Haemoproteus Infection Research Articles

The Study of Biting Midges Culicoides Latreille, 1809 (Diptera: Ceratopogonidae) and the Prevalence of Haemoproteus Kruse, 1890 (Haemosporida: Haemoproteidae) on the Curonian Spit of the Baltic Sea

The part of the life cycle concerning the vectors of avian haemosporidians of the genus Haemoproteus remains only partially studied. This work presents the results of capturing and analyzing female Culicoides biting midges for Haemoproteus infection, collected on the Curonian Spit of the Baltic Sea. The midges were collected from April to August 2023 in dry and wet habitats of the Spit using light traps. Each parous female midge was identified to the species level and then its salivary glands were isolated to prepare a thin smear. The preparation was examined under a light microscope for the presence of parasite stages infecting the birds (sporozoites). PCR analysis was also conducted to assess the prevalence of infection in the midges and the genetic diversity of Haemoproteus spp. among vectors on the Curonian Spit. As a result, 995 Culicoides females belonging to 12 species were collected over the course of 4 months. The highest number of midges was recorded in June. The dominant species were Culicoides kibunensis and Culicoides pictipennis. Molecular analysis showed that 2.71% (n = 27) of the examined individuals contained DNA of Haemoproteus spp. Parasites were found in midges of C. pictipennis, C. kibunensis, C. segnis, C. obsoletus, C. punctatus, C. reconditus, C. festivipennis, and C. pallidicornis from May 15 to July 13. The DNA of the identified parasites belonged to six genetic lineages of Haemoproteus—Haemoproteus parabelopolskyi hSYAT02, H. asymmetricus hTUPHI01, H. minutus hTURDUS2, H. spp. hBRAM1, hHAWF6, and hHIICT1. Sporozoites of H. parabelopolskyi hSYAT02 were detected in two individuals of C. pictipennis and one of C. kibunensis. Thus, taking into account the previous results of other studies, we have assumed that these two midge species are competent vectors for Haemoproteus parasites on the Curonian Spit.

Haemoparasite infection risk in multi-host avian system: an integrated analysis.

Avian blood parasites play a crucial role in wildlife health and ecosystem dynamics, exhibiting heterogeneous spatial distribution influenced by various factors. Although factors underlying heterogeneity in infection with blood parasites have been explored in many avian hosts, their importance in the context of host species and the parasite taxon remains poorly understood, particularly in cohabiting host species. Using next-generation sequencing for parasite screening, we investigate the association between Haemoproteus, Plasmodium and Trypanosoma infections in relation to individual parameters, host densities and landscape features in 3 cavity-nesting passerines: great tit (Parus major), blue tit (Cyanistes caeruleus) and collared flycatcher (Ficedula albicollis) in a highly fragmented forest habitat. Overall, Haemoproteus infections predominated, followed by Plasmodium and Trypanosoma, with great tits most and collared flycatchers least parasitized. There were no common patterns across host species in the probability of infection with locally transmitted parasites from each genus. Specifically, in all cases, the effect of particular parameters, if present, was observed only in 1 host species. Body condition influenced Haemoproteus and Plasmodium infections differently in tits. Host density, whether own species or all pooled, explained Haemoproteus infections in great tits and collared flycatchers, and Plasmodium in great tits. Landscape metrics, such as moisture index and distance to coast edge and pastures, affected infection probability in specific host–parasite combinations. Relative risk maps revealed infection risk gradients, but spatial variation repeatability over time was low. Our study highlights the complex dynamics of avian blood parasites in multi-host systems, shedding light on host–parasite interactions in natural ecosystems.

Identification of Haemoproteus infection in an imported grey crowned crane (Balearica regulorum) in China

Blood parasites from the order Haemosporida infect many vertebrates and cause malaria-like diseases. In this study, a haemosporidian infection was detected in a sick grey crowned crane imported into China using a combination of morphological and molecular approaches. Blood samples were collected from the jugular vein and processed for morphological identification of infective parasites using stained blood smears and microscopy. No merogony occurs in the blood cells, and sporadic pigment granules were observed. Nested-PCR assays were employed for a molecular examination, which indicated that the cytb gene of this parasite had 94.1–94.9% identity to Haemoproteus antigonis. Subsequently, its mitochondrial genome structure was determined by high-throughput sequencing using the DNBSEQ-T7 platform. The determined structure was confirmed by the Sanger sequencing using amplicons. The mitochondrial genome obtained for this parasite exhibited a low CG content (32.0%) and possessed three protein-coding genes, encoding 1068 amino acids, which constituted 53.7% of the genome. Phylogenetic analysis indicated that this parasite clustered with Haemoproteus sp. is detected in grey crowned cranes from Africa. This parasite was likely acquired during importation of this animal; thus, strict quarantine of imported ornamental animals is required to prevent the entry of new pathogens.

