High Trypanosoma spp. diversity is maintained by bats and triatomines in Espírito Santo state, Brazil

The aim of this study was to reevaluate the ecology of an area in the Atlantic Forest, southeast Brazil, where Chagas disease (CD) has been found to occur. In a previous study, immediately after the occurrence of a CD case, we did not observe any sylvatic small mammals or dogs with Trypanosoma cruzi cruzi infections, but Triatoma vitticeps presented high T. c. cruzi infection rates. In this study, we investigated bats together with non-volant mammals, dogs, and triatomines to explore other possible T. c. cruzi reservoirs/hosts in the area. Seventy-three non-volant mammals and 186 bats were captured at three sites within the Guarapari municipality, Espírito Santo state. Rio da Prata and Amarelos sites exhibited greater richness in terms of non-volant mammals and bats species, respectively. The marsupial Metachirus nudicaudatus, the rodent Trinomys paratus, and the bats Artibeus lituratus and Carollia perspicillata were the most frequently captured species. As determined by positive hemocultures, only two non-volant mammals were found to be infected by Trypanosoma species: Monodelphis americana, which was infected by T. cascavelli, T. dionisii and Trypanosoma sp., and Callithrix geoffroyi, which was infected by T. minasense. Bats presented T. c. cruzi TcI and TcIII/V, T. c. marinkellei, T. dionisii, T. rangeli B and D, and Trypanosoma sp. infections. Seven dogs were infected with T. cruzi based only on serological exams. The triatomines T. vitticeps and Panstrongylus geniculatus were found to be infected by trypanosomes via microscopy. According to molecular characterization, T. vitticeps specimens were infected with T. c. cruzi TcI, TcII, TcIII/V, and TcIV, T. c. marinkellei and T. dionisii. We observed high trypanosome diversity in a small and fragmented region of the Atlantic Forest. This diversity was primarily maintained by bats and T. vitticeps. Our findings show that the host specificity of the Trypanosoma genus should be thoroughly reviewed. In addition, our data show that CD cases can occur without an enzootic cycle near residential areas

Ecological scenario and Trypanosoma cruzi DTU characterization of a fatal acute Chagas disease case transmitted orally (Espírito Santo state, Brazil)

Submitted by Sandra Infurna ([email protected]) on 2016-12-09T13:37:11Z No. of bitstreams: 1 samanta_xavier_etal_IOC_2016.pdf: 1232916 bytes, checksum: cb48d61d779f9c21eabb66900de216bd (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2016-12-09T13:49:04Z (GMT) No. of bitstreams: 1 samanta_xavier_etal_IOC_2016.pdf: 1232916 bytes, checksum: cb48d61d779f9c21eabb66900de216bd (MD5)Made available in DSpace on 2016-12-09T13:49:04Z (GMT). No. of bitstreams: 1 samanta_xavier_etal_IOC_2016.pdf: 1232916 bytes, checksum: cb48d61d779f9c21eabb66900de216bd (MD5) Previous issue date: 2016Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia de Tripanossomatídeos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia de Tripanossomatídeos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia de Tripanossomatídeos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia de Tripanossomatídeos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia e Parasitologia de Mamíferos Silvestres Reservatórios. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia de Tripanossomatídeos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia de Tripanossomatídeos. Rio de Janeiro, RJ, Brasil.Trypanosoma cruzi infection via oral route results in outbreaks or cases of acute Chagas disease (ACD) in different Brazilian regions and poses a novel epidemiological scenario. In the Espírito Santo state (southeastern Brazil), a fatal case of a patient with ACD led us to investigate the enzootic scenario to avoid the development of new cases. At the studied locality, Triatoma vitticeps exhibited high T. cruzi infection rates and frequently invaded residences

Focal persistence of soil-transmitted helminthiases in impoverished areas in the State of Piaui, Northeastern Brazil

This study aims to describe the prevalence, distribution, and factors associated with soil-transmitted helminthiases (STHs) in rural localities in Piaui, Brazil. Two cross-sectional surveys (n=605 subjects; 172 families) were carried out in order to obtain socio-demographic, anthropometric, spatial and parasitological data. Parasites were evaluated using Kato-Katz and centrifugal sedimentation techniques. Eggs were measured to assess infection with zoonotic Strongylida parasites. Kernel maps were constructed with Q-GIS. The prevalence of hookworm infection was 12.4% (75/605). Other helminthes found were Trichuris trichiura (n=1; 0.2%) and Hymenolepis nana (n=1; 0.2%). The hookworm positivity rate was significantly lower among subjects who had used albendazole when compared with individuals who had not used anthelmintics or had used antiprotozoal drugs in the last 6 months (8/134 [6.0%] vs. 59/415 [14.2%]; p=0.009). A total of 39/172 (22.7%) families had at least one infected member. The association between the number of dwellers and hookworm positivity in the family was present in a logistic regression multivariate model. Assessment of worm burdens showed 92.2% light, 6.2% moderate, and 1.6% heavy infections. Hookworm eggs (n=34) measured 57.2 - 75.4 µm in length and 36.4 - 44.2 µm in width (mean ± SD = 65.86 ± 4.66 µm L and 40.05 ± 1.99 µm W), commensurate with human hookworms. Hotspots suggest that transmission has a focal pattern. STHs persist in impoverished rural areas in Northeastern Brazil where currently available control strategies (mass drug administration) apparently do not allow the elimination of the infection

