Search

Your search keyword '"Chauvancy G"' showing total 5 results
Start Over Author "Chauvancy G" Topic insect vectors
5 results on '"Chauvancy G"'

1. [Efficacy of permethrin-impregnated Olyset Net mosquito nets in a zone with pyrethroid resistant vectors. I--Entomologic evaluation].

Author

Doannio JM, Dossou-Yovo J, Diarrassouba S, Chauvancy G, Darriet F, Chandre F, Henry MC, Nzeyimana I, Guillet P, and Carnevale P

Subjects
Adolescent, Adult, Animals, Anopheles genetics, Anopheles parasitology, Cote d'Ivoire epidemiology, Feeding Behavior, Female, Humans, Insect Vectors genetics, Insect Vectors parasitology, Insecticide Resistance genetics, Malaria epidemiology, Malaria parasitology, Malaria transmission, Male, Permethrin, Seasons, Anopheles physiology, Bedding and Linens, Insect Vectors physiology, Insecticides, Malaria prevention & control, Mosquito Control instrumentation, Pyrethrins
Abstract

The efficacy of permethrin-treated Olyset Net mosquito nets on malaria transmission and morbidity was studied in Kafine, a village located in the savanna region of the Cote d'Ivoire in Africa. After collecting sociodemographic, entomological, and parasitological data, bednets were distributed first in the southern half of the village and then in the whole village. Throughout the study period, mosquito specimens were captured on the skin of inhabitants at four points in the village between 6 PM and 6 AM both inside (but outside bednets) and outside houses. Prior to distribution of bednets, the mean biting rate (MBR) by Anopheles gambiae was 77.4 bites per man per night (b/m/n). The mean parturity rate (MPR) was 40.6 p. 100, the sporozootic index (SI) was 0.99 p. 100, and the mean entomological inoculation rate (MEIR) was 0.7 infectious bites per man per night (b+/m/n). Six months after distribution of bednets in the southern half of the village, MBR was 80.2 b/m/n, MPR was 32 p. 100, SI was 1.8 p. 100, and MEIR was 0.83 b+/m/n. After extending distribution to the whole village, data from November 1996 to July 1997 were as follows: MBR, 67.8 b/m/n; MPR, 20.1 p. 100; SI, 0.65 p. 100; and MEIR, 0.66 p. 100. From August 1977 to July 1998, data were as follows: MBR, 102.6 b/m/n; MPR, 26.2 p. 100; SI, 1.15 p. 100; and MEIR, 0.74 b+/m/n. Comparative analysis of these data showed that use of bednets had no effect on the bite or entomological inoculation rate. This is in agreement with the documented resistance of vectors in the study zone to permethrin. Despite the known stimulation/repulsion effect of permethrin, use of treated bednets had no real impact on transmission. This inefficacy could be related to the high prevalence (80 p. 100) of the Kdr gene (responsible for resistance) in the savanna form of Anopheles gambiae.

Published
1999

2. Malaria in Côte d'Ivoire wet savannah region: the entomological input.

Author

Dossou-yovo J, Doannio JM, Rivière F, and Chauvancy G

Subjects
Animals, Breeding, Cote d'Ivoire, Humans, Insect Bites and Stings, Longitudinal Studies, Malaria, Male, Population Dynamics, Seasons, Anopheles classification, Appetitive Behavior, Insect Vectors classification
Abstract

A two years study has been carried out in Alloukoukro, a traditional wet savannah village in the central region of Côte d'Ivoire. The productive breeding sites of malaria vectors are natural puddles and some man-made shelters around the village. 576 man-nights of capture have identified Anopheles gambiae s.l. and An. funestus as vectors of malaria in the study area. The low densities of An. phaorensis and An coustani implies that their possible role in transmission is very negligible. An. gambiae s.l. was the predominant species throughout the year with a mean of 19.2 b/m/n in 1991 and 13.6 b/m/n in 1992. The densities of An. funestus increased gradually during the rainy season and reached its peak values towards the end of the season. An. gambiae s.l. assures transmission throughout the year. An. funestus maintains a seasonal transmission which is spread over seven months. In 1991, each person would have received an average of 264.5 infected bites altogether with 204.5 infected bites from An. gambiae s.l. and 62 infected bites from An. funestus. In 1992, there would have been 196.5 infected bites per man with 160 and 36.5 infected bites respectively from An. gambiae s.l. and An. funestus. This study has shown that in wet savannah areas, the rainy season spreading almost all over the year, allows the breeding sites to retain water much longer and thus, to keep alive a more important residual vector populations capable to ensure malaria transmission even during the dry season. The great majority of infected glands (96.7%) were observed between 11 p.m. and 04 a.m. So, the large scale use of treated bednets has been therefore strongly recommended as key measure against malaria transmission in this area.

Published
1995

3. [Evaluation of the immunological and entomological indices of yellow fever in the subprefecture of Taï, Ivory Coast].

Author

Thonnon J and Chauvancy G

Subjects
Adolescent, Adult, Animals, Child, Child, Preschool, Cote d'Ivoire, Female, Humans, Immunoglobulin G blood, Immunoglobulin M blood, Male, Middle Aged, Yellow Fever transmission, Yellow fever virus immunology, Aedes, Antibodies, Viral blood, Insect Vectors, Yellow Fever immunology
Abstract

The authors report the results of a serological sample survey managed to evaluate the prevalence of yellow fever antibodies, connected with an entomological survey, in the area of Taï in Côte d'Ivoire. The refugee population has a high rate of non protected people, contrary to the Ivory population especially under 15 years old, because Côte d'Ivoire has included YF vaccine in his Expanded Programme on Immunization. A campaign of vaccination has been carried out.

