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Background: In Brazil, Leishmania (Leishmania) infantum is a widely distributed protozoan parasite. The human leishmaniasis caused by this species is often associated with visceral form. Tegumentary leishmaniasis (TL) cases due to L. (L.) infantum in the country are considered rare but may be underestimated. Although probably uncommon, these cases represent a new challenge to the prevention and control of leishmaniasis., Objectives: Here, we describe two distinct cases of TL with atypical clinical presentations caused by L. (L.) infantum., Methods and Findings: Parasites were isolated from cutaneous lesions of the two patients and typed as L. (L.) infantum after sequencing of the ribosomal DNA internal transcribed spacer. The dermotropic L. (L.) infantum isolates were compared in terms of growth culture patterns, metacyclogenesis and in vitro infectivity in macrophages., Main Conclusions: This study addresses the emergence of L. (L.) infantum as a causative agent of cutaneous disease in a visceral leishmaniasis hotspot located in northeast Brazil. The data presented provides novel information about the presence of dermotropic L. (L.) infantum in the country and demonstrates the infectivity potential of theses isolates.

Haemogregarine (Apicomplexa: Adeleorina) parasites are considered to be the most common and widespread haemoparasites in reptiles. The genus Hepatozoon (Apicomplexa: Adeleorina: Hepatozoidae) can be found parasitizing a broad range of species and, in reptiles, they infect mainly peripheral blood erythrocytes. The present study detected and characterized a haemogregarine isolated from the lizard species, Ameiva ameiva , collected from the municipality of Capanema, Pará state, north Brazil. Blood smears and imprints from lungs, brain, heart, kidney, liver, bone marrow and spleen were observed using light microscopy and the parasite was genetically identified by molecular analysis. Morphological, morphometric and molecular data were obtained. Parasite gamonts were found in 49.5% (55/111) of the blood smears from A. ameiva , and were characterized as oval, averaging 12.0 ± 0.8 × 5.9 ± 0.6 μm 2 in size, which displaced the nuclei of parasitized monocytes laterally. Parasite forms resembling immature gamonts were observed in the spleen and bone marrow of the lizards. Furthermore, phylogenetic analyses of 18S rRNA sequences did not reveal gene similarity with other Hepatozoon spp. sequences from reptiles. Thus, morphological and molecular analyses have identified a new species of Hepatozoon parasite, Hepatozoon lainsoni sp. nov., which infects monocytes of the A. ameiva lizard.

In the last few years, the number of studies on feline hepatozoonosis has increased, but our knowledge on the actual species of Hepatozoon and/or different genotypes affecting felines is still incipient. At least three species, namely Hepatozoon felis, H. canis, and H. silvestris, have been isolated from domestic cats in various countries. Additionally, there are indications that other species and genotypes may affect felines in given geographic areas. This study was carried out to investigate the occurrence of Hepatozoon spp. in cats from Niterói, a municipality within the metropolitan area of Rio de Janeiro, Brazil. Individual blood samples were collected from 28 cats enrolled in a spaying/castration program. DNA was extracted from all samples and subjected to sequencing specific for Hepatozoon spp. DNA of H. felis was found in 21/28 cats (75%), and four genetic polymorphisms never described thus far were detected. This is the first report of H. felis in cats living in the State of Rio de Janeiro, and the present data confirm that H. felis is a species complex encompassing different genotypes circulating within cat populations. Further studies are warranted to investigate whether different genotypes have different biology or pathogenicity for felids., (© D. Traversa et al., published by EDP Sciences, 2024.)

