Contribution of Transcriptome to Elucidate the Biology of Plasmodium spp.

The present review discusses some of the new technologies that have been applied to elucidate how Plasmodium spp escape from the immune system and subvert the host physiology to orchestrate the regulation of its biological pathways. Our manuscript describes how techniques such as microarray approaches, RNA-Seq, and single-cell RNA sequencing have contributed to the discovery of transcripts and changed the concept of gene expression regulation in closely related malaria parasite species. Moreover, the text highlights the contributions of high-throughput RNA sequencing for the current knowledge of malaria parasite biology, physiology, vaccine target, and the revelation of new players in parasite signaling.

The Search of a Malaria Vaccine: The Time for Modified Immuno-Potentiating Probes.

Malaria is a deadly disease that takes the lives of more than 420,000 people a year and is responsible for more than 229 million clinical cases globally. In 2019, 95% of malaria morbidity occurred in African countries. The development of a highly protective vaccine is an urgent task that remains to be solved. Many vaccine candidates have been developed, from the use of the entire attenuated and irradiated pre-erythrocytic parasite forms (or recombinantly expressed antigens thereof) to synthetic candidates formulated in a variety of adjuvants and delivery systems, however these have unfortunately proven a limited efficacy. At present, some vaccine candidates are finishing safety and protective efficacy trials, such as the PfSPZ and the RTS,S/AS01 which are being introduced in Africa. We propose a strategy for introducing non-natural elements into target antigens representing key epitopes of Plasmodium spp. Accordingly, chemical strategies and knowledge of host immunity to Plasmodium spp. have served as the basis. Evidence is obtained after being tested in experimental rodent models for malaria infection and recognized for human sera from malaria-endemic regions. This encourages us to propose such an immune-potentiating strategy to be further considered in the search for new vaccine candidates.

A novel platform for peptide-mediated affinity capture and LC-MS/MS identification of host receptors involved in Plasmodium invasion.

Successful Plasmodium falciparum invasion of red blood cells includes the orderly execution of highly specific receptor-ligand molecular interactions between the parasite's proteins and the red blood cell membrane proteins. There is a growing need for elucidating receptor-ligand pairings, which will help in understanding the parasite's biology and provide the fundamental basis for developing prophylactic or therapeutic alternatives leading to mitigating or eliminating this type of malaria. We have thus used Plasmodium falciparum RH5 - derived peptides and ghost red blood cell proteins in synthetic peptide affinity capture assays to identify important host receptors used by Plasmodium spp. in the invasion of red blood cells. LC-MS/MS analysis confirmed the extensively described interaction between PfRH5 and the basigin receptor on the red blood cell membrane. As shown here, tagged synthetic peptides displaying high binding ability to erythrocytes can be used to identify receptors present in protein extracts from ghost red blood cells via affinity capture and LC-MS/MS. SIGNIFICANCE: The article describes a novel approach for identifying red blood cell receptors based on the ability of synthetic peptides having high red blood cell binding capacity to capture Plasmodium spp. receptors on proteins extracted from ghost red blood cells. Specifically, novel methods to identify Plasmodium falciparum reticulocyte binding protein homolog 5 PfRH5 and basigin interaction using a combination of affinity capture and LC-MS/MS assays is described. Identification of these host RBC receptors interacting with malarial parasite proteins is of utmost importance in studying the disease's pathogenesis and will provide crucial information in understanding the parasite's biology. In addition, data from these studies can be used to identify potential therapeutic target(s) to mitigate or eliminate this debilitating disease.

Recent Advances in the Development of Broad-Spectrum Antiprotozoal Agents.

