Does host migration affect host-parasite interaction? Migrant birds harbor exclusive parasites but have similar roles in parasite-host networks.

Parasites comprise a substantial portion of global biodiversity and play critical roles in shaping ecosystems by modulating trophic networks and affecting their hosts' abundance and distribution. The dynamics of host migration introduce new complexity to these relationships. From the host perspective, migratory behavior can either act as a defense mechanism or augment exposure to a broader spectrum of pathogens. Conversely, for parasites, host migration represents a mechanism for their dispersion and an opportunity to infect new host species. This study investigates the complex interplay between migration and parasite-host interactions, focusing on the interaction between hosts and avian malaria and malaria-like parasites in the Brazilian Atlantic Rain Forest. We captured 1466 birds representing 70 different species, uncovering 322 infections with Plasmodium/Haemoproteus parasites. We observed variations in migration timing and fluctuations in host abundance across months. By comparing the observed patterns of interaction of migratory and non-migratory birds to patterns of interaction expected at random, we show that migration affects the roles hosts take in the parasite-host network. Interestingly, despite the fact migratory species hosted more exclusive and distinct parasites, migrants did not occupy central network positions, which are mostly occupied by resident birds. Overall, we highlight the role of resident birds as a key species within parasite-host communities and the high specialization among avian haemosporidians and their hosts.

Identification and serological responses to a novel Plasmodium vivax merozoite surface protein 1 (PvMSP-1) derived synthetic peptide: a putative biomarker for malaria exposure.

Background: The integration of diagnostic methods holds promise for advancing the surveillance of malaria transmission in both endemic and non-endemic regions. Serological assays emerge as valuable tools to identify and delimit malaria transmission, serving as a complementary method to rapid diagnostic tests (RDT) and thick smear microscopy. Here, we evaluate the potential of antibodies directed against peptides encompassing the entire amino acid sequence of the PvMSP-1 Sal-I strain as viable serological biomarkers for P. vivax exposure. Methods: We screened peptides encompassing the complete amino acid sequence of the Plasmodium vivax Merozoite Surface Protein 1 (PvMSP-1) Sal-I strain as potential biomarkers for P. vivax exposure. Here, immunodominant peptides specifically recognized by antibodies from individuals infected with P. vivax were identified using the SPOT-synthesis technique followed by immunoblotting. Two 15-mer peptides were selected based on their higher and specific reactivity in immunoblotting assays. Subsequently, peptides p70 and p314 were synthesized in soluble form using SPPS (Solid Phase Peptide Synthesis) and tested by ELISA (IgG, and subclasses). Results: This study unveils the presence of IgG antibodies against the peptide p314 in most P. vivax-infected individuals from the Brazilian Amazon region. In silico B-cell epitope prediction further supports the utilization of p314 as a potential biomarker for evaluating malaria transmission, strengthened by its amino acid sequence being part of a conserved block of PvMSP-1. Indeed, compared to patients infected with P. falciparum and uninfected individuals never exposed to malaria, P. vivax-infected patients have a notably higher recognition of p314 by IgG1 and IgG3.

Investigating the Yanomami malaria outbreak puzzle: surge in mining during Bolsonaro's government triggered peak in malaria burden.

The Yanomami, an Indigenous people from the Amazon, confront multifaceted challenges endangering their health and cultural integrity. Of immediate concern is the surge in malaria cases in their territory during Bolsonaro's government. We investigated the impact of land use on malaria incidence among the Yanomami leveraging satellite imagery and ran difference-in-differences analyses to ask whether the Yanomami suffered disproportionately from malaria when illegal mining was rising in the region (2016-2022). We show a remarkable ~300% rise in malaria from 2016 to 2022 and point to mining as the primary driver of malaria among the Yanomami; when mining increases by 1%, malaria increases by 31%. After mining unfolded, the burden of malaria among the Yanomami was disproportionately higher, up to 15%, than in non-indigenous communities. Our findings underscore the impact of illegal mining on the high malaria burden suffered by the Yanomami and the importance of rainforest conservation and land sovereignty for Indigenous health.

