Bat flies (Diptera: Nycteribiidae and Streblidae) infesting cave-dwelling bats in Gabon: Diversity, dynamics and potential role in Polychromophilus melanipherus transmission

Background Evidence of haemosporidian infections in bats and bat flies has motivated a growing interest in characterizing their transmission cycles. In Gabon (Central Africa), many caves house massive colonies of bats that are known hosts of Polychromophilus Dionisi parasites, presumably transmitted by blood-sucking bat flies. However, the role of bat flies in bat malaria transmission remains under-documented. Methods An entomological survey was carried out in four caves in Gabon to investigate bat fly diversity, infestation rates and host preferences and to determine their role in Polychromophilus parasite transmission. Bat flies were sampled for 2–4 consecutive nights each month from February to April 2011 (Faucon and Zadie caves) and from May 2012 to April 2013 (Kessipoughou and Djibilong caves). Bat flies isolated from the fur of each captured bat were morphologically identified and screened for infection by haemosporidian parasites using primers targeting the mitochondrial cytochrome b gene. Results Among the 1,154 bats captured and identified as Miniopterus inflatus Thomas (n = 354), Hipposideros caffer Sundevall complex (n = 285), Hipposideros gigas Wagner (n = 317), Rousettus aegyptiacus Geoffroy (n = 157, and Coleura afra Peters (n = 41), 439 (38.0 %) were infested by bat flies. The 1,063 bat flies recovered from bats belonged to five taxa: Nycteribia schmidlii scotti Falcoz, Eucampsipoda africana Theodor, Penicillidia fulvida Bigot, Brachytarsina allaudi Falcoz and Raymondia huberi Frauenfeld group. The mean infestation rate varied significantly according to the bat species (ANOVA, F (4,75) = 13.15, P < 0.001) and a strong association effect between bat fly species and host bat species was observed. Polychromophilus melanipherus Dionisi was mainly detected in N. s. scotti and P. fulvida and less frequently in E. africana, R. huberi group and B. allaudi bat flies. These results suggest that N. s. scotti and P. fulvida could potentially be involved in P. melanipherus transmission among cave-dwelling bats. Sequence analysis revealed eight haplotypes of P. melanipherus. Conclusions This work represents the first documented record of the cave-dwelling bat fly fauna in Gabon and significantly contributes to our understanding of bat fly host-feeding behavior and their respective roles in Polychromophilus transmission. (Résumé d'auteur

Malaria risk in Corsica, former hot spot of malaria in France

Background: The prevalence of Plasmodium falciparum and Plasmodium vivax malaria was very high in Corsica just before the Second World War. The last outbreak was in 1972 and the most recent indigenous case was in 2006. Results: Analysis of historical data shows that anopheline vectors were abundant. Recent surveys demonstrated that potential vectors are still present in Corsica, despite the likely disappearance of Anopheles sacharovi. Moreover, P. falciparum can develop experimentally into these mosquitoes, notably Anopheles labranchiae, which is locally abundant, and parasites are regularly introduced into the island. Discussion, Conclusions: The presence of vectors, the introduction of parasites and the conducive climate raise questions about the possibility of malaria re-emerging and becoming re-established in Corsica. Analysis of historic and current parasitological and entomological data shows that the current theoretical risk of indigenous cases or malaria foci is negligible, particularly since there is very little contact between humans and Anopheles mosquitoes, Plasmodium carriers are reliably treated and there is a widespread vector control on the island

Haemosporidian parasites of Antelopes and other vertebrates from Gabon, Central Africa

Re-examination, using molecular tools, of the diversity of haemosporidian parasites (among which the agents of human malaria are the best known) has generally led to rearrangements of traditional classifications. In this study, we explored the diversity of haemosporidian parasites infecting vertebrate species (particularly mammals, birds and reptiles) living in the forests of Gabon (Central Africa), by analyzing a collection of 492 bushmeat samples. We found that samples from five mammalian species (four duiker and one pangolin species), one bird and one turtle species were infected by haemosporidian parasites. In duikers (from which most of the infected specimens were obtained), we demonstrated the existence of at least two distinct parasite lineages related to Polychromophilus species (i. e., bat haemosporidian parasites) and to sauropsid Plasmodium (from birds and lizards). Molecular screening of sylvatic mosquitoes captured during a longitudinal survey revealed the presence of these haemosporidian parasite lineages also in several Anopheles species, suggesting a potential role in their transmission. Our results show that, differently from what was previously thought, several independent clades of haemosporidian parasites (family Plasmodiidae) infect mammals and are transmitted by anopheline mosquitoes

Citizen Science as an Approach for Responding to the Threat of 'Anopheles stephensi' in Africa