The etiological agent of Chagas disease is the protozoan Trypanosoma cruzi. According to the World Health Organization, about seven to eight million people are infected with T. cruzi worldwide. The main routes of transmission are vectorial and oral, which has assumed great epidemiological importance, since there is no legislation that requires the pasteurization of açaí pulp. The present work aimed to look T. cruzi in 35 samples of açaí ice cream sold at different points of sale, covering 11 different cities in São Paulo State. Thus, the parasitological technique of forced sieving and the molecular test of Polymerase Chain Reaction were performed. For PCR analysis were used the 121/122 primer that amplifies the kinetoplast of the T. cruzi DNA (kDNA). By the forced sieving technique, the açaí pulp aliquots were analyzed under different storage temperatures and in different periods. One positive sample (2.86%) were observed at six hours at room temperature, but without motility and negative to the PCR technique. Two other açaí samples (5.71%) were positive by PCR, but negative by forced sieving. The results indicate the need for quality control and good manufacturing practices for the safe consumption of açaí-derived products., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The present study aimed to evaluate the occurrence of Blastocystis sp. in Brazilian studies over a period of years (2000-2020), as well as point out relevant aspects of this enigmatic organism. We performed a literature search using six sources of international databases. The data were divided into diagnostic by parasitological and molecular techniques, and relevant aspects. After applying the inclusion and exclusion criteria, 52 studies were included in the final analysis. The occurrence of Blastocystis sp. in Brazil ranged from 0.5% to 86.6%, as determined using parasitological techniques. The highest occurrence was in the North (27.3%) and the lowest, in the Midwest region (13.4%). In Brazil, most studies have employed molecular techniques and are concentrated in the Southeast region. The Blastocystis sp. subtype ST3 had the highest average positivity, followed by ST1 and ST2. These findings represent a panorama that reflects the reality of Brazil; thus, we believe that the effectiveness of parasitological diagnosis should be considered with regard to making an appropriate choice of technique for detecting Blastocystis sp. Additionally, we emphasize the importance of further studies in the context of molecular epidemiology with regard to this genus. Blastocystis sp. is not well understood yet, and very little information regarding this genus is available; hence, further research regarding this genus is urgently needed.

This study aimed to identify members of the Sarcocystidae family in naturally infected wild birds at a rescue center in the state of Minas Gerais, southeastern Brazil. The heart and brain of 44 wild birds were evaluated by bioassay in mice to detect T. gondii, and extracted DNA was used for nested PCR of the 18S ribosomal DNA gene to detect members of the Sarcocystidae family. The positive samples were sequenced, assembled, edited and compared with sequences deposited in GenBank. Toxoplasma gondii was isolated from six (13.6%) out of 44 birds. Toxoplasma gondii DNA was identified in 10/44 (22.7%) of the birds. The amplified sequences exhibited 100% similarity with the DNA of the ME49 strain of T. gondii. Sarcocystis DNA (99% similarity) was identified in 5/44 (11.4%) of the birds. T. gondii and Sarcocystis spp. are common in wild birds in Minas Gerais, Brazil.

Introduction: Leishmania infantum was considered to be absent from Amapá until 2017 when canine infection was detected. However, there is a lack of knowledge about which reservoir species are involved in transmission in this region., Methods: Between 2014 and 2016, 86 samples from wild mammals and 74 from domestic dogs were collected in Wajãpi Indigenous Territory and were tested for the presence of deoxyribonucleic acid (DNA) of Leishmania., Results: The DNA of Le. infantum was detected in two rodent samples, Dasyprocta sp. and Proechimys cuvieri., Conclusions: This is the first evidence characterizing a sylvatic transmission cycle of Le. infantum in the State of Amapá.

