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J Mouchet

Publications and source records attributed to J Mouchet.

At least 55 records · Page 3Linked to original sources
PubMed1994

[Leishmaniasis in Ecuador. 3. Lutzomyia trapidoi, vector of Leishmania panamensis].

Lutzomyia trapidoi, the more abundant anthropophilic species, is a presumed leishmaniasis vector in the Pacific foothills of Ecuador. Three biotopes have been sampled (dwelling, and nearby coffee crop and primary forest) in the focus of Paraiso Escondido, by human bait catches, from August 1991 to October 1992. A large number of sandflies, 6,965 specimens, have been dissected to estimate peri and hypopyloric infections. All the peripyloric infections, characterized by isoenzyme electrophoresis, were Leishmania panamensis. The percentage of these infections was low, around 3%, but they were massive. They occurred only in dry season. Hypopyloric infections were observed in Lu. trapidoi all the year round in the three biotopes. Their percentage was high, reaching 40%. Despite of many trials to cultivate the parasite on NNN medium, no stain could be isolated. It is suggested that the parasite could be L. equatorensis.

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

[Epidemiological stratification of malaria in Madagascar].

Madagascar is considered as a sub-region of the Afrotropical geographical Region in spite of the high endemicity of 95% of the invertebrates. Nevertheless the three malaria vectors An. gambiae s.s., An. arabiensis and An. funestus are quite similar to those of the continental Africa. This support the hypothesis of their recent introduction. Plasmodium falciparum is the dominant parasite but the prevalence of P. vivax is not negligible. It is linked to the Asian component of the human population. P. malariae and P. ovale are of minor importance. The main epidemiological "facies" of Africa are found in Madagascar. The equatorial facies on the East Coast is characterized by a high transmission all year long. In the tropical facies on the West Coast transmission is seasonal (7 months at least). In both areas, malaria is stable and the inhabitants acquire a high immunity before the age of ten; most of the severe cases touch children below 10. The three vectors can be found but An. gambiae s.s. is dominant. In the exophilic southern facies the transmission is seasonal (two to four months). The only vector is An. arabiensis. Malaria is unstable and severe epidemics occur during the years of high rainfall. All age groups are vulnerable because the population is not immune in the Plateaux facies above 1,000 m., malaria is unstable. Severe epidemics occurred in 1987-1988. The vectors are An. Arabiensis and An. funestus. The occurrence of P. falciparum on the Plateaux seems linked to the development of irrigation of rice farming in the XIXth century. Most of the anopheles breeding places on the Plateaux are dependent on rice cultivation. Urban development has brought the inhabitants of the suburbs in close contact with rice fields. Despite the high number of anopheline bites the number of malaria cases remains by far lower than in the neighbouring rural areas. Regional migrations inside the island bring non-immune populations, from the south and the plateaux, in highly malarious areas of the coast, where the migrants are exposed to high risk. In spite of 40 years of uncontrolled use, chloroquine can still cure most, if not all, of malaria cases. Control measures appropriated to the different areas of Madagascar are discussed.

Agriculture↗
PubMed1993

[Malaria in the Saharan region of Senegal. 1. Entomological transmission findings].

An 18 months longitudinal survey on the entomological aspects of the transmission of malaria has been carried out in a village practising rice field irrigation and in another village with traditional rain water agriculture. Both are located in the Sahelian area of the Senegal river central valley, in Senegal. The study is based on mosquito samples caught on human baits. The vectors A. arabiensis and A. gambiae could be found all year long in the village with rice field irrigation, but only during the rainy season in the other village distant from the rice field area. The average aggressive density decreases with the remoteness from the rice field area. From 16 bites/man/night (BMN) in the rice field area, it decreases to 7 BMN at 500 m and to 1 BMN at 5 km distance. The malaria transmission rate is weak and was not perceptible in the villages located far away from the rice field area. In the village close to the irrigated rice field, only one infected A. gambiae s.l. has been caught during the period of study. Physiological age is higher in the rice field area, but the anthropophilic index is lower. The different parameters involved in malaria transmission show important seasonal and yearly variations. Irrigation has, on the whole, increased mosquito population densities and particularly that of A. gambiae s.l., but malaria transmission does not seem to be influenced by this increase.

