Prevalence of Leukocytozoon spp. in Rescued Wild Birds in Korea

Leukocytozoon spp. is a protozoan that causes infection in the blood, causing economic losses to the poultry industry. The aim of this study was to investigate the prevalence of leukocytozoonosis in wild birds rescued from January 2019 to December 2020. The medical records and the preserved residual blood samples of rescued and treated wild birds were analyzed. After DNA extraction from the preserved blood samples, real-time polymerase chain reaction (PCR) was used to test the extracted DNA. A total of 336 wild birds were tested in this study, of which 3.6% (6/336) were positive. Leukocytozoonosis was detected in four bird species, two of which were winter migratory birds and two were summer migratory birds in Korea. The results of this study suggest that wild birds visiting or staying in Korea may be infected with the Leukocytozoon spp., and there is a possibility that the pathogen may be transmitted to other domestic or wild bird species or shared with each other. It is necessary to conduct an extensive investigation focusing on important migratory bird habitats and to analyze the genetic relationships between domestic and wild bird-origin pathogens.