Evolutionary drivers of sex-specific parasite prevalence in wild birds.

Males and females often differ in ecology, behaviour and lifestyle, and these differences are expected to lead to sex differences in parasite susceptibility. However, neither the sex differences in parasite prevalence, nor their ecological and evolutionary drivers have been investigated across a broad range of taxa using phylogenetically corrected analyses. Using the most extensive dataset yet that includes 755 prevalence estimates from 151 wild bird species in a meta-analytic framework, here we compare sex differences in blood and gastrointestinal parasites. We show that despite sex differences in parasite infection being frequently reported in the literature, only Haemoproteus infections were more prevalent in females than in males. Notably, only seasonality was strongly associated with the sex-specific parasite prevalence of both Leucocytozoon and Haemoproteus, where birds showed greater female bias in prevalence during breeding periods compared to the non-breeding period. No other ecological or sexual selection variables were associated with sex-specific prevalence of parasite prevalence. We suggest that much of the variation in sex-biased prevalence could be idiosyncratic, and driven by local ecology and behavioural differences of the parasite and the host. Therefore, breeding ecology and sexual selection may only have a modest influence on sex-different parasite prevalence across wild birds.

High prevalence of haemosporidian parasites in Eurasian jays

Avian haemosporidians are vector-borne parasites, infecting a great variety of birds. The order Passeriformes has the highest average infection probability; nevertheless, some common species of Passeriformes have been rather poorly studied. We investigated haemosporidians in one such species, the Eurasian jay Garrulus glandarius (Corvidae), from a forest population in Hesse, Central Germany. All individuals were infected with at least one haemosporidian genus (overall prevalence: 100%). The most common infection pattern was a mixed Haemoproteus and Leucocytozoon infection, whereas no Plasmodium infection was detected. Results on lineage diversity indicate a rather pronounced host-specificity of Haemoproteus and Leucocytozoon lineages infecting birds of the family Corvidae.

Sudden death and Haemoproteus infection in captivity Burrowing Owls (Athene cunicularia) from Brazil

The present study aims to report the sudden death of two captive individuals of the Burrowing Owl Athene cunicularia that coexisted in the same enclosure with other raptor birds in a Zoo of Brazil. Despite Haemoproteus infections generally being considered benign, they can lead to sudden death, particularly in stressful environments. Through hematological examinations and microscopic analyses, this article reports two cases of Haemoproteus in Burrowing Owls, suggesting a potential correlation between its presence and owl’s deaths. Also, discusses the prevalence of this infection in captive raptorial birds, emphasizing the significance of immunity and proper management to prevent infections and reveal the importance of early diagnosis for the preservation of the health of these captive birds.

The association between haemosporidian infection and non-breeding moult location in great reed warblers revisited by combining feather stable isotope profiles and geolocator data

Stable isotope analysis provides valuable insights into the ecology of long-distance migratory birds during periods spent away from a specific study site. In a previous study, Swedish great reed warblers (Acrocephalus arundinaceus) infected with haemosporidian parasites differed in feather isotope ratios compared to non-infected birds, suggesting that infected and non-infected birds spent the non-breeding season in different locations or habitats. Here, we use a novel dataset comprising geolocator data, isotopes, and haemosporidian infection status of 92 individuals from four Eurasian populations to investigate whether parasite transmission varies with geography or habitats. We found that the probability of harbouring Plasmodium and Leucocytozoon parasites was higher in birds moulting in the eastern region of the non-breeding grounds. However, no geographic pattern occurred for Haemoproteus infections or overall infection status. In contrast to the previous study, we did not find any relationship between feather isotope ratios and overall haemosporidian infection for the entire current dataset. Plasmodium-infected birds had lower feather δ15N values indicating that they occupied more mesic habitats. Leucocytozoon-infected birds had higher feather δ34S values suggesting more coastal sites or wetlands with anoxic sulphate reduction. As the composition and prevalence of haemosporidian parasites differed between the old and the current dataset, we suggest that the differences might be a consequence of temporal dynamics of haemosporidian parasites. Our results emphasize the importance of replicating studies conducted on a single population over a restricted time period, as the patterns can become more complex for data from wider geographical areas and different time periods.