Leucocytozoon cariamae n. sp. and Haemoproteus pulcher coinfection in Cariama cristata (Aves: Cariamiformes): first mitochondrial genome analysis and morphological description of a leucocytozoid in Brazil.

The distribution of avian haemosporidians of the genus Leucocytozoon in the Neotropics remains poorly understood. Recent studies confirmed their presence in the region using molecular techniques alone, but evidence for gametocytes and data on putative competent hosts for Leucocytozoon are still lacking outside highland areas. We combined morphological and molecular data to characterize a new Leucocytozoon species infecting a non-migratory red-legged seriema (Cariama cristata), the first report of a competent host for Leucocytozoon in Brazil. Leucocytozoon cariamae n. sp. is distinguished from the Leucocytozoon fringillinarum group by its microgametocytes that are not strongly appressed to the host cell nucleus. The bird studied was coinfected with Haemoproteus pulcher, and we present a Bayesian phylogenetic analysis based on nearly complete mitochondrial genomes of these 2 parasites. Leucocytozoon cariamae n. sp. morphology is consistent with our phylogenetic analysis indicating that it does not share a recent common ancestor with the L. fringillinarum group. Haemoproteus pulcher and Haemoproteus catharti form a monophyletic group with Haemocystidium parasites of Reptilia, supporting the polyphyly of the genus Haemoproteus. We also discussed the hypothesis that H. pulcher and H. catharti may be avian Haemocystidium, highlighting the need to study non-passerine parasites to untangle the systematics of Haemosporida.

Host phylogeny and seasonality shapes avian haemosporidian prevalence in a Brazilian biodiverse and dry forest: the Caatinga.

The relationships between host phylogenetics, functional traits and parasites in wildlife remain poorly understood in the Neotropics, especially in habitats with marked seasonal variation. Here, we examined the effect of seasonality and host functional traits on the prevalence of avian haemosporidians (Plasmodium and Haemoproteus) in the Brazilian Caatinga, a seasonally dry tropical forest. 933 birds were evaluated for haemosporidian infections. We found a high parasitism prevalence (51.2%), which was correlated with phylogenetic relatedness among avian species. Prevalence varied drastically among the 20 well-sampled species, ranging from 0 to 70%. Seasonality was the main factor associated with infections, but how this abiotic condition influenced parasite prevalence varied according to the host-parasite system. Plasmodium prevalence increased during the rainy season and, after excluding the large sample size of Columbiformes (n = 462/933), Plasmodium infection rate was maintained high in the wet season and showed a negative association with host body mass. No association was found between non-Columbiform bird prevalence and seasonality or body mass when evaluating both Plasmodium and Haemoproteus or only Haemoproteus infections. Parasite community was composed of 32 lineages including 7 new lineages. We evidenced that even dry domains can harbour a high prevalence and diversity of vector-borne parasites and pointed out seasonality as a ruling factor.

Polyester Nanocapsules for Intravenous Delivery of Artemether: Formulation Development, Antimalarial Efficacy, and Cardioprotective Effects In Vivo.

Artemether (ATM) is an effective antimalarial drug that also has a short half-life in the blood. Furthermore, ATM is also cardiotoxic and is associated with pro-arrhythmogenic risks. We aimed to develop a delivery system enabling the prolonged release of ATM into the blood coupled with reduced cardiotoxicity. To achieve this, we prepared polymeric nanocapsules (NCs) from different biodegradable polyesters, namely poly(D,L-lactide) (PLA), poly-ε-caprolactone (PCL), and surface-modified NCs, using a monomethoxi-polyethylene glycol-block-poly(D,L-lactide) (PEG5kDa-PLA45kDa) polymer. Using this approach, we were able to encapsulate high yields of ATM (>85%, 0−4 mg/mL) within the oily core of the NCs. The PCL-NCs exhibited the highest percentage of ATM loading as well as a slow release rate. Atomic force microscopy showed nanometric and spherical particles with a narrow size dispersion. We used the PCL NCs loaded with ATM for biological evaluation following IV administration. As with free-ATM, the ATM-PCL-NCs formulation exhibited potent antimalarial efficacy using either the "Four-day test" protocol (ATM total at the end of the 4 daily doses: 40 and 80 mg/kg) in Swiss mice infected with P. berghei or a single low dose (20 mg/kg) of ATM in mice with higher parasitemia (15%). In healthy rats, IV administration of single doses of free-ATM (40 or 80 mg/kg) prolonged cardiac QT and QTc intervals and induced both bradycardia and hypotension. Repeated IV administration of free-ATM (four IV doses at 20 mg/kg every 12 h for 48 h) also prolonged the QT and QTc intervals but, paradoxically, induced tachycardia and hypertension. Remarkably, the incorporation of ATM in ATM-PCL-NCs reduced all adverse effects. In conclusion, the encapsulation of ATM in biodegradable polyester NCs reduces its cardiovascular toxicity without affecting its antimalarial efficacy.