Trypanosoma cruzi is a parasitic protozoan that infects a diversity of hosts constituting the cycle of enzootic transmission in wild environments and causing disease in humans (Chagas disease) and domestic animals. Wild mammals constitute natural reservoirs of this parasite, which is transmitted by hematophagous kissing bugs of the family Reduviidae. T. cruzi is genetically subdivided into six discrete typing units (DTUs), T. cruzi (Tc)I to TcVI. In Brazil, especially in the state of Paraná, TcI and TcII are widely distributed. However, TcII is less frequently found in wild reservoirs and triatomine, and more frequently found in patients. The goal of this study was to investigate the natural occurrence of T. cruzi in wild synanthropic mammals captured in urban forest fragments of the Atlantic Forest of Paraná, southern Brazil. In this way, 12 opossums and 35 bats belonging to five species were captured in urban forest parks of the city of Maringá, Paraná, an area considered endemic for Chagas disease. PCR-kinetoplast DNA molecular diagnostic reveals Trypanosoma sp. infection in 12 (100%) Didelphis albiventris and 10 (40%) Artibeus lituratus . In addition to demonstrating the presence of Trypanosoma in the two groups of mammals studied, we obtained an isolate of the parasite genotyped as TcII by amplification of the cytochrome oxidase II gene by PCR, followed by restriction fragment length polymorphism with Alu I, and confirmed by PCR of rDNA 24Sα. This is the first record of the encounter in wild mammals of Trypanosoma DNA (in A. lituratus ) and T. cruzi DTU TcII (in D. albiventris ) in the state of Paraná.

Objective: Despite malaria epidemiology has been extensively studied in primates, few studies were conducted in ungulates. After half a century without descriptions of Plasmodium spp. in deer since its first identification, recent research has rediscovered Plasmodium on ungulates in Africa, Asia, North America and South America, including Central Brazil. Here, a captive herd was evaluated in southern Brazil using light microscopy and PCR. DNA samples were tested for fragment amplification of two Plasmodium spp. genes: mitochondrial cytochrome b and small subunit ribosomal RNA., Results: All analyses were negative. However, the tests were performed on samples that were collected at a single time point, and parasitemia may fluctuate over the parasite's life cycle. Thus, the possibility of occult infection cannot be ruled out. Despite the negative results of all of the methods applied, it cannot be categorically stated that these animals are free from Plasmodium sp. infection. Further monitoring and/or multiple sequential sampling may improve the success rate of detecting parasites. Moreover, although this survey of Plasmodium represents the first molecular study on ungulate malaria parasites from Southern Brazil, further analysis of samples from different ungulate species is important for characterizing the epidemiology of Plasmodium of these mammals in this region.

Introduction: Determining the genetic similarities among Trypanosoma cruzi populations isolated from different hosts and vectors is very important to clarify the epidemiology of Chagas disease., Methods: An epidemiological study was conducted in a Brazilian endemic area for Chagas disease, including 76 chronic chagasic individuals (96.1% with an indeterminate form; 46.1% with positive hemoculture)., Results: T. cruzi I (TcI) was isolated from one child and TcII was found in the remaining (97.1%) subjects. Low-stringency single-specific-primer-polymerase chain reaction (LSSP-PCR) showed high heterogeneity among TcII populations (46% of shared bands); however, high similarities (80-100%) among pairs of mothers/children, siblings, or cousins were detected., Conclusions: LSSP-PCR showed potential for identifying similar parasite populations among individuals with close kinship in epidemiological studies of Chagas disease.

Avian malaria is a mosquito-borne disease caused by Plasmodium spp. Avian plasmodia are recognized conservation-threatening pathogens due to their potential to cause severe epizootics when introduced to bird populations with which they did not co-evolve. Penguins are considered particularly susceptible, as outbreaks in captive populations will often lead to high morbidity and rapid mortality. We used a multidisciplinary approach to investigate an outbreak of avian malaria in 28 Magellanic penguins (Spheniscus magellanicus) at a rehabilitation center during summer 2009 in Florianópolis, Brazil. Hemosporidian infections were identified by microscopic and molecular characterization in 64% (18/28) of the penguins, including Plasmodium (Haemamoeba) tejerai, Plasmodium (Huffia) elongatum, a Plasmodium (Haemamoeba) sp. lineage closely related to Plasmodium cathemerium, and a Haemoproteus (Parahaemoproteus) sp. lineage closely related to Haemoproteus syrnii. P. tejerai played a predominant role in the studied outbreak and was identified in 72% (13/18) of the hemosporidian-infected penguins, and in 89% (8/9) of the penguins that died, suggesting that this is a highly pathogenic parasite for penguins; a detailed description of tissue meronts and lesions is provided. Mixed infections were identified in three penguins, and involved P. elongatum and either P. tejerai or P. (Haemamoeba) sp. that were compatible with P. tejerai but could not be confirmed. In total, 32% (9/28) penguins died over the course of 16 days despite oral treatment with chloroquine followed by sulfadiazine-trimethoprim. Hemosporidian infections were considered likely to have occurred during rehabilitation, probably from mosquitoes infected while feeding on local native birds, whereas penguin-mosquito-penguin transmission may have played a role in later stages of the outbreak. Considering the seasonality of the infection, rehabilitation centers would benefit from narrowing their efforts to prevent avian malaria outbreaks to the penguins that are maintained throughout summer.