Infections caused by Trypanosoma brucei, Trypanosoma cruzi, Leishmania spp., Entamoeba histolytica, Giardia lamblia, Plasmodium spp., and Trichomonas vaginalis, are part of a large list of human parasitic diseases. Together, they cause more than 500 million infections per year. These protozoa parasites affect both low- and high-income countries and their pharmacological treatments are limited. Therefore, new and more effective drugs in preclinical development could improve overall therapy for parasitic infections even when their mechanisms of action are unknown. In this review, a number of heterocyclic compounds (diamidine, guanidine, quinoline, benzimidazole, thiazole, diazanaphthalene, and their derivatives) reported as antiprotozoal agents are discussed as options for developing new pharmacological treatments for parasitic diseases.

Blood Meal Sources of Anopheles spp. in Malaria Endemic Areas of Honduras.

Malaria remains a life-threatening disease in many tropical countries. Honduras has successfully reduced malaria transmission as different control methods have been applied, focusing mainly on indoor mosquitoes. The selective pressure exerted by the use of insecticides inside the households could modify the feeding behavior of the mosquitoes, forcing them to search for available animal hosts outside the houses. These animal hosts in the peridomicile could consequently become an important factor in maintaining vector populations in endemic areas. Herein, we investigated the blood meal sources and Plasmodium spp. infection on anophelines collected outdoors in endemic areas of Honduras. Individual PCR reactions with species-specific primers were used to detect five feeding sources on 181 visibly engorged mosquitoes. In addition, a subset of these mosquitoes was chosen for pathogen analysis by a nested PCR approach. Most mosquitoes fed on multiple hosts (2 to 4), and 24.9% of mosquitoes had fed on a single host, animal or human. Chicken and bovine were the most frequent blood meal sources (29.5% and 27.5%, respectively). The average human blood index (HBI) was 22.1%. None of the mosquitoes were found to be infected with Plasmodium spp. Our results show the opportunistic and zoophilic behavior of Anopheles mosquitoes in Honduras.

Cell invasion by intracellular parasites - the many roads to infection.

Intracellular parasites from the genera Toxoplasma, Plasmodium, Trypanosoma, Leishmania and from the phylum Microsporidia are, respectively, the causative agents of toxoplasmosis, malaria, Chagas disease, leishmaniasis and microsporidiosis, illnesses that kill millions of people around the globe. Crossing the host cell plasma membrane (PM) is an obstacle these parasites must overcome to establish themselves intracellularly and so cause diseases. The mechanisms of cell invasion are quite diverse and include (1) formation of moving junctions that drive parasites into host cells, as for the protozoans Toxoplasma gondii and Plasmodium spp., (2) subversion of endocytic pathways used by the host cell to repair PM, as for Trypanosoma cruzi and Leishmania, (3) induction of phagocytosis as for Leishmania or (4) endocytosis of parasites induced by specialized structures, such as the polar tubes present in microsporidian species. Understanding the early steps of cell entry is essential for the development of vaccines and drugs for the prevention or treatment of these diseases, and thus enormous research efforts have been made to unveil their underlying biological mechanisms. This Review will focus on these mechanisms and the factors involved, with an emphasis on the recent insights into the cell biology of invasion by these pathogens.

Contribution of Murine Models to the Study of Malaria During Pregnancy.

Annually, many pregnancies occur in areas of Plasmodium spp. transmission, particularly in underdeveloped countries with widespread poverty. Estimations have suggested that several million women are at risk of developing malaria during pregnancy. In particular cases, systemic infection caused by Plasmodium spp. may extend to the placenta, dysregulating local homeostasis and promoting the onset of placental malaria; these processes are often associated with increased maternal and fetal mortality, intrauterine growth restriction, preterm delivery, and reduced birth weight. The endeavor to understand and characterize the mechanisms underlying disease onset and placental pathology face several ethical and logistical obstacles due to explicit difficulties in assessing human gestation and biological material. Consequently, the advent of murine experimental models for the study of malaria during pregnancy has substantially contributed to our understanding of this complex pathology. Herein, we summarize research conducted during recent decades using murine models of malaria during pregnancy and highlight the most relevant findings, as well as discuss similarities to humans and the translational capacity of achieved results.