Animals↗
PubMed1993

[Mosquito nets impregnated against malaria in Zaire].

On the Bateké plateau 60 km east of Kinshasa, Zaïre, where malaria is stable, three villages have been selected for a trial of malaria control using bednets impregnated with deltamethrin at 25 mg per square meter from February to November 1991. One village (3,000 inhabitants) has been provided 800 impregnated bednets and an other one (2,900 inhabitants) kept 800 non impregnated bednets. The third village (900 inhabitants) served as a control and has remained without nets. Anopheles gambiae was the main and nearly exclusive vector of malaria. Its biting density was reduced by 94% in the village protected by impregnated bednets and the inoculation rate dropped from 182 infective bites/man/year to 3.7 a decrease of 98%. The longevity of the vector expressed by its expectation of life decreased from 11.02 days to 3.64 days. In the village where inhabitants were protected by non impregnated nets, as well as in the control, the entomological indexes did not change. In the village protected with impregnated nets the malaria prevalence decreased by 50%, five months after the beginning of the experiment. The high parasitemia, above 10,000 and 20,000 parasites per mm3 decreased by 77% and 83% in the 0-7 year age group and by 67% and 65% in the 8-14 year group in the protected village. These high parasitemias are good markers of the clinical malaria risk. The experiment can be considered as very satisfactory on the point of view of public health.

Adolescent↗
PubMed1993

[Introduction of onchocerciasis in Central America: the role of the French expeditionary corps to Mexico (1861-1867)].

Close relationships between American and African strains (from savanna) of onchocerciasis have been confirmed by biochemical analysis. It is admitted that the parasite could have been introduced by slave trade. But in Mexico, Torroela supported the hypothesis that onchocerciasis was introduced by Nubian soldiers of the French troops between 1861 and 1867. Some of the 600 soldiers of the Egyptian bataillon, included in the French expeditionnary corps, could have been onchocerciasis carriers. But these troops caserned in Vera Cruz remained in the littoral plain and have not been in contact with the Oxoaca focus of onchocerciasis. It is very unlikely that they can have been at the origin of the disease focus.

Egypt↗
PubMed1992

Transmission factors in malaria epidemiology and control in Africa.

Genetic and environmental components of factors contributing in malaria transmission are reviewed. Particular attention is given to density dependent regulation of vector populations in relation to the survival rate of anophelines. The expectation of vector control activities are different according to the epidemiological characteristics of malaria, mainly its stability. In areas with perennial and high transmission (stable malaria) vector control could reduce malaria related morbidity and mortality, without any effect on the endemicity. However this need further investigations. In areas where the transmission period is very short (unstable malaria), vector control will have an important impact on the disease and on the endemicity. Control projects using indoor spraying with insecticide and impregnated bed nets are discussed.

Africa↗
PubMed1992

[Anopheles paludis: important vector of malaria in Zaire].

An entomological study was carried out on the transmission of malaria in the Bandundu region, Zaïre, during the dry season (July and August 1991). Five Anopheles species were recorded: Anopheles paludis, A. gambiae, A. funestus, A. moucheti and A. nili. A paludis was the dominant species and represents 55.1% of the total; the average number of A. paludis bites per man/day was 4.2. The sporozoite index was 6.2%; the inoculation rate due to A. paludis was h = 0.26, 1 infective bite each 4 days. A. paludis plays an important role with A. gambiae and is considered as one of the main vectors of malaria in this region.

Animals↗
PubMed1992

[Evaluation of the efficacy of fenitrothion (Sumithion PM40) on vector density and the prevalence of malaria in Pout (Thiès, Sénégal)].

House-spraying with fenitrothion for malaria control was evaluated in three villages of the Pout rural community (Senegal) between August 1988 and October 1990. The baseline data were collected during the first year. The malaria vector was identified as Anopheles arabiensis and the highest malaria prevalence was observed in October 1988 (38%) in the child population (2-9 years old). A simple round of fenitrothion house-spraying at 1 g/m2 was carried out in the second part of July 1989. About 90% of the houses were treated. The malaria vector was reduced to negligible density and a rapid decrease of malaria prevalence was observed. In this area of short seasonal transmission, where the stability of malaria is low, one single round of spraying led to a marked reduction of malaria transmission and prevalence. The cost of the treatment was about 50 US cents per capita.

