108 research outputs found
Jean-Louis Camicas (1940-2017) Obituary
No full textFigure 1 From left to right: Jean Paul Cornet, Beth Anne Schmidt, Hervé Zeller, Marc WiIson, Jean-Louis Camicas, Jean Paul Gonzalez.Published as part of Sylla, Massamba, Gonzalez, Jean-Paul, Saluzzo, Jean-Francois, Pourrut, Xavier, Uilenberg, Gerrit, Cornet, Jean-Paul & Cuisance, Dominique, 2018, Jean-Louis Camicas (1940-2017) Obituary, pp. 754-758 in Acarologia 58 (3) on page 754, DOI: 10.24349/acarologia/20184268, http://zenodo.org/record/539477
Ticks of the genus <em>Rhipicephalus Koch</em>, 1844 in Senegal: Review host associations, chorology, and associated human and animal pathogens
No full textTicks of the genus Rhipicephalus (Acari: Ixodidae) in Senegal were reviewed. The data presented originate from a tick collection maintained at IRD’s Laboratory of Medical Entomology since 1967 and continuously enriched with samples obtained from different vertebrate hosts captured during various projects conducted in Senegal from 1987 to 2007. Fifteen Rhipicephalus tick species were collected and characterized, resulting in 1127 referenced collections. Three species were of the Boophilus subgenus: Rhipicephalus (Bo.) annulatus, Rh. (Bo.) decoloratus and Rh. (Bo.) geigyi. The twelve others were Rh. boueti, Rh. cuspidatus, Rh. evertsi, Rh. guilhoni, Rh. lunulatus, Rh. muhsamae, Rh. sanguineus, Rh. senegalensis, Rh. sulcatus, Rh. tricuspis, Rh. turanicus and Rh. ziemanni. Although there were recent indications that Rh. turanicus should have been considered as part of the Rh. sanguineus s.l. complex, data regarding these two ticks were presented separately. The collection comprised 14,165 tick specimens at different developmental stages. Data concerning their host relationships as well as distribution and seasonal dynamics were also presented. Vertebrate hosts were identified and listed in the different ecological zones of Senegal. The role of the ticks as potential vectors of pathogens has been reviewed. Climate change, causing variations in rainfall and temperature, will impact tick distribution and dynamics. The situation supports the necessity of this inventory of tick populations for (re)emerging tick-borne diseases surveillance and monitoring
Tiques du genre Rhipicephalus Koch, 1844 au Sénégal : synthèse hôtes associés, chorologie, et agents pathogènes transmis aux humains et aux animaux
No full textTicks of the genus Rhipicephalus (Acari: Ixodidae) in Senegal were reviewed. The data presented originate from a tick collection maintained at IRD’s Laboratory of Medical Entomology since 1967 and continuously enriched with samples obtained from different vertebrate hosts captured during various projects conducted in Senegal from 1987 to 2007. Fifteen Rhipicephalus tick species were collected and characterized, resulting in 1127 referenced collections. Three species were of the Boophilus subgenus: Rhipicephalus (Bo.) annulatus, Rh. (Bo.) decoloratus and Rh. (Bo.) geigyi. The twelve others were Rh. boueti, Rh. cuspidatus, Rh. evertsi, Rh. guilhoni, Rh. lunulatus, Rh. muhsamae, Rh. sanguineus, Rh. senegalensis, Rh. sulcatus, Rh. tricuspis, Rh. turanicus and Rh. ziemanni. Although there were recent indications that Rh. turanicus should have been considered as part of the Rh. sanguineus s.l. complex, data regarding these two ticks were presented separately. The collection comprised 14,165 tick specimens at different developmental stages. Data concerning their host relationships as well as distribution and seasonal dynamics were also presented. Vertebrate hosts were identified and listed in the different ecological zones of Senegal. The role of the ticks as potential vectors of pathogens has been reviewed. Climate change, causing variations in rainfall and temperature, will impact tick distribution and dynamics. The situation supports the necessity of this inventory of tick populations for (re)emerging tick-borne diseases surveillance and monitoring.Se revisaron las garrapatas del género Rhipicephalus (Acari: Ixodidae) en Senegal. Los datos presentados se originan de una colección de garrapatas mantenida en el Laboratorio de Entomología Médica del IRD desde 1967 y enriquecida continuamente con muestras obtenidas de diferentes huéspedes vertebrados, capturadas durante varios proyectos llevados a cabo en Senegal entre 1987 y 2007. Se recolectaron y caracterizaron quince especies de garrapatas Rhipicephalus, conduciendo a 1127 colecciones de referencia. Tres especies fueron de subgéneros Boophilus: Rhipicephalus (Bo.) annulatus, Rh. (Bo.) decoloratus y Rh. (Bo.) geigyi. Las otras doce fueron Rh. boueti, Rh. cuspidatus, Rh. evertsi, Rh. guilhoni, Rh. lunulatus, Rh. muhsamae, Rh. sanguineus, Rh. senegalensis, Rh. sulcatus, Rh. tricuspis, Rh. turanicus y Rh. ziemanni. A pesar de que hubo indicios recientes de que Rh. turanicus debería de haber sido considerada como parte del complejo Rh. sanguineus s.l., los datos concernientes a estas dos garrapatas se presentaron separadamente. La colección incluyó 14 165 especímenes de garrapatas en diferentes estadios de desarrollo. Se presentan también los datos concernientes a las relaciones con los huéspedes, así como la dinámica de