Effects of Political Instability in Venezuela on Malaria Resurgence at Ecuador-Peru Border, 2018.

Mass migration from Venezuela has increased malaria resurgence risk across South America. During 2018, migrants from Venezuela constituted 96% of imported malaria cases along the Ecuador-Peru border. Plasmodium vivax predominated (96%). Autochthonous malaria cases emerged in areas previously malaria-free. Heightened malaria control and a response to this humanitarian crisis are imperative.

Pathological and molecular characterization of avian malaria in captive Magellanic penguins (Spheniscus magellanicus) in South America.

Avian malaria is a mosquito-borne disease that affects multiple avian species and is caused by protozoans of the genus Plasmodium. An avian malaria infection caused by Plasmodium sp. in Magellanic penguins (Spheniscus magellanicus) with high mortality is described in a zoo in Southern Brazil. Clinically, three birds presented signs of inappetence, anorexia, pale mucosa, dyspnea, and opisthotonus, with death in a clinical course of 5-8 h. At the necropsy, all birds exhibited pale mucosa, marked splenomegaly and hepatomegaly, in addition to moderate leptomeningeal blood vessels ingurgitation in the brain. Microscopically, multiple exoerythrocytic meronts were observed in the cytoplasm of endothelial cells in the spleen, liver, heart, lungs, brain, kidneys, and pancreas. The spleen had a multifocal perivascular inflammatory infiltrate of lymphocytes, plasma cells, and macrophages, which also exhibited hemosiderosis and erythrophagocytosis. The liver had a multifocal periportal inflammatory infiltrate of lymphocytes, macrophages, and plasma cells, in addition to marked hemosiderosis in the hepatic sinusoids. Fragments of spleen, liver, brain, skeletal muscle, and lung were tested by the polymerase chain reaction technique for the detection of a fragment of the cytochrome B gene from haemosporidians, which resulted positive for Plasmodium spp. After sequencing, the samples were phylogenetically associated to Plasmodium sp. detected in Turdus albicollis (KU562808) in Brazil and matched to the lineage TURALB01 previously detected in T. albicollis. Avian malaria infections caused by Plasmodium sp. of lineage TURALB01 may occur in S. magellanicus with high mortality, and, thus, it is essential to detect and characterize the agent involved to obtain the differential diagnosis of the condition.

New Molecular Targets and Strategies for Antimalarial Discovery.

Malaria remains a major health problem, especially because of the emergence of resistant P. falciparum strains to artemisinin derivatives. In this context, safe and affordable antimalarial drugs are desperately needed. New proteins have been investigated as molecular targets for research and development of innovative compounds with welldefined mechanism of action. In this review, we highlight genetically and clinically validated plasmodial proteins as drug targets for the next generation of therapeutics. The enzymes described herein are involved in hemoglobin hydrolysis, the invasion process, elongation factors for protein synthesis, pyrimidine biosynthesis, post-translational modifications such as prenylation, phosphorylation and histone acetylation, generation of ATP in mitochondrial metabolism and aminoacylation of RNAs. Significant advances on proteomics, genetics, structural biology, computational and biophysical methods provided invaluable molecular and structural information about these drug targets. Based on this, several strategies and models have been applied to identify and improve lead compounds. This review presents the recent progresses in the discovery of antimalarial drug candidates, highlighting the approaches, challenges, and perspectives to deliver affordable, safe and low single-dose medicines to treat malaria.

