OBJECTIVE: France and Britain have similar size populations, yet the incidence of AIDS is threefold higher in France. The objective of this study was to compare data from two surveys recently performed in the two countries, in order to determine whether differences in sexual and drug-use behaviour could explain the different epidemiological patterns. DESIGN: Cross-sectional random sample surveys of France and Britain. RESPONDENTS: In France, 20,055 persons aged 18-69 years and in Britain, 18,876 persons aged 16-59 years were interviewed in 1990-1991. The following indicators were compared in the respondents aged 18-59 years: prevalence of homosexual experience and injecting drug use, number of sexual partners, prevalence of sexual practices, condom use and sex with prostitutes, age of sexual partners. RESULTS: Very similar results were found for the prevalence of male homosexual partnerships. Slightly higher numbers of lifetime partners were reported by French than British men, but no difference was found for recent periods. Anal intercourse and sex with prostitutes was more frequent among heterosexual French people than British people. Condom use was more systematic in Britain than in France. CONCLUSION: Only small differences were found between the two countries, although prevalence of risk indicators were higher in France. These differences combined with early development of prevention policies in Britain, together with the timing of virus introduction, may contribute to differences between the epidemics in the two countries.

Acquired Immunodeficiency Syndrome↗
PubMed1994

[Leishmaniasis in Ecuador. 1. Incidence of cutaneous leishmaniasis on the Pacific coast].

A clinico-epidemiologic survey on cutaneous leishmaniasis, due to Leishmania panamensis, was carried out on 961 persons in two study areas of the Pacific coast of Ecuador, to estimate the prevalence and the incidence of the disease. In the preandean hills, at Paraiso Escondido, the prevalence of active lesions was 4.8%; in the hills of the coastal cordillera, at La Tablada, it was 3.6%. The incidence of new cases in 1991 was high: 147% in the first village, and 106% in the second. These data are far higher than the Health Ministry statistics. The cumulated prevalence, obtained by addition of the scars and active lesions of leishmaniasis, was as high as 66% at Paraiso Escondido, and 47% at La Tablada. Most of the patients (62%) had only one ulcer or scar. Most of the people are contaminated during the first five years they live in these endemic areas. Nevertheless, the incidence remains high in all the age groups, because large numbers of migrants coming from non endemic regions are continuously settling in these colonization areas. Interviews have shown that the contaminations had occurred in the dry season, between July and December. These findings were confirmed by passive case detection at the Hospital A. Egas of Santo Domingo which covered the region. Contamination of young children and position of the lesions on the face suggested a domiciliary transmission, like in Panama and on the Pacific coast of Colombia.

Adult↗
PubMed1994

[Leishmaniasis in Ecuador. 4. Natural infestation of the dog by Leishmania panamensis].

In two endemic leishmaniasis foci of the Pacific coast of Ecuador 34 dogs suspected of having the disease have been surveyed clinically, serologically and parasitologically; immunofluorescence and electrosyneresis tests, lymph node aspirates, biopsies and smears have been performed. From two dogs with ulcers only one had ulcers on the muzzle and the scrotum infected by Leishmania (L. guyanensis complex). The isolated strain was identified as Leishmania panamensis. The disease was strictly cutaneous. In the study area the dog seems to be more a victim-host than a reservoir.

Animals↗
PubMed1994

[Leishmaniasis in Ecuador. 5. Leishmaniasis and anthropization on the Pacific coast].

