Hippoboscid-transmitted Haemoproteus parasites (Haemosporida) infect Galapagos Pelecaniform birds: evidence from molecular and morphological studies, with a description of Haemoproteus iwa

Haemosporidian intensity and nestlings' life-history along an urban-to-rural gradient

Urban areas, i.e. dense housing and reduced green spaces, can significantly impact avian health, through altering land use and increasing biotic and abiotic stress. This study assessed the association of urbanization on haemosporidian infections, vectors, immune response, and body condition in Parus major nestlings, across four classes of urbanization along an urban-to-rural gradient in Vienna, Austria. Contrary to our expectations, vector abundance remained consistent across the gradient, while an increase in leukocyte count is positively associated with total parasite intensity. We found that nestlings in more urbanized areas exhibited higher parasite intensity and altered immune response, as evidenced by variations in the heterophil to lymphocyte ratio and leukocyte counts. Culicidae female vectors were associated with nestlings' total parasites, scaled mass index, and industrial units. Nestlings in highly developed areas had higher infection rates than those in forests, suggesting increased exposure to infections. However, there was no clear relationship between total female vectors and total parasites. The level of urbanization negatively affected nestling body condition, with a decrease in fat deposits from forested to highly urbanized areas. Our findings highlight the complex interplay between urbanization, vector-borne parasite transmission, and host immune response, emphasizing the need for comprehensive urban planning to improve wildlife health and guarantee ecosystem functioning. Understanding how urbanization affects bird immunity and parasite infections is critical for adapting urban landscapes for wildlife health and ecosystem integrity.

Haemoproteus jenniae (Haemoproteidae, Haemosporida) infects gulls (Larus spp.) in South Africa, with redescription of Haemoproteus skuae

Haemoproteus spp. are dipteran-borne protozoa that infect erythrocytes and reticulo-endothelial cells of birds. These parasites are not usually transmitted between birds belonging to different orders. The suborder Lari (order Charadriiformes) comprises ~170 avian species, the majority of which are aquatic, including gulls, terns, auklets, murres and skuas, among others. In spite of the diversity of this avian group, there is limited known diversity of haemosporidian parasites, with only 4 recorded Haemoproteus morphospecies thus far. We examined the blood smears of 21 kelp gulls (Larus dominicanus) captured at a breeding colony in South Africa, as well as Haemoproteus-positive archival blood smears of 15 kelp gulls and 1 Hartlaub's gull (Larus hartlaubii) sampled while under care at seabird rehabilitation facilities in South Africa. Haemoproteus sp. infection was detected in 19% of wild-caught kelp gulls. All parasites from the gulls were morphologically identified as Haemoproteus jenniae, a species previously recorded in Lari birds at the Galapagos Islands (Ecuador), Rocas Atoll (Brazil) and Poland. Gene sequencing uncovered a new cytochrome b lineage, LARDOM01, which was closely related to the previously reported H. jenniae lineage CREFUR01. Additionally, we evaluated a hapantotype blood smear of Haemoproteus skuae, which had been described infecting a brown skua (Catharacta antarctica) in South Africa. We provide a redescription of H. skuae and discuss the morphological characters distinguishing it from H. jenniae. Further research is necessary to improve our knowledge about the host and geographic distribution, health effects and phylogeny of H. jenniae and H. skuae.

Exo-erythrocytic development of two Haemoproteus species (Haemosporida, Haemoproteidae), with description of Haemoproteus dumbbellus, a new blood parasite of bunting birds (Emberizidae)

Avian haemosporidians are widespread parasites categorized into four families of the order Haemosporida (Apicomplexa). Species of the subgenus Parahaemoproteus (genus Haemoproteus) belong to the Haemoproteidae and are transmitted by Culicoides biting midges. Reports of death due to tissue damage during haemoproteosis in non-adapted birds have raised concerns about these pathogens, especially as their exo-erythrocytic development is known for only a few Haemoproteus spp. More research is needed to better understand the patterns of the parasites' development in tissues and their impact on avian hosts. Yellowhammers Emberiza citrinella (Emberizidae) and common house martins Delichon urbicum (Hirundinidae) were screened for Haemoproteus parasites by microscopic examination of blood films and PCR-based testing. Individuals with single infection were selected for histological investigations. H & E-stained sections were screened for detection and characterization of the exo-erythrocytic stages, while chromogenic in situ hybridization (CISH) and phylogenetic analysis were performed to confirm the Haemoproteus origin and their phylogenetic relationships. Haemoproteus dumbbellus n. sp. was discovered in Emberiza citrinella single-infected with the lineage hEMCIR01. Meronts of H. dumbbellus n. sp. developed in various organs of five of six tested individuals, a pattern which was reported in other Haemoproteus species clustering in the same clade, suggesting this could be a phylogenetic trait. By contrast, in Delichon urbicum infected with the Haemoproteus lineage hDELURB2, which was linked to the more distantly related parasite Haemoproteus hirundinis, only megalomeronts were found in the pectoral muscles of two of six infected individuals. All exo-erythrocytic stages were confirmed to be Haemoproteus parasites by CISH using a Haemoproteus genus-specific probe. While the development of meronts seems to be typical for species of the clade containing H. dumbbellus, further investigations and data from more species are needed to explore whether a phylogenetic pattern occurs in meront or megalomeront formation.

Haemosporidian Parasites of White-Breasted Waterhens (Amaurornis phoenicurus), with a Report and Molecular Characterization of Haemoproteus gallinulae in Thailand

Haemosporidian parasites are vector-borne parasites infecting terrestrial vertebrates as well as avian species, such as the White-breasted Waterhen, a Gruiformes waterbird found in lowlands near wetlands and distributed throughout Thailand. However, information regarding haemosporidia infection in this species is lacking. To establish regional information, 17 blood samples were collected from White-breasted Waterhens. Four haemoparasite lineages were identified in six blood samples: Haemoproteus gallinulae, Plasmodium collidatum, Plasmodium elongatum, and an unidentified Plasmodium species. H. gallinulae was characterized with morphological features in White-breasted Waterhens for the first time; the morphological characteristics were consistent with previous descriptions. H. gallinulae was more closely related to Haemoproteus species of Passeriformes birds than to those of Gruiformes birds. The Plasmodium parasites infecting these White-breasted Waterhens previously caused severe avian malaria in other host species. The unidentified Plasmodium species had rarely been documented, although it was reported in the Culex vector and was possibly associated with specialist parasites either as host or habitat. Our findings reveal multiple haemosporidian species reflecting the role of this avian host as a carrier of haemosporidians. This study offers species records and molecular materials that may provide critical information for further targeted research into these haemosporidia.

An annotated checklist of the Diptera of the Galápagos Archipelago (Ecuador)

The Diptera fauna of the Galápagos Archipelago is updated and an annotated checklist is presented. Currently 50 families, 207 genera, and a minimum of 324 species are recorded from the islands. Approximately 107 species are considered to have arrived on the Galápagos Islands through human introductions, an estimated 101 species are considered endemic, 42 species have naturally colonized the islands from mainland Americas, 21 species are either introduced or arrived naturally and 53 species remain unidentified. The following new combination is proposed: Chrysanthrax primitivus (Walker) is moved to Hemipenthes Loew as H. primitivus (Walker) comb. nov. All references to the Galápagos taxonomic literature are included, known island species distributions listed and general remarks on the biology of many species are provided.

Keys to the avian Haemoproteus parasites (Haemosporida, Haemoproteidae)

BACKGROUND

Haemoproteus is a sister genus to malaria parasites (Plasmodium), which both belong to the order Haemosporida (Apicomplexa). Parasites of both genera are flourishing in birds, however, Haemoproteus species are noticeably less investigated. This is unfortunate because knowledge about close relatives of malaria pathogens is important for better understanding the evolutionary origin and basic biological features of the entire group of haemosporidian infections. Moreover, recent findings show that Haemoproteus species can cause severe damage of various bird organs due to megalomeronts and other exo-erythrocytic stages. These haemosporidians are remarkably diverse, but remain neglected partly due to difficulties in species identification. Hundreds of Haemoproteus genetic lineages have been reported in birds, and numerous new lineages are found each year, but most remain unidentified to the species level. Numerous new Haemoproteus pathogens were described during the past 20 years. However, keys for their identification are absent. Identification of Haemoproteus species remains a difficult task and is an obstacle for better understanding of the distribution and epidemiology of these parasites. This study aimed to develop comprehensive keys for the identification of described avian Haemoproteus species using morphological features of their blood stages (gametocytes).

METHODS

Type and voucher preparations of avian Haemoproteus species were accessed in museums in Europe, Australia and the USA. Gametocytes of most described species were examined, and these data formed a background for this study. The data also were considered from published articles containing parasite species descriptions. The method of dichotomous keys was applied. The most difficult steps in the keys were accompanied with references to the corresponding parasite pictures.