Natural Plasmodium infection in neotropical primates in the island of São Luís, state of Maranhão, Brazil / Infecção natural de Plasmodium em primatas neotropicais da Ilha de São Luís, Estado do Maranhão, Brasil

The states that make up the Legal Amazon Region, which include the state of Maranhão, account for 99% of registered cases of human malaria in Brazil. It is also believed that transmission of malaria from nonhuman primates (NHP) to humans occurs in this region, because of current reports of seroepidemiological results from samples from humans and NHP coexisting in the same areas. This study aimed to make morphological, serological and molecular diagnoses of Plasmodium spp. in neotropical primates on the island of São Luís, state of Maranhão, Brazil. The diagnostic techniques used were optical microscopy, the polymerase chain reaction (PCR) and the indirect immunofluorescence assay (IFA). From June 2009 to April 2010, 70 NHP were sampled: 50 at the Wild Animal Screening Center (CETAS), located in the municipality of São Luís and 20 free-living individuals that were caught in a private reserve located in the municipality of São Jose de Ribamar, state of Maranhão. Under an optical microscope, 140 slides (two from each animal) were evaluated and five animals (7.1%) were found to be positive. IFA did not detect anti-Plasmodium spp. From PCR on the 70 animals sampled, amplified Plasmodium spp. products were observed in 13 samples, of which eight (61.5%) were from free-living animals and five (38.5%) were from animals at CETAS.(AU)

Os Estados que compõem a Amazônia Legal, entre eles o Estado do Maranhão, respondem a 99% dos casos registrados de malária humana no Brasil. Também se acredita que nessa região ocorra a transmissão de malária de primatas não humanos (PNH) para humanos, devido a relatos atuais de resultados soroepidemiológicos de amostras de humanos e PNH que coexistem nas mesmas áreas. O presente estudo objetivou realizar o diagnóstico morfológico, sorológico e molecular de Plasmodium spp. em primatas neotropicais na Ilha de São Luís, Estado do Maranhão, Brasil. Foram utilizadas como técnicas de diagnóstico: a microscopia de luz, a reação em cadeia pela polimerase (PCR) e a imunofluorescência indireta (RIFI). No período de junho de 2009 a abril de 2010, foram amostrados 70 PNH, sendo 50 provenientes do Centro de Triagem de Animais Silvestres (CETAS), localizado no município de São Luís, e 20 de vida livre, capturados em reserva particular localizada no município de São José de Ribamar, Estado do Maranhão. Foram avaliadas pela microscopia de luz 140 lâminas (duas de cada animal), das quais cinco animais (7,1%) foram positivos. Pela RIFI não se detectou anticorpos anti-Plasmodium spp. Pela PCR, dos 70 animais amostrados, foi possível observar produtos amplificados para Plasmodium spp. em 13 amostras, das quais oito (61,5%) eram de animais de vida livre e cinco (38,5%) de CETAS.(AU)

Natural Plasmodium infection in neotropical primates in the island of São Luís, state of Maranhão, Brazil / Infecção natural de Plasmodium em primatas neotropicais da Ilha de São Luís, Estado do Maranhão, Brasil

The states that make up the Legal Amazon Region, which include the state of Maranhão, account for 99% of registered cases of human malaria in Brazil. It is also believed that transmission of malaria from nonhuman primates (NHP) to humans occurs in this region, because of current reports of seroepidemiological results from samples from humans and NHP coexisting in the same areas. This study aimed to make morphological, serological and molecular diagnoses of Plasmodium spp. in neotropical primates on the island of São Luís, state of Maranhão, Brazil. The diagnostic techniques used were optical microscopy, the polymerase chain reaction (PCR) and the indirect immunofluorescence assay (IFA). From June 2009 to April 2010, 70 NHP were sampled: 50 at the Wild Animal Screening Center (CETAS), located in the municipality of São Luís and 20 free-living individuals that were caught in a private reserve located in the municipality of São Jose de Ribamar, state of Maranhão. Under an optical microscope, 140 slides (two from each animal) were evaluated and five animals (7.1%) were found to be positive. IFA did not detect anti-Plasmodium spp. From PCR on the 70 animals sampled, amplified Plasmodium spp. products were observed in 13 samples, of which eight (61.5%) were from free-living animals and five (38.5%) were from animals at CETAS.

