Survey of Haemosporidian Parasites in Wild Stone-Curlews (Burhinus oedicnemus) in the Canary Islands: First Molecular and Histopathological Evidence of Leucocytozoon sp. Infection

Avian haemosporidians are globally distributed protozoan parasites transmitted by hematophagous vectors, yet information on their occurrence in the Stone-curlew (<i>Burhinus oedicnemus</i>), particularly from the Canary Islands, is scarce. Between 2020 and 2024, 47 Stone-curlews were examined for <i>Haemoproteus</i>, <i>Plasmodium</i>, and <i>Leucocytozoon</i> spp. using nested PCR targeting the <i>cytochrome b</i> gene, followed by sequencing and phylogenetic analysis. Histopathological examination was performed on formalin-fixed tissues. <i>Leucocytozoon</i> sp. DNA was detected in one individual (case FS415/23), with identical sequences amplified from multiple organs. Phylogenetic analysis placed this isolate within lineage CIAE02, previously reported in raptors and other avian taxa. Microscopic evaluation revealed megalomeronts in the liver, kidney, and skin, consistent with <i>Leucocytozoon</i> infection. Despite concurrent infection with <i>Avipoxvirus</i> and <i>Aspergillus fumigatus</i>, no prominent inflammatory reaction surrounded the haemosporidian tissue states. The only prior haemosporidian reported in <i>Burhinus</i> is <i>Haemoproteus burhinus</i>, described from <i>B. oedicnemus saharae</i> in Iraq, and no <i>Leucocytozoon</i> infections have previously been recorded in this genus. Therefore, this represents the first evidence of <i>Leucocytozoon</i> infection in the Stone-curlew, extending the known host range of lineage CIAE02. These findings highlight the relevance of integrative diagnostic approaches for detecting latent or cryptic haemosporidian infections in non-passerine avian hosts.