Natural Vector of Avian Haemoproteus asymmetricus Parasite and Factors Altering the Spread of Infection.

Avian haemosporidians (Apicomplexa, Haemosporida) are widespread blood protists, often causing severe haemosporidiosis, pathology, or even mortality in their hosts. Migrant birds regularly bring various haemosporidian parasites from wintering grounds to European breeding areas. Some haemosporidian parasites are prevalent in breeding sites and complete their life cycles in temperate climate zones and can be transmitted, but others do not. The factors altering the spread of these haemosporidians are not fully understood. Culicoides biting midges (Diptera: Ceratopogonidae) play an important role in the transmission of worldwide distributed avian haemosporidian parasites belonging to the genus Haemoproteus, but this information is particularly scarce and insufficient. The key factors limiting the spread of these pathogens in temperate climate zones, which we suspect and aim to study, are the absence of susceptible vectors and the ecological isolation of birds from vectors during the breeding period when transmission occurs. The primary objective of this study was to evaluate how the habitats of biting midges and bird breeding sites influence parasite transmission while also seeking to expand our understanding of the natural vectors for these parasites. Biting midges were collected using UV traps on the Curonian Spit, Lithuania, in different habitats, such as woodland and reeds, from May to September. Parous Culicoides females were identified, dissected, and investigated for the presence of Haemoproteus parasites using both microscopy and PCR-based tools. Among the dissected 1135 parous Culicoides females, the sporozoites of Haemoproteus asymmetricus (genetic lineage hTUPHI01) have been detected for the first time in the salivary glands of Culicoides festivipennis. The sporozoites of four Haemoproteus lineages were detected in Culicoides segnis, C. festivipennis, and Culicoides kibunensis biting midges. PCR-based screening showed that the females of seven Culicoides species were naturally infected with Haemoproteus parasites. The DNA of the parasite of owls, Haemoproteus syrnii (hSTAL2), was detected for the first time in Culicoides punctatus. The highest abundance of collected Culicoides females was in June, but the highest prevalence of Haemoproteus parasites in biting midges was in July. The abundance of Culicoides was higher in the woodland compared with reeds during the season. The acquired findings indicate the varied abundance and diversity of biting midges throughout the season and across distinct habitats. This variability could potentially impact the transmission of Haemoproteus parasites among birds with diverse breeding site ecologies. These outcomes hold the potential to enhance our understanding of the epizootiology of Haemoproteus infections within temperate climatic zones.

Haemosporidian parasite infections of Malagasy Philepittidae and Nectariniidae are driven by phylogeny rather than ecology.

The nectarivorous common sunbird asity (Neodrepanis coruscans) is phylogenetically closely related to the frugivorous velvet asity (Philepitta castanea), yet it shares similar habitat and foraging behaviour as the Malagasy sunbirds (Cinnyris spp.). As ecological factors have been shown to influence blood parasite prevalence, it should be tested whether parasite abundance, prevalence and diversity of N. coruscans are more similar to the sunbirds than to its relative. Therefore, blood samples (n = 156) and smears (n = 60) were tested for different blood parasites (Haemosporida, trypanosomes, filarioid nematodes) using molecular and microscopic methods. High prevalence of haemosporidian parasites was observed in all bird taxa, with rates ranging from 23% in N. coruscans to 84.6% in C. notatus. The Malagasy Cinnyris spp. exhibited a high occurrence of mixed haemosporidian infections (>76%) with various specialized lineages. Within the Philepittidae family, no Haemoproteus infection was detected and just a few cases of mixed infections. Nectariniidae species predominantly had specialized haemosporidian lineages, while Philepittidae had infections mainly caused by generalist lineages. These findings emphasize the diverse range of blood parasites in Nectariniidae, while additionally highlighting the high diversity of trypanosomes and filarioid nematodes in Philepittidae. Additionally, several newly discovered haemosporidian lineages, Trypanosoma isolates and filarioid nematode isolates were identified. Notably, Philepittidae exhibited a lower prevalence of avian haemosporidian parasites compared to Nectariniidae, possibly due to potential resistance mechanisms. Despite N. coruscans sharing similar habitat and behavioural ecology with both Cinnyris spp., it closely resembles its relative, P. castanea, in all aspects of haemosporidian parasitism.