Animals↗
PubMed1992

[Diversity of malaria in the Sahelo-Saharan region. A review apropos of the status in Niger, West Africa].

The concept of epidemiologic facies of malaria underlines the diversity in the expression of the disease in areas where important ecological variations interfere largely with transmission. Niger is quite a border region between the afrotropical fauna from the south and the Palearctic fauna from the north. The last one filters through the mountains where it maybe represents a relic of ancient paleoclimates. Annual variations of the northern limit of Anopheles arabiensis, in the Sahelo-Saharan region including some oasis, are related to temporary breeding places produced by seasonal rainfall, after estivation during the dry season or after a long migration with the wind. An. gambiae s.s is present in the south and along the Niger river, with An. funestus, even till Zinder. The northern limit of An. nili is the Niger river. The permanent variations of the environment induce great differences in the level of transmission between an intermediate stable situation in the south to an unstable one in the north. Epidemic outbreaks appear some years in vulnerable populations. The implementation of a malaria program supposes to take account of the various eco-epidemiologic situations all over the country. Even if mortality and morbidity became lower, natural precaution in some groups of people must be preserved.

Adolescent↗
PubMed1991

[The impact of impregnated mosquito nets on prevalence and morbidity related to malaria in sub-Saharan africa].

Insecticide treated bed nets (permethrin, deltamethrin and lambda cyalothrin) were used for malaria control in The Gambia, Burkina Faso and Tanzania where Anopheles gambiae (and An.funestus in Burkina Faso) is the main vector. Treated mosquito nets are efficient when used on a large scale and not on an individual level. Such a large scale use, acting on longevity and infectivity of vectors, always induced a decrease of malaria transmission by more than 90%. Treated bed nets had no significant effect on the overall parasite rate, showing that malaria transmission was not stopped. But it was usually found that there was a significantly smaller number of children with parasitemia higher than a critical threshold, a sensitive parameter of malaria morbidity. Indeed, in the three situations studied, malaria morbidity (fever + high parasitemia greater than critical level in the concerned area) has generally shown a similar drop of 60%. These data demonstrate that treated bed nets are useful to reduce transmission and morbidity. Advised as a new way for reduction of nuisance, treated bed nets were always welcomed by the populations and this method may be considered as a complementary weapon in public health.

Adolescent↗
PubMed1991

[Which structures in anti-vector control?].

The lack of efficient tools is often incriminated to explain the absence of anti-vectorial activities in control programmes of vector borne diseases. However, we must recognize that the available tools are under utilized due to the lack of appropriate structures. Existing structures are reviewed. So far, results achieved by the Primary Health Care System (PHCS) are scarce. In fact, even simple methods need specific know-how for execution and specialised knowledge for planning and supervision, which differ from those needed for medical care committed to the PHCS. To develop the use of simple methods, adequate structures have to be elaborated, maintaining a peripheral character but in direct connection with a central level, which provides expertise, supervision of the activities and evaluation of the results. The association of research and operational programmes is essential to face problems linked with epidemiological, environmental, socio-economical modifications or changes in sensitivity to insecticides and for the integration of new techniques. It is also this tandem "research-control operations" which will provide the best environment for training.

Animals↗
PubMed1990

[Recent achievements and perspectives in medical entomology and vector control].

High technologies of molecular biology and genetics, supported by computer use brought considerable advances in taxonomy, physiology, host/parasite relationships, ecology and epidemiology. New insecticides, IGR and bacteria are now available. Both simple methods (e.g. tsetse trapping, impregnated bednets) and large programs using heavy material (e.g. O. C. P. in West Africa, mosquito control in Northern hemisphere) have been successful. Guineaworm control lies in an intermediate position. Malaria control has difficulties and needs new tools and a better use of those already existing. A few progresses are noticed in biological and genetical control. Appropriate structures, well trained and motivated personnel, adequate funding and political willingness are the keys for the implementation of any control programme.

Animals↗
PubMed1990

[Current strategies for the prevention of malaria].