We have evaluated the impact of anthropization of the forest on the incidence of leishmaniasis, due to Leishmania panamensis, in three coastal study areas, Corriente Grande (primary forest), Paraiso Escondido and La Tablada (secondary forest). The situation of isolated dwellings, in deforested areas, has also been analysed in the last two stations. In each station, the study of the density of anthropophilic sand flies, specially Lutzomyia trapidoi, has been conducted in the domestic environment, coffee plantations and undergrowth. The incidence of leishmaniasis was nearly non existent in primary forest, though it ranged from 106 to 147% in the more or less cleared forest. At Corriente Grande, none Lu. trapidoi was caught in houses. In the undergrowth, catches were low (8% of the total). At Paraiso Escondido, Lu. trapidoi was the dominant species, with more than 83% of the catches in the undergrowth and in the coffee plantations (41 Man/hour), as well as in dwellings (10.6 M/h). At La Tablada, in the domestic environment, Lu. gomezi, was the dominant species: 2.8 M/h against 0.1 M/h for Lu. trapidoi. In the coffee plantations and in the undergrowth Lu. trapidoi was the main species, 21 M/h and 14 M/h. Thus in the primary rainforest, leishmaniasis transmission can be very low. In disturbed forest, coffee plantations near houses are good biotopes for Lu. trapidoi. The cycle of L. panamensis has been adapted to this new ecological situation, by being closer to the houses. The reservoirs live and circulate throughout coffee plantations. In deforested areas, neither aggressive sand flies have been observed, nor leishmaniasis transmission.

Animals↗
PubMed1994

[Leishmaniasis in Ecuador. 6. Epidemiological and entomological note on the focus of leishmaniasis in Zumba].

The Zumba focus of tegumentary leishmaniasis lies in the southwards Amazonian region of Ecuador. A clinico-epidemiological study has been carried out in the area on 83 patients attending health centers. All the biotopes suitable for sandflies, including dwellings, have been sampled from February to September 1992 by light trap and human bait catches. The number of sandflies caught amounts to 2,547. Anthropophilic sandfly fauna is poor and only three species have been recorded. Lutzomyia serrana abounds inside dwellings where it bites men even during daytime. The parasite was identified as an intermediate form between Leishmania panamensis and L. braziliensis. It will be described elsewhere. The high proportion of facial lesions suggests a domiciliary transmission for which Lu. serrana could be a good vector candidate.

Adolescent↗
PubMed1993

[Notes on the phlebotomus of Aïr (Niger)].

238 phlebotomine sandfly belonging to seven species have been collected in four localities of Niger, in the Aïr mountain range. Phlebotomus bergeroti was the dominant species in animal bait and in collections inside dwellings. Some attention has to be paid to P. alexandri, a recognized vector of kala-azar elsewhere.

Animals↗
PubMed1993

[Development of a factual model for the dynamics of the transmission of infection by the human immunodeficiency virus: an example for animal epidemiology].

In order to simulate the spreading mechanism of human immunodeficiency virus (HIV), a factual approach was developed given the ease of incorporating new knowledge and taking into account the variability of a large number of sociological, biological and demographic factors, and also on account of the dynamics of the relational network of individuals. By way of example, the model was applied to data concerning homosexuals in San Francisco (United States of America) between 1980 and 1987, which enabled an evaluation to be made of the probability of HIV transmission from each partner, using two hypotheses about the evolution of contagiousness of an infected individual during the incubation period. An analysis of the sensitivity of the model revealed certain factors which had a strong influence on the growth of the epidemic. Application of this technique to the entire population of France is planned.

Animals↗
PubMed1991

The supply and demand dynamics of sexual behavior: implications for heterosexual HIV epidemics.

This article investigates the supply and demand dynamics of sexual behavior in a simple epidemiological model of heterosexual transmission of human immunodeficiency virus (HIV). The supply and demand dynamics of sexual behavior are modeled by specifying implicit sexual behavior change (ISBC) mechanisms. These mechanisms specify how males and females modify their rates of sex partner change in response to changes in the availability of the opposite sex. During an epidemic, the availability of both sexes will change owing to recruitment and mortality; consequently, implicit sexual behavior changes will be induced. These behavior changes will be independent of any explicit sexual behavioral changes that may occur as a result of intervention strategies. We investigate four different ISBC mechanisms: the two extremes of the continuum of possible mechanisms (where only one sex changes behavior), as well as two intermediate possibilities (where both sexes change behavior). The results show that the epidemiological effects of these ISBC mechanisms depend upon the transmission speed of the virus. If HIV transmission is slow, the epidemiological effects of the four ISBC mechanisms cannot be differentiated. If HIV transmission is fast, the four ISBC mechanisms differ considerably in the degree to which they modify the gender-specific rates of sex partner change, but the sexual behavioral changes occur too late to significantly decrease the cumulative number of infected persons. However, if HIV transmission is moderately fast, the four different ISBC mechanisms produce significantly different epidemics. The differences between the epidemics, produced by the four ISBC mechanisms, are magnified as the degree of asymmetry between the heterosexual transmission efficiencies increases. We discuss the implications of our results for both the future number of AIDS cases that will be observed in the "real world" and the number of AIDS cases that will be predicted from mathematical models. We also discuss the implications for studies that evaluate the causation of sexual behavior changes.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Separation of Psychodopygus carrerai carrerai and P. yucumensis (Diptera: Psychodidae) by gas chromatography of cuticular hydrocarbons.