distribución y estacional. Los huéspedes vertebrados fueron identificados y enumerados en las diferentes zonas ecológicas de Senegal. Se revisó el papel de las garrapatas como potenciales vectores de patógenos. Los cambios climáticos, causantes de variaciones en la pluviometría y la temperatura, impactarán la distribución y la dinámica de las garrapatas. La situación indujo la necesidad de este inventario de las poblaciones de garrapatas para la vigilancia y supervisión de enfermedades (re)emergentes transmitidas por garrapatas.Les tiques du genre Rhipicephalus (Acari : Ixodidae) connues au Sénégal ont été passées en revue. Les données présentées proviennent d’une collection de tiques conservée au Laboratoire d’entomologie médicale de l’IRD depuis 1967 et continuellement enrichie d’échantillons prélevés sur différents hôtes vertébrés capturés au cours de divers projets conduits au Sénégal de 1987 à 2007. Quinze espèces de Rhipicephalus, provenant de 1127 collectes référencées, ont été caractérisées. Parmi elles, se trouvaient trois espèces du sous-genre Boophilus : Rhipicephalus (Bo.) annulatus, Rh. (Bo.) decoloratus et Rh. (Bo.) geigyi. Les douze autres espèces étaient Rh. boueti, Rh. cuspidatus, Rh. evertsi, Rh. guilhoni, Rh. lunulatus, Rh. muhsamae, Rh. sanguineus, Rh. senegalensis, Rh. sulcatus, Rh. tricuspis, Rh. turanicus et Rh. ziemanni. De récentes études ont conclu que Rh. turanicus devrait être considéré comme faisant partie du complexe Rh. sanguineus s.l. Les données concernant ces deux tiques ont cependant été présentées séparément. Au total, 14 165 spécimens de tiques à différents stades de développement ont été échantillonnés. Les données concernant les préférences d’hôtes des différentes espèces, ainsi que leur distribution et leur dynamique saisonnière ont été précisées. Les hôtes vertébrés ont été identifiés et listés dans les différentes zones écologiques du Sénégal. Le rôle vecteur de pathogènes des tiques est passé en revue. Les changements climatiques en cours, entraînant des variations de température et de précipitations, affecteront la distribution et la dynamique des tiques. Cela justifie qu’un tel inventaire soit réalisé, permettant une surveillance précise des risques dus aux maladies (ré)émergentes à tiques
Mermithid nematodes found in adult <it>Anopheles</it> from southeastern Senegal
No full textAbstract Background Over two dozen mermithid nematodes have been described parasitizing mosquitoes worldwide, however, only two species were found in Africa. Mermithid nematodes kill their mosquito host upon emergence, which suggests that they could be developed as biological control agents of mosquitoes. Both Romanomermis culicivorax and Romanomermis iyengari have been reared for mass release to control numerous Anopheles species vector populations, and in one instance this may have led to reduced malaria prevalence in a human population. Methods Anopheles mosquitoes were collected during a malaria study in southeastern Senegal. Two different adult blood fed mosquitoes had a single mermithid nematode emerge from their anus while they were being held post-capture. Primers from the 18 S rDNA were developed to sequence nematode DNA and screen mosquitoes for mermithid DNA. 18 S rDNA from the Senegalese mermithid and other mermithid entries in GenBank were used to create a Maximum Parsimony tree of the Mermithidae family. Results The mermithid was present in 1.8% (10/551) of the sampled adult Anopheles species in our study area. The mermithid was found in An. gambiae s.s., An. funestus, and An. rufipes from the villages of Ndebou, Boundoucondi, and Damboucoye. Maximum parsimony analysis confirmed that the nematode parasites found in Anopheles were indeed mermithid parasites, and of the mermithid sequences available in GenBank, they are most closely related to Strelkovimermis spiculatus. Conclusions To our knowledge, this is the first report of mermithids from adult Anopheles mosquitoes in Senegal. The mermithid appears to infect Anopheles mosquitoes that develop in diverse larval habitats. Although maximum parsimony analysis determined the mermithid was closely related to Strelkovimermis spiculatus, several characteristics of the mermithid were more similar to the Empidomermis genus. Future mermithid isolations will hopefully allow: formal taxonomic identification, laboratory colonization, determination of life history traits and species specificity, and characterize its usefulness as a biological control agent.</p
Ticks (Acari: Ixodida) of the genus Haemaphysalis Koch, 1844 in Senegal : a review of host associations, chorology, and identification
No full textInternational audienceThe Haemaphysalis genus (Acari, Ixodidae) in Senegal is reviewed. This embodies a summary of specimens collected from vertebrate hosts over three decades. 454 collections were performed over this period (408 from mammals and 46 from birds), representing a total of 5752 ticks in different developmental stages. Seven Haemaphysalis spp. were collected, identified, and inventoried including: H. (Kaiseriana) rugosa, H. (Ornithophysalis) hoodi, H. (Rhipistoma) houyi, as well as four other species belonging to the leachi group, namely H. (Rhipistoma) leachi, H. (Rh.) moreli, H. (Rh.) muhsamae and H. (Rh.) spinulosa. Vertebrate hosts of Haemaphysalis species were identified and listed in different ecological zones of Senegal. An identification key of the haemaphysalids of Senegal is proposed, which is also applicable to the haemaphysalid fauna of the Occidental sub-region of the Afrotropical zoogeographical region. The role of these species as potential vectors of zoonotic diseases in Senegal is also discussed
