Molecular detection of Plasmodium huffi (Apicomplexa: Haemosporida) in birds from Mato Grosso state, midwestern Brazil with new host data

Haemosporidians are heteroxenous, cosmopolitan protozoa that infect birds, using hematophagous dipterans as vectors. The genus Plasmodium has a moderate species diversity and is known for great flexibility in alternating host species, mild to severe pathogenicity, and generally low prevalence. Plasmodium huffi was first described in 1950 and considered insufficiently characterized, however, in 2021, this species was re-described as infecting two different Brazilian toucans, Ramphastos toco and Pteroglossus aracari. Herein, we describe four new potential avian host species for P. huffi: Pavo cristatus, Cariama cristata, Rhea americana, and Porphyrio martinica by employing molecular diagnostics and conducting phylogenetic analysis, providing the detection of the RTCE206 and PACE173 lineages of P. huffi, previously described in Toco Toucan and Black-necked Araçari, respectively. Our study reinforces the data in the literature on the great flexibility of the genus Plasmodium in alternating host species. In addition, it highlights the current knowledge about P. huffi encompassing its underestimated potential for host diversity. Further research is essential, particularly involving bird groups frequently excluded from haemosporidian studies in Brazil, such as non-passeriform birds, to accurately elucidate the P. huffi host-parasite relationships.