Haemosporidian blood parasites of the Plasmodium genus are the causative agents of avian malaria in many parts of the world. Despite the great diversity of Brazilian avifauna, few studies have been conducted to examine the haemosporidians of wild birds found in the Brazilian Atlantic Forest, especially those kept in captivity. This study aimed to re-examine and further characterize the South American avian parasite Plasmodium paranucleophilum using a multidisciplinary approach. Blood samples were collected from 68 captive birds representing 15 species found in the Atlantic Forest of southeastern Brazil. Morphometric and morphological characterization was performed, in addition to PCR and sequencing of the mitochondrial cytochrome b gene and subsequent phylogenetic analysis. The overall prevalence of P. paranucleophilum infection in the study was 13.23% (n = 9), with a mean parasitemia of 0.58%. We observed the highest parasitemia of 3.88% in Rupornis magnirostris. In our phylogenetic analysis, P. paranucleophilum and P lasmodium nucleophilum formed distinct, highly supported clades, with a mean genetic divergence of 2.48%. This study provides new morphological and molecular data, expanding our knowledge of the haemosporidians of wild birds in Brazil and highlighting the need for further investigation. The true depth of diversity in Brazilian avian haemosporidians remains largely unknown, and given the enormous variety of vectors and avian species, there may be many more species of these blood parasites yet to be described.

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Captive terrestrial tortoises of the species Chelonoidis carbonaria (n = 17) and Chelonoidis denticulata (n = 37) in the state of Minas Gerais, southeastern Brazil, were examined for hematozoans by using a combination of microscopic and molecular methods. Microscopic examination revealed young intra-erythrocytic forms in blood smears from both species of tortoises. The results of PCR, sequencing, and phylogenetic analysis indicated that these parasites belonged to the Haemoproteus spp., whose observed prevalence was 17.6 % in C. carbonaria and 13.5 % in C. denticulata. Phylogenetic analysis indicated that these sequences formed a clade that was grouped with other sequences of Haemoproteus spp. parasites in birds, separate from the clade formed by Haemoproteus spp. of reptiles. This study expands the information regarding the occurrence and distribution of hemosporidia in turtles and is the first study of blood parasites in C. carbonaria.

Haemoproteid species have a wide global distribution, and they have been described in falcon species in several parts of the world. However, few studies in South America have focused on these birds. Haemoproteus spp. infections have been reported as the causative agents of serious histopathological changes, which can lead to the death of the host. Thus, this study aimed to molecularly and phylogenetically characterize Haemoproteus spp. in Caracara plancus, to characterize aspects of parasitism through clinical analysis and biochemical parameters, and to describe the histopathology of infection. To examine these aspects, 5 southern caracaras were examined clinically, and blood samples were collected. Blood smears were subsequently utilized in parasitemia calculations, PCR amplification, and serum biochemical investigations. Histological sections of the liver, kidneys, spleen, and heart were examined to check for possible histopathological changes. The birds showed clinical signs such as pallor and prostration that are consistent with Haemoproteus spp. infection. Moreover, the examination of the blood smears revealed 0.07% parasitemia in young gametocytes only. The PCR and sequencing results confirmed that the parasites belonged to Haemoproteus spp. The activity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) enzymes, albumin, total serum proteins, and enzymatic urea were first described in C. plancus and serve as reference for future studies of bird species parasitized by Haemoproteus spp. Histopathology results showed signs of injury that were consistent with haemosporidian infection in the tissues of the analyzed organs. The present study is preliminary, and additional studies of Haemoproteus spp. infections in other bird species are needed to better understand the relationship between parasites and hosts, because despite the low parasitemia recorded, biochemical and histopathological changes in various organs were observed.

Plasmodium spp. are haemosporidian protozoans that alternate their live cycles between bloodsucking Culicidae dipterans and vertebrate hosts (mammals, reptiles, and birds). In birds, these parasites are the causative agents of the so-called avian malaria, a disease associated with considerable declines and extinctions in the avifauna in different geographical regions. In this work, we applied a multidisciplinary approach, light microscopy and cytochrome oxidase b (cyt b) gene sequence analysis, for characterization of Plasmodium spp. found in association with wild birds of the genus Turdus, collected in Atlantic forest fragments of southeastern Brazil. From the total 90 analyzed birds, 58 (47 Turdus rufiventris, 9 Turdus leucomelas, 1 Turdus albicollis, and 1 Turdus flavipes) were positively infected with Plasmodium unalis, a haemosporidian that was previously detected in Turdus fuscater in Colombia and in penguins in Brazil, but has never been found in association with these Turdus species of this present work. Moreover, all 7 new sequences of P. unalis cyt b gene clustered into a monophyletic clade with previously characterized P. unalis sequences with a mean genetic divergence of 1.6% and with a maximum divergence of 3.1%, indicating for a high degree of intraspecific polymorphism within this parasitic species. Together, our data highlight the existence a high degree of intraspecific variation within P. unalis and highlight the importance of integrative taxonomy to an accurate identification and characterization of avian haemosporidian parasites.

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