PLoS Negl Trop Dis
No full textBackgroundAedes aegypti is the primary global vector to humans of yellow fever and dengue flaviviruses. Over the past 50 years, many population genetic studies have documented large genetic differences among global populations of this species. These studies initially used morphological polymorphisms, followed later by allozymes, and most recently various molecular genetic markers including microsatellites and mitochondrial markers. In particular, since 2000, fourteen publications and four unpublished datasets have used sequence data from the NADH dehydrogenase subunit 4 mitochondrial gene to compare Ae. aegypti collections and collectively 95 unique mtDNA haplotypes have been found. Phylogenetic analyses in these many studies consistently resolved two clades but no comprehensive study of mtDNA haplotypes have been made in Africa, the continent in which the species originated.Methods and FindingsND4 haplotypes were sequenced in 426 Ae. aegypti s.l. from Senegal, West Africa and Kenya, East Africa. In Senegal 15 and in Kenya 7 new haplotypes were discovered. When added to the 95 published haplotypes and including 6 African Aedes species as outgroups, phylogenetic analyses showed that all but one Senegal haplotype occurred in a basal clade while most East African haplotypes occurred in a second clade arising from the basal clade. Globally distributed haplotypes occurred in both clades demonstrating that populations outside Africa consist of mixtures of mosquitoes from both clades.ConclusionsPopulations of Ae. aegypti outside Africa consist of mosquitoes arising from one of two ancestral clades. One clade is basal and primarily associated with West Africa while the second arises from the first and contains primarily mosquitoes from East Africa201
Gene flow, subspecies composition, and dengue virus-2 susceptibility among Aedes aegypti collections in Senegal.
No full textBackgroundAedes aegypti, the "yellow fever mosquito", is the primary vector to humans of the four serotypes of dengue viruses (DENV1-4) and yellow fever virus (YFV) and is a known vector of Chikungunya virus. There are two recognized subspecies of Ae. aegypti sensu latu (s.l.): the presumed ancestral form, Ae. aegypti formosus (Aaf), a primarily sylvan mosquito in sub-Saharan Africa, and Ae. aegypti aegypti (Aaa), found globally in tropical and subtropical regions typically in association with humans. The designation of Ae. aegypti s.l. subspecies arose from observations made in East Africa in the late 1950s that the frequency of pale "forms" of Ae. aegypti was higher in populations in and around human dwellings than in those of the nearby bush. But few studies have been made of Ae. aegypti s.l. in West Africa. To address this deficiency we have been studying the population genetics, subspecies composition and vector competence for DENV-2 of Ae. aegypti s.l. in Senegal.Methods and findingsA population genetic analysis of gene flow was conducted among 1,040 Aedes aegypti s.l. from 19 collections distributed across the five phytogeographic regions of Senegal. Adults lacking pale scales on their first abdominal tergite were classified as Aedes aegypti formosus (Aaf) following the original description of the subspecies and the remainder were classified as Aedes aegypti aegypti (Aaa). There was a clear northwest-southeast cline in the abundance of Aaa and Aaf. Collections from the northern Sahelian region contained only Aaa while southern Forest gallery collections contained only Aaf. The two subspecies occurred in sympatry in four collections north of the Gambia in the central Savannah region and Aaa was a minor component of two collections from the Forest gallery area. Mosquitoes from 11 collections were orally challenged with DENV-2 virus. In agreement with the early literature, Aaf had significantly lower vector competence than Aaa. Among pure Aaa collections, the disseminated infection rate (DIR) was 73.9% with a midgut infection barrier (MIB) rate of 6.8%, and a midgut escape barrier (MEB) rate of 19.3%, while among pure Aaf collections, DIR = 34.2%, MIB rate = 7.4%, and MEB rate = 58.4%. Allele and genotype frequencies were analyzed at 11 nuclear single nucleotide polymorphism (SNP) loci using allele specific PCR and melting curve analysis. In agreement with a published isozyme gene flow study in Senegal, only a small and statistically insignificant percentage of the variance in allele frequencies was associated with subspecies.ConclusionsThese results add to our understanding of the global phylogeny of Aedes aegypti s.l., suggesting that West African Aaa and Aaf are monophyletic and that Aaa evolved in West Africa from an Aaf ancestor
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