¿Son las aves infectadas por malaria más atractivas para los mosquitos vectores?

According to the host manipulation hypothesis, parasites modify the hosts’ phenotype to maximise their transmission success. Avian malaria parasites and related haemosporidians are vectorborne parasites infecting birds worldwide. Recent studies have reported a greater attraction of mosquitoes to infected birds, supporting the host manipulation hypothesis. Changes in the composition of the uropygial gland secretion of birds associated with infections have been proposed as the potential mechanisms explaining this pattern. Here we critically review the published information on the host manipulation hypothesis in the context of avian malaria infections. We focus this article on the suggested role of the secretions of the uropygial gland and bird odours as mosquito attractants. The role of uropygial gland secretions as attractants of mosquitoes was poorly supported by available literature. In contrast, changes in the odour profile of infected birds or a reduction in the anti-mosquito behaviour of infected individuals may explain the parasite-mediated effects on mosquito attraction and biting rates. Finally, we propose future research approaches to identify the role of parasite infections on the interaction between birds and insect vectors.Según la hipótesis de manipulación del hospedador, los parásitos modifican el fenotipo del hospedador para maximizar su éxito de transmisión. Los parásitos de la malaria aviar y los hemosporidios relacionados son parásitos transmitidos por vectores que infectan a las aves de todo el mundo. Estudios recientes han encontrado apoyo para una mayor atracción de mosquitos hacia las aves infectadas, lo que respalda la hipótesis de la manipulación del hospedador. Cambios en la composición de la secreción de la glándula uropigial de las aves asociados a las infecciones se han propuesto como un posible mecanismo para explicar este patrón. Aquí, revisamos críticamente la información publicada sobre la hipótesis de la manipulación del hospedador en el contexto de las infecciones por malaria aviar. Centramos este artículo en el papel sugerido de las secreciones de la glándula uropigial y los olores de las aves como atrayentes de mosquitos. El papel de las secreciones de la glándula uropigial como atrayentes de mosquitos tuvo poco apoyo en la literatura. Por el contrario, los cambios en el perfil de olor de las aves infectadas o una reducción del comportamiento antimosquitos de los individuos infectados pueden explicar los efectos mediados por parásitos en la atracción de mosquitos y las tasas de picadura. Finalmente, proponemos perspectivas de investigación futuras para identificar el papel de las infecciones parasitarias en la interacción entre las aves y los insectos vectores.Spanish Government CGL2015-65055-P PGC 2018-095704-B-I00European Commission CGL2015-65055-P PGC 2018-095704-B-I002017 Leonardo Grant for Researchers and Cultural Creators, of the BBVA FoundationSevero-Ochoa grant from the Spanish ministry of Economy and Competitiveness SVP-2014-06857

Editorial: Factors Affecting Host Selection by Mosquitoes: Implications for the Transmission of Vector-Borne Pathogens

Project PGC2018- 095704-B-I00 from the Spanish Ministry of Economy and Competition and from the European Regional Development Fund (FEDER

A One Health view of the West Nile virus outbreak in Andalusia (Spain) in 2020

Reports of West Nile virus (WNV) associated disease in humans were scarce in Spain until summer 2020, when 77 cases were reported, eight fatal. Most cases occurred next to the Guadalquivir River in the Sevillian villages of Puebla del Río and Coria del Río. Detection of WNV disease in humans was preceded by a large increase in the abundance of Culex perexiguus in the neighborhood of the villages where most human cases occurred. The first WNV infected mosquitoes were captured approximately one month before the detection of the first human cases. Overall, 33 positive pools of Cx. perexiguus and one pool of Culex pipiens were found. Serology of wild birds confirmed WNV circulation inside the affected villages, that transmission to humans also occurred in urban settings and suggests that virus circulation was geographically more widespread than disease cases in humans or horses may indicate. A high prevalence of antibodies was detected in blackbirds (Turdus merula) suggesting that this species played an important role in the amplification of WNV in urban areas. Culex perexiguus was the main vector of WNV among birds in natural and agricultural areas, while its role in urban areas needs to be investigated in more detail. Culex pipiens may have played some role as bridge vector of WNV between birds and humans once the enzootic transmission cycle driven by Cx. perexiguus occurred inside the villages. Surveillance of virus in mosquitoes has the potential to detect WNV well in advance of the first human cases.m CSIC under grant number 202030E263Research State Agency under grant numbers PGC2018-095704-B-I00 and PID2020-116768RR-C21/C22 FEDEREuropean Commission – NextGenerationEU (Regulation EU 2020/2094)Instituto de Salud Carlos III Project “PI19CIII_00014