Os Estados que compõem a Amazônia Legal, entre eles o Estado do Maranhão, respondem a 99% dos casos registrados de malária humana no Brasil. Também se acredita que nessa região ocorra a transmissão de malária de primatas não humanos (PNH) para humanos, devido a relatos atuais de resultados soroepidemiológicos de amostras de humanos e PNH que coexistem nas mesmas áreas. O presente estudo objetivou realizar o diagnóstico morfológico, sorológico e molecular de Plasmodium spp. em primatas neotropicais na Ilha de São Luís, Estado do Maranhão, Brasil. Foram utilizadas como técnicas de diagnóstico: a microscopia de luz, a reação em cadeia pela polimerase (PCR) e a imunofluorescência indireta (RIFI). No período de junho de 2009 a abril de 2010, foram amostrados 70 PNH, sendo 50 provenientes do Centro de Triagem de Animais Silvestres (CETAS), localizado no município de São Luís, e 20 de vida livre, capturados em reserva particular localizada no município de São José de Ribamar, Estado do Maranhão. Foram avaliadas pela microscopia de luz 140 lâminas (duas de cada animal), das quais cinco animais (7,1%) foram positivos. Pela RIFI não se detectou anticorpos anti-Plasmodium spp. Pela PCR, dos 70 animais amostrados, foi possível observar produtos amplificados para Plasmodium spp. em 13 amostras, das quais oito (61,5%) eram de animais de vida livre e cinco (38,5%) de CETAS.

Plasmodium spp. and Haemoproteus spp. infection in birds of the Brazilian Atlantic Forest detected by microscopy and polymerase chain reaction / Infecção por Plasmodium spp. e Haemoproteus spp. em aves da Mata Atlântica brasileira detectada por microscopia e reação em cadeia da polimerase

In recent years haemosporidian infection by protozoa of the genus Plasmodium and Haemoproteus, has been considered one of the most important factors related to the extinction and/or population decline of several species of birds worldwide. In Brazil, despite the large avian biodiversity, few studies have been designed to detect this infection, especially among wild birds in captivity. Thus, the objective of this study was to analyze the prevalence of Plasmodium spp. and Haemoproteus spp. infection in wild birds in captivity in the Atlantic Forest of southeastern Brazil using microscopy and the polymerase chain reaction. Blood samples of 119 different species of birds kept in captivity at IBAMA during the period of July 2011 to July 2012 were collected. The parasite density was determined based only on readings of blood smears by light microscopy. The mean prevalence of Plasmodium spp. and Haemoproteus spp. infection obtained through the microscopic examination of blood smears and PCR were similar (83.19% and 81.3%, respectively), with Caracara plancus and Saltator similis being the most parasitized. The mean parasitemia determined by the microscopic counting of evolutionary forms of Plasmodium spp. and Haemoproteus spp. was 1.51%. The results obtained from this study reinforce the importance of the handling of captive birds, especially when they will be reintroduced into the wild.(AU)

Nos últimos anos infecção por protozoários hemosporídeos dos gêneros Plasmodium e Haemoproteus, tem sido considerada um dos fatores mais importantes relacionados com a extinção e / ou declínio da população de várias espécies de aves em todo o mundo. No Brasil, apesar da grande biodiversidade aviária, poucos estudos foram desenvolvidos para detectar a infecção, especialmente entre as aves silvestres mantidas em cativeiro. Assim, o objetivo deste estudo foi analisar a prevalência de infecção por Plasmodium spp. e Haemoproteus spp. em aves silvestres em cativeiro na Mata Atlântica do sudeste do Brasil, utilizando microscopia convencional e reação em cadeia da polimerase. Amostras de sangue de 119 aves mantidas em cativeiro no Ibama durante o período de julho de 2011 a julho de 2012, foram coletadas. A densidade parasitária foi determinada com base apenas em leituras de esfregaços de sangue por microscopia fotônica. A prevalência média de infecção por Plasmodium spp. e Haemoproteus spp. obtida por exame microscópico de esfregaços sanguíneos e PCR foi semelhante (83,19% e 81,3%, respectivamente), com Caracara plancus e Saltator similis sendo as espécies mais parasitadas. A parasitemia média determinada pela contagem microscópica de formas evolutivas de Plasmodium spp. e Haemoproteus spp. foi de 1,51%. Os resultados obtidos neste estudo reforçam a importância do manejo de aves em cativeiro, especialmente quando serão reintroduzidas na natureza.(AU)

