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Sylvie Manguin

Publications and source records attributed to Sylvie Manguin.

12 recordsLinked to original sources
PubMed2006

Impact of the Rift Valley on restriction fragment length polymorphism typing of the major African malaria vector Anopheles funestus (Diptera: Culicidae).

Anopheles funestus Giles (Diptera: Culicidae) is one of Africa's major malaria vectors. To understand population structure within An. funestus, various molecular markers have recently been developed. We investigated the impact of the Rift Valley on one such molecular marker, a polymerase chain reaction-restriction fragment length polymorphism (RFLP). This system distinguishes An. funestus populations into types M, W, and MW. Generally, these types correlate between geographical location and RFLP type, whereby M associates essentially with eastern Africa, W with western and central Africa, and MW with southern Africa. In total, 606 specimens were screened from 12 countries. Specimens from southern African localities were of the expected MW-type with the exception of the sample from Malawi, which showed all three types. The specimens from Tanzania showed the M- and MW-types, whereas specimens from Kenya showed M- and W-types. We also recorded different RFLP types not recorded previously. Type Y was recorded in Malawi, and Z-type was recorded from four localities: Angola, Malawi, Ghana, and Zambia.

Africa, Eastern↗
PubMed2006

How reliable is the humeral pale spot for identification of cryptic species of the Minimus Complex?

The Anopheles minimus Complex Theobald (Diptera: Culicidae) is composed of the 3 sibling species A, C, and E. The malaria vectors An. minimus A and C are distributed over the Southeast Asian region, whereas species E is restricted to the Ryukyu Japanese Islands. Because species A and C can be sympatric and present specific behaviors and have a role in malaria transmission, it is important to differentiate them. The literature mentioned the presence of a presector pale spot on the wing costa of An. minimus A, whereas species C may exhibit both presector and humeral pale spots. However, the reliability of their diagnostic power has not been established over large temporal and geographic surveys. From the analyses of 9 populations throughout Southeast Asia, including published data and field populations from 2 sites in Thailand, we showed that the wing patterns present spatial and temporal variations that make these two morphological characters unreliable for the precise identification of An. minimus A and C. Therefore, molecular identification remains the most efficient method to obtain an unambiguous differentiation of these 2 species. Correct species identification is essential and mandatory for any relevant study on the Minimus Complex and for the application of successful control strategies.

Animals↗
PubMed2005

Systematics and biogeographical implications of the phylogenetic relationships between members of the funestus and minimus groups of Anopheles (Diptera: Culicidae).

The Afrotropical Funestus and the Oriental-African Minimus Groups of the Myzomyia Series of Anopheles subgenus Cellia are considered distinct only because of their geographical separation. For the first time, a phylogenetic study was done on six Oriental and four Afrotropical species based on the comparison of ribosomal (ITS2, D3) and mitochondrial (COI) nucleotide sequences. Both maximum parsimony (MP) and maximum likelihood (ML) analyses revealed that the groups form a monophyletic assemblage containing four clades. The inclusion of Afrotropical An. leesoni with the Oriental species was confirmed, whereas An. rivulorum, also an Afrotropical species, was placed in a basal position relative to the African and Oriental species. The biogeography of the Afrotropical and Oriental species was examined in relation to the phylogeny and estimates of divergence time. Divergence events correspond to periods of major tectonic movement as well as periods of great aridity or humidity.

Animals↗
PubMed2005

Morphological assessment and molecular phylogenetics of the Funestus and Minimus groups of Anopheles (Cellia).