Performance of recombinant chimeric proteins in the serological diagnosis of Trypanosoma cruzi infection in dogs.

Background: Dogs are considered sentinels in areas of Trypanosoma cruzi transmission risk to humans. ELISA is generally the method of choice for diagnosing T. cruzi exposure in dogs, but its performance substantially depends on the antigenic matrix employed. In previous studies, our group has developed four chimeric antigens (IBMP-8.1, 8.2, 8.3, and 8.4) and evaluated their potential for diagnosing T. cruzi exposure in humans. For human sera, these chimeric antigens presented superior diagnostic performances as compared to commercial tests available in Brazil, Spain, and Argentina. Therefore, in this study we have evaluated the potential of these antigenic proteins for detection of anti-T. cruzi IgG antibodies in dog sera. Methodology/Principal findings: The IBMP-ELISA assays were optimized by checkerboard titration. Subsequently, the diagnostic potential was validated through analysis of ROC curves and the performance of the tests was determined using double entry tables. Cross-reactivity was also evaluated for babesiosis, ehrlichiosis, dirofilariosis, anaplasmosis, and visceral leishmaniasis. Best performance was shown by IBMP-8.3 and IBMP-8.4, although all four antigens demonstrated a high diagnostic performance with 46 positive and 149 negative samples tested. IBMP-8.3 demonstrated 100% sensitivity, followed by IBMP-8.4 (96.7?100%), IBMP-8.2 (73.3?87.5%), and IBMP-8.1 (50?100%). The highest specificities were achieved with IBMP-8.2 (100%) and IBMP-8.4 (100%), followed by IBMP-8.3 (96.7?97.5%) and IBMP 8.1 (89.1?100%). Conclusions/Significance: The use of chimeric antigenic matrices in immunoassays for anti-T. cruzi IgG antibody detection in sera of infected dogs was shown to be a promising tool for veterinary diagnosis and epidemiological studies. The chimeric antigens used in this work allowed also to overcome the common hurdles related to serodiagnosis of T. cruzi infection, especially regarding variation of efficiency parameters according to different strains and cross-reactivity with other infectious diseases

Lower Richness of Small Wild Mammal Species and Chagas Disease Risk

A new epidemiological scenario involving the oral transmission of Chagas disease, mainly in the Amazon basin, requires innovative control measures. Geospatial analyses of the Trypanosoma cruzi transmission cycle in the wild mammals have been scarce. We applied interpolation and map algebra methods to evaluate mammalian fauna variables related to small wild mammals and the T. cruzi infection pattern in dogs to identify hotspot areas of transmission. We also evaluated the use of dogs as sentinels of epidemiological risk of Chagas disease. Dogs (n = 649) were examined by two parasitological and three distinct serological assays. kDNA amplification was performed in patent infections, although the infection was mainly sub-patent in dogs. The distribution of T. cruzi infection in dogs was not homogeneous, ranging from 11–89% in different localities. The interpolation method and map algebra were employed to test the associations between the lower richness in mammal species and the risk of exposure of dogs to T. cruzi infection. Geospatial analysis indicated that the reduction of the mammal fauna (richness and abundance) was associated with higher parasitemia in small wild mammals and higher exposure of dogs to infection. A Generalized Linear Model (GLM) demonstrated that species richness and positive hemocultures in wild mammals were associated with T. cruzi infection in dogs. Domestic canine infection rates differed significantly between areas with and without Chagas disease outbreaks (Chi-squared test). Geospatial analysis by interpolation and map algebra methods proved to be a powerful tool in the evaluation of areas of T. cruzi transmission. Dog infection was shown to not only be an efficient indicator of reduction of wild mammalian fauna richness but to also act as a signal for the presence of small wild mammals with high parasitemia. The lower richness of small mammal species is discussed as a risk factor for the re-emergence of Chagas disease

Análise espacial como ferramenta para definição de áreas de risco de emergência de surtos de doença de Chagas aguda no estado do Pará