Differences in fatty acids composition between Plasmodium infected and uninfected house sparrows along an urbanization gradient

This study was funded by project P11-RNM-7038 from the Junta de Andalucia and projects PGC2018-095704-B-I00 and PID2020-118205GB-I00 from the Spanish Ministry of Science and Innovation and European (FEDER) funds. CI was funded by the Swedish Research Council for Sustainable Development, FORMAS, no. 2015-00526. JJP was funded by the Fundacion Tatiana Perez Guzman el Bueno, MF is supported by the European Union'sHorizon 2020 research and innovation programme under the Marie Sklodowska-Curie (grant agreement No 844285, 'EpiEcoMod'). Alberto Pastoriza, Manuel Vazquez, Manuel Lobon, Isabel Martin, Laura Gomez, Johan Kjellberg-Jensen and Hong-Lei Wang helped with the field and laboratory work. We are grateful to all the landowners and to Consejeria de Medio Ambiente for allowing us to work on their properties.Anthropogenic activities such as intensification of agriculture, animal husbandry and expansion of cities can negatively impact wildlife through its influence on the availability of high-quality food resources and pathogen transmission. The house sparrow (Passer domesticus), an urban exploiter, is undergoing a population decline. Nutritional constrains and infectious diseases has been highlighted as potential causes. Fatty acids (FAs) play an important role in modulating certain immune responses needed to combat parasite infections. FAs are highly influenced by dietary availability and have been shown to vary between urban and rural birds. Habitat anthropization also affects avianmalaria epidemiology but little attention has been given to the relationship between blood parasite infection, host FAs composition and anthropization. Here, we analysed 165 juvenile birds either infected by Plasmodium or uninfected, captured at 15 localities grouped in triplets containing urban, rural and natural habitats. The total level of FAs was higher in birds fromurban than from rural habitats, suggesting a greater availability of fat-rich foods sources. Furthermore, Plasmodium infected birds had higher relative levels of ω-3 polyunsaturated fatty acids (PUFAs) but lower of ω-6 PUFAs than uninfected birds. In concordance, the ω-6/ω-3 ratiowas also lower in infected than in uninfected birds, but only from natural habitats, likely driven by the slightly higher ω-3 PUFAs in infected birds from natural habitats. Birds from anthropized environments may metabolize the ω-3 PUFAs to promote anti-inflammatory responses against stressors, which would result in lower ω-3 affecting their response against Plasmodium. Alternatively, lower ω-6 PUFAs may influence birds susceptibility to infection due to a weaker pro-inflammatory response. These descriptive results do not allow us to identify the causality of these associations but highlight the need to further investigate the relevance of FAs for birds to fight infectious diseases in habitats with different degree of urbanization.Junta de Andalucia P11-RNM-7038Spanish Ministry of Science and Innovation and European (FEDER) funds PGC2018-095704-B-I00 PID2020-118205GB-I00Swedish Research Council Formas 2015-00526Fundacion Tatiana Perez Guzman el BuenoEuropean Commission 84428

Ecological Effects on the Dynamics of West Nile Virus and Avian Plasmodium: The Importance of Mosquito Communities and Landscape

Humans and wildlife are at risk from certain vector-borne diseases such as malaria, dengue, and West Nile and yellow fevers. Factors linked to global change, including habitat alteration, land-use intensification, the spread of alien species, and climate change, are operating on a global scale and affect both the incidence and distribution of many vector-borne diseases. Hence, understanding the drivers that regulate the transmission of pathogens in the wild is of great importance for ecological, evolutionary, health, and economic reasons. In this literature review, we discuss the ecological factors potentially affecting the transmission of two mosquito-borne pathogens circulating naturally between birds and mosquitoes, namely, West Nile virus (WNV) and the avian malaria parasites of the genus Plasmodium. Traditionally, the study of pathogen transmission has focused only on vectors or hosts and the interactions between them, while the role of landscape has largely been ignored. However, from an ecological point of view, it is essential not only to study the interaction between each of these organisms but also to understand the environmental scenarios in which these processes take place. We describe here some of the similarities and differences in the transmission of these two pathogens and how research into both systems may facilitate a greater understanding of the dynamics of vector-borne pathogens in the wild