Background: Rhodnius prolixus is an obligate haematophagous insect and one of the most important vectors of Trypanosoma cruzi, the causative agent of Chagas disease in the Americas. T. cruzi is a highly variable parasite which is not transmitted in the same efficiency by the different triatomine vectors. Because different T. cruzi genotypes are aetiopathologically divergent, further elucidation of the transmission abilities of different Chagas disease vectors is extremely important., Findings: In the present study, the growth behaviour of two T. cruzi isolates, MDID/BR/1993/C45 (TcI) and TBRA/BR/1999/JCA3 (TcII), sharing the same microhabitat (intestinal tract) in single and mixed infections, was examined. The distribution patterns and parasite population densities were evaluated at 7, 14 and 21 days after feeding (daf) by quantification of parasites using Neubauer haemocytometric measurements and mini-exon PCR to identify TcI and TcII subpopulations. Parasitic colonization in the small intestine was more successful in the mixed infection model than the single infection models at 21 daf. In the rectal lumen and wall, the growth behaviour of the mixed infection was similar to that of the TcI group, although the total parasite number was lower. In the TcII group, no metacyclic trypomastigote forms were found. PCR analysis of the contents of each dissected region showed different genotype fractions in the mixed infection model, in which TcI seemed to be the predominant isolate., Conclusion: The different growth behaviour of the TcI and TcII isolates in single and mixed infection models demonstrated that possibly an intraspecific factor modulates parasitic development in the intestine of R. prolixus.

Giardia infections in captive nonhuman primates (NHP) housed at a Brazilian zoo were investigated in order to address their zoonotic potential. Fresh fecal samples were collected from the floors of 22 enclosures where 47 primates of 18 different species were housed. The diagnosis of intestinal parasites after concentration by sedimentation and flotation methods revealed the following parasites and their frequencies: Giardia (18%); Entamoeba spp. (18%); Endolimax nana (4.5%); Iodamoeba spp. (4.5%); Oxyurid (4.5%) and Strongylid (4.5%). Genomic DNA extracted from all samples was processed by PCR methods in order to amplify fragments of gdh and tpi genes of Giardia. Amplicons were obtained from samples of Ateles belzebuth, Alouatta caraya, Alouatta fusca and Alouatta seniculus. Clear sequences were only obtained for the isolates from Ateles belzebuth (BA1), Alouatta fusca (BA2) and Alouatta caraya (BA3). According to the phenetic analyses of these sequences, all were classified as assemblage A. For the tpi gene, all three isolates were grouped into sub-assemblage AII (BA1, BA2 and BA3) whereas for the gdh gene, only BA3 was sub-assemblage AII, and the BA1 and BA2 were sub-assemblage AI. Considering the zoonotic potential of the assemblage A, and that the animals of the present study show no clinical signs of infection, the data obtained here stresses that regular coproparasitological surveys are necessary to implement preventive measures and safeguard the health of the captive animals, of their caretakers and of people visiting the zoological gardens.