Haemosporidian parasites and incubation period influence plumage coloration in tanagers (Passeriformes: Thraupidae).

Birds are highly visually oriented and use plumage coloration as an important signalling trait in social communication. Hence, males and females may have different patterns of plumage coloration, a phenomenon known as sexual dichromatism. Because males tend to have more complex plumages, sexual dichromatism is usually attributed to female choice. However, plumage coloration is partly condition-dependent; therefore, other selective pressures affecting individuals' success may also drive the evolution of this trait. Here, we used tanagers as model organisms to study the relationships between dichromatism and plumage coloration complexity in tanagers with parasitism by haemosporidians, investment in reproduction and life-history traits. We screened blood samples from 2849 individual birds belonging to 52 tanager species to detect haemosporidian parasites. We used publicly available data for plumage coloration, bird phylogeny and life-history traits to run phylogenetic generalized least-square models of plumage dichromatism and complexity in male and female tanagers. We found that plumage dichromatism was more pronounced in bird species with a higher prevalence of haemosporidian parasites. Lastly, high plumage coloration complexity in female tanagers was associated with a longer incubation period. Our results indicate an association between haemosporidian parasites and plumage coloration suggesting that parasites impact mechanisms of sexual selection, increasing differences between the sexes, and social (non-sexual) selection, driving females to develop more complex coloration.

Host life-history traits predict haemosporidian parasite prevalence in tanagers (Aves: Thraupidae).

Vector-borne parasites are important ecological drivers influencing life-history evolution in birds by increasing host mortality or susceptibility to new diseases. Therefore, understanding why vulnerability to infection varies within a host clade is a crucial task for conservation biology and for understanding macroecological life-history patterns. Here, we studied the relationship of avian life-history traits and climate on the prevalence of Plasmodium and Parahaemoproteus parasites. We sampled 3569 individual birds belonging to 53 species of the family Thraupidae. Individuals were captured from 2007 to 2018 at 92 locations. We created 2 phylogenetic generalized least-squares models with Plasmodium and Parahaemoproteus prevalence as our response variables, and with the following predictor variables: climate PC1, climate PC2, body size, mixed-species flock participation, incubation period, migration, nest height, foraging height, forest cover, and diet. We found that Parahaemoproteus and Plasmodium prevalence was higher in species inhabiting open habitats. Tanager species with longer incubation periods had higher Parahaemoproteus prevalence as well, and we hypothesize that these longer incubation periods overlap with maximum vector abundances, resulting in a higher probability of infection among adult hosts during their incubation period and among chicks. Lastly, we found that Plasmodium prevalence was higher in species without migratory behaviour, with mixed-species flock participation, and with an omnivorous or animal-derived diet. We discuss the consequences of higher infection prevalence in relation to life-history traits in tanagers.

Blood parasites of passerines in the Brazilian Pampas and their implications for a potential population supplementation program for the endangered Yellow Cardinal (Gubernatrix cristata).