Plasmodium spp. and Haemoproteus spp. infection in birds of the Brazilian Atlantic Forest detected by microscopy and polymerase chain reaction / Infecção por Plasmodium spp. e Haemoproteus spp. em aves da Mata Atlântica brasileira detectada por microscopia e reação em cadeia da polimerase

In recent years haemosporidian infection by protozoa of the genus Plasmodium and Haemoproteus, has been considered one of the most important factors related to the extinction and/or population decline of several species of birds worldwide. In Brazil, despite the large avian biodiversity, few studies have been designed to detect this infection, especially among wild birds in captivity. Thus, the objective of this study was to analyze the prevalence of Plasmodium spp. and Haemoproteus spp. infection in wild birds in captivity in the Atlantic Forest of southeastern Brazil using microscopy and the polymerase chain reaction. Blood samples of 119 different species of birds kept in captivity at IBAMA during the period of July 2011 to July 2012 were collected. The parasite density was determined based only on readings of blood smears by light microscopy. The mean prevalence of Plasmodium spp. and Haemoproteus spp. infection obtained through the microscopic examination of blood smears and PCR were similar (83.19% and 81.3%, respectively), with Caracara plancus and Saltator similis being the most parasitized. The mean parasitemia determined by the microscopic counting of evolutionary forms of Plasmodium spp. and Haemoproteus spp. was 1.51%. The results obtained from this study reinforce the importance of the handling of captive birds, especially when they will be reintroduced into the wild...

Nos últimos anos infecção por protozoários hemosporídeos dos gêneros Plasmodium e Haemoproteus, tem sido considerada um dos fatores mais importantes relacionados com a extinção e / ou declínio da população de várias espécies de aves em todo o mundo. No Brasil, apesar da grande biodiversidade aviária, poucos estudos foram desenvolvidos para detectar a infecção, especialmente entre as aves silvestres mantidas em cativeiro. Assim, o objetivo deste estudo foi analisar a prevalência de infecção por Plasmodium spp. e Haemoproteus spp. em aves silvestres em cativeiro na Mata Atlântica do sudeste do Brasil, utilizando microscopia convencional e reação em cadeia da polimerase. Amostras de sangue de 119 aves mantidas em cativeiro no Ibama durante o período de julho de 2011 a julho de 2012, foram coletadas. A densidade parasitária foi determinada com base apenas em leituras de esfregaços de sangue por microscopia fotônica. A prevalência média de infecção por Plasmodium spp. e Haemoproteus spp. obtida por exame microscópico de esfregaços sanguíneos e PCR foi semelhante (83,19% e 81,3%, respectivamente), com Caracara plancus e Saltator similis sendo as espécies mais parasitadas. A parasitemia média determinada pela contagem microscópica de formas evolutivas de Plasmodium spp. e Haemoproteus spp. foi de 1,51%. Os resultados obtidos neste estudo reforçam a importância do manejo de aves em cativeiro, especialmente quando serão reintroduzidas na natureza...