RESULTS

In all, 201 published articles were included in this review. Morphological diagnostic features of gametocytes of all described Haemoproteus species were analysed and compared. Illustrated keys for identification of these parasite species were developed. Available information about the molecular characterization of Haemoproteus parasites was provided.

CONCLUSION

This review shows that 177 described species of avian Haemoproteus can be distinguished and identified in blood films using morphological characters of their gametocytes and host cells. These species were incorporated in the keys. Information about possible morphologically cryptic parasites was provided. Molecular markers are available for only 42% of the described Haemoproteus parasites, calling for researchers to fill this gap.

Is Haemoproteus gabaldoni a valid species? An approach from morphology and molecular tools applied to parasites of Anseriformes

Currently, there are three recognized species of haemoproteids infecting Anseriformes: Haemoproteus nettionis, H. macrovacuolatus, and H. greineri. Unfortunately, genetic information associated with a morphotype is available only for H. macrovacuolatus. We recently found a parasite morphologically compatible with Haemoproteus gabaldoni, a species Bennet (1993) described in a Cairina moschata (Muscovy duck) from Venezuela. This species was synonymized to H. nettionis by Valkiūnas (2005), arguing not enough morphological differentiation between them; it was said that H. greineri could be as well a synonym of H. nettionis. In this study, we aimed to provide evidence to determine if Haemoproteus gabaldoni is a different species of H. nettionis and help to clarify other species status. We first performed morphological and morphometrical analyses and compared this information against the parahapantotypes of H. greineri, H. gabaldoni and material diagnosed as H. nettionis provided by the International Reference center for Avian Haematozoa (IRCAH), and H. macrovacuolatus from the Host-Parasite Relationship Study Group (GERPH, in Spanish Grupo de Estudio Relación Parásito Hospedero) biological collection. We used Principal Component Analysis (PCA) of dimensionless standard morphometrical variables from gametocytes. Furthermore, we amplified a small fragment of cytochrome b (cyt b) to compare the sequence with information in GenBank and Malavi through phylogenetic analyses and haplotype networks. PCA analyses revealed the presence of three distinct groups in the samples studied, supported in the morphological traits of each parasite species analyzed; phylogenetic analyses grouped parasite lineages separately according to the host and continent of provenance. Such results indicate that, H. gabaldoni, is a different species from H. nettionis. One more time, it is demonstrated the importance of linking barcode surveys to morphological studies. Finally, it is highlighted the importance of biological collections as repositories of worldwide biodiversity.

Apparent absence of avian malaria and malaria-like parasites in northern blue-footed boobies breeding on Isla Isabel

Haemosporidian parasites are common in birds but are seldom reported in seabirds. The absence of vectors or genetic resistance to infection have been proposed to explain this pattern. However, screening of blood parasites in many seabirds has been done only by visual inspection of blood smears, which can miss low-intensity infections, and molecular detection of blood parasites must be supported by detection in blood smears to confirm the presence of haemosporidians and avoid false positive cases. Here, we tested for the presence of blood parasites of the genera Plasmodium, Haemoproteus and Leucocytozoon, combining inspection of blood smears and PCR-based detection methods in a highly philopatric colony of blue-footed boobies (Sula nebouxii) in the Tropical North Pacific. Our results indicate that adults in this colony are likely free of these blood parasites, probably due to unsuitable conditions for insect vectors in booby breeding sites, although potential genetic resistance of blue-footed boobies to infection deserves examination. Apparent absence of blood parasites in Isla Isabel boobies indirectly adds to the growing evidence of variation in parasite infections among avian host species that coexist locally.

Impact of Subclinical Haemoproteus columbae Infection on Farmed Domestic Pigeons from Central Java (Yogyakarta), Indonesia, with Special Reference to Changes in the Hemogram

Pigeon haemoproteosis caused by Haemoproteus columbae (Apicomplexa: Haemosporida: Haemoproteidae) is globally prevalent in rock doves (Columba livia), although little is known regarding this disease in pigeons and doves in Indonesia. Blood samples of 35 farmed domestic pigeons (C. livia f. domestica) from four localities in Yogyakarta Special Region, Central Java, Indonesia, were collected from March to June, 2016, subjected to a hemogram, and analyzed for the presence of hemoprotozoan infections. Microscopic examination of blood smears revealed a prevalence of 62.5–100% of H. columbae at the four localities (n = 8–10 for each locality), and geometric means of 3.0–5.6% of erythrocytes were parasitized by young and mature gametocytes, suggesting that all infected pigeons were in the chronic phase of infection with repeated recurrences and/or reinfections. Nucleotide sequencing of mitochondrial cytochrome b gene (cytb) for haemosporidian species demonstrated the distribution of four major cytb lineages of H. columbae (mainly HAECOL1, accompanied by COLIV03, COQUI05, and CXNEA02 according to the MalAvi database). Hemogram analysis, involving the estimation of packed cell volume, erythrocyte counts, mean corpuscular volume, mean corpuscular hemoglobin concentration, and plasma protein and fibrinogen levels of 20 parasitized pigeons and five non-infected pigeons demonstrated significant macrocytic hypochromic anemia with hypoproteinemia and hyperfibrinogenemia in the infected pigeons. This study shows the profound impact of long-lasting subclinical pigeon haemoproteosis caused by H. columbae on the health of farmed domestic pigeons.

Prevalence and genetic diversity of avian haemosporidian parasites in wild bird species of the order Columbiformes

Diseases can play a role in species decline. Among them, haemosporidian parasites, vector-transmitted protozoan parasites, are known to constitute a risk for different avian species. However, the magnitude of haemosporidian infection in wild columbiform birds, including strongly decreasing European turtle doves, is largely unknown. We examined the prevalence and diversity of haemosporidian parasites Plasmodium, Leucocytozoon and subgenera Haemoproteus and Parahaemoproteus in six species of the order Columbiformes during breeding season and migration by applying nested PCR, one-step multiplex PCR assay and microscopy. We detected infections in 109 of the 259 screened individuals (42%), including 15 distinct haemosporidian mitochondrial cytochrome b lineages, representing five H. (Haemoproteus), two H. (Parahaemoproteus), five Leucocytozoon and three Plasmodium lineages. Five of these lineages have never been described before. We discriminated between single and mixed infections and determined host species-specific prevalence for each parasite genus. Observed differences among sampled host species are discussed with reference to behavioural characteristics, including nesting and migration strategy. Our results support previous suggestions that migratory birds have a higher prevalence and diversity of blood parasites than resident or short-distance migratory species. A phylogenetic reconstruction provided evidence for H. (Haemoproteus) as well as H. (Parahaemoproteus) infections in columbiform birds. Based on microscopic examination, we quantified parasitemia, indicating the probability of negative effects on the host. This study provides a large-scale baseline description of haemosporidian infections of wild birds belonging to the order Columbiformes sampled in the northern hemisphere. The results enable the monitoring of future changes in parasite transmission areas, distribution and diversity associated with global change, posing a potential risk for declining avian species as the European turtle dove.

Contaminations contaminate common databases

The polymerase chain reaction (PCR) is a very powerful method to detect and identify pathogens. The high sensitivity of the method, however, comes with a cost; any of the millions of artificial DNA copies generated by PCR can serve as a template in a following experiment. If not identified as contaminations, these may result in erroneous conclusions on the occurrence of the pathogen, thereby inflating estimates of host range and geographic distribution. In the present paper, we evaluate whether several published records of avian haemosporidian parasites, in either unusual host species or geographical regions, might stem from PCR contaminations rather than novel biological findings. The detailed descriptions of these cases are shedding light upon the steps in the work process that might lead to PCR contaminations. By increasing the awareness of this problem, it will aid in developing procedures that keep these to a minimum. The examples in the present paper are from haemosporidians of birds, however the problem of contaminations and suggested actions should apply generally to all kinds of PCR‐based identifications, not just of parasites and pathogens.

Baseline haematology, biochemistry, blood gas values and health status of the Galapagos swallow-tailed gull (Creagrus furcatus)

The swallow-tailed gull, Creagrus furcatus, is a seabird endemic to the Galápagos archipelago. In general health, blood chemistry and haematology, parameters have not been published for this species. Blood analyses were run on samples drawn from 58 clinically healthy swallow-tailed gulls captured at Islote Pitt on San Cristóbal Island in July 2016 (28) and South Plaza Island in June 2017 (30). A point of care blood analyzer (iSTAT) was used in the field to obtain results for HCO₃ ^-, pH, pCO₂, pO₂, TCO₂, anion gap, chloride, creatinine, glucose, haematocrit, haemoglobin, ionized calcium, potassium, sodium and urea nitrogen. A portable Lactate Plus™ analyzer was used to measure lactate. The baseline data reported is valuable for comparisons amongst different populations in the archipelago and to detect changes in health status of Galápagos swallow-tailed gulls.