Avian Haemosporidians Infecting Short- and Long-Distance Migratory Old World Flycatcher Species and the Variation in Parasitaemia After Endurance Flights

PurposeAvian haemosporidians are widespread parasites, occurring in many bird families and causing pathologies ranging from rather benign infections to highly virulent diseases. The state of knowledge about lineage-specific intensities of haemosporidian infection (i.e., parasitaemia) is mainly based on infection experiments conducted under laboratory conditions. The levels and range of parasitaemia in natural host–parasite associations as well as their influencing factor remain largely unexplored.MethodsThus, we explored the parasitaemia of four songbird species (i.e., European Robins, Black and Common Redstarts and Whinchats) during migration by screening individuals upon landing on an insular passage site after extensive endurance flights to (1) describe their natural host–parasite associations, (2) quantify parasitaemia and (3) explore potential host- and parasite-related factors influencing parasitaemia.ResultsWe found 68% of Whinchats to be infected with haemosporidians, which is more frequent than any other of the studied host species (30–34%). Furthermore, we confirmed that parasitaemia of Haemoproteus infections was higher than average Plasmodium infections. Median parasitaemia levels were rather low (parasite cells in 0.01% of hosts’ red blood cells) and varied largely among the different parasite lineages. However, we found four individuals hosting infections with parasitaemia higher than typical chronic infections.ConclusionsBased on the known transmission areas of the respective lineages, we argue that these higher intensity infections might be relapses of consisting infections rather than acute phases of recent primary infections.

Host phylogeny and seasonality shapes avian haemosporidian prevalence in a Brazilian biodiverse and dry forest: the Caatinga.

The relationships between host phylogenetics, functional traits and parasites in wildlife remain poorly understood in the Neotropics, especially in habitats with marked seasonal variation. Here, we examined the effect of seasonality and host functional traits on the prevalence of avian haemosporidians (Plasmodium and Haemoproteus) in the Brazilian Caatinga, a seasonally dry tropical forest. 933 birds were evaluated for haemosporidian infections. We found a high parasitism prevalence (51.2%), which was correlated with phylogenetic relatedness among avian species. Prevalence varied drastically among the 20 well-sampled species, ranging from 0 to 70%. Seasonality was the main factor associated with infections, but how this abiotic condition influenced parasite prevalence varied according to the host-parasite system. Plasmodium prevalence increased during the rainy season and, after excluding the large sample size of Columbiformes (n = 462/933), Plasmodium infection rate was maintained high in the wet season and showed a negative association with host body mass. No association was found between non-Columbiform bird prevalence and seasonality or body mass when evaluating both Plasmodium and Haemoproteus or only Haemoproteus infections. Parasite community was composed of 32 lineages including 7 new lineages. We evidenced that even dry domains can harbour a high prevalence and diversity of vector-borne parasites and pointed out seasonality as a ruling factor.

The first detection of avian haemosporidia from Culicoides biting midges in Japan, with notes on potential vector species and the transmission cycle.

Biting midges (Ceratopogonidae) are capable of transmitting a variety of pathogens including viruses, trypanosomes and haemosporidia. The majority of Haemoproteus parasites are transmitted by biting midges predominantly of the genus Culicoides and are known to cause significant physical and reproductive impacts on both wild and domestic birds. In Japan, Haemoproteus had been detected from various avian hosts, but not from arthropod vectors. In this study, we investigated the prevalence of avian haemosporidia at an educational forest in central Japan in attempt to reveal possible vector species of Haemoproteus, which would help to better understand the transmission cycle of Haemoproteus within Japan and to develop preventative measures for captive and domestic birds. Biting midges were caught using UV light traps from 2016 to 2018. The collected samples were morphologically identified, and haemosporidian parasites were detected using PCR-based methods. The detected lineages were phylogenetically analyzed and compared with lineages previously detected from birds. Bloodmeal analyses were also carried out for part of the blood-fed individuals. Six Haemoproteus lineages were detected from 17 of 1042 female Culicoides (1.63%), including three species (C. sigaensis, C. arakawae, and C. pictimargo) in which Haemoproteus was detected for the first time. All detected lineages were placed in the subgenus Parahaemoproteus clade and were previously detected from crows of central Japan, strongly suggesting that parasites of these genetic lineages are transmitted between Culicoides and crows. Two Plasmodium lineages were also detected but are thought to be transmitted between Culex mosquitoes and birds of the educational forest based on previous detections. No amplifications were seen in bloodmeal analysis, possibly due to insufficient amount of blood, denaturation via digestion, or insufficient detectability of the used protocol. Haemoproteus DNA was detected from Culicoides for the first time in Japan, suggesting that transmission is possible within the country. These findings highlight the necessity to investigate Culicoides populations and Haemoproteus infections dynamics in Japan. However, vector competence could not be confirmed in this study and further studies are anticipated.