Two billion of persons live in regions where endemic malaria prevails or has reappeared. An estimated on hundred million infected individuals per year have been reported around the world. In front of this alarming situation, the diversity and even the incoherence of the currently proposed prophylactic regimens confuses the therapists and renders difficult the adoption of an efficacious strategy. The extension and gravity of drug resistance of P. falciparum and the withdrawal of anti-vectorial campaign constitute two reasons for the present recrudescence of malaria. The preventive strategies in 1990 are based on: rehabilitation of anti-vectorial campaign particularly against nocturnal mosquito bites, applicable to all, everywhere and at all times, by the means of individual and collective measures and mostly by impregnated nets; chemoprophylaxis for which two situations should be distinguished: the non immune traveler leaving for a short period (inferior or equal to 3 months) to an endemic area: individuals living permanently or for long periods in tropical regions. Prevention for short stays In low risk transmission zone (North Africa, Mexico, large cities of South East Asia) whatever the duration, suppression of chemoprophylaxis is acceptable. In high risk transmission zone, three strategies exist according to the intensity and frequency of drug resistance: zone 1 (P. vivax or drug sensitive P. falciparum): chloroquine at a dose of 100 mg/day for adults (1.5 mg/kg/day for children) 6 days out of 7, from the day of departure trough the whole stay and for one month after the return, is still efficacious; zone 2 (moderate frequency of drug resistance): protection is again ensured by chloroquine only, as in zone 1, or better than that by the association of chloroquine 300 mg once a week and proguanil 200 mg/day (3 mg/kg/day for children). The side effects of mefloquine and the risk of generation drug resistance argue against its general use in this zone particularly in West Africa. In one year, we have already observed three chemoprophylactic failures with mefloquine in individuals returning from this region; zone 3 (high frequency of drug resistance and multiresistance): mefloquine, if well tolerated is justified in weekly intake. In case of contraindications or intolerance to mefloquine, which are becoming more frequent, no substitution for that chemoprophylactic regimen is presently available. In view of these facts, indications, contraindications and posologies of mefloquine should be reviewed to better profit from the remarkable characteristics of this antimalarial. Mefloquine should only be prescribed (excluding curative treatment) for chemoprophylaxis of short stays in zone 3. Some contraindications of this drug should be maintained (pregnant women) or made relative (treatment with B-blockers and in the absence of pediatric studies, children weighing less than 15 kg).(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

[Agriculture-health interface in the field of epidemiology of vector-borne diseases and the control of vectors].

This paper is a review of the interactions between agriculture and vector borne diseases. Rain forest clearing makes possible the development of heliophilous species of anophelines and snails leading to an increase of malaria and schistosomiasis in Africa. But in Asia, clearing is a control method against Anopheles balabacensis, an important malaria vector. Clearing of forest galleries is followed by the disappearance of shore-dwelling tsetse flies. Woodcutters and pioneer farmers are contaminated with arbovirus and leishmaniasis when entering in natural sylvatic foci of these diseases. Management of drinking water reduces guinea worm as well as cholera and other diarrhoeal diseases. More over when piped water becomes available people are no more obliged to store drinking water in containers where vectors use to breed. Reservoirs of dams offer large possibilities for the development of mosquitoes including anophelines vectors of malaria and filariasis and of snails hosts of schistosomiasis. The medical importance of these man-made breeding sites depends of the local epidemiological features of the diseases. Dam spillways provide breeding for blackflies and man-made foci of onchocerciasis have been described in West Africa. Irrigation channels mainly when non cleared of vegetation are good breeding places for anophelines and snails. Irrigated surfaces like rice fields are highly productive in anophelines and other dangerous species of Culicinae. Insecticides used in agriculture, mainly to control cotton and rice pests, have been at the origin of insecticide resistance of several anopheline species. On an other hand, sometimes rice pests control lead to the control of rice field mosquitoes until they become resistant, e.g. for Culex tritaeniorhynchus the vector of Japanese encephalitis in South Korea. Many international organizations have emphasized the role of intersectorial collaboration to control man-made vector borne diseases foci. Good planning of the infrastructures (e.g. twin spillways) and adequate maintenance are essential. Vector control in rice field is a puzzling question. Wet irrigation was a hope but it cannot be done everywhere. Biological control methods have not been proven to be very efficient. Even Bacillus thuringiensis H14 and B. sphaericus have severe limitation. New tools for intersectorial activities should be a goal for scientists imagination.

Agriculture↗