Made available in DSpace on 2014-03-18T17:17:54Z (GMT). No. of bitstreams: 2 samanta_xavier_ioc_dout_2013.pdf: 10283235 bytes, checksum: 159d2a0096921c251fd5eff48ab974d1 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2013-11-21Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, BrasilAtualmente, os casos de doença de Chagas aguda (DCA) vêm sendo devidos à ingestão de alimento contaminado por formas infectivas do vetor, as formas metacíclicas, e/ou devido à invasão de domicílios por triatomíneos silvestres infectados atraídos pela luz. O novo perfil epidemiológico que a doença de Chagas vem adquirindo, exige um novo olhar e o delineamento de novas ferramentas na definição de medidas de vigilância e controle. O carater recorrente dos surtos de DCA demonstra que ainda não se encontrou medidas de controle efetivas dentro deste novo perfil epidemiológico. Trypanosoma cruzi é um táxon extremamente heterogêneo, inclui 6 genótipos que infectam centenas de espécies de mamíferos e vetores em ciclos de transmissão complexos com características e particularidades locais e temporais. Nosso objetivo foi avaliar a aplicação da análise geoespacial por Lógica Fuzzy, como ferramenta a ser utilizada para reconhecer áreas de risco e fornecer elementos para definição de ações sustentáveis de vigilância epidemiológica na região Amazônica. Para tanto, inicialmente geramos dados referentes à distribuição das DTUs TcIII e TcIV, descritas como típicas da Amazônia, nos biomas brasileiros Observamos que estas DTUs não estão restritas à Amazônia e sim estão amplamente dispersas na natureza tendo sido encontradas infectando seis ordens de mamíferos e distribuidas por cinco biomas. Em seguida geramos dados sobre as variáveis envolvidas no ciclo enzóotico de T. cruzi em três localidades de Abaetetuba/Pará, onde são registrados casos recorrentes de DCA. Este estudo mostrou distintos perfis enzóoticos em cada localidade sendo a infecção de cães por T. cruzi a única característica comum às áreas e sinalizadora da existência de um ciclo silvestre de transmissão em áreas de atividade humana. Esses dados nos levaram a avaliar e validar o uso de cães como sentinela de áreas de risco e a sua detecção como medida de vigilância epidemiológica. Assim, concluímos como ponto de corte para definir uma área de risco epidemiológico e a implementação de programas de sensibilização e educação a soroprevalência de cães deve ser >=30%. O conjunto destes resultados nos permitiu concluir que o ciclo enzóotico de transmissão de T. cruzi é dinâmico, sazonal, multifatorial e modifica-se conforme as condições ambientais naturais e conseqüentemente com a utilização da paisagem pelo homem Com o conjunto de variáveis gerados por nós e obtidos referentes as variáveis entomológicas, ambientais, meteorológicos (CEPETEC) e dados de casos de doença de Chagas (SINAN e SESPA). Após iniciou-se a construção de mapas protótipos de áreas de risco como forma de consolidar critérios de definição de áreas estratégicas de ação e assim prevenir novos casos de DCA. Foi testada a abordagem geoespacial por interpolação e álgebra de mapas como uma ferramenta do diagnóstico ambiental das variáveis reguladoras da transmissão de T. cruzi na natureza. O conjunto das variáveis primárias e secundárias foi tratado pelo método fuzzy de inferência espacial na construção de um modelo de integração. O modelo demonstrou a possibilidade de usar essa nova abordagem na identificação de áreas com diferentes graus de risco, permitindo uma representação contínua e integrada das variáveis envolvidas na transmissão de T. cruzi na naturezaCurrently, cases of Acute Chagas Disease (ACD) have occurred due to the ingestion of food contaminated with infective forms of the vector, me tacyclic forms, and or due to the household invasion by infected triatomines attracte d by artificial light. This new Chagas disease epidemiological profile, requires a new loo k and the design of new tools for the definition of surveillance and control strategies. The character recurrent ACD outbreaks demonstrate that we still haven ́t found effective c ontrol measures for this new epidemiological profile. Trypanosoma cruzi is an extremely heterogeneous taxon that includes 6 genotypes, which infect hundreds of mamm als and vectors species within complex transmission cycles with local and temporal peculiarities.. Our objective was to evaluate the application of geospatial analysis by Fuzzy Logic as a tool to be used to recognize risk areas and provide elements for defin ing sustainable epidemiological surveillance in the Amazon region. Therefore, we in itially generated data regarding the distribution of DTUs TcIII and TcIV, described as t ypical of the Amazon, throughout other Brazilian biomes. We observed that these DTUs are n ot restricted to the Amazon but they are widely dispersed in nature as they were found i nfecting six mammalian orders and were distributed in five biomes. Then, we generated data on the variables involved in the T. cruzi enzootic cycles in three different localities of th e municipality of Abaetetuba, Pará State, where recurrent cases of ACD are registered. This s tudy revealed distinct enzootic profiles in each location. Dogs’ infection by T. cruzi was the only common feature among those areas, thus they signaling the existence of a sylvatic tra nsmission cycle in areas of human activity. These results led us to evaluate and validate the u se of dogs as sentinel of risk areas and its use as a surveillance tool. We defined that dogs’ s eroprevalence of ≥ 30% is the cut off to define an area of epidemiological risk and thus can didate to the implementation of surveillance and education programs. Altogether, th ese results allowed us to conclude that the T. cruzi enzootic transmission cycle is dynamic, seasonal, multifunctional and modifies itself according to the environmental conditions an d, consequently, with the human landscape modification. Putting together the set of variables generated by us, the assembled entomological, environmental and meteorological (CE PETEC) variables, and the data on Chagas disease cases (SINAN and SESPA), we began to build prototypes of risk maps as an approach to consolidate criteria for the demarca tion of strategic areas for the implementation of actions to prevent further ACD ca ses. We tested the geospatial interpolation and map algebra approach as a diagnos tic tool of the environmental variables which regulate the T. cruzi transmission in nature. The set of primary and sec ondary variables were treated by the fuzzy method of spati al inference in order to build an integrated model. This model demonstrated the possibility to u se this novel approach in order to identify areas with different degrees of risk, thus allowing a continuous and integrated representation of the variables involved in the T. cruzi transmission in natur