Fur or feather? Feeding preferences of species of Culicoides biting midges in Europe

© 2014 Elsevier Ltd. Understanding the feeding preferences of haematophagous insects is critical to depicting the amplification and transmission networks of pathogens and identifying key vector species for surveillance programs. In the case of species from genus Culicoides, many of which are important vectors of pathogens causing animal diseases, information from molecular studies on the feeding habits of females is expanding but still limited for a significant fraction of competent vectors of Culicoides-borne pathogens. In spite of these limitations, recent studies highlight that most Culicoides species are able to feed on several vertebrate species, but present clear preferences for mammals or birds.Peer Reviewe

The interplay between vector microbial community and pathogen transmission on the invasive Asian tiger mosquito, Aedes albopictus: current knowledge and future directions

The invasive Asian tiger mosquito Aedes albopictus is nowadays broadly distributed with established populations in all continents except Antarctica. In the invaded areas, this species represents an important nuisance for humans and, more relevant, it is involved in the local transmission of pathogens relevant under a public health perspective. Aedes albopictus is a competent vector of parasites such as Dirofilaria and viruses including dengue virus, Zika virus, and chikungunya virus, among others. The mosquito microbiota has been identified as one of the major drivers of vector competence, acting upon relevant vector functions as development or immunity. Here, we review the available literature on the interaction between Ae. albopictus microbiota and pathogen transmission and identify the knowledge gaps on the topic. Most studies are strictly focused on the interplay between pathogens and Wolbachia endosymbiont while studies screening whole microbiota are still scarce but increasing in recent years, supported on Next-generation sequencing tools. Most experimental trials use lab-reared mosquitoes or cell lines, exploring the molecular mechanisms of the microbiota-pathogen interaction. Yet, correlational studies on wild populations are underrepresented. Consequently, we still lack sufficient evidence to reveal whether the microbiota of introduced populations of Ae. albopictus differ from those of native populations, or how microbiota is shaped by different environmental and anthropic factors, but especially, how these changes affect the ability of Ae. albopictus to transmit pathogens and favor the occurrence of outbreaks in the colonized areas. Finally, we propose future research directions on this research topic.This study was financed by the PID2020-118205GB-I00 grant to JM-P funded by MCIN/AEI/10.13039/501100011033. MGarrido was supported by the María Zambrano program and JV received financial support from the Margarita Salas and Juan de la Cierva programs. MGarrigós was supported by a FPI grant (PRE2021-098544)

On the specificity of avian blood parasites: Revealing specific and generalist relationships between haemosporidians and biting midges

The study of host-parasite relationships involving vector-borne parasites requires understanding interactions between parasites and vectors. The capacity of haemosporidians to infect insects has clear evolutionary consequences for the transmission of diseases. Here, we investigated (i) the associations between blood parasites, biting midges and birds and (ii) the potential specificity between biting midge and haemosporidian haplotypes. A total of 629 parous biting midges Culicoides and 224 wild birds (belonging to seven species) from a locality of central Spain were individually examined for the presence of Haemoproteus and Plasmodium parasites by sequencing a fragment of cytochrome B. Biting midges were identified morphologically and characterized on the basis of a fragment of the cytochrome c oxidase (COI) gene. Overall, 12 Haemoproteus and three Plasmodium haplotypes were isolated and sequenced. Among them, 10 haplotypes were exclusively isolated from biting midges, three haplotypes only from birds and two haplotypes from both biting midges and birds. Biting midge haplotypes showed both specific and generalist relationships with Haemoproteus haplotypes but only generalist relationships with Plasmodium haplotypes. Several C. festivipennis and C. kibunesis haplotypes established significant coevolutionary links with Haemoproteus haplotypes. These results shed light on the specificity of interactions between vectors and blood parasites. © 2011 Blackwell Publishing Ltd.Peer Reviewe

Genetic colour polymorphism is associated with avian malarial infections

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Genetic colour polymorphism is associated with avian malarial infections

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