Espinilho savanna ("seasonal steppe savanna") is a unique vegetation formation of the Pampas biome that is found near the tri-border of Brazil, Uruguay, and Argentina. The Yellow Cardinal (Gubernatrix cristata) is a flagship species of this ecosystem, but it is classified as "critically endangered" in Brazil due to habitat loss and poaching for the illegal trade. Population supplementation through the release of individuals that were captive-bred or apprehended by authorities from the illegal trade has been considered as a conservation strategy for this species; however, the risk of pathogen introduction is a critical concern. We used microscopy and molecular methods to investigate the occurrence of blood parasites in wild passerines (n = 64, including three Yellow Cardinals) at Espinilho State Park, Rio Grande do Sul, Brazil, and in captive Yellow Cardinals (n = 30) at three facilities in Brazil. Haemosporidian parasites were detected in the blood smears of 10.9% of the wild passerines, comprising the morphospecies Haemoproteus erythrogravidus in Rufous-collared Sparrow (Zonotrichia capensis), H. quiscalus in Grayish Baywing (Agelaioides badius), and H. tyranni in Great Kiskadee (Pitangus sulphuratus); these are the southernmost records for these morphospecies and their first record for the Pampas biome. No haemosporidian parasites were detected in the blood smears of the Yellow Cardinals, wild or captive. Microfilariae were detected in the blood smears of 14.1% of the wild passerines, including all wild Yellow Cardinals, and in 43.3% of captive Yellow Cardinals. Trypanosoma sp. was detected in the blood smear of one captive Yellow Cardinal. Nested PCR and gene sequencing of the cyt-b gene of Haemoproteus/Plasmodium was used to test a subset of wild passerines and captive Yellow Cardinals, allowing for the molecular barcoding of H. quiscalus lineage AGEBAD04 and H. tyranni lineage PITSUL01; additionally, DNA identical to that of lineage PITSUL01 was detected in the blood of one captive Yellow Cardinal. This study provides valuable data to support the conservation management of the Yellow Cardinal and other threatened passerines from the Pampas and highlights the need for further studies on the epidemiology and pathology of filarioid worms and trypanosomes in passerines from this biome.

Prevalence and richness of malaria and malaria-like parasites in wild birds from different biomes in South America.

South America has different biomes with a high richness of wild bird species and Diptera vectors, representing an ideal place to study the influence of habitat on vector-borne parasites. In order to better understand how different types of habitats do or do not influence the prevalence of haemosporidians, we performed a new analysis of two published datasets comprising wild birds from the Brazilian Savanna (Cerrado) as well as wild birds from the Venezuelan Arid Zone. We investigated the prevalence and genetic diversity of haemosporidian parasites belonging to two genera: Plasmodium and Haemoproteus. We evaluated data from 676 wild birds from the Cerrado and observed an overall prevalence of 49%, whereas, in the Venezuelan Arid Zone, we analyzed data from 527 birds and found a similar overall prevalence of 43%. We recovered 44 lineages, finding Plasmodium parasites more prevalent in the Cerrado (15 Plasmodium and 12 Haemoproteus lineages) and Haemoproteus in the Venezuelan Arid Zone (seven Plasmodium and 10 Haemoproteus lineages). No difference was observed on parasite richness between the two biomes. We observed seven out of 44 haemosporidian lineages that are shared between these two distinct South American biomes. This pattern of parasite composition and prevalence may be a consequence of multiple factors, such as host diversity and particular environmental conditions, especially precipitation that modulate the vector's dynamics. The relationship of blood parasites with the community of hosts in large and distinct ecosystems can provide more information about what factors are responsible for the variation in the prevalence and diversity of these parasites in an environment.

Molecular detection of Leucocytozoon in red-legged seriemas (Cariama cristata), a non-migratory bird species in the Brazilian Cerrado.

Avian Haemosporidian parasites - Plasmodium, Haemoproteus, Leucocytozoon and Fallisia - have a wide distribution except for Antarctica. Leucocytozoon sp. has been poorly described in Brazil, and few studies have indicated infections in birds from the Atlantic Forest, Pantanal, Pampa and Amazon biomes. This study describes, for the first time, the occurrence of Leucocytozoon infection in red-legged seriemas (Cariama cristata) in the Brazilian savanna (Cerrado biome) using molecular diagnosis. Leucocytozoon spp. lineage CARCRI01 was detected in three C. cristata, a non-migratory bird, confirming transmission in mid-elevation areas in central Brazil. Further studies are needed to certify whether infections in red-legged seriemas were not abortive and to elucidate Leucocytozoon infection at low altitudes in the Brazilian lands.