Even as novel technologies emerge and medicines advance, pathogen-transmitting mosquitoes pose a deadly and accelerating public health threat. Detecting and mitigating the spread of Anopheles stephensi in Africa is now critical to the fight against malaria, as this invasive mosquito poses urgent and unprecedented risks to the continent. Unlike typical African vectors of malaria, An. stephensi breeds in both natural and artificial water reservoirs, and flourishes in urban environments. With An. stephensi beginning to take hold in heavily populated settings, citizen science surveillance supported by novel artificial intelligence (AI) technologies may offer impactful opportunities to guide public health decisions and community-based interventions. Coalitions like the Global Mosquito Alert Consortium (GMAC) and our freely available digital products can be incorporated into enhanced surveillance of An. stephensi and other vector-borne public health threats. By connecting local citizen science networks with global databases that are findable, accessible, interoperable, and reusable (FAIR), we are leveraging a powerful suite of tools and infrastructure for the early detection of, and rapid response to, (re)emerging vectors and diseases

A new species in the Anopheles gambiae complex reveals new evolutionary relationships between vector and non-vector species

Complexes of closely related species provide key insights about the rapid and independent evolution of adaptive traits. Here, we described and studied a presumably new species in the Anopheles gambiae complex, Anopheles fontenillei, recently discovered in the forested areas of Gabon, Central Africa. Our analysis placed the new taxon in the phylogenetic tree of the An. gambiae complex, revealing important introgression events with other members of the complex. In particular, we detected recent introgression with An. gambiae and An. coluzzii of genes directly involved in vectorial capacity. Moreover, genome analysis of the new species also allowed us to resolve the evolutionary history of inversion 3La. Overall, Anopheles fontenillei has implemented our understanding about the relationship of species within the gambiae complex and provides insight into the evolution of vectorial capacity traits, relevant for the successful control of malaria in Africa.Funding was provided by the “Institut de Recherche pour le Developpément”, the “Agence Universitaire de la Francophonie” (grant: OKANDA), the “Centre National de la Recherche Scientifique” (CNRS) and the “Consejo Superior de Investigaciones Cientificas” (CSIC) (grant PICS ANCESTRAL to DA and JG), the “ANR” (grant ANR--18-CE35-0002-01-WILDING to DA), and the “Ministerio de Ciencia, Innovación y Universidades/AEI” (grant BFU2017-82937-P to JG).N

Global genetic diversity of Aedes aegypti

Mosquitoes, especially Aedes aegypti, are becoming important models for studying invasion biology. We characterized genetic variation at 12 microsatellite loci in 79 populations of Ae. aegypti from 30 countries in six continents, and used them to infer historical and modern patterns of invasion. Our results support the two subspecies Ae. aegypti formosus and Ae. aegypti aegypti as genetically distinct units. Ae. aegypti aegypti populations outside Africa are derived from ancestral African populations and are monophyletic. The two subspecies co-occur in both East Africa (Kenya) and West Africa (Senegal). In rural/forest settings (Rabai District of Kenya), the two subspecies remain genetically distinct, whereas in urban settings, they introgress freely. Populations outside Africa are highly genetically structured likely due to a combination of recent founder effects, discrete discontinuous habitats and low migration rates. Ancestral populations in sub-Saharan Africa are less genetically structured, as are the populations in Asia. Introduction of Ae. aegypti to the New World coinciding with trans-Atlantic shipping in the 16th to 18th centuries was followed by its introduction to Asia in the late 19th century from the New World or from now extinct populations in the Mediterranean Basin. Aedes mascarensis is a genetically distinct sister species to Ae. aegypti s.l. This study provides a reference database of genetic diversity that can be used to determine the likely origin of new introductions that occur regularly for this invasive species. The genetic uniqueness of many populations and regions has important implications for attempts to control Ae. aegypti, especially for the methods using genetic modification of populations.Centro de Estudios Parasitológicos y de Vectore

Global genetic diversity of Aedes aegypti

Mosquitoes, especially Aedes aegypti, are becoming important models for studying invasion biology. We characterized genetic variation at 12 microsatellite loci in 79 populations of Ae. aegypti from 30 countries in six continents, and used them to infer historical and modern patterns of invasion. Our results support the two subspecies Ae. aegypti formosus and Ae. aegypti aegypti as genetically distinct units. Ae. aegypti aegypti populations outside Africa are derived from ancestral African populations and are monophyletic. The two subspecies co-occur in both East Africa (Kenya) and West Africa (Senegal). In rural/forest settings (Rabai District of Kenya), the two subspecies remain genetically distinct, whereas in urban settings, they introgress freely. Populations outside Africa are highly genetically structured likely due to a combination of recent founder effects, discrete discontinuous habitats and low migration rates. Ancestral populations in sub-Saharan Africa are less genetically structured, as are the populations in Asia. Introduction of Ae. aegypti to the New World coinciding with trans-Atlantic shipping in the 16th to 18th centuries was followed by its introduction to Asia in the late 19th century from the New World or from now extinct populations in the Mediterranean Basin. Aedes mascarensis is a genetically distinct sister species to Ae. aegypti s.l. This study provides a reference database of genetic diversity that can be used to determine the likely origin of new introductions that occur regularly for this invasive species. The genetic uniqueness of many populations and regions has important implications for attempts to control Ae. aegypti, especially for the methods using genetic modification of populations.Centro de Estudios Parasitológicos y de Vectore