Effect of predation risk and ectoparasitic louse flies on physiological stress condition of the red-tailed tropicbird (Phaethon rubricauda) from Rapa Nui and Salas & Gómez islands

Background

Introduced predators at seabird colonies and parasites may have lethal and/or sub-lethal consequences for bird populations. We assessed the potential sub-lethal negative effects of these stressors in a native seabird listed as vulnerable in its south-eastern pacific distribution. This study was conducted in two red-tailed tropicbird (Phaethon rubricauda) colonies, one located in Rapa Nui Island, which is threatened by the presence of introduced predators, and the other located in Salas & Gómez Island, which has no introduced predators, but birds are infested by ectoparasitic louse flies.

Methods

The effects on physiological stress traits of both, predation risk on different nest types (protected and exposed) on Rapa Nui, and different levels of louse flies' parasitic loads on Salas & Gómez were studied. Three variables were analyzed: the heterophil/lymphocyte (H/L) ratio, the transcriptional levels of mRNA HSP70 in blood, and the body condition. These stress indicators and leukocyte counts were compared between colonies.

Results

No significant differences were found in any stress indicator between different nest types within Rapa Nui, showing that the effect of predator's presence was the same for adults nesting in both, protected and exposed nests. No significant correlation was found between louse flies' parasitic loads and any stress indicators in the birds of Salas & Gómez. Also, there was no difference in any stress indicator between islands. However, a significant opposite trend between islands was found in the eosinophil, lymphocyte, and monocyte counts when related to body condition.

Conclusions

We found a lack of significant differentiation in all the stress level indicators assessed within and between islands. The presence of louse flies in Salas & Gómez vs. the absence of this parasite at Rapa Nui may be the cause for the significant difference in the trend of eosinophil, lymphocyte and monocyte counts between the islands. However, further studies are necessary to elucidate the reason for this difference and to better investigate the lethal effects of introduced predators on the Rapa Nui colony to evaluate appropriate conservation measures for this native seabird.

Haemosporidian Parasites of Chilean Ducks: The Importance of Biogeography and Nonpasserine Hosts

Biogeography is known to have shaped the diversity and evolutionary history of avian haemosporidian parasites across the Neotropics. However, a paucity of information exists for the temperate Neotropics and especially from nonpasserine hosts. To understand the effect of biogeography in the temperate Neotropics on haemosporidians of nonpasserine hosts we screened ducks (Anseriformes) from central Chile for the presence of these parasites. Forty-two individuals of 4 duck species (Anas flavirostris, Anas georgica, Mareca sibilatrix, Spatula cyanoptera cyanoptera) were collected and assessed for haemosporidian parasite infections by real-time polymerase chain reaction screening and subsequent sequencing of the mitochondrial cytochrome b gene. Haemoproteus (subgenus Haemoproteus) and Plasmodium were detected in 2 host species, A. georgica and S. c. cyanoptera, with no Leucocytozoon found. Overall haemosporidian prevalence was low (14.2%), with the prevalence of Plasmodium (11.9%) being substantially greater than that of Haemoproteus (4.8%). Six haemosporidian cytochrome b lineages were recovered, 2 Haemoproteus and 4 Plasmodium, with all 6 lineages identified for the first time. In phylogenetic reconstruction, the Chilean Plasmodium lineages were more closely related to South American lineages from passerine birds than to known lineages from anseriforms. The subgenus Haemoproteus known from nonpasseriformes has never been identified from any anseriform host; however, we recovered 2 lineages from this subgenus, one from each A. georgica and S. c. cyanoptera. Further work is needed to determine if this presents true parasitism in ducks or only a spillover infection. The results of phylogenetic reconstruction demonstrate a unique evolutionary history of these Chilean parasites, differing from what is known for this host group. The unique geography of Chile, with a large part of the country being relatively isolated by the Atacama Desert in the north and the Andes in the east and south, would present opportunities for parasite diversification. Further work is needed to investigate how strongly the biogeographical isolation has shaped the haemosporidian parasites of this area. Our results add to the growing body of evidence that nonpasserine hosts support unique lineages of haemosporidian parasites, while also demonstrating the role of biogeography in haemosporidian parasite diversity in the temperate Neotropics.

Characterizing the microbiome of ectoparasitic louse flies feeding on migratory raptors

Louse flies (Diptera: Hippoboscidae) are obligate ectoparasites that often cause behavioral, pathogenic, and evolutionary effects on their hosts. Interactions between ectoparasites and avian hosts, especially migrating taxa, may influence avian pathogen spread in tropical and temperate ecosystems and affect long-term survival, fitness and reproductive success. The purpose of this study was to characterize the vector-associated microbiome of ectoparasitic louse flies feeding on migrating raptors over the fall migration period. Surveys for louse flies occurred during fall migration (2015-2016) at a banding station in Pennsylvania, United States; flies were collected from seven species of migrating raptors, and we sequenced their microbial (bacteria and archaea) composition using high-throughput targeted amplicon sequencing of the 16S rRNA gene (V4 region). All louse flies collected belonged to the same species, Icosta americana. Our analysis revealed no difference in bacterial communities of louse flies retrieved from different avian host species. The louse fly microbiome was dominated by a primary endosymbiont, suggesting that louse flies maintain a core microbial structure despite receiving blood meals from different host species. Thus, our findings highlight the importance of characterizing both beneficial and potentially pathogenic endosymbionts when interpreting how vector-associated microbiomes may impact insect vectors and their avian hosts.

Evolutionary ecology, taxonomy, and systematics of avian malaria and related parasites

Haemosporidian parasites of the genera Plasmodium, Leucocytozoon, and Haemoproteus are one of the most prevalent and widely studied groups of parasites infecting birds. Plasmodium is the most well-known haemosporidian as the avian parasite Plasmodium relictum was the original transmission model for human malaria and was also responsible for catastrophic effects on native avifauna when introduced to Hawaii. The past two decades have seen a dramatic increase in research on avian haemosporidian parasites as a model system to understand evolutionary and ecological parasite-host relationships. Despite haemosporidians being one the best studied groups of avian parasites their specialization among avian hosts and variation in prevalence amongst regions and host taxa are not fully understood. In this review we focus on describing the current phylogenetic and morphological diversity of haemosporidian parasites, their specificity among avian and vector hosts, and identifying the determinants of haemosporidian prevalence among avian species. We also discuss how these parasites might spread across regions due to global climate change and the importance of avian migratory behavior in parasite dispersion and subsequent diversification.

High prevalence and genetic diversity of Haemoproteus columbae (Haemosporida: Haemoproteidae) in feral pigeons Columba livia in Cape Town, South Africa

In this study, we explore blood parasite prevalence, infection intensity, and co-infection levels in an urban population of feral pigeons Columba livia in Cape Town. We analyze the effect of blood parasites on host body condition and the association between melanin expression in the host's plumage and parasite infection intensity and co-infection levels. Relating to the haemosporidian parasite itself, we study their genetic diversity by means of DNA barcoding (cytochrome b) and show the geographic and host distribution of related parasite lineages in pigeons worldwide. Blood from 195 C. livia individuals was collected from April to June 2018. Morphometric measurements and plumage melanism were recorded from every captured bird. Haemosporidian prevalence and infection intensity were determined by screening blood smears and parasite lineages by DNA sequencing. Prevalence of Haemoproteus spp. was high at 96.9%. The body condition of the hosts was negatively associated with infection intensity. However, infection intensity was unrelated to plumage melanism. The cytochrome b sequences revealed the presence of four Haemoproteus lineages in our population of pigeons, which show high levels of co-occurrence within individual birds. Three lineages (HAECOL1, COLIV03, COQUI05) belong to Haemoproteus columbae and differ only by 0.1% to 0.8% in the cytochrome b gene. Another lineage (COLIV06) differs by 8.3% from the latter ones and is not linked to a morphospecies, yet. No parasites of the genera Leucocytozoon and Plasmodium were detected.

Assessing the blood meal hosts of Culex quinquefasciatus and Aedes taeniorhynchus in Isla Santa Cruz, Galápagos

Background

Blood meal host selection by mosquito vectors is an important component in understanding disease dynamics of pathogens that threaten endemic fauna in isolated islands such as Galápagos. Research on the feeding behavior of mosquitoes can provide clues to the hosts and vectors involved in disease transmission. This information is particularly critical for endemic wildlife fauna in island systems that have evolved without resistance to novel diseases such as avian malaria. The aims of this study were to determine the blood-feeding patterns of two species of mosquitoes found in Galápagos and discuss how their feeding behavior may influence the transmission of pathogens such as avian malaria.

Methods

In the summer of 2015, we sampled two mosquito species (Aedes taeniorhynchus and Culex quinquefasciatus) across 18 different sites on Isla Santa Cruz, which is the second largest island in Galápagos and has the largest human population. We trapped mosquitoes using CDC light traps and CDC gravid traps and identified sources of blood meals for engorged mosquitoes by sequencing a portion of the vertebrate mitochondrial cytochrome b gene.