Specimens of two species of sandfly, Psychodopygus carrerai carrerai and P. yucumensis, vectors of Leishmania braziliensis braziliensis in the subandean lowlands of Bolivia, were subjected to cuticular hydrocarbon analysis to ascertain if the technique could separate the females. A high degree of separation (87%) was obtained based on significant differences in the cuticular hydrocarbon composition of these two species. Statistical treatment of the data shows that these species, initially identified by the colour of the mesonotum, can also be distinguished by their hydrocarbons.

Animals↗
PubMed1990

[Attraction of the armadillo (Dasypus novemcinctus, L.) and guinea pigs for phlebotomines in French Guiana].

During 60 night-catches of sand-flies using armadillo baited Disney-traps, 7 Psychodopygus species were recorded. They account for 84% of the whole catches; eight times more flies were recorded from "terra firme" forest than in the marshy shallows. P. ayrozai (Barretto and Coutinho) is the main species all the year long (45% to 85% of the catches); it is followed by P. squamiventris maripaensis (Ready et al.). In Brazil, P. ayrozai is the presumptive vector of the Leishmania (V.) naiffi Lainson and Shaw of armadillo, and P. s. maripaensis has been found infected by parasites of the subgenus Viannia. Lutzomyia (Nyssomyia) flaviscutellata (Mangabeira), a forest-floor vector of Le. (Le.) amazonensis Lainson and Shaw is also attracted by the armadillo. In guinea-pig baited traps (44 night trappings), L. (N.) flaviscutellata and P. claustrei Abonnenc et al. were the dominant species.

Animals↗
PubMed1989

[Impact of the spraying of deltamethrin in a focus of leishmaniasis in Bolivia].

After one month of entomological observations to record pretreatment data, a sub Andean village of Yungas, Bolivia (alt. 1500 m) was sprayed at the beginning of the rainy season (January 1987). Houses were treated inside and outside with deltamethrin at 0.025 g/sq.m.; kennels, hen-houses and stacks of adobe were also sprayed in the same way. As a result of the treatment, Lutzomyia longipalpis, the local vector of visceral leishmaniasis, disappeared from houses and animal shelters for 9 and 10 months respectively. The impact of the treatment on the populations of Lu. nuneztovari and anglesi, the presumed vector of tegumentary leishmaniasis, was not obvious. As compared with pretreatment data, the rate of engorged females in houses decreased by two, and their density was also reduced. But these data are difficult to interpret due to the natural seasonal variation in density in this species. Moreover, the information from the control village did not correspond as expected. Lu. n. anglesi is a highly exophilic species in this area, a behaviour which could explain the limited impact of the treatment on this sandfly.

Aerosols↗
PubMed1989

[Epidemiology of cutaneous leishmaniasis in Bolivia. 1. Description of study zone and prevalence of the disease].