Migratory behaviour does not alter cophylogenetic congruence between avian hosts and their haemosporidian parasites.

Parasites display various degrees of host specificity, reflecting different coevolutionary histories with their hosts. Avian hosts follow multiple migration patterns representing short but also long distances. As parasites infecting migratory birds are subjected to multiple environmental and biotic changes through their flyways, migration may disrupt or strengthen cophylogenetic congruence between hosts and parasites. On the one hand, parasites might adapt to a single migratory host, evolving to cope with the specific challenges associated with the multiple habitats occupied by the host. On the other, as migrants can introduce parasites into new habitats, higher rates of host switching could also disrupt cophylogenetic patterns. We analysed whether migratory behaviour shapes avian haemosporidian parasite­host cophylogenetic congruence by testing if contributions of host­parasite links to overall congruence differ among resident and short-, variable- and long-distance migrants globally and within South America only. On both scales, we found significant overall cophylogenetic congruence by testing whether overall congruence differed between haemosporidian lineages and bird species. However, we found no difference in contribution towards congruence among links involving resident vs migratory hosts in both models. Thus, migratory behaviour neither weakens nor strengthens bird­haemosporidian cophylogenetic congruence, suggesting that other avian host traits are more influential in generating phylogenetic congruence in this host­parasite system.

A new haemosporidian parasite from the Red-legged Seriema Cariama cristata (Cariamiformes, Cariamidae).

Haemoproteids (Haemosporida, Haemoproteidae) are a diverse group of avian blood parasites that are transmitted by hematophagous dipterans. In this study, we describe Haemoproteus pulcher sp. nov. from a Red-legged Seriema (Cariama cristata) in southeast Brazil. Analysis of the mitochondrial cytb gene indicates this parasite is closely related to Haemoproteus catharti (from Turkey Vulture, Cathartes aura) and the unidentified haemosporidian lineages PSOOCH01 (from Pale-winged Trumpeter, Psophia leucoptera) and MYCAME08 (from Wood Stork, Mycteria americana). This group of parasites appears to represent an evolutionary lineage that is distinct from other Haemoproteus spp., being instead more closely related to Haemocystidium spp. (from reptiles), Plasmodium spp. (from reptiles, birds, and mammals) and other mammal-infecting haemosporidians (Nycteria, Polychromophilus, and Hepatocystis). Current evidence suggests that parasites of this newly discovered evolutionary lineage may be endemic to the Americas, but further studies are necessary to clarify their taxonomy, life cycle, vectors, hosts, geographic distribution and host health effects. Additionally, it should be borne in mind that some PCR protocols targeting the cytb gene might not reliably detect H. pulcher due to low primer affinity.

Haemosporidian taxonomic composition, network centrality and partner fidelity between resident and migratory avian hosts.

Migration can modify interaction dynamics between parasites and their hosts with migrant hosts able to disperse parasites and impact local community transmission. Thus, studying the relationships among migratory hosts and their parasites is fundamental to elucidate how migration shapes host-parasite interactions. Avian haemosporidians are some of the most prevalent and diverse group of wildlife parasites and are also widely studied as models in ecological and evolutionary research. Here, we contrast partner fidelity, network centrality and parasite taxonomic composition among resident and non-resident avian hosts using presence/absence data on haemosporidians parasitic in South American birds as study model. We ran multilevel Bayesian models to assess the role of migration in determining partner fidelity (i.e., normalized degree) and centrality (i.e., weighted closeness) in host-parasite networks of avian hosts and their respective haemosporidian parasites. In addition, to evaluate parasite taxonomic composition, we performed permutational multivariate analyses of variance to quantify dissimilarity in haemosporidian lineages infecting different host migratory categories. We observed similar partner fidelity and parasite taxonomic composition among resident and migratory hosts. Conversely, we demonstrate that migratory hosts play a more central role in host-parasite networks than residents. However, when evaluating partially and fully migratory hosts separately, we observed that only partially migratory species presented higher network centrality when compared to resident birds. Therefore, migration does not lead to differences in both partner fidelity and parasite taxonomic composition. However, migratory behavior is positively associated with network centrality, indicating migratory hosts play more important roles in shaping host-parasite interactions and influence local transmission.