Results

Out of 947 female mosquitoes captured, 320 were blood-fed, and PCR amplifications were successful for 301 of the blood meals. Results revealed that both Aedes taeniorhynchus and Culex quinquefasciatus feed from a variety of vertebrate taxa, numerically dominated by humans on Isla Santa Cruz.

Conclusions

The high proportion of mammalian blood meals could represent locally available and abundant hosts on Santa Cruz. However, host surveys and estimates of relative abundances of vertebrate species will need to accompany mosquito trapping studies on non-inhabited and inhabited islands in Galápagos to further validate this.

Louse flies of Eleonora's falcons that also feed on their prey are evolutionary dead-end hosts for blood parasites

Host shifts are widespread among avian haemosporidians, although the success of transmission depends upon parasite‐host and parasite‐vector compatibility. Insular avifaunas are typically characterized by a low prevalence and diversity of haemosporidians, although the underlying ecological and evolutionary processes remain unclear. We investigated the parasite transmission network in an insular system formed by Eleonora's falcons (the avian host), louse flies that parasitize the falcons (the potential vector), and haemosporidians (the parasites). We found a great diversity of parasites in louse flies (16 Haemoproteus and 6 Plasmodium lineages) that did not match with lineages previously found infecting adult falcons (only one shared lineage). Because Eleonora's falcon feeds on migratory passerines hunted over the ocean, we sampled falcon kills in search of the origin of parasites found in louse flies. Surprisingly, louse flies shared 10 of the 18 different parasite lineages infecting falcon kills. Phylogenetic analyses revealed that all lineages found in louse flies (including five new lineages) corresponded to Haemoproteus and Plasmodium parasites infecting Passeriformes. We found molecular evidence of louse flies feeding on passerines hunted by falcons. The lack of infection in nestlings and the mismatch between the lineages isolated in adult falcons and louse flies suggest that despite louse flies’ contact with a diverse array of parasites, no successful transmission to Eleonora's falcon occurs. This could be due to the falcons’ resistance to infection, the inability of parasites to develop in these phylogenetically distant species, or the inability of haemosporidian lineages to complete their development in louse flies.

Low occurrence of hemosporidian parasites in the Neotropic cormorant (Phalacrocorax brasilianus) in Chile

Hemosporidian parasites rarely infect aquatic birds. Few studies have been conducted in South America identifying some lineages of the genera Plasmodium, Leucocytozoon, and Haemoproteus, but none has been done in the Neotropic cormorant (Phalacrocorax brasilianus). This species is widely distributed through the American continent, from Southern USA to Tierra del Fuego, using a wide range of aquatic habitats. We molecularly studied the occurrence and diversity of hemosporidian lineages infecting individuals of Neotropic cormorant across a broad latitudinal gradient in Chile (Arica to Tierra del Fuego). As expected, a very low occurrence of individuals infected by Plasmodium sp. (4/123, 3.3%) and Leucocytozoon sp. (2/123, 1.6%) was detected. We found no evidence of Haemoproteus sp. We identified one lineage of Plasmodium (ZEMAC01) and one new lineage of Leucocytozoon (PHABRA01) infecting cormorants. Individuals infected by Plasmodium sp. were birds from only one site (i.e., Chillán), whereas Leucocytozoon sp. was found in one bird from Valdivia and another one from Tierra del Fuego. Our results expand the known range of hemosporidian parasite lineages in aquatic birds providing an essential baseline data that contribute to a better understanding of the geographic range of hemosporidian parasites infecting Phalacrocoracidae in South America.

Delineation of the Genera Haemoproteus and Plasmodium Using RNA-Seq and Multi-gene Phylogenetics

Members of the order Haemosporida are protist parasites that infect mammals, reptiles and birds. This group includes the causal agents of malaria, Plasmodium parasites, the genera Leucocytozoon and Fallisia, as well as the species rich genus Haemoproteus with its two subgenera Haemoproteus and Parahaemoproteus. Some species of Haemoproteus cause severe disease in avian hosts, and these parasites display high levels of diversity worldwide. This diversity emphasizes the need for accurate evolutionary information. Most molecular studies of wildlife haemosporidians use a bar coding approach by sequencing a fragment of the mitochondrial cytochrome b gene. This method is efficient at differentiating parasite lineages but insufficient for accurate phylogenetic inferences in highly diverse taxa such as haemosporidians. Recent studies have utilized multiple mitochondrial genes (cyt b, cox1 and cox3), sometimes combined with a few apicoplast and nuclear genes. These studies have been highly successful with one notable exception: the evolutionary relationships of the genus Haemoproteus remain unresolved. Here we describe the transcriptome of Haemoproteus columbae and investigate its phylogenetic position recovered from a multi-gene dataset (600 genes). This genomic approach restricts the taxon sampling to 18 species of apicomplexan parasites. We employed Bayesian inference and maximum likelihood methods of phylogenetic analyses and found H. columbae and a representative from the subgenus Parahaemoproteus to be sister taxa. This result strengthens the hypothesis of genus Haemoproteus being monophyletic; however, resolving this question will require sequences of orthologs from, in particular, representatives of Leucocytozoon species.

Combining morphological and molecular data to reconstruct the phylogeny of avian Haemosporida

The traditional classification of avian Haemosporida is based mainly on morphology and life history traits. Recently, molecular hypotheses have challenged the traditional classification, leading to contradictory opinions on whether morphology is phylogenetically informative. However, the morphology has never been used to reconstruct the relationships within the group. We inferred the phylogeny of avian Haemosporida from 133 morphological characters present in blood stages. We included all species with at least one mitochondrial gene characterized (n = 93). The morphological hypothesis was compared with the one retrieved from mitochondrial DNA (mtDNA) nucleotide sequences and a hypothesis that used a combination of morphological and molecular data (i.e., total evidence). In order to recover the evolutionary history and identify phylogenetically and taxonomically informative characters, they were mapped on the total evidence phylogeny. The morphological hypothesis presented more polytomies than the other two, especially within Haemoproteus. In the molecular hypothesis, the two Haemoproteus subgenera are paraphyletic, and some relationships within Parahaemoproteus were resolved. By combining the morphological and molecular data, we were able to resolve the majority of polytomies and posterior probabilities increased. We identified a unique combination of morphological traits, clearly differentiating avian Haemosporida genera, sub-genera of Leucocytozoon and Haemoproteus, and some Plasmodium sub-genera. Plasmodium had the highest number of synapomorphies. Furthermore, 86% of the species presented a unique combination of taxonomically informative characters. A limiting factor was the mismatch of traits characterized in species descriptions, leading to a morphological matrix with a considerable amount of missing data, particularly for the stages of early young and young gametocytes (67% of all missing data). Characters lacking information for the majority of species included the colour of pigment granules, the cytoplasm appearance, and the presence and dimensions of vacuoles. According to our results, the combination of morphology and mtDNA proved to be a robust alternative to reconstruct the relationships among avian Haemosporida, obtaining a resolution and support similar to that obtained using full mitochondrial genome sequences for over 100 lineages.

A new blood parasite of leaf warblers: molecular characterization, phylogenetic relationships, description and identification of vectors

BACKGROUND

Blood parasites of the genus Haemoproteus Kruse, 1890 are cosmopolitan, might be responsible for mortality in non-adapted birds, and often kill blood-sucking insects. However, this group remains insufficiently investigated in the wild. This is particularly true for the parasites of leaf warblers of the Phylloscopidae Alström, Ericson, Olsson & Sundberg the common small Old World passerine birds whose haemoproteid parasite diversity and vectors remain poorly studied. This study reports a new species of Haemoproteus parasitizing leaf warblers, its susceptible vector and peculiar phylogenetic relationships with other haemoproteids.

METHODS

Wood warblers (Phylloscopus sibilatrix Bechstein) were caught in Lithuania during spring migration, and blood films were examined microscopically. Laboratory reared Culicoides nubeculosus Meigen were exposed experimentally by allowing them to take blood meals on one individual harbouring mature gametocytes of the new Haemoproteus species (lineage hPHSIB2). To follow sporogonic development, the engorged insects were dissected at intervals. The parasite lineage was distinguished using sequence data, and morphological analysis of blood and sporogonic stages was carried out. Bayesian phylogeny was constructed in order to determine the phylogenetic relationships of the new parasite with other haemoproteids.

RESULTS

Haemoproteus (Parahaemoproteus) homopalloris n. sp. was common in wood warblers sampled after arrival to Europe from their wintering grounds in Africa. The new parasite belongs to a group of avian haemoproteid species with macrogametocytes possessing pale staining cytoplasm. All species of this group clustered together in the phylogenetic analysis, indicating that intensity of the cytoplasm staining is a valuable phylogenetic character. Laboratory-reared biting midges C. nubeculosus readily supported sporogony of new infections. Phylogenetic analysis corroborated vector experiments, placing the new parasite in the clade of Haemoproteus (Parahaemoproteus) parasites transmitted by biting midges.