An epidemiological survey of tegumentary leishmaniasis (Leishmania (Viannia) braziliensis) was carried out in three regions of Bolivia in the Andean foothill and Amazonian forest. It was based on the record of lesions and scars on all the inhabitants of selected representative villages. In the Yungas, an area cultivated from the XVIIth century, males and females are equally infested, mostly before they were 10 years old (65%); 48% of scars were on the head. In Alto Beni and Pando, areas covered with primary rain forest, males are significantly more affected than females. The majority of scars were on the legs. The males of the three areas were equally affected. These results suggest that: --in the Yungas, contamination takes place among children in villages during the night; --in the Alto Beni and in the Pando, the infection rate is linked to the professional activities of adults, and men are more at risk than women. Only 7% of the lesions are evolving in grave forms of mucocutaneous ulcers. These forms represent the main load of the disease from the public health point of view. It has been found heavier in the Yungas (1.32%) and in the Alto Beni (1.14%) than in the Pando (0.21%). It should be noted that the first infection can give raise to several lesions. But reinfections are rare, which supports the view that the first infection is protective against the following ones.

Adolescent↗
PubMed1989

[Epidemiology of cutaneous leishmaniasis in Bolivia. 2. Transmission patterns].

In Bolivia the transmission of tegumentary leishmaniasis due to Leishmania (V.) braziliensis depends both on environmental factors and human activities. In the Yungas, transmission takes place in the houses during the night. The vector is Lutzomyia nuneztovari anglesi Le Pont & Desjeux, which enters the houses after 10 p.m. and leaves them before 6 a.m. This transmission pattern explains why men and women are equally infected, generally before 10 years old. Some more adults are infected very likely in coffee plantations or in the relict forest where the same vector species abounds and bites in daytime. In the Alto Beni, pioneers, mainly males, are infected when clearing the forest. Three Psychodopygus species have been shown to be the vectors. The risk is drastically decreasing when people establish in plantations or nearby villages because sandfly vectors do not get easily out of the forest cover. In the Pando, forest people are infected when harvesting Brazil-nuts or bleeding the rubber-trees, the two main activities in the area. It is very likely that Ps. c. carrerai is one of the vectors. Pando and Alto Beni primary rain-forests are natural primary foci of Le. braziliensis. So far the mammalian reservoirs are unknown but the circulation of the parasite has been proven by the fast contamination of receptive people entering the forest. The Yungas primary forest may be also considered as a relict focus. The cultivated area of the Yungas is an anthropic secondary focus. The vector Lu. n. anglesi became adapted to coffee plantations from which it enters the houses and transmits the parasite to man.

Adolescent↗
PubMed1989

Blood donation and HIV infection: impact of seroconversion delay on the sensitivity of the testing procedure.

This study estimates the impact of the delay of seroconversion on the global sensitivity of the testing procedure among regular blood donors who give 80% of blood donations in France and in the USA. When applied to the 1987 French data, an estimate of 77 to 161 false negative donations, depending on the assumption concerning the mean seroconversion delay, was obtained, as compared to the 388 positive donations detected. The global sensitivity of the testing procedure ranged from 70 to 83%. When applied to the 1986-87 American data, an estimate of 192 to 432 false negative donations was obtained, as compared to the 1728 positive donations detected. The global sensitivity of the testing procedure ranged from 80 to 90%. These results emphasize the need to recruit blood donors in low risk subgroup populations and to develop more sensitive biological tests.

Blood↗
PubMed1987

Cutaneous leishmaniasis in Bolivia. A study of 185 human cases from Alto Beni (La Paz Department). Isolation and isoenzyme characterization of 26 strains of Leishmania braziliensis braziliensis [corrected].

A clinical, serological, parasitological and therapeutic study of cutaneous leishmaniasis was carried out in a low sub-andean area (250-800 metres) of the La Paz Department, Bolivia. A team of seismic prospectors (350 workers) was surveyed for 12 months. Of 200 suspected cases of cutaneous leishmaniasis, 185 were serologically or parasitologically confirmed (incidence 52.8%). Those exposed to the greatest risk of infection were working in a virgin forest environment. Leishmanial organisms were isolated from 26 of the workers, either by in vitro cultivation or inoculation into hamsters. Isoenzyme characterization of the organisms by cellulose acetate electrophoresis showed them to be Leishmania braziliensis braziliensis [corrected]. The results of treatment of 168 patients with a pentavalent antimonial drug are also reported.

Animals↗