The Hippoboscidae (Insecta : Diptera) from Madagascar, with new records from the "Parc National de Midongy Befotaka"

The Hippoboscidae or “louse-flies” is a family of pupiparous Diptera, which in their adult stage are ectoparasites of mammals and birds. This paper presents a comprehensive review of Malagasy Hippoboscidae. In total, amongst the 213 species of this family known worldwide, 14 have been reported in Madagascar, among which six are considered as endemic to the Malagasy region. In addition, data are presented from a collection of 17 Hippoboscidae obtained from seven species of forest-dwelling birds in the “Parc National de Midongy Befotaka”, southeastern Madagascar, in 2003. The flies in this collection belong to three different species: Icosta malagasii (one), Ornithoica podicipis (ten) and Ornithoctona laticornis (six). The two former species were previously only known from single specimens in museum collections; the later species is distributed across much of the Afrotropical region and the records presented herein are the first for Madagascar. All the seven bird species are new hosts for hippoboscids. We present the first description of the male of Icosta malagasii. An illustrated dichotomous determination key of the 14 Malagasy species, based on morphological criteria only, is presented

Inventory of mosquitoes in Mayotte, French Departement in the Indian Ocean

Mayotte is an island situated in a region of the world particularly exposed to vector borne diseases. Several potential vectors, a tropical climate, an increasing urbanization, important movements of populations in the region, are among the relevant factors which favour the endemicity, the emergence or the re-emergence of vector transmitted diseases. Many vector born diseases are transmitted by mosquitoes: malaria, dengue, chikungunya, Rift Valley fever and, in the past, the Bancroftian filariosis. A collaborative project was recently initiated between IRD and ARS-OI to update the inventory of the mosquito species present in Mayotte. With the final goal to facilitate an integrated control against vector born diseases transmitted by mosquitoes, an entomological survey was performed in 2011 from March 21st till April 8th, at the end of the rainy season, with special attention in the best-protected natural areas. The breeding sites positive for preimaginal mosquitoes were geolocalised with a GPS and its environment was characterized. A semi-individual breeding of specimens was realized in the insectary from larval and pupal stages. Some mosquitoes were put in collections and the others were put in alcohol to allow further genetic researches by DNA sequencings, in Montpellier. The data concern 27 visited sites, and 426 points of collections. Our provisional results count 26 species (among 36 previously listed). A noticeable result is the discovery of Aedes (Stegomyia) nov. sp., belonging to a new species for Mayotte and for the science, collected in the humid forest at the top of the island (forest reserve of Majimbini) near the locality "The convalescence"

Inventory of mosquitoes in Mayotte, French Departement in the Indian Ocean

Mayotte is an island situated in a region of the world particularly exposed to vector borne diseases. Several potential vectors, a tropical climate, an increasing urbanization, important movements of populations in the region, are among the relevant factors which favour the endemicity, the emergence or the re-emergence of vector transmitted diseases. Many vector born diseases are transmitted by mosquitoes: malaria, dengue, chikungunya, Rift Valley fever and, in the past, the Bancroftian filariosis. A collaborative project was recently initiated between IRD and ARS-OI to update the inventory of the mosquito species present in Mayotte. With the final goal to facilitate an integrated control against vector born diseases transmitted by mosquitoes, an entomological survey was performed in 2011 from March 21st till April 8th, at the end of the rainy season, with special attention in the best-protected natural areas. The breeding sites positive for preimaginal mosquitoes were geolocalised with a GPS and its environment was characterized. A semi-individual breeding of specimens was realized in the insectary from larval and pupal stages. Some mosquitoes were put in collections and the others were put in alcohol to allow further genetic researches by DNA sequencings, in Montpellier. The data concern 27 visited sites, and 426 points of collections. Our provisional results count 26 species (among 36 previously listed). A noticeable result is the discovery of Aedes (Stegomyia) nov. sp., belonging to a new species for Mayotte and for the science, collected in the humid forest at the top of the island (forest reserve of Majimbini) near the locality "The convalescence"