CONCLUSIONS

Haemoproteus homopalloris n. sp. is the third haemoproteid, which is described from and is prevalent in wood warblers. Phylogenetic analysis identified a clade containing seven haemoproteids, which are characterised by pale staining of the macrogametocyte cytoplasm and with ookinetes maturing exceptionally rapidly (between 1 to 1.5 h after exposure to air). Both these features may represent valuable phylogenetic characters. Studies targeting mechanisms of sporogonic development of haemoproteids remain uncommon and should be encouraged. Culicoides nubeculosus is an excellent experimental vector of the new parasite species.

Evidence of multiple colonizations as a driver of black fly diversification in an oceanic island

True oceanic islands typically host reduced species diversity together with high levels of endemism, which make these environmental set-ups ideal for the exploration of species diversification drivers. In the present study, we used black fly species (Diptera: Simuliidae) from Reunion Island as a model to highlight the main drivers of insect species diversification in this young and remote volcanic island located in the Southwestern Indian Ocean. Using local and regional (Comoros and Seychelles archipelagos) samples as well as specimens from continental Africa, we tested the likelihood of two distinct scenarios, i.e. multiple colonizations vs. in-situ diversification. For this, posterior odds were used to test whether species from Reunion did form a monophyletic group and we estimated divergence times between species. Three out of the four previously described Reunion black fly species could be sampled, namely Simulium ruficorne, Simulium borbonense and Simulium triplex. The phylogenies based on nuclear and mitochondrial markers showed that S. ruficorne and S. borbonense are the most closely related species. Interestingly, we report a probable mitochondrial introgression between these two species although they diverged almost six million years ago. Finally, we showed that the three Reunion species did not form a monophyletic group, and, combined with the molecular datation, the results indicated that Reunion black fly diversity resulted from multiple colonization events. Thus, multiple colonizations, rather than in-situ diversification, are likely responsible for an important part of black fly diversity found on this young Darwinian island.

Colonization of Parasites and Vectors

Colonization comprises the physical arrival of a species in a new area, but also its successful establishment within the local community. Oceanic islands, like the Hawaiian and the Galapagos archipelagos, represent excellent systems to study the mechanisms of colonization because of their historical isolation. In this chapter, we first review some of the major mechanisms by which parasites and vectors could arrive to an oceanic island, both naturally or due to human activities, and the factors that may influence their successful establishment in the insular host community. We then explore examples of natural and anthropogenic colonization of the Galapagos Islands by parasites and vectors, focusing on one or more case studies that best represent the diversity of colonization mechanisms that has shaped parasite distribution in the archipelago. Finally, we discuss future directions for research on parasite and vector colonization in Galapagos Islands.

From Galapagos doves to passerines: Spillover of Haemoproteus multipigmentatus

Haemoproteus (Haemoproteus) multipigmentatus, a haemosporidian parasite thought to be specific to columbiform birds, was detected in passeriform birds on Santiago Island in the Galapagos archipelago. We surveyed birds along an altitudinal gradient on the islands of Santa Cruz, Isabela and Santiago between June 2013 and July 2015. Molecular screening of 2254 individuals from 25 species of endemic and introduced birds revealed clusters of passerine birds positive for H. multipigmentatus on Santiago Island that coincide with captures of Galapagos doves at sampled sites. Of 507 individuals from 10 species of endemic passerines sampled on Santiago, 58 individuals from 6 species were found positive (11% prevalence). However, no gametocytes were found in the blood smears of positive passerines, suggesting that these species are not competent hosts for the parasite. All 31 doves captured were positive and gametocytes were found upon microscopic examination of all thin blood smears (averaging 357 gametocytes per 10,000 erythrocytes). These findings indicate parasite spillover from doves to passerines, but that passerines are possibly not competent hosts for further parasite transmission. The endemic Galapagos dove acts as a reservoir host for the introduced H. multipigmentatus, however the effect of this parasite on passerines has not been studied. We report on these findings because parasites can have large effects on individual host populations and on the ecology of a community, but may go undetected.

Blood parasites of penguins: a critical review

Blood parasites are considered some of the most significant pathogens for the conservation of penguins, due to the considerable morbidity and mortality they have been shown to produce in captive and wild populations of these birds. Parasites known to occur in the blood of penguins include haemosporidian protozoans (Plasmodium, Leucocytozoon, Haemoproteus), piroplamid protozoans (Babesia), kinetoplastid protozoans (Trypanosoma), spirochete bacteria (Borrelia) and nematode microfilariae. This review provides a critical and comprehensive assessment of the current knowledge on these parasites, providing an overview of their biology, host and geographic distribution, epidemiology, pathology and implications for public health and conservation.

Mechanisms of mortality in Culicoides biting midges due to Haemoproteus infection

We examined the effects of Haemoproteus infection on the survival and pathology caused in the biting midges. Forty-six females of Culicoides impunctatus were exposed experimentally by allowing them to feed on a naturally infected red-backed shrike infected with Haemoproteus lanii (lineage hRB1, gametocytaemia 5·2%). Seventeen females were fed on an uninfected bird (controls). Dead insects were collected, counted and used for dissection, histological examination and polymerase chain reaction-based testing. Parasites were present in all experimentally infected biting midges, but absent from control insects. Survivorship differed significantly between the control and infected groups. Twelve hours post-exposure (PE), 45 (98%) experimentally infected midges were dead, but all control midges remained alive, and many of them survived until 7 day PE. The migrating ookinetes of H. lanii overfilled midgut, markedly damaged the midgut wall, entered the haemocoel and overfilled the abdomen and thorax of exposed biting midges. Massive infection by migrating ookinetes led to damage of abdomen and thorax of biting midges. The parasites often present in large clumps in the haemocoel in abdomen and thorax, leading to the interruption of the haemolymph circulation. These are the main reasons for rapid death of biting midges after feeding on high-intensity infections of Haemoproteus parasites.

The role of seabirds of the Iles Eparses as reservoirs and disseminators of parasites and pathogens

The role of birds as reservoirs and disseminators of parasites and pathogens has received much attention over the past several years due to their high vagility. Seabirds are particularly interesting hosts in this respect. In addition to incredible long-distance movements during migration, foraging and prospecting, these birds are long-lived, site faithful and breed in dense aggregations in specific colony locations. These different characteristics can favor both the local maintenance and large-scale dissemination of parasites and pathogens. The Iles Eparses provide breeding and feeding grounds for more than 3 million breeding pairs of seabirds including at least 13 species. Breeding colonies on these islands are relatively undisturbed by human activities and represent natural metapopulations in which seabird population dynamics, movement and dispersal can be studied in relation to that of circulating parasites and pathogens. In this review, we summarize previous knowledge and recently-acquired data on the parasites and pathogens found in association with seabirds of the Iles Eparses. These studies have revealed the presence of a rich diversity of infectious agents (viruses, bacteria and parasites) carried by the birds and/or their local ectoparasites (ticks and louse flies). Many of these agents are widespread and found in other ecosystems confirming a role for seabirds in their large scale dissemination and maintenance. The heterogeneous distribution of parasites and infectious agents among islands and seabird species suggests that relatively independent metacommunities of interacting species may exist within the western Indian Ocean. In this context, we discuss how the patterns and determinants of seabird movements may alter parasite and pathogen circulation. We conclude by outlining key aspects for future research given the baseline data now available and current concerns in eco-epidemiology and biodiversity conservation.

Prevalence of Haemoproteus sp. in Galápagos blue-footed boobies: effects on health and reproduction

Populations of blue-footed boobies in the Galápagos Islands have declined by at least 50% compared with numbers recorded during the 1960s. Recently, concern has been expressed about potential adverse effects of introduced blood parasites; in particular, malarial parasites (i.e.Plasmodiumsp.), which are frequently pathogenic and can cause mortality and morbidity in birds, and blood parasites of the genusHaemoproteus, which can reduce fitness. We screened blue-footed boobies at six breeding colonies within Galápagos for both genera of parasite. At two sites, we also investigated whether there was any relationship between infection status and physiological condition or breeding success. We found a high prevalence ofHaemoproteusspp. in adults and chicks using PCR, although none was found on blood smears. We found no evidence ofPlasmodium.Effects of parasitism on the condition of birds were limited. Also, there was no evidence that infection withHaemoproteusadversely affected breeding success or chick growth. Our results suggest that poor success of breeding birds was not strongly associated withHaemoproteusinfection. However, regular colony monitoring and examination of dead birds are necessary to assess whether acuteHaemoproteusinfection might be responsible for some mortality, particularly of chicks.