Blood parasites (Trypanosoma, Leucocytozoon, Haemoproteus) in the Eurasian sparrowhawk (Accipiter nisus): diversity, incidence and persistence of infection at the individual level

BackgroundA high prevalence of parasites may result from life-long persistence of infection or from high reinfection rates. We have studied blood parasites in a breeding population of the accipitrid raptor, Eurasian sparrowhawk (Accipiter nisus), to determine parasite diversity and turnover.MethodsDuring this 7-year study, 210 adult Eurasian sparrowhawks breeding in the city of Prague were checked for parasites using several diagnostic methods.ResultsIn both female and male raptors, parasites of the genus Leucocytozoon were the most prevalent (92% and 85%, respectively) followed in decreasing order of prevalence by those of genus Trypanosoma (74% and 68%, respectively) and genus Haemoproteus (46% and 16%, respectively). The prevalence of all parasites increased with age in both sexes, with the females at each respective age having the higher prevalence. There was a positive association between Haemoproteus and Leucocytozoon infections. Persistence at the individual level was higher than incidence for Trypanosoma and Haemoproteus. In the case of Leucocytozoon and Trypanosoma, most individuals probably become infected in their first year of life or even before dispersal from the nest. The detected parasites belonged to Trypanosoma avium sensu stricto, Leucocytozoon sp. (haplotypes ACNI1 and ACNI3) and Leucocytozoon mathisi (haplotype ACNI4) and two new lineages of the Haemoproteus elani complex (ACCNIS6 and ACCNIS7). Detailed analysis of parasite lineages in individuals that were repeatedly sampled revealed lineage turnover that would otherwise remain hidden. Phylogenetic analysis revealed that the detected Haemoproteus belongs to a phylogenetically distant group whose taxonomic position requires further analysis.ConclusionsAll three genera of blood parasites persist in infected individuals, thus enabling sustainability of vector transmission cycles. Prevalence increases with age; however, there is a high turnover of Leucocytozoon lineages. No clear evidence of parasite-induced mortality was found, and most of the individuals were infected early in life, particularly in the case of Leucocytozoon.Graphical abstract

High Prevalence of Plasmodium Infection in Fighting Cocks in Thailand Determined with a Molecular Method.

Avian malaria caused by Plasmodium and the malaria-like parasites of the genus Haemoproteus has been regularly described in multiple regions worldwide. These parasites significantly affect many avian taxa, including domestic chickens and fighting cocks. There are limited epidemiological studies of these blood parasites in vertebrate hosts, especially in Thailand. This study used microscopic examination of blood samples and PCR amplification exploiting primers for nucleotide sequences of Plasmodium or Haemoproteus species based on the cytochrome b gene to determine the occurrence of Plasmodium spp. in fighting cocks. Examination of 249 blood samples of fighting cocks revealed that 41.37% (103/249) were positive for malaria by microscopic examination and 88.76% (221/249) were positive by DNA amplification. Sequencing and DNA analysis of 61 PCR products revealed that infection by Plasmodium juxtanucleare was the most common avian malaria in fighting cocks in Thailand followed by infections by Plasmodium gallinaceum; however, Haemoproteus infection was not discovered. This study indicated that plasmodiasis is widespread in fighting cocks in Thailand although the prevalence was not clearly determined; therefore, prevention and control strategies for these protozoa should be improved, especially those for avoiding vector exposure and eliminating mosquito breeding sites.

