Description of Haemoproteus ciconiae sp. nov. (Haemoproteidae, Haemosporida) from the white stork Ciconia ciconia, with remarks on insensitivity of established polymerase chain reaction assays to detect this infection.

Haemoproteus ciconiae sp. nov. (Haemosporida, Haemoproteidae) was found in the white stork Ciconia ciconia (Ciconiiformes, Ciconiidae) after spring migration in Lithuania. This organism is illustrated and described based on the morphology of its blood stages. The new species can be readily distinguished from all other haemoproteids parasitizing ciconiiform birds due to the presence of large number (approximately 20 on average) small (<1 μm) pigment granules in its mature gametocytes. Growing and mature gametocytes of H. ciconiae were readily visible in all blood films (parasitemia of 0.001 %). However, experienced researchers were unable to detect sequences of its mitochondrial cytochrome b (cyt b) or apicoplast genes from the microscopically positive sample by using five established assays for polymerase chain reaction (PCR)-based detection of avian haemosporidian parasites. The white stork cyt b sequence was readily detectable, indicating the well-optimised PCR protocols and the good quality of total DNA in the sample containing the new species. The failure to amplify this parasite DNA indicates insufficient sensitivity of the currently used PCR-based assays in diagnostics of avian haemosporidian infections. We suggest possible explanations of this observation. To minimize number of the false negative PCR reports, we call for the continued use of optical microscopy in parallel with molecular diagnostics in studies of haemosporidian parasites, particularly in wildlife.