There seems to be no Plasmodium species that exclusively infects corvids. According to Valkiunas, two Haemoproteus species ( Haemoproteus danilewskii and Haemoproteus picae) and two Leucocytozoon species ( Leucocytozoon berestneffi and Leucocytozoon sakharoffi) are the most important Haemosporida species for corvids. Past studies of haemosporidian parasites in Corvidae relied mostly on morphological examination of blood smears (e.g. Aphelocoma spp., Calocitta spp., Cyanocitta spp.), magpies ( Pica spp.) and allies, has an almost worldwide distribution and is present in almost all habitats. The bird family Corvidae consists of more than 100 species of crows ( Corvus spp.), jays (e.g. It has been suggested that the species diversity of Haemosporida may be at the same level of avian species diversity or even higher. Īvian haemosporidian parasites have been detected worldwide except Antarctica (e.g. After a latent stage of infection, a period of chronic parasitaemia, a secondary increase of parasitaemia can occur due to an reactivation of exoerythrocytic merogony. Avian haemosporidian parasites can also develop dormant stages which remain inactive in the tissues. During an acute infection, the merozoites within erythrocytes or leucocytes develop into gametocytes, which can then infect a new vector. In contrast to most other avian haemosporidians, Plasmodium parasites also undergo schizogony in erythrocytes. Once released, the merozoites infect new cells of various tissues where they undergo another cycle of asexual schizogony. When the vector feeds on a vertebrate host, the sporozoites enter the blood stream and invade hepatocytes or endothelial cells where the parasites then undergo the first cycle of asexual schizogony. The sexual reproduction occurs in the gut of the vector and the infectious sporozoites develop in their salivary glands. Plasmodium species are known to be transmitted by several species of mosquitoes (Culicidae) from different genera, Haemoproteus species by several species of hippoboscid and ceratopogonid flies and Leucocytozoon species are known to be transmitted by simuliid and ceratopogonid flies. They use blood-feeding dipterans as vectors. All haemosporidian parasites share similar but complex life cycles. Due to the high diversity of haemosporidian parasites found in corvids, they seem to be excellent model organisms to test species deliminations in haemosporidian parasites.Īvian malaria parasites ( Plasmodium spp.) and other Haemosporida ( Haemoproteus and Leucocytozoon spp.) form a diverse group of vector-transmitted blood parasites that are abundant in many avian families. Very high prevalences were found and based on the applied diagnostic method also a high amount of multiple infections could be detected. This study provides the first insight into the diversity of haemosporidian parasites of corvids in Germany. Female carrion crows were more likely infected with haemosporidian parasites than males. Thirteen haemosporidian lineages were isolated from the corvid samples. 65.3% of the samples (n = 62) contained multiple infections. The most abundant parasite genus was Leucocytozoon with a prevalence of 85.3% (n = 95). Haemosporidian DNA was detected in 85 carrion crows (89.5%) and in all five Eurasian Magpies. The phylogenetic relationship of parasite lineages obtained from these birds was inferred. To investigate the diversity of Haemosporida of resident carrion crows ( Corvus corone) and Eurasian Magpies ( Pica pica) in southwest Germany, 100 liver samples of corvids were examined using a nested PCR method to amplify a 1063 bp fragment of the haemosporidian mitochondrial cytochrome b gene. Recent studies have suggested that corvids may be an important host for Plasmodium spp. Avian malaria parasites ( Plasmodium spp.) and other Haemosporida ( Haemoproteus and Leucocytozoon spp.) form a diverse group of vector-transmitted blood parasites that are abundant in many bird families.
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