Delay in arrival: lineage-specific influence of haemosporidians on autumn migration of European robins

Haemosporidian blood parasites are widely used in evolutionary ecological research when exploring the effects of parasites on different life-history traits of their bird hosts. However, their roles in bird migration are less studied. If these parasites deteriorate the body condition of the birds strongly, they might negatively affect the whole migration phenology and the survival of the birds as well. In our study, we tested the relationships between infection for parasite genera (Haemoproteus or Plasmodium), the three most frequent parasite lineages and body condition (body mass, fat deposit), and the timing of autumn migration in the European Robin (Erithacus rubecula). We found that mean body mass and fat scores did not differ between parasitized and non-parasitized individuals, but infected juveniles arrived later than their non-infected counterparts. The difference in the arrival time of parasitized and non-parasitized birds was greater in the case of Haemoproteus infections. However, when we analysed the effects of the distinct parasite lineages separately, we found that prevalence of parasite lineages correlated with the body mass, fat storage, and timing of autumn migration of the birds in a different direction. Our results therefore emphasize the importance of testing the impacts of the different parasites individually, because possible lineage-specific effects on bird condition during migration might exist.

A novel one-step multiplex PCR protocol to detect avian haemosporidian parasites in the subgenus Haemoproteus (Kruse, 1890) used to quantify parasite prevalence in domestic pigeons (Columba livia) in Turkey.

Infections of avian haemosporidian parasites are regularly identified by molecular methods including multiplex PCR, which allows researchers to distinguish mixed infections of parasites from multiple genera. Here we extend the utility of a previously designed multiplex PCR by designing a primer set specific to parasites of the subgenus Haemoproteus (genus: Haemoproteus). The updated one-step multiplex PCR protocol we describe here allows for the detection of the genera Plasmodium and Leucocytozoon and the two subgenera (Haemoproteus and Parahaemoproteus) of the genus Haemoproteus. A sensitivity analysis showed that the multiplex PCR could amplify DNA of parasites in the subgenus Haemoproteus at very low levels of infection. We used this multiplex PCR to identify haemosporidian infections in 250 adult domestic pigeons (Columba livia) in Turkey. All samples were also screened by microscopy and a widely used nested PCR to compare with the results of multiplex PCR, to detect low levels of parasitemia, and to identify possible abortive infections. In total, 71 pigeons (28.4%) were found to be infected by all three methods. The multiplex PCR protocol successfully detected and discriminated both subgenera Haemoproteus and Parahaemoproteus infections. We compared our results with previous host species records to assess the host specificity of the parasite lineages we found. Our findings provide novel data on the prevalence of avian haemosporidians in domestic pigeons and demonstrate the utility of the new one-step multiplex PCR protocol for the determination of mixed avian haemosporidian infections. We expect that this protocol will contribute to a better understanding of the distribution, epizootiology, and ecology of avian haemosporidians.

Differential effects of environmental climatic variables on parasite abundances in blue tit nests during a decade.

Models on climate change have predicted an increase of temperature over the earth's surface with potential drastic effects on living organisms. We analyzed the relationships between climatic conditions (temperature, rainfall, and wind speed) and the abundance of blood‐sucking flying insects (biting midges and blackflies) and nest‐dwelling ectoparasites (mites, fleas, and blowflies) collected from blue tit nests during bird breeding seasons for a period of 10 years. Average temperature, rainfall, and wind speed showed significant differences among years. Temperature and wind speed increased during the period of study while rainfall decreased. Biting midge, blackfly, and blowfly abundances increased across years but not flea and mite abundances. Hatching date decreased and brood size increased across years. Independently of year variation, parasites were related to climatic variables. For example, biting midge, blowfly, mite, and flea abundances were positive and significantly related to average temperature. We also found a positive and significant relationship between abundances of Haemoproteus infections and biting midge abundances during the first year of life of birds out of nests. However, abundance and prevalence of Lankesterella infections in yearlings were positive and significantly related to mite abundances during the year of birth of birds. Leucocytozoon and Lankesterella infections were also significantly related to climatic variables and Haemoproteus and Lankesterella infections increased across years. In addition, body condition of adult females and males were negatively related to flea larvae and blowfly abundance respectively. Nestling body condition was also negatively related to biting midge abundance. Changes in climatic conditions across years could therefore affect several parasites of birds but also to birds themselves.

