Loss of forest cover and host functional diversity increases prevalence of avian malaria parasites in the Atlantic Forest.

Host phylogenetic relatedness and ecological similarity are thought to contribute to parasite community assembly and infection rates. However, recent landscape level anthropogenic changes may disrupt host-parasite systems by impacting functional and phylogenetic diversity of host communities. We examined whether changes in host functional and phylogenetic diversity, forest cover, and minimum temperature influence the prevalence, diversity, and distributions of avian haemosporidian parasites (genera Haemoproteus and Plasmodium) across 18 avian communities in the Atlantic Forest. To explore spatial patterns in avian haemosporidian prevalence and taxonomic and phylogenetic diversity, we surveyed 2241 individuals belonging to 233 avian species across a deforestation gradient. Mean prevalence and parasite diversity varied considerably across avian communities and parasites responded differently to host attributes and anthropogenic changes. Avian malaria prevalence (termed herein as an infection caused by Plasmodium parasites) was higher in deforested sites, and both Plasmodium prevalence and taxonomic diversity were negatively related to host functional diversity. Increased diversity of avian hosts increased local taxonomic diversity of Plasmodium lineages but decreased phylogenetic diversity of this parasite genus. Temperature and host phylogenetic diversity did not influence prevalence and diversity of haemosporidian parasites. Variation in the diversity of avian host traits that promote parasite encounter and vector exposure (host functional diversity) partially explained the variation in avian malaria prevalence and diversity. Recent anthropogenic landscape transformation (reduced proportion of native forest cover) had a major influence on avian malaria occurrence across the Atlantic Forest. This suggests that, for Plasmodium, host phylogenetic diversity was not a biotic filter to parasite transmission as prevalence was largely explained by host ecological attributes and recent anthropogenic factors. Our results demonstrate that, similar to human malaria and other vector-transmitted pathogens, prevalence of avian malaria parasites will likely increase with deforestation.

Ocorrência de anticorpos anti-toxoplasma gondii em aves silvestres de três unidades de conservação federais da Paraíba e da Bahia / Occurrence of antibodies to toxoplasma gondii in wild birds from three federal conservation units of Paraíba and Bahia, Brazil

A vigilância e monitoramento de doenças em animais silvestres são imprescindíveis no contexto ambiental e de saúde pública, pois estes animais agem como sentinelas, refletindo alterações ambientais precocemente, o que proporciona maior eficácia no monitoramento ambiental e permite o acesso rápido a informações sobre as condições da área. Neste contexto, as aves são importantes no ciclo biológico do Toxoplasma gondii e na epidemiologia da toxoplasmose, principalmente porque seus tecidos representam importantes fontes de proteína na alimentação de felídeos e humanos. Objetivou-se detectar anticorpos anti-T. gondii, por meio do teste de aglutinação modificada em aves silvestres de três Unidades de Conservação (UC) Federais dos Estados da Paraíba e Bahia. No período de dezembro de 2011 a outubro de 2013 foram capturadas com redes de neblina 222 aves silvestres pertencentes a 67 espécies, 27 famílias e 12 ordens. Após a captura, foi colhido sangue de cada animal e separado o soro, que foi submetido ao Teste de Aglutinação Modificada (MAT≥1:25) utilizando taquizoítos inativados na formalina e 2-mercaptoetanol. Dentre as 222 amostras analisadas, três (1,3%) foram sororreagentes: 1 de 16 (6,2%) pipira-preta Tachyphonus rufus (título 50), 1 de 5 (20%) juriti-gemedeira Leptotila rufaxilla (título 50) e 1 de 1 (100%) caneleiro-enxofre Casiornis fuscus (título 25). Este é o primeiro relato da ocorrência de anticorpos anti-T. gondii nas referidas espécies de aves silvestres de vida livre nas duas UC Federais estudadas.

Surveillance and monitoring of wildlife pathogens are essential in the environmental context and human public health, as these animals act as sentinels, reflecting environmental changes early on, whath gives more efficient environmental monitoring and allows quick access to information on the conditions of area. Birds are important in the epidemiology and life cycle of Toxoplasma gondii, because their tissues are important source of protein in the diet of felids and humans. The objective was to determine antibodies to Toxoplasma gondii in wild birds from three Federal Conservation Units of the states of Paraíba and Bahia by Modified Agglutination Test (MAT). From December 2011 to October 2013, 222 wild birds of 67 species from 27 families and 12 Orders were captured with mist nets. Blood samples were then collected and the serum was separated by centrifugation. The sera were tested (MAT≥1:25) using formalin-fixed whole tachyzoites and 2-mercaptoethanol. Antibodies to T. gondii were found in 3 of 222 (1.3%) birds: in 1 of 16 (6.2%) white-lined tanager (Tachyphonus rufus, titer 50), in 1 of 5 (20%) gray-fronted dove (Leptotilla rufaxila, titer 50), and in 1 of 1 (100%) ashy-throated casiornis (Casiornis fuscus, titer 25). This is the first report of occurrence of antibodies to T. gondii in these tree bird species from two Federal Conservation Units.