Biting midges (Culicoides, Diptera) transmit Haemoproteus parasites of owls: evidence from sporogony and molecular phylogeny

BACKGROUND

Haemoproteus parasites are widespread, and several species cause diseases both in birds and blood-sucking insects. These pathogens are transmitted by dipterans belonging to the Ceratopogonidae and Hippoboscidae, however certain vector species remain unknown for the majority of Haemoproteus spp. Owls are often infected by Haemoproteus parasites, but experimental studies on vectors of these infections are lacking. The aim of this study was to investigate sporogonic development of two widespread Haemoproteus parasites of owls, H. noctuae and H. syrnii in experimentally infected biting midges Culicoides impunctatus and Culicoides nubeculosus. We also followed in vitro sporogonic development of these infections and determined their phylogenetic relationships with Haemoproteus spp., for which vectors have been identified.

METHODS

Wild-caught C. impunctatus and laboratory reared C. nubeculosus were infected experimentally by allowing them to take blood meals on one individual long-eared owl (Asio otus) and one tawny owl (Strix aluco) harbouring mature gametocytes of H. noctuae (lineage hCIRCUM01) and H. syrnii (hCULCIB01), respectively. The engorged insects were maintained in the laboratory at 16-18 °C, and dissected at intervals in order to follow the development of ookinetes, oocysts and sporozoites. We also observed in vitro development of sexual stages of both parasites by exposure of infected blood to air. The parasite lineages were determined by polymerase chain reaction-based methods. Bayesian phylogeny was constructed in order to determine the relationships of owl parasites with other avian Haemoproteus spp., for which vectors have been identified.

RESULTS

Both H. noctuae and H. syrnii completed sporogony in C. nubeculosus, and H. noctuae completed sporogony in C. impunctatus. Ookinetes, oocysts and sporozoites of these parasites were reported and described. Gametes and ookinetes of both species readily developed in vitro. In accordance with sporogony data, the phylogenetic analysis placed both parasite lineages in a clade of Culicoides spp.-transmitted avian Haemoproteus (Parahaemoproteus) spp.

CONCLUSIONS

Culicoides nubeculosus and C. impunctatus are vectors of H. noctuae and H. syrnii. Phylogenies based on cytochrome b gene indicate parasite-vector relationships, and we recommend using them in predicting possible parasite-vector relationships and planning research on avian Haemoproteus spp. vectors in wildlife.

Phylogeny, Diversity, Distribution, and Host Specificity of Haemoproteus spp. (Apicomplexa: Haemosporida: Haemoproteidae) of Palaearctic Tortoises

A complex wide-range study on the haemoproteid parasites of chelonians was carried out for the first time. Altogether, 811 samples from four tortoise species from an extensive area between western Morocco and eastern Afghanistan and between Romania and southern Syria were studied by a combination of microscopic and molecular-genetic methods. Altogether 160 Haemoproteus-positive samples were gathered in the area between central Anatolia and eastern Afghanistan. According to variability in the cytochrome b gene, two monophyletic evolutionary lineages were distinguished; by means of microscopic analysis it was revealed that they corresponded to two previously described species-Haemoproteus anatolicum and Haemoproteus caucasica. Their distribution areas overlap only in a narrow strip along the Zagros Mts. range in Iran. This fact suggests the involvement of two different vector species with separated distribution. Nevertheless, no vectors were confirmed. According to phylogenetic analyses, H. caucasica represented a sister group to H. anatolicum, and both of them were most closely related to H. pacayae and H. peltocephali, described from South American river turtles. Four unique haplotypes were revealed in the population of H. caucasica, compared with seven haplotypes in H. anatolicum. Furthermore, H. caucasica was detected in two tortoise species, Testudo graeca and Testudo horsfieldii, providing evidence that Haemoproteus is not strictly host-specific to the tortoise host species.

Different meal, same flavor: cospeciation and host switching of haemosporidian parasites in some non-passerine birds

Background

Previous studies have shown that haemosporidian parasites (Haemoproteus (Parahaemoproteus) and Plasmodium) infecting passerine birds have an evolutionary history of host switching with little cospeciation, in particular at low taxonomic levels (e.g., below the family level), which is suggested as the main speciation mechanism of this group of parasites. Recent studies have characterized diverse clades of haemosporidian parasites (H. (Haemoproteus) and H. (Parahaemoproteus)) infecting non-passerine birds (e.g., Columbiformes, Pelecaniiformes). Here, we explore the cospeciation history of H. (Haemoproteus) and H. (Parahaemoproteus) parasites with their non-passerine hosts.

Methods

We sequenced the mtDNA cyt b gene of both haemosporidian parasites and their avian non-passerine hosts. We built Bayesian phylogenetic hypotheses and created concensus phylograms that were subsequently used to conduct cospeciation analyses. We used both a global cospeciation test, PACo, and an event-cost algorithm implemented in CoRe-PA.

Results

The global test suggests that H. (Haemoproteus) and H. (Parahaemoproteus) parasites have a diversification history dominated by cospeciation events particularly at the family level. Host-parasite links from the PACo analysis show that host switching events are common within families (i.e., among genera and among species within genera), and occasionally across different orders (e.g., Columbiformes to Pelecaniiformes). Event-cost analyses show that haemosporidian coevolutionary history is dominated by host switching and some codivergence, but with duplication events also present. Genetic lineages unique to raptor species (e.g., FALC11) commonly switch between Falconiformes and Strigiformes.

Conclusions

Our results corroborate previous findings that have detected a global cospeciation signal at the family taxonomic level, and they also support a history of frequent switching closer to the tips of the host phylogeny, which seems to be the main diversification mechanism of haemosporidians. Such dynamic host-parasite associations are relevant to the epidemiology of emerging diseases because low parasite host specificity is a prerequisite for the emergence of novel diseases. The evidence on host distributions suggests that haemosporidian parasites have the potential to rapidly develop novel host-associations. This pattern has also been recorded in fish-monogenean interactions, suggesting a general diversification mechanism for parasites when host choice is not restricted by ecological barriers.

Haemoproteus iwa in Great Frigatebirds (Fregata minor) in the Islands of the Western Indian Ocean

Blood parasites of the sub-genus Haemoproteus have been reported in seabirds, in particular in species in the Suliformes order. These parasites are transmitted by hippoboscid flies of the genus Olfersia; strong specificity has been suggested between the vector and its vertebrate host. We investigated the prevalence of Haemoproteus infection in Suliformes and hippoboscid flies in two oceanic islands of the Western Indian Ocean: Europa and Tromelin. In total, 209 blood samples were collected from great frigatebirds (Fregata minor), masked boobies (Sula dactylatra) and red-footed boobies (Sula sula). Forty-one hippoboscid flies were also collected from birds. Seventeen frigatebirds and one fly collected on Europa tested positive for the presence of Haemoproteus parasites by polymerase chain reaction. Phylogenetic analyses based on partial sequences of the Cytochrome b gene showed that parasites were closely related to Haemoproteus iwa reported from frigatebirds in the Pacific Ocean and in the Caribbean. Plasmodium was also detected in a frigatebird on Europa; however, its placement on the phylogenetic tree could not be resolved. We provide strong support for transmission of blood parasites in seabirds in the Western Indian Ocean and suggest that migrations between the Pacific and the Indian oceans could favor the large-scale distribution of Haemoproteus iwa in frigatebird populations.

Two new species of Haemoproteus Kruse, 1890 (Haemosporida, Haemoproteidae) from European birds, with emphasis on DNA barcoding for detection of haemosporidians in wildlife

Two new species of Haemoproteus Kruse, 1890 (Haemosporida, Haemoproteidae) are described: Haemoproteus (Parahaemoproteus) homovelans n. sp. from Grey-faced Woodpecker, Picus canus Gmelin, and Haemoproteus (Parahaemoproteus) concavocentralis n. sp. recorded in Hawfinch, Coccothraustes coccothraustes (Linnaeus), both sampled in Bulgaria. The morphology of the gametocytes and their host-cells are described and mitochondrial cytochrome b (cyt b) gene sequences are generated. Haemoproteus homovelans possesses circumnuclear gametocytes lacking volutin granules. This parasite is particularly similar to Haemoproteus velans Coatney & Roudabush, 1937 also possessing circumnuclear gametocytes that are, however, overfilled with volutin. Haemoproteus concavocentralis can be readily distinguished from all described avian haemoproteids due to the presence of an unfilled concave space between the central part of advanced gametocytes and erythrocyte nucleus. Bayesian phylogenetic analyses of 40 haemosporidian cyt b lineages showed close relationships of H. concavocentralis (hHAWF2) with a group of Haemoproteus spp. possessing gametocytes that are pale-stained with Giemsa. The lineage hPICAN02 of H. homovelans clustered with parasites infecting non-passerine birds. Phylogenetic analyses support the current subgeneric classification of the avian haemoproteids and suggest that cyt b lineage hPIPUB01 (GenBank EU254552) has been incorrectly assigned to Haemoproteus picae Coatney & Roudabush, 1937, a common parasite of corvid birds (Passeriformes). This study emphasises the importance of combining molecular techniques and light microscopy in the identification and field studies of avian haemosporidian parasites. Future development of barcodes for molecular identification of haemoproteids will allow better diagnostics of these infections, particularly in veterinary studies addressing insufficiently investigated tissue pathology caused by these parasites.