Published
1994

4. [Dynamics of malaria transmission in Kafine, a rice growing village in a humid savannah area of Cote d'Ivoire]

Author

Jm, Doannio, Dossou-Yovo J, Diarrassouba S, Me, Rakotondraibé, Chauvancy G, Fabrice Chandre, Rivière F, and Carnevale P

Subjects
Population Density, Mosquito Control, Climate, Insect Bites and Stings, Agriculture, Humidity, Oryza, Insect Vectors, Malaria, Culex, Cote d'Ivoire, Aedes, Anopheles, Animals, Humans, Seasons
Abstract

A study on malaria transmission based on samples of mosquitoes caught on human subjects was conducted from February to August 1995 in the rice growing area of Kafine, a village located in the Niakaramandougou district of northern Côte d'Ivoire. The village is surrounded by 117,500 acres of rice fields. Irrigation is sub-permanent in the rice field and harvests number two a year. During the 6 months of the study, 12.353 mosquitoes were caught. The average biting rate was 118.8 bites per man per night (b/m/n). Mansonia, Culex and Aedes represented only 17.5% of the total number of mosquitoes caught. Anopheles accounted for 82.5% of the number of anthropophilic mosquitoes. Anopheles gambiae s.s. represented 83.7% of the total Anopheles species. As a whole, the average biting rate recorded for the Anopheles was 98 b/m/n. The average biting rate of An. gambiae was 90.4 b/m/n. The highest rate (121.5 b/m/n) was recorded in April. During the dry and rainy season, the indoor biting cycle per hour of An. gambiae s.s. was studied from 6 p.m. to 6 a.m. In both seasons, a marked biting activity was noticed between 10 p.m. and 5 a.m. The average annual parity rate reached 40.2% but it ranged from 59.8% (n = 82) in February to 19% (n = 63) in May. The mean sporozoitic index of An. gambiae throughout the study period was 1.1% (14 positive salivary glands/1.251 dissected). The index ranged from 0 in April, May and June to 6.2 (n = 192) in July. The rate did not vary with rainfall but with the different stages of rice growing. The non-synchronisation of agricultural practises for each growing cycle seemed to be a conclusive factor in the transmission of malaria in this locality. Malaria transmission at Kafine can be characterised by 3 main elements: transmission is intensive with an estimated inoculation rate of 1 ib/m/n; transmission is more related to double phase rice cultivation (regardless of synchronisation on plots) than to rainfall; transmission shows particular variations linked to rice cultivation cycles with an increase during periods of ripeness and harvest. The nuisance caused by higher mosquito density has brought people to comply with use of pyrethroid impregnated bed nets advocated for wide use by the National Malaria Control Program.

5. [Efficacy of permethrin-impregnated Olyset Net mosquito nets in a zone with pyrethroid resistant vectors. I--Entomologic evaluation]

Author

Jm, Doannio, Dossou-Yovo J, Diarrassouba S, Chauvancy G, Darriet F, Fabrice Chandre, Mc, Henry, Nzeyimana I, Guillet P, and Carnevale P

Subjects
Adult, Male, Insecticides, Mosquito Control, Adolescent, Bedding and Linens, Feeding Behavior, Insect Vectors, Malaria, Insecticide Resistance, Cote d'Ivoire, Anopheles, Pyrethrins, Animals, Humans, Female, Seasons, Permethrin
Abstract

The efficacy of permethrin-treated Olyset Net mosquito nets on malaria transmission and morbidity was studied in Kafine, a village located in the savanna region of the Cote d'Ivoire in Africa. After collecting sociodemographic, entomological, and parasitological data, bednets were distributed first in the southern half of the village and then in the whole village. Throughout the study period, mosquito specimens were captured on the skin of inhabitants at four points in the village between 6 PM and 6 AM both inside (but outside bednets) and outside houses. Prior to distribution of bednets, the mean biting rate (MBR) by Anopheles gambiae was 77.4 bites per man per night (b/m/n). The mean parturity rate (MPR) was 40.6 p. 100, the sporozootic index (SI) was 0.99 p. 100, and the mean entomological inoculation rate (MEIR) was 0.7 infectious bites per man per night (b+/m/n). Six months after distribution of bednets in the southern half of the village, MBR was 80.2 b/m/n, MPR was 32 p. 100, SI was 1.8 p. 100, and MEIR was 0.83 b+/m/n. After extending distribution to the whole village, data from November 1996 to July 1997 were as follows: MBR, 67.8 b/m/n; MPR, 20.1 p. 100; SI, 0.65 p. 100; and MEIR, 0.66 p. 100. From August 1977 to July 1998, data were as follows: MBR, 102.6 b/m/n; MPR, 26.2 p. 100; SI, 1.15 p. 100; and MEIR, 0.74 b+/m/n. Comparative analysis of these data showed that use of bednets had no effect on the bite or entomological inoculation rate. This is in agreement with the documented resistance of vectors in the study zone to permethrin. Despite the known stimulation/repulsion effect of permethrin, use of treated bednets had no real impact on transmission. This inefficacy could be related to the high prevalence (80 p. 100) of the Kdr gene (responsible for resistance) in the savanna form of Anopheles gambiae.

Catalog

Books, media, physical & digital resources
See catalog results