A morphological comparison and molecular study of the Afrotropical Funestus and Afro-Oriental Minimus groups within the Myzomyia series of Anopheles (Cellia) was conducted to determine their phylogenetic affinities. Relationships were investigated using morphological characters and ribosomal (D3) and mitochondrial (COII) nucleotide sequences. Cross-identification of specimens from one group by using keys for the other group confirmed their morphological similarity, i.e., members of one group shared the key characters with members of the other group. Molecular analyses recognized five clades, not strictly related to geographical distribution: the Aconitus, Culicifacies, Funestus, Minimus, and Rivulorum subgroups. Morphological observations were congruent with the results of molecular analyses. Anopheles leesoni, an Afrotropical species, is closely related to the Oriental Minimus complex, and these taxa share a close relationship with the Fluviatilis complex that occurs from the Arabian Peninsula through India. The immature and adult stages of An. rivulorum in Africa bear morphological characters that distinguish this species from members of the Afrotropical Funestus subgroup. A composite scheme of classification based on the results and previously published information is proposed for the two groups. It is noted that An. fluviatilis species S is conspecific with An. minimus species C.

Animals↗
PubMed2005

First record of Anopheles minimus C and significant decrease of An. minimus A in central Vietnam.

Before August 1998, in the Khanh Phu commune (central Vietnam), Anopheles minimus s.l. individuals were identified as species A and showed the typical species A wing form. After a significant decrease over the 3 years 1999-2001, an increase in 2002 of An. minimus s.l. possessing a different wing pattern was observed. To determine the specific status of the An. minimus species collected in 2002 and to follow changes in the species composition, an allele-specific polymerase chain reaction was applied to samples collected from 1993 to 2002. This study reports the first record of An. minimus C in central Vietnam and, since 1998, a significant reduction of An. minimus A that coincided with the wide use of permethrin-treated bednets. This change in anopheline composition may have important consequences on malaria transmission. This work shows that the geographic distribution of malaria vectors in southeast Asia is only partially known and highlights the importance of species identification for understanding changes in the vector composition as a result of selective vector control.

Animals↗
PubMed2004

Anopheles (Anopheles) pseudopunctipennis Theobald (Diptera: Culicidae): neotype designation and description.

Detailed morphological descriptions and illustrations are provided for the adult male and female, male genitalia, pupal, and larval stages of Anopheles (Anopheles) pseudopunctipennis Theobald, a major vector of human malaria in Central and South America. Taxonomic and related literature records, diagnostic features, distribution, and bionomics of the species are included. A neotype male for the species from the type locality of Grenada is designated.

Animals↗
PubMed2004

Molecular evidence of speciation between island and continental populations of Anopheles (Cellia) sundaicus (Diptera: Culicidae), a principal malaria vector taxon in Southeast Asia.

Anopheles sundaicus s.l. is a principal malaria vector taxon on islands and along the coastal areas of Southeast Asia. It has a wide geographical distribution and exhibits a high level of ecological and behavioral variability. Study of this taxon is crucial for understanding its biology and implementing effectise vector control measures. We compared populations of An. sundaicus from Vietnam, Thailand, and Malaysian Borneo by using two mitochondrial DNA markers: cytochrome oxidase I and cytochrome b. Genetic divergence, geographic separation, and cladistic analysis of relationships revealed the presence of two cryptic species: Anopheles sundaicus s.s. on Malaysian Borneo and An. sundaicus species A in coastal areas of Thailand and Vietnam. A polymerase chain reaction (PCR) assay was developed to easily identify these two species throughout their geographic distributions. The assay was based on sequence characterized amplified region derived from random amplified polymorphic DNA. This PCR identification method needs to be validated and adapted for the recognition of other possible species in the Sundaicus Complex.

Animals↗
PubMed2004

A single multiplex assay to identify major malaria vectors within the African Anopheles funestus and the Oriental An. minimus groups.

The African Anopheles funestus and the Oriental An. minimus groups are closely related and composed of major malaria vectors in Africa and Southeast Asia, respectively. None of the species of either the An. funestus or the An. minimus group can be identified with absolute certainty using the adult morphology. Polymorphisms present on the internal transcribed spacer 2 (ITS2) of ribosomal DNA allowed the development of 10 primers that combined with an universal forward primer lead to a simple and sensitive multiplex allele-specific polymerase chain reaction (AS-PCR). Moreover, the possible additional amplification of the entire ITS2 allows one to detect other anopheline species in sympatry with members of both groups not included in this assay and serves as a control band. This universal PCR method permits the discrimination of 10 species within the subgenus Cellia, among which figure three major malaria vectors, and constitutes a very efficient and powerful tool to improve our knowledge on these species distribution and biology. Not only restricted to anophelines, this AS-PCR could also be developed and applied to other insect groups.