First molecular characterization of a Hepatozoon species (Apicomplexa: Hepatozoidae) infecting birds and description of a new species infecting storm petrels (Aves: Hydrobatidae)

During a survey of blood parasites in a population of Leach's and black storm petrels ( Oceanodroma leucorhoa and Oceanodroma melania) in Mexico, infection by a Hepatozoon species in erythrocytes of several birds was noted. Here we describe the species as Hepatozoon peircei sp. nov. Some species of Hepatozoon described from birds have been identified as lankesterellids when DNA molecular analyses were conducted. However, a sequence of 1,774 bp of the parasite found infecting storm petrels in this study clearly show the parasite is a species of the genus Hepatozoon. This is the first Hepatozoon species infecting birds to be characterized at the molecular level and the first found infecting erythrocytes and not leucocytes.

Infection with Haemoproteus iwa affects vector movement in a hippoboscid fly--frigatebird system

Haemosporidian parasites, which require both a vertebrate and invertebrate host, are most commonly studied in the life stages occurring in the vertebrate. However, aspects of the vector's behaviour and biology can have profound effects on parasite dynamics. We explored the effects of a haemosporidian parasite, Haemoproteus iwa, on a hippoboscid fly vector, Olfersia spinifera. Olfersia spinifera is an obligate ectoparasite of the great frigatebird, Fregata minor, living among bird feathers for all of its adult life. This study examined the movements of O. spinifera between great frigatebird hosts. Movement, or host switching, was inferred by identifying host (frigatebird) microsatellite genotypes from fly bloodmeals that did not match the host from which the fly was collected. Such host switches were analysed using a logistic regression model, and the best-fit model included the H. iwa infection status of the fly and the bird host sex. Uninfected flies were more likely to have a bird genotype in their bloodmeal that was different from their current host's genotype (i.e. to have switched hosts) than infected flies. Flies collected from female birds were more likely to have switched hosts than those collected on males. Reduced movement of infected flies suggests that there may be a cost of parasitism for the fly. The effect of host sex is probably driven by differences in the sex ratio of bird hosts available to moving flies.

Multiple lineages of Avian malaria parasites (Plasmodium) in the Galapagos Islands and evidence for arrival via migratory birds

Haemosporidian parasites in the genus Plasmodium were recently detected through molecular screening in the Galapagos Penguin (Spheniscus mendiculus). We summarized results of an archipelago-wide screen of 3726 endemic birds representing 22 species for Plasmodium spp. through a combination of molecular and microscopy techniques. Three additional Plasmodium lineages were present in Galapagos. Lineage A-infected penguins, Yellow Warblers (Setophaga petechia aureola), and one Medium Ground Finch (Geospiza fortis) and was detected at multiple sites in multiple years [corrected]. The other 3 lineages were each detected at one site and at one time; apparently, they were transient infections of parasites not established on the archipelago. No gametocytes were found in blood smears of infected individuals; thus, endemic Galapagos birds may be dead-end hosts for these Plasmodium lineages. Determining when and how parasites and pathogens arrive in Galapagos is key to developing conservation strategies to prevent and mitigate the effects of introduced diseases. To assess the potential for Plasmodium parasites to arrive via migratory birds, we analyzed blood samples from 438 North American breeding Bobolinks (Dolichonyx oryzivorus), the only songbird that regularly migrates through Galapagos. Two of the ephemeral Plasmodium lineages (B and C) found in Galapagos birds matched parasite sequences from Bobolinks. Although this is not confirmation that Bobolinks are responsible for introducing these lineages, evidence points to higher potential arrival rates of avian pathogens than previously thought. Linajes Múltiples de Parásitos de Malaria Aviar (Plasmodium) en las Islas Galápagos y Evidencia de su Arribo por Medio de Aves Migratorias.

Malaria's many mates: past, present, and future of the systematics of the order Haemosporida

Malaria has been one of the most important diseases of humans throughout history and continues to be a major public health concern. The 5 species of Plasmodium that cause the disease in humans are part of the order Haemosporida, a diverse group of parasites that all have heteroxenous life cycles, alternating between a vertebrate host and a free-flying, blood-feeding dipteran vector. Traditionally, the identification and taxonomy of these parasites relied heavily on life-history characteristics, basic morphological features, and the host species infected. However, molecular approaches to resolving the phylogeny of the group have sometimes challenged many of these traditional hypotheses. One of the greatest debates has concerned the origin of the most virulent of the human-infecting parasites, Plasmodium falciparum, with early results suggesting a close relationship with an avian parasite. Subsequent phylogenetic studies placed it firmly within the mammalian clade instead, but the avian origin hypothesis has been revived with recent genome-based analyses. The rooting of the tree of Haemosporida has also been inconsistent, and the various topologies that result certainly affect our interpretation of the history of the group. There is clearly a pressing need to obtain a much more complete degree of taxon sampling of haemosporidians, as well as a greater number of characters before confidence can be placed in any hypothesis regarding the evolutionary history of the order. There are numerous challenges moving forward, particularly for generating complete genome sequences of avian and saurian parasites.

Haemoproteus syrnii in Strix aluco from France: morphology, stages of sporogony in a hippoboscid fly, molecular characterization and discussion on the identification of Haemoproteus species

In France, Haemoproteus syrnii is frequently found in the Tawny Owl, Strix aluco. Additional and complementary features of this species, and in particular the characteristics of volutin, are presented. The authors consider the volutin granules as constant in a given species, and discuss their taxonomic value. These cytoplasmic inclusions appear early during the first stages of development of the gametocytes as an initial granule which multiplies as the parasite develops. They were reported in some species of Haemoproteus but are seldom considered as a specific character and described with precision. Sporogony from ookinete to apparently mature sporozoites appears to take place in a pupiparous hippoboscid (Ornithomyia sp.). One specimen was crushed between two slides and stained with Giemsa. Gametocytes of H. syrnii, many ookinetes, an immature oocyst and mature sporozoites were observed spread all over the smear. This would allow classifying this species in the Haemoproteus subgenus. We provide associated molecular data derived from the cyt b and cox 1 gene from this parasite. We discuss the problems of multiple infections and the difficulties in identifying Haemoproteus species and in deriving conclusions from sequences deposited in databases.

Comparative host–parasite population genetic structures: obligate fly ectoparasites on Galapagos seabirds

Parasites often have shorter generation times and, in some cases, faster mutation rates than their hosts, which can lead to greater population differentiation in the parasite relative to the host. Here we present a population genetic study of two ectoparasitic flies, Olfersia spinifera and Olfersia aenescens compared with their respective bird hosts, great frigatebirds (Fregata minor) and Nazca boobies (Sula granti). Olfersia spinifera is the vector of a haemosporidian parasite, Haemoproteus iwa, which infects frigatebirds throughout their range. Interestingly, there is no genetic differentiation in the haemosporidian parasite across this range despite strong genetic differentiation between Galapagos frigatebirds and their non-Galapagos conspecifics. It is possible that the broad distribution of this one H. iwa lineage could be facilitated by movement of infected O. spinifera. Therefore, we predicted more gene flow in both fly species compared with the bird hosts. Mitochondrial DNA sequence data from three genes per species indicated that despite marked differences in the genetic structure of the bird hosts, gene flow was very high in both fly species. A likely explanation involves non-breeding movements of hosts, including movement of juveniles, and movement by adult birds whose breeding attempt has failed, although we cannot rule out the possibility that closely related host species may be involved.

Altitudinal variation in haemosporidian parasite distribution in great tit populations

BACKGROUND

One of the major issues concerning disease ecology and conservation is knowledge of the factors that influence the distribution of parasites and consequently disease outbreaks. This study aimed to investigate avian haemosporidian composition and the distribution of these parasites in three altitudinally separated great tit (Parus major) populations in western Switzerland over a three-year period. The objectives were to determine the lineage diversity of parasites occuring across the study populations and to investigate whether altitudinal gradients govern the distribution of haemosporidian parasites by lineage.

METHODS

In this study molecular approaches (PCR and sequencing) were used to detect avian blood parasites (Plasmodium sp., Haemoproteus sp. and Leucocytozoon sp.) in populations of adult great tits caught on their nests during three consecutive breeding seasons.

RESULTS

High levels of parasite prevalence (88-96%) were found across all of the study populations with no significant altitude effect. Altitude did, however, govern the distribution of parasites belonging to different genera, with Plasmodium parasites being more prevalent at lower altitudes, Leucocytozoon parasites more at high altitude and Haemoproteus parasite prevalence increasing with altitude. A total of 27 haemosporidian parasite lineages were recorded across all study sites, with diversity showing a positive correlation to altitude. Parasites belonging to lineage SGS1 (P. relictum) and PARUS4 and PARUS19 (Leucocytozoon sp.) dominated lower altitudes. SW2 (P. polare) was the second most prevalent lineage of parasite detected overall and these parasites were responsible for 68% of infections at intermediate altitude, but were only documented at this one study site.