Fatal toxoplasmosis in Little Penguins (Eudyptula minor) from Penguin Island, Western Australia.

Routine post mortems of deceased penguins from Penguin Island, Western Australia, found that a temporal cluster of cases presented with characteristic gross and microscopic changes, namely birds in good body condition with hepatomegaly and splenomegaly, multifocal hepatic and splenic necrosis and numerous, 1–2 μm diameter protozoan parasites within the necrotic foci.Electron microscopy identified the protozoa as belonging to the phylum Apicomplexa. Molecular investigations by PCR gave inconsistent results. PCR performed by an external laboratory identified a novel Haemoproteus spp. organism in samples from 4 of 10 cases from this group, while PCR at Murdoch University identified Toxoplasma gondii in 12 of 13 cases (including 9 of the 10 assayed at the external laboratory). Immunohistochemistry of formalin fixed tissues also identified Toxoplasma in the hepatic and splenic lesions.The distinctive mortalities which were observed in this group of penguins are attributed to a fulminant toxoplasmosis, with a concurrent Haemoproteus infection in some cases. Though the clinical signs of infection are unknown, the gross and microscopic appearance at post mortem is sufficiently characteristic to allow a diagnosis to be made on these features. Definitive confirmation of Toxoplasma infection can be made by immunohistochemistry or PCR.

The drivers of avian-haemosporidian prevalence in tropical lowland forests of New Guinea in three dimensions.

Haemosporidians are among the most common parasites of birds and often negatively impact host fitness. A multitude of biotic and abiotic factors influence these associations, but the magnitude of these factors can differ by spatial scales (i.e., local, regional and global). Consequently, to better understand global and regional drivers of avian‐haemosporidian associations, it is key to investigate these associations at smaller (local) spatial scales. Thus, here, we explore the effect of abiotic variables (e.g., temperature, forest structure, and anthropogenic disturbances) on haemosporidian prevalence and host–parasite networks on a horizontal spatial scale, comparing four fragmented forests and five localities within a continuous forest in Papua New Guinea. Additionally, we investigate if prevalence and host–parasite networks differ between the canopy and the understory (vertical stratification) in one forest patch. We found that the majority of Haemosporidian infections were caused by the genus Haemoproteus and that avian‐haemosporidian networks were more specialized in continuous forests. At the community level, only forest greenness was negatively associated with Haemoproteus infections, while the effects of abiotic variables on parasite prevalence differed between bird species. Haemoproteus prevalence levels were significantly higher in the canopy, and an opposite trend was observed for Plasmodium. This implies that birds experience distinct parasite pressures depending on the stratum they inhabit, likely driven by vector community differences. These three‐dimensional spatial analyses of avian‐haemosporidians at horizontal and vertical scales suggest that the effect of abiotic variables on haemosporidian infections are species specific, so that factors influencing community‐level infections are primarily driven by host community composition.

Studies on infectious etiologies associated with neurological disorders in pigeons in Kerala

Pigeons are reared as a symbol of peace, love, gentleness and spirit messengers and now-a-days also for meat, as ornamental pet bird or as an experimental animal. There are about 400 varieties of fancy pigeons and little is known about the diseases and management of these birds. Heavy mortality has been observed in the pigeons that shows neurological manifestations. The present study is aimed at diagnosis of infectious diseases causing neurological signs in pigeons. The study was conducted in the different pigeon lofts of four districts in Kerala and a total of 44 pigeons comprising 21 fancy breeds were included. These birds were screened for major infectious etiologies causing neurological signs like paramyxoviral infection, salmonellosis and Haemoproteus infection. The birds were also screened for presence of ectoparasites by visual examination. The study showed 63.63 per cent positive for paramyxoviral infection using antigen NDV kits. The occurrence of Haemoproteus infection was 54.7 per cent in Giemsa-stained blood smears and 63.63 per cent in PCR amplifying cyt b gene. Pseudolynchia canariensis could be detected in pigeons. Isolation and identification of Salmonella from faecal samples were done by culture and biochemical tests and found to be 22.2 per cent. Combined infections of paramyxovirus infection with Haemoproteus, paramyxovirus infection with Salmonella, Haemoproteus with Salmonella and infection of all the three etiologies were the interesting finding of the study. The present study is one of its kind in Kerala and also in India. The study warrants the prevention and control of these infectious diseases which has great zoonotic potential.