Africa↗
PubMed2004

Bionomics and systematics of the oriental Anopheles sundaicus complex in relation to malaria transmission and vector control.

The taxonomic history, distribution, bionomics, systematics, and vector control strategies for the Anopheles sundaicus complex are reviewed in relation to malaria epidemiology. The lack of data on the bionomics, insecticide resistance, and vector capacity, as well as the general lack of surveillance and monitoring of potential vector populations, make the development of targeted control measures problematic. It will be necessary to elucidate, characterize and identify all members of the complex to determine their distributions, disease relationships, ecologic relationships, and resistance to insecticides. This knowledge is essential for epidemiologic studies, the design and implementation of appropriate vector control measures, and the development of strategies for monitoring and assessing the potential risk of malaria outbreaks due to members of the complex.

Animals↗
PubMed2002

Spatial distribution of adult Anopheles darlingi and Anopheles albimanus in relation to riparian habitats in Belize, Central America.

Collections of Anopheles darlingi Root and An. albimanus Wiedemann from central and northern Belize were conducted as landing captures from 6:30 to 8:00 p.m. to define spatial distributions and outdoor:indoor ratios of biting during the early evening. In central Belize, collections were made at 31 houses in riparian zones (> or = 1 km from rivers) and 14 houses in upland zones (>1 km from rivers) during the dry and wet seasons of 1993 and 1994. Females of both species were abundant in houses < or = 1 km from rivers. Females were not present in houses located in upland areas during the dry season, but were present in the wet season. A total of 63 paired collections (representing 130 individual captures) from 42 houses showed An. darlingi females were more endophagic (ratio of 1:0.6) during the early evening than were An. albimanus females (ratio of 1:0.21). Paired landing collections from 22 houses in riparian zones in April-May were analyzed in an index of species abundance (ISA). ISA values rated An. darlingi as the dominant Anopheles mosquito indoors and An. albimanus was dominant outside. Although An. darlingi and An. albimanus were abundant in riparian zones, there was no association in their numerical abundance, suggesting that different environmental factors influenced their abundance. In northern Belize, one house for each of 16 villages was sampled during April and May 1994. Large numbers ofAn. albimanus were captured outdoors in houses located in riparian and marshland areas (means of 217.5 and 247.5/1.5 personhours outdoors, respectively). Numbers of An. albimanus were low at houses located away from rivers and marshes (12.2 per collection). Anopheles darlingi was uncommon at sites in northern Belize. Proportionally fewer An. albimanus females entered houses in the north (outdoor:indoor ratio of 1:0.16) compared to the central region (ratio of 1:0.21), which probably reflects differences in house construction, anti-mosquito behavior (i.e., closing windows and doors at sunset), and insecticide treatments. The ISA gave a quantitative assessment of vector dominance in relation to the parameters of spatial distribution and numerical abundance. The index was also sensitive to the variables of indoor and outdoor biting behaviors.

Animals↗
PubMed2002

Role of residual spraying for malaria control in Belize.

We studied the impact of reduced residual spraying in Belize by developing a logistic regression model on relationships between numbers of houses sprayed (mostly with DDT) and numbers of malaria cases. We defined the "minimum effective house spray rate" (MEHSR) as the level of spraying that will prevent increases in malaria rates for a defined population. Under the total coverage approach (all houses sprayed), the MEHSR for Belize was 134.6. The model also showed that the odds for decreasing malaria is 1.086 for each increase of 10 houses sprayed per 1,000 population. In further testing, highly significant and differential changes in malaria rates were documented for paired groups of years with house spray rates that were either above or below the MEHSR. Numbers of malaria cases since 1995 are used to show how stratification methods are used in Belize to spray fewer houses (at levels below the MEHSR of 134.6).

Animals↗