CONCLUSIONS

Avian haemosporidian parasites are not homogeneously distributed across host populations, but differ by altitude. This difference is most probably brought about by environmental factors influencing vector prevalence and distribution. The high occurrence of co-infection by different genera of parasites might have pronounced effects on host fitness and should consequently be investigated more rigorously.

The pathology and pathogenicity of a novel Haemoproteus spp. infection in wild Little Penguins (Eudyptula minor)

One hundred and thirty four Little Penguin (Eudyptula minor) carcases found since 2004 in south west Australia were necropsied. The livers and spleens from ten of the penguins exhibited varying degrees of multifocal, randomly scattered areas of necrosis and varying numbers of parasites were associated with these areas. Hepatomegaly and splenomegaly were noted in many of these ten cases. Necrosis and parasites were also observed in the cardiac muscle of four of the cases and in the lung tissue in one of the penguins. Using PCR, the parasites were positively identified in four of the cases as Haemoproteus spp. and morphologically identical tissue stage parasites associated with histopathological changes were observed in all ten dead penguins. This is the first study to demonstrate both the in situ presence of the Haemoproteus parasite in any member of the Sphensicidae family and mortality due to its presence. We postulate the involvement of anomalous environmental conditions in a potential increase in local vectors.

Seroprevalence of malarial antibodies in Galapagos penguins (Spheniscus mendiculus)

A parasite species of the genus Plasmodium has recently been documented in the endangered Galapagos penguin (Spheniscus mendiculus). Avian malaria causes high mortality in several species after initial exposure and there is great concern for the conservation of the endemic Galapagos penguin. Using a Plasmodium spp. circumsporozoite protein antigen, we standardized an enzyme-linked immunosorbent assay to test the level of exposure in this small population, as indicated by seroprevalence. Sera from adult and juvenile Galapagos penguins collected between 2004 and 2009 on the Galapagos archipelago were tested for the presence of anti- Plasmodium spp. antibodies. Penguins were also tested for the prevalence of avian malaria parasite DNA using a polymerase chain reaction (PCR) screening. Total seroprevalence of malarial antibodies in this sample group was 97.2%, which suggests high exposure to the parasite and low Plasmodium-induced mortality. However, total prevalence of Plasmodium parasite DNA by PCR screening was 9.2%, and this suggests that parasite prevalence may be under-detected through PCR screening. Multiple detection methods may be necessary to measure the real extent of Plasmodium exposure on the archipelago.

Molecular characterization and distribution of Haemoproteus minutus (Haemosporida, Haemoproteidae): a pathogenic avian parasite

Recently, the lineage hTURDUS2 of Haemoproteus minutus (Haemosporida, Haemoproteidae) was reported to cause mortality in captive parrots. This parasite lineage is widespread and prevalent in the blackbird Turdus merula throughout its entire distribution range. Species identity of other closely related lineages recently reported in dead parrots remains unclear, but will be important to determine for a better understanding of the epidemiology of haemoproteosis. Using polymerase chain reaction (PCR)-based and microscopic methods, we analyzed 265 blood samples collected from 52 species of wild birds in Eurasia (23 samples from Kamchatka Peninsula, 73 from Sakhalin Island, 150 from Ekaterinburg and 19 from Irkutsk regions of Russia). Single infections of the lineages hTURDUS2 (hosts are redwing Turdus iliacus and fieldfare Turdus pilaris), hTUPHI1 (song thrush Turdus philomelos) and hTUCHR01 (fieldfare, redwing, song thrush and brown-headed thrush Turdus chysolaus) were detected. We identified species of these haemoproteids based on morphology of their blood stages and conclude that these lineages belong to H. minutus, a widespread parasite of different species of thrushes (genus Turdus), which serve as reservoir hosts of this haemoproteid infection. Phylogenetic analysis shows that the lineages hTURDUS2, hTUCHR01 and hTUPHI1 of H. minutus are closely related to Haemoproteus pallidus (lineages hPFC1 and hCOLL2), Haemoproteus pallidulus (hSYAT03), and Haemoproteus sp. (hMEUND3); genetic distance among their mitochondrial cytochrome b (cyt b) lineages is small (<1% or<4 nucleotides). All these blood parasites are different in many morphological characters, but are similar due to one feature, which is the pale staining of their macrogametocytes' cytoplasm with Giemsa. Because of the recent publications about mortality caused by the lineages hTUPHI1 and hTURDUS2 of H. minutus in captive parrots in Europe, H. minutus and the closely related H. pallidus and H. pallidulus are worth more attention as these are possible agents of haemoproteosis in exotic birds. The present study provides barcodes for molecular detection of different lineages of H. minutus, and extends information about the distribution of this blood parasite.

Plasmodium relictum (lineages pSGS1 and pGRW11): complete synchronous sporogony in mosquitoes Culex pipiens pipiens

Plasmodium relictum is a widespread invasive agent of avian malaria, responsible for acute, chronic and debilitating diseases in many species of birds. Recent PCR-based studies revealed astonishing genetic diversity of avian malaria parasites (genus Plasmodium), with numerous genetic lineages deposited in GenBank. Many studies addressed distribution and evolutionary relationships of avian Plasmodium lineages, but information about patterns of development of different lineages in mosquito vectors remains insufficient. Here we present data on sporogonic development of 2 widespread mitochondrial cytochrome b lineages (cyt b) of P. relictum (pSGS1 and pGRW11) in mosquito Culex pipiens pipiens. Genetic distance between these lineages is 0.2%; they fall in a well-supported clade in the phylogenetic tree. Three P. relictum strains were isolated from common crossbill (Loxia curvirostra, lineage pSGS1), domestic canary (Serinus canaria domestica, pSGS1) and house sparrow (Passer domesticus, pGRW11). These strains were multiplied in domestic canaries and used as donors of malarial gametocytes to infect C. p. pipiens. Mosquitoes were allowed to take blood meal on infected canaries and then dissected on intervals to study development of sporogonic stages. All 3 strains developed synchronously and completed sporogony in this vector, with infective sporozoites reported in the salivary glands on the day 14 after infection. Ookinetes, oocysts and sporozoites of all strains were indistinguishable morphologically. This study shows that patterns of sporogonic development of the closely related lineages pSGS1 and pGRW11 and different strains of the lineage pSGS1 of P. relictum are similar indicating that phylogenetic trees based on the cyt b gene likely can be used for predicting sporogonic development of genetically similar avian malaria lineages in mosquito vectors.

A new species of Haemoproteus from a tortoise (Testudo graeca) in Turkey, with remarks on molecular phylogenetic and morphological analysis

Haemoproteus anatolicum n. sp. was identified in the tortoise Testudo graeca. The new species is described based on the morphology of its blood stages and a segment of the mitochondrial cytochrome b gene, which can be used for molecular identification and diagnosis. Chelonian haemoproteids recorded in the past were defined solely on the basis of their morphological characteristics. The chelonian haemoproteid we describe as a new species has a close genetic relationship to lizard haemoproteids, i.e., Haemoproteus ptyodactylii and Haemoproteus kopki. The new species description provides significant new information for little-known chelonian haemoproteids.

Host selection and parasite infection in Aedes taeniorhynchus, endemic disease vector in the Galápagos Islands

Host selection in blood-sucking arthropods has important evolutionary and ecological implications for the transmission dynamics, distribution and host-specificity of the parasites they transmit. The black salt-marsh mosquito (Aedes taeniorhynchus Wiedemann) is distributed throughout tropical to temperate coastal zones in the Americas, and continental populations are primarily mammalphilic. It is the only indigenous mosquito in the Galápagos Islands, having colonised the archipelago around 200,000 years ago, potentially adapting its host selection, and in the process, altering the dynamics of vector mediated pathogen interactions in the archipelago. Here, we use blood-meal analysis and PCR-based parasite screening approach to determine the blood-feeding patterns of A. taeniorhynchus in the Galápagos Islands and identify potential parasite transmission with which this mosquito could be involved. Our results show that A. taeniorhynchus feeds equally on mammals and reptiles, and only one avian sample was observed in 190 successful PCR amplifications from blood meals. However, we detected endemic filarial worms and Haemoproteus parasites known to infect various Galápagos bird species in mosquito thoraces, suggesting that feeding on birds must occur at low frequency, and that A. taeniorhynchus may play a role in maintaining some avian vector-borne pathogens, although more work is needed to explore this possibility. We also isolated three different DNA sequences corresponding to hemogregarine parasites of the genus Hepatozoon from mosquito and iguana blood samples, suggesting that more than one species of Hepatozoon parasites are present in Galápagos. Phylogenetic analysis of Hepatozoon 18sRNA sequences indicates that A. taeniorhynchus may have facilitated a recent breakdown in host-species association of formerly isolated Hepatozoon spp. infecting the reptile populations in the Galápagos Islands.