Analysis of hematologic and serum chemistry values of Spheniscus magellanicus with molecular detection of avian malarial parasites (Plasmodium spp) / Análise dos valores hematológicos e bioquímicos de Spheniscus magellanicus com detecção molecular de parasitos maláricos aviários (Plasmodium spp)

Magellanic penguins (Spheniscus magellanicus) routinely migrate from their breeding colonies to Southern Brazil often contracting diseases during this migration, notably avian malaria, which has been already reported in Brazil and throughout the world. Detection of Plasmodium spp. in blood smears is the routine diagnostic method of avian malaria, however it has a low sensitivity rate when compared to molecular methods...

O pinguim-de-Magalhães (Spheniscus magellanicus) migra das suas colônias reprodutivas até o extremo sul do Brasil. Esses pinguins frequentemente são acometidos por doenças, notavelmente a malária aviária, que é relatada no Brasil e no mundo. A detecção de Plasmodium spp. no esfregaço sanguíneo é o método de rotina mas apresenta baixa sensibilidade quando comparado aos métodos moleculares...

Analysis of hematologic and serum chemistry values of Spheniscus magellanicus with molecular detection of avian malarial parasites (Plasmodium spp) / Análise dos valores hematológicos e bioquímicos de Spheniscus magellanicus com detecção molecular de parasitos maláricos aviários (Plasmodium spp)

Magellanic penguins (Spheniscus magellanicus) routinely migrate from their breeding colonies to Southern Brazil often contracting diseases during this migration, notably avian malaria, which has been already reported in Brazil and throughout the world. Detection of Plasmodium spp. in blood smears is the routine diagnostic method of avian malaria, however it has a low sensitivity rate when compared to molecular methods. Considering the negative impact of avian malaria on penguins, the aim of this study was to detect the presence of Plasmodium spp. in Magellanic penguins using Polymerase Chain Reaction (PCR) and by verifying clinical, hematological, and biochemical alterations in blood samples as well as to verify the likely prognosis in response to infection. Blood samples were obtained from 75 penguins to determine packed cell volume (PCV), red blood cell (RBC) and white blood cell (WBC) counts, mean corpuscular volume (MCV), uric acid, total protein, albumin, globulin and aspartate aminotransferase (AST) activity levels. Whole blood samples were used for PCR assays. Plasmodium spp. was detected in 32.0% of the specimens using PCR and in 29.3% using microscopic analyses. Anorexia, diarrhea and neurological disorders were more frequent in penguins with malaria and a significant weight difference between infected and non-infected penguins was detected. PCV and MCV rates showed no significant difference. RBC and WBC counts were lower in animals with avian malaria and leukopenia was present in some penguins. Basophil and lymphocyte counts were lower in infected penguins along with high monocyte counts. There was no significant difference in AST activities between infected and non-infected animals. There was a significant increase in uric acid values, however a decrease in albumin values was observed in infected penguins. Based on this study, we concluded that Plasmodium spp. occurs in Magellanic penguins of rehabilitation centers in Southeastern Brazil, compromising the weight of infected animals with clinical alterations appearing in severe cases of this disease. It was also noted that, although the hematological abnormalities presented by these animals may not have been conclusive, leukopenia, monocytosis and the decrease of basophils and lymphocytes revealed an unfavorable prognosis, and Plasmodium spp. infections may progress with elevated uric acid concentration and low albumin levels.(AU)