Trypanosoma cruzi transmission in the wild and its most important reservoir hosts in Brazil

Abstract Trypanosoma cruzi (Kinetoplastea: Trypanosomatidae) infects all tissues of its hosts, which along with humans, include hundreds of mammalian species in the Americas. The epidemiology of T. cruzi has been changing in that currently the majority of the cases and/or outbreaks of Chagas disease occur by the ingestion of comestibles contaminated by T. cruzi metacyclic forms. These cases/outbreaks occur in distinct regional scenarios, mainly in the Amazon biome and are related to the local interaction mode of humans with their surroundings, as well as with the overall local ecological peculiarities. As trypanosomiasis caused by T. cruzi is primarily a zoonosis, understanding the variables that influences its transmission in the wild as well as the role played by the extant fauna in the maintenance of the parasite, is critical in establishing control measures. Here, we present the results of our studies of T. cruzi infection of free ranging wild mammalian fauna in the five biomes of Brazil, a country of continental dimensions. From 1992 up to 2017, we examined a total of 6587 free-ranging non-volant wild mammal specimens. Our studies found that 17% of mammals were seropositive and 8% of all animals displayed positive hemocultures indicative of high parasitemia and, consequently, of infectivity potential. We observed that opossums, mainly Philander spp. and Didelphis spp., the coati Nasua nasua, the capuchin monkey Sapajus libidinosus and the golden lion tamarin Leontopithecus rosalia, were mammal taxa that demonstrated higher rates of positive hemocultures. Additionally, Didelphis spp. demonstrated to be a competent bioaccumulator of TcI diversity. Chiroptera were distinguished for hosting the greatest diversity of species and genotypes of Trypanosoma spp. Additionally the observation of the higher host range of some Trypanosoma spp., shows the need to reassess the ecology of representatives of the taxon. Altogether, our results showed that each locality, may display distinct enzootiological and epidemiological scenarios that must be taken into account when it comes to establishing control and/or clarification campaigns of the local population

Biological and Genetic Heterogeneity in Trypanosoma dionisii Isolates from Hematophagous and Insectivorous Bats

This study describes the morphological, biochemical, and molecular differences among Trypanosoma dionisii isolates from hemocultures of hematophagous (Desmodus rotundus; n = 2) and insectivorous (Lonchorhina aurita; n = 1) bats from the Atlantic Rainforest of Rio de Janeiro, Brazil. Fusiform epimastigotes from the hematophagous isolates were elongated, whereas those of the insectivorous isolate were stumpy, reflected in statistically evident differences in the cell body and flagellum lengths. In the hemocultures, a higher percentage of trypomastigote forms (60%) was observed in the hematophagous bat isolates than that in the isolate from the insectivorous bat (4%), which demonstrated globular morphology. Three molecular DNA regions were analyzed: V7V8 (18S rDNA), glycosomal glyceraldehyde 3-phosphate dehydrogenase gene, and mitochondrial cytochrome b gene. The samples were also subjected to multilocus enzyme electrophoresis and random amplified polymorphic DNA analysis. All isolates were identified as T. dionisii by phylogenetic analysis. These sequences were clustered into two separate subgroups with high bootstrap values according to the feeding habits of the bats from which the parasites were isolated. However, other T. dionisii samples from bats with different feeding habits were found in the same branch. These results support the separation of the three isolates into two subgroups, demonstrating that different subpopulations of T. dionisii circulate among bats