Host migration and environmental temperature influence avian haemosporidians prevalence: a molecular survey in a Brazilian Atlantic rainforest.

Avian haemosporidians are parasites with great capacity to spread to new environments and new hosts, being considered a good model to host-parasite interactions studies. Here, we examine avian haemosporidian parasites in a protected area covered by Restinga vegetation in northeastern Brazil, to test the hypothesis that haemosporidian prevalence is related to individual-level traits (age and breeding season), species-specific traits (diet, foraging strata, period of activity, species body weight, migratory status, and nest shape), and climate factors (temperature and rainfall). We screened DNA from 1,466 birds of 70 species captured monthly from April 2013 to March 2015. We detected an overall prevalence (Plasmodium/Haemoproteus infection) of 22% (44 host species) and parasite's lineages were identified by mitochondrial cyt b gene. Our results showed that migration can be an important factor predicting the prevalence of Haemoproteus (Parahaemoproteus), but not Plasmodium, in hosts. Besides, the temperature, but not rainfall, seems to predict the prevalence of Plasmodium in this bird community. Neither individual-level traits analyzed nor the other species-specific traits tested were related to the probability of a bird becoming infected by haemosporidians. Our results point the importance of conducting local studies in particular environments to understand the degree of generality of factors impacting parasite prevalence in bird communities. Despite our attempts to find patterns of infection in this bird community, we should be aware that an avian haemosporidian community organization is highly complex and this complexity can be attributed to an intricate net of factors, some of which were not observed in this study and should be evaluated in future studies. We evidence the importance of looking to host-parasite relationships in a more close scale, to assure that some effects may not be obfuscated by differences in host life-history.

Plasmodium ouropretensis, n. sp., a new case of non-erythrocytic species within lizard malaria parasites.

Delimiting and describing Plasmodium species in reptiles remains a pressing problem in Haemosporida taxonomy. The few morphological characters used can overlap, and the significance of some life-history traits is not fully understood. Morphologically identical lizard Plasmodium forms have been reported infecting different cell types (red and white blood cells) in the same host and have been considered the same species. An example is Plasmodium tropiduri tropiduri, a species known to infect erythrocytes, thrombocytes and lymphocyte-like cells. Here, both forms of P. t. tropiduri were analysed using light microscope-based morphological characteristics and phylogenetic inferences based on almost complete mitochondrial genomes of parasites naturally infecting lizards in southeastern Brazil. Although morphologically similar, two distinct phylogenetic lineages infecting erythrocytes and non-erythrocytic cells were found. The lineage found in the erythrocytes forms a monophyletic group with species from Colombia. However, the non-erythrocytic lineage shares a recent common ancestor with Plasmodium leucocytica, which infects leucocytes in lizards from the Caribbean islands. Here, Plasmodium ouropretensis n. sp. is described as a species that infects thrombocytes and lymphocyte-like cells.

Migratory birds have higher prevalence and richness of avian haemosporidian parasites than residents.

Individuals of migratory species may be more likely to become infected by parasites because they cross different regions along their route, thereby being exposed to a wider range of parasites during their annual cycle. Conversely, migration may have a protective effect since migratory behaviour allows hosts to escape environments presenting a high risk of infection. Haemosporidians are one of the best studied, most prevalent and diverse groups of avian parasites, however the impact of avian host migration on infection by these parasites remains controversial. We tested whether migratory behaviour influenced the prevalence and richness of avian haemosporidian parasites among South American birds. We used a dataset comprising ~ 11,000 bird blood samples representing 260 bird species from 63 localities and Bayesian multi-level models to test the impact of migratory behaviour on prevalence and lineage richness of two avian haemosporidian genera (Plasmodium and Haemoproteus). We found that fully migratory species present higher parasite prevalence and higher richness of haemosporidian lineages. However, we found no difference between migratory and non-migratory species when evaluating prevalence separately for Plasmodium and Haemoproteus, or for the richness of Plasmodium lineages. Nevertheless, our results indicate that migratory behaviour is associated with an infection cost, namely a higher prevalence and greater variety of haemosporidian parasites.