O pinguim-de-Magalhães (Spheniscus magellanicus) migra das suas colônias reprodutivas até o extremo sul do Brasil. Esses pinguins frequentemente são acometidos por doenças, notavelmente a malária aviária, que é relatada no Brasil e no mundo. A detecção de Plasmodium spp. no esfregaço sanguíneo é o método de rotina mas apresenta baixa sensibilidade quando comparado aos métodos moleculares. Considerando o impacto negativo da malária aviária nos pinguins, o objetivo deste estudo foi detectar a presença de Plasmodium spp. em pinguins-de-Magalhães usando a Reação em Cadeia da Polimerase (PCR), verificar as alterações clínicas, hematológicas e bioquímicas e o provável prognóstico em resposta à infecção. Amostras de sangue foram obtidas de 75 pinguins para determinar o hematócrito (Ht), contagens totais de eritrócitos e leucócitos, volume globular médio (VGM), concentração de ácido úrico, proteínas totais, albumina, globulinas e atividade da aspartato aminotransferase (AST). O sangue total foi usado para ensaios de PCR. A detecção de Plasmodium spp. foi obtida em 32,0% dos indivíduos pela PCR e em 29,3% pela análise microscópica. Anorexia, diarreia e alterações neurológicas foram mais frequentes nos pinguins com malária, e uma diferença significativa no peso entre pinguins infetados e não infectados foi detectada. Ht e VGM não mostraram diferença significativa. A contagem de eritrócitos e leucócitos foi menor nos animais com a malária aviária e leucopenia esteve presente em alguns pinguins. Contagens de basófilos e linfócitos foram mais baixas nos pinguins infectados, bem como elevadas contagens de monócitos estavam presentes. Não houve diferença significativa para a atividade da AST entre os animais infectados e não infectados. Houve um aumento significativo nos valores de ácido úrico, entretanto houve redução nos valores da albumina entre os pinguins infectados avaliados. Concluiu-se que Plasmodium spp. ocorre em pinguins-de-Magalhães de centros de reabilitação no sudeste brasileiro, comprometendo o peso dos animais infectados e com alterações clínicas aparecendo em casos graves da doença. Percebeu-se que embora alterações hematológicas possam não ser conclusivas, leucopenia, monocitose e diminuição de basófilos e linfócitos revelaram prognóstico desfavorável. A infecção por Plasmodium spp. pode cursar com aumento da concentração de ácido úrico e baixos valores de albumina.(AU)

Survey of Plasmodium spp. in Free-Ranging Neotropical Primates from the Brazilian Amazon Region impacted by Anthropogenic Actions

This study investigated Plasmodium spp. infection in free-ranging neotropical primates from Brazilian Amazon regions under the impact of major anthropogenic actions. Blood samples from 19 new world primates were collected and analyzed with microscopic and molecular procedures. The prevalence of Plasmodium infection was 21.0% (4/19) and PCR positive samples were identified as P. brasilianum. Considering the social-economic changes that the Amazon is facing, the prevalence of P. brasilianum infection highlights the necessity to closely monitor the movement of both human and non-human primate populations, in order tomitigate pathogen exposure and the introduction of new agents into previously...

Asymptomatic Plasmodium spp. infection in Tierralta, Colombia

With the aim of determining the prevalence of asymptomatic Plasmodium spp. infection by thick smear and PCR and its association with demographic and epidemiological characteristics in the village of Nuevo Tay, Tierralta, Córdoba, Colombia, a cross-sectional population study was carried out, using random probabilistic sampling. Venous blood samples were taken from 212 people on day 0 for thick smear and PCR. Clinical follow-up and thick smears were carried out on days 14 and 28. The prevalence of Plasmodium spp. infection was 17.9 percent (38/212; 95 percent CI: 12.5-23.3 percent) and the prevalence of asymptomatic Plasmodiumspp. infection was 14.6 percent (31/212; 95 percent CI: 9.6-19.6 percent). Plasmodium vivax was found more frequently (20/31; 64.5 percent) than Plasmodium falciparum (9/31; 29 percent) and mixed infections (2/31; 6.5 percent). A significantly higher prevalence of asymptomatic infection was found in men (19.30 percent) than in women (9.18 percent) (prevalence ratio: 2.10; 95 percent CI: 1.01-4.34 percent; p = 0.02). People who developed symptoms had a significantly higher parasitemia on day 0 than those who remained asymptomatic, of 1,881.5 ± 3,759 versus 79 ± 106.9 (p = 0.008). PCR detected 50 percent more infections than the thick smears. The presence of asymptomatic Plasmodium spp. infection highlights the importance of carrying out active searches amongst asymptomatic populations residing in endemic areas.