Wild bird parasites in the Atlantic Forest: diversity and prevalence across forested and anthropogenic landscapes

Wild birds are important for public health, as they have epidemiological characteristics that make them host species for the transmission and maintenance of several pathogens, either as reservoirs or by the dispersal of infected arthropod vectors. Recently, several bird species have been used as model organisms in several scientific studies. Investigations have used wild bird populations as bioindicators and sentinels to identify changes in habitat quality, exposure to chemical pollutants, and disease surveillance. The objective of this study was to investigate the prevalence and diversity of parasites in birds in forest and anthropic areas of the Atlantic Forest in southeastern Brazil. The birds were captured between 2021 and 2023 using mist nets. Blood samples were obtained from each individual by brachial vein puncture to screen for hemoparasites. Fecal samples were collected to identify intestinal parasites. The overall prevalence of parasites in the study population was 44%, most of which came from the wild environment. Trypanosoma sp. was the most prevalent parasite in birds (34.6%), followed by Plasmodium sp. (18%) and the intestinal parasites microfilariae (9%), Cryptosporidium sp. (4.5%), Entamoeba sp. (4.5%), Giardia sp. (4.5%) and Isospora sp. (3%). All samples were negative for Toxoplasma gondii. The prevalence of parasites observed in this study was higher than that recorded in other studies conducted in the Neotropical Region and the Brazilian Atlantic Forest. Investigating parasites in birds provides valuable insights into understanding the epidemiology of various diseases and formulating prevention and control strategies. Due to their biological and ecological characteristics, birds act as important sentinels of the presence of infectious agents in ecosystems. In a global context of climate and environmental change, recognizing this role reinforces the importance of valuing their contributions and adopting effective conservation measures.