This study investigated the genetic characteristics of Leishmania infantum samples from São Paulo (SP) State, Brazil in order to collaborate with information about the possible origins of the parasites, as well as, the introduction and spread of visceral leishmaniasis in this Brazilian State. Multilocus microsatellite typing (MLMT) was performed using a set of 17 microsatellite markers. DNA was extracted from 250 samples collected from dogs diagnosed with visceral leishmaniasis and 112 (45%) were genotyped: 67 from the northwest region (NWSP), and 29 from the southeast region (SESP) of SP. The results were correlated with other 16 samples from Mato Grosso do Sul State (MS) (which borders NWSP). Although, a small portion of samples was genotyped, it was possible to genotype multiple loci using small amounts of Leishmania DNA extracted directly from dog tissues. Despite the fact that MLMT analysis defined 33 different genotypes, a low polymorphism was detected within the parasites studied with 10 polymorphic loci. There are two main genetic clusters circulating in SP with strong genetic differentiation, one (POP-A) is composed by samples from SESP and NWSP and presented a weak signal of geographical substructure. The other, belongs to the same cluster found in the state of MS (POP-B), which was the main one. The majority (93.75%) of MS parasite genotypes belonged to POP-B, with just one sample (6.25%) grouped in POP-A. POP-B also comprised 10.34% of SESP and 26.87% of NWSP samples. Besides one sample from MS, POP-A is composed by 73.13% of NWSP and 89.66% of SESP samples. The MLMT analysis supported the idea of canine visceral leishmaniasis being introduced in the Northwest region of SP State by the traffic of humans and dogs from MS. In the southeast region of SP occurred an introduction of a new L. infantum genetic cluster. Probably the transmission was spread by traffic of infected dogs from other Brazilian regions, or by introduction of imported dogs from other countries. All these data together contributed to the detection of the genetic profile of L. infantum population in SP State., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Objective: To investigate risk factors associated with the acquisition of antibodies against Plasmodium vivax Duffy binding protein (PvDBP) - a leading malaria vaccine candidate - in a well-consolidated agricultural settlement of the Brazilian Amazon Region and to determine the sequence diversity of the PvDBP ligand domain (DBP(II)) within the local malaria parasite population., Methods: Demographic, epidemiological and clinical data were collected from 541 volunteers using a structured questionnaire. Malaria parasites were detected by conventional microscopy and PCR, and blood collection was used for antibody assays and molecular characterisation of DBP(II)., Results: The frequency of malaria infection was 7% (6% for P. vivax and 1% for P. falciparum), with malaria cases clustered near mosquito breeding sites. Nearly 50% of settlers had anti-PvDBP IgG antibodies, as detected by enzyme-linked immunosorbent assay (ELISA) with subject's age being the only strong predictor of seropositivity to PvDBP. Unexpectedly, low levels of DBP(II) diversity were found within the local malaria parasites, suggesting the existence of low gene flow between P. vivax populations, probably due to the relative isolation of the studied settlement., Conclusion: The recognition of PvDBP by a significant proportion of the community, associated with low levels of DBP(II) diversity among local P. vivax, reinforces the variety of malaria transmission patterns in communities from frontier settlements. Such studies should provide baseline information for antimalarial vaccines now in development., (© 2012 Blackwell Publishing Ltd.)

We characterized four Brazilian trypanosomes isolated from domestic rats and three from captive non-human primates that were morphologically similar to T. lewisi, a considered non-pathogenic species restricted to rodents and transmitted by fleas, despite its potential pathogenicity for infants. These isolates were identified as T. lewisi by barcoding using V7V8 SSU rDNA sequences. In inferred phylogenetic trees, all isolates clustered tightly with reference T. lewisi and T. lewisi-like trypanosomes from Europe, Asia and Africa and despite their high sequence conservation formed a homogeneous clade separate from other species of the subgenus T. (Herpetosoma). With the aim of clearly resolving the relationships between the Brazilian isolates from domestic rats and primates, we compared sequences from more polymorphic ITS rDNA. Results corroborated that isolates from Brazilian rats and monkeys were indeed of the same species and quite close to T. lewisi isolates of humans and rats from different geographical regions. Morphology of the monkey isolates and their behaviour in culture and in experimentally infected rats were also compatible with T. lewisi. However, infection with T. lewisi is rare among monkeys. We have examined more than 200 free-ranging and 160 captive monkeys and found only three infected individuals among the monkeys held in captivity. The findings of this work suggest that proximity of monkeys and infected rats and their exposure to infected fleas may be responsible for the host switching of T. lewisi from their natural rodent species to primates. This and previous studies reporting T. lewisi in humans suggest that this trypanosome can cause sporadic and opportunistic flea-borne infection in primates., (Copyright (c) 2010 Elsevier B.V. All rights reserved.)