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.

Higher infection probability of haemosporidian parasites in Blue-black Grassquits (Volatinia jacarina) inhabiting native vegetation across Brazil.

Human induced changes on landscape can alter the biotic and abiotic factors that influence the transmission of vector-borne parasites. To examine how infection rates of vector-transmitted parasites respond to changes on natural landscapes, we captured 330 Blue-black Grassquits (Volatinia jacarina) in Brazilian biomes and assessed the prevalence and diversity of avian haemosporidian parasites (Plasmodium and Haemoproteus) across avian host populations inhabiting environment under different disturbance and climatic conditions. Overall prevalence in Blue-black Grassquits was low (11%) and infection rates exhibited considerable spatial variation, ranging from zero to 39%. Based on genetic divergence of cytochrome b gene, we found two lineages of Haemoproteus (Parahaemoproteus) and 10 of Plasmodium. We showed that Blue-black Grassquit populations inhabiting sites with higher proportion of native vegetation cover were more infected across Brazil. Other landscape metrics (number of water bodies and distance to urban areas) and climatic condition (temperature and precipitation) known to influence vector activity and promote avian malaria transmission did not explain infection probability in Blue-black Grassquit populations. Moreover, breeding season did not explain prevalence across avian host populations. Our findings suggest that avian haemosporidian prevalence and diversity in Blue-black Grassquit populations are determined by recent anthropogenic changes in vegetation cover that may alter microclimate, thus influencing vector activity and parasite transmission.

Changes in malaria patterns in Brazil over 28 years (1990-2017): results from the Global Burden of Disease Study 2017.

BACKGROUND: This study presents the malaria burden in Brazil from 1990 to 2017 using data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017), by analyzing disease burden indicators in federated units of the Legal Amazon and Extra-Amazon regions, as well as describing malaria cases according to Plasmodium species occurring in the country. METHODS: We used estimates from the GBD 2017 to report years of life lost due to premature death (YLLs), years lived with disability (YLDs), and disability-adjusted life years (DALYs) for malaria in Brazil, grouped by gender, age group, and Brazilian federated unit, from 1990 to 2017. Results are presented as absolute numbers and age-standardized rates (per 100,000 inhabitants) with 95% uncertainty intervals (UI). RESULTS: At the national level, the age-standardized DALYs rate due to malaria decreased by 92.0%, from 42.5 DALYs per 100,000 inhabitants (95% UI 16.6-56.9) in 1990 to 3.4 DALYs per 100,000 inhabitants (95% UI 2.7-4.7) in 2017. The YLLs were the main component of the total DALYs rate for malaria in 1990 (67.3%), and the YLDs were the main component of the metric in 2017 (61.8%). In 2017, the highest sex-age DALYs rate was found among females in the "< 1-year-old" age group, with a 6.4 DALYs per 100,000 inhabitants (95% UI 1.8-14.7) and among males in the age group of "20 to 24 years old", with a 4.7 DALYs per 100,000 inhabitants (95% UI 3.3-9.9). Within the Brazilian Amazon region, the three federated units with the highest age-standardized DALYs rates in 2017 were Acre [28.4 (95% UI 14.2-39.1)], Roraima [28.3 (95% UI 13.5-40.2)], and Rondônia [24.7 (95% UI 11.4-34.8)]. Concerning the parasite species that caused malaria, 73.5% of the total of cases registered in the period had Plasmodium vivax as the etiological agent. CONCLUSIONS: The results of the GBD 2017 show that despite the considerable reduction in the DALYs rates between 1990 and 2017, malaria remains a relevant and preventable disease, which in recent years has generated more years of life lost due to disability than deaths. The states endemic for malaria in the Amazon region require constant evaluation of preventive and control measures. The present study will contribute to the direction of current health policies aimed at reducing the burden of malaria in Brazil, as knowing the geographical and temporal distribution of the risk of death and disability of this disease can facilitate the planning, implementation, and improvement of control strategies aimed at eliminating the disease.