Avian haemosporidian parasites in captive and free-ranging, wild birds from zoological institutions in Switzerland: Molecular characterization and clinical importance.

Avian haemosporidian parasites are widespread and infect birds from a broad variety of avian families with diverse consequences ranging from subclinical infections to severe and fatal disease. This study aimed to determine the occurrence and diversity of avian haemosporidia including associated clinical signs and pathomorphological lesions in captive and free-ranging, wild birds from two zoos and the near environment in Switzerland. Blood samples from 475 birds, including 230 captive and 245 free-ranging, wild individuals belonging to 42 different avian species from 15 orders were examined for the presence of avian haemosporidian DNA by a one-step multiplex PCR designed to simultaneously detect and discriminate the genera , and by targeting mitochondrial genome sequences. Positive samples were additionally tested using a nested PCR targeting the cytochrome gene of and . The obtained amplicons were bidirectionally sequenced. This study revealed haemosporidian DNA in 42 samples, belonging to ten host species. The most commonly detected lineage was SGS1, which was identified in 29 birds (: n = 24, : n = 1, : n = 1, : n = 1, : n = 1, : n = 1), followed by sp. STRURA03 in six avian hosts (: n = 5,  = 1), GRW11 in four individuals (: n = 3, : n = 1) and GRW06 in one . A was infected with , but the exact lineage could not be determined. One mixed infection with and sp. was detected in a . Only five individuals (: n = 2, : n = 1, : n = 1, : n = 1) showed clinical and pathomorphological evidence of a haemosporidian infection.