The stout razor clam Tagelus plebeius (Bivalvia, Psammobiidae) has a wide geographic distribution range, including the Brazilian coasts from the northeast (Alagoas) to the south (Santa Catarina). In March 2008, an episode of mass T. plebeius mortality (70%) occurred in an intertidal bed at The Pontal da Daniela, State of Santa Catarina, Brazil. We report here high prevalences (to 100%) of the trematode parasite Parvatrema sp. Cable, 1953 (Digenea, Gymnophallidae) infecting T. plebeius at high intensities. We describe the gymnophalid, echinostomatid and unidentified metacercariae parasites infecting the clam and the host reactions elicited by them. The use of special diagnostic techniques such as Ray's fluid thioglycollate medium (RFTM) and PCR assays to detect Perkinsus sp. pathogens, hemolymph cytology, and histopathological examinations did not show Perkinsus sp. infections, microcell infections, or neoplastic conditions. However, neither infections or pathology caused by trematode parasites; nor any other pathological condition could be uniquely correlated with the mortality event. A coincident flash flood might have contributed to cause the mortality episode. This is the first report of the Parvatrema sp. metacercariae larvae infecting the stout razor clam T. plebeius from Brazil.

Leishmania infected of Lutzomyia spp. are rare in endemic areas. We tested the hypothesis that there is clustering of infected vectors by combining pinpoint capture with sensitive L. braziliensis kDNA minicircle specific PCR/dot blot in an endemic area in the State of Bahia. Thirty out of 335 samples (10 to 20 sand flies/sample; total of 4,027 female sand flies) were positive by PCR analysis and dot blot leading to a underestimated overall rate of 0.4% positive phlebotomines. However, 83.3% of the positive samples were contributed by a single sector out of four sectors of the whole studied area. This resulted in a rate of 1.5% Leishmania positive phlebotomines for this sector, far above rates of other sectors. Incidence of American cutaneous leishmaniasis cases for this sector was about twice that for other sectors. Our results show that there is a non-homogeneous distribution of Leishmania-infected vectors. Such a clustering may have implications in control strategies against leishmaniasis, and reinforces the necessity of understanding the ecological and geographical factors involved in leishmanial transmission.

Seventy-nine adults with Plasmodium vivax malaria, from the Porto Velho area of Rond nia (western Amazon region, Brazil), gave informed consent to participate in a blind, clinical study of two regimens of treatment with chloroquine (CQ) and primaquine. The effectiveness of the 'classical' regimen (CQ for 3 days, followed by primaquine for 14 days) was compared with that of a 'short' regimen in which the two drugs were given simultaneously for 5 days. There were no cases of recrudescence indicative of CQ resistance (i.e. within 30 days of the first treatment dose) among the 73 patients who each completed a full, supervised course of treatment. However, 10 cases of apparent relapse were observed (all > 60 days after first treatment dose), representing 6.5% (2/31) of the patients who completed 60 days of follow-up after the classical treatment and 26.7% (8/30) of the short-regimen patients who completed the same period of follow-up. PCR-based comparison of parasitic DNA collected pre- and post-treatment was successful for eight of the 10 cases of apparent relapse and indicated that two such cases, both given the short regimen of treatment, were, in fact, probable cases of re-infection rather than of relapse. The results indicate that the classical schedule of treatment with chloroquine and primaquine was more effective at preventing relapses than the short regimen. However, since prolonged treatment with primaquine often produces side-effects that are severe enough to reduce compliance, the short schedule could be a useful alternative for malaria control in endemic areas of the Amazon region.