48 research outputs found
Leishmaniose cutânea no nordeste do Brasil: uma avaliação crÃtica dos estudos realizados no Estado de Pernambuco
American cutaneous leishmaniasis (ACL) is a complex disease with clinical and epidemiological features that may vary from region to region. In fact, at least seven different Leishmania species, including Leishmania (Viannia) braziliensis, Leishmania (Viannia) guyanensis, Leishmania (Viannia) lainsoni, Leishmania (Viannia) naiffi, Leishmania (Viannia) shawi, Leishmania (Viannia) lindenbergi, and Leishmania (Leishmania) amazonensis, have been implicated in the etiology of ACL in Brazil, and numerous phlebotomine sandfly species of the genus Lutzomyia have been regarded as putative or proven vectors. Because ACL is a focal disease, understanding the disease dynamics at the local level is essential for the implementation of more effective control measures. The present paper is a narrative review about the ACL epidemiology in Pernambuco, northeastern Brazil. Furthermore, the need for more effective diagnosis, treatment, control and prevention strategies for the affected populations is highlighted. This paper will provide researchers with a critical appraisal of ACL in Pernambuco. Hopefully, it will also be helpful for public health authorities to improve current control strategies against ACL at the state and country levels
Development and evaluation of system based on real-time in PCR for the diagnosis of Leishmania (Leishmania) infantum infection in dogs
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Previous issue date: 2008Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Recife, PE, Brasil.O diagnóstico precoce da leishmaniose visceral (LV) é importante para evitar danos severos que podem levar o paciente à morte. Neste contexto, os métodos moleculares vêm sendo desenvolvidos com destaque para a tecnologia da reação em cadeia da polimerase (PCR). Recentemente, a PCR apresentou um significativo avanço em sua tecnologia; é a PCR quantitativa em tempo real (qPCR). Objetivouse desenvolver e avaliar um sistema baseado em qPCR para o diagnóstico da infecção por Leishmania infantum em cães, bem como efetuar uma análise comparativa com a PCR convencional utilizada no Serviço de Referência em Leishmanioses de Pernambuco. Com base na seqüência NCBI Z35273.1 de L. infantum disponÃvel no BLAST-NCBI foram desenhados primers especÃficos para o complexo L. donovani. A combinação dos primers gerou sistemas de detecção, sendo o sistema Linf 1 B o mais promissor. A curva-padrão foi gerada resultando em limite de detecção de 10 fg de DNA genômico de L. infantum (7x10-2 parasitas), e = 0.9417, R2= 0.931 e slope= -3.47. O sistema desenvolvido foi avaliado em sangue de cães positivos e negativos para leishmaniose visceral canina, apresentando sensibilidade de 100 por cento e especificidade de 83,33 por cento. A análise comparativa com o PCR convencional mostrou que, utilizando-se amostras de sangue, o qPCR é mais sensÃvel (sensibilidade PCR= 23,8 por cento, qPCR= 100 por cento). Em relação à especificidade, apesar da PCR convencional ter apresentado valor de 100 por cento, as análises por meio dos intervalos de confiança e o teste 2? mostraram que os dois testes (PCR convencional e qPCR) são equivalentes. Desta forma, conclui-se que os resultados obtidos para o sistema de qPCR, em amostra de sangue de cães e, a análise comparativa com a PCR convencional (RV1/RV2), sugerem sua utilização nas rotinas de diagnóstico da infecção por L. infantu
Clinical and hematological findings in Leishmania braziliensis-infected dogs from Pernambuco, Brazil Achados clÃnicos e hematológicos em cães infectados por Leishmania braziliensis de Pernambuco, Brasil
Abstract Canine cutaneous leishmaniasis by Leishmania braziliensis is a neglected, but widespread disease of dogs in South America. This paper describes clinical and hematological alterations in 17 L. braziliensis-infected dogs from Brazil. The most common hematological findings were thrombocytopenia (82.4%), anemia (70.6%), low packed cell volume (52.9%) and eosinophilia (41.2%). Twelve (70.6%) dogs displayed at least one evident physical alteration; 11 dogs (64.7%) presented skin lesions, four (23.5%) had weight loss and two (11.8%) onychogryphosis. L. braziliensis-infected dogs present clinical and hematological signs often observed in dogs infected by other pathogens. This indicates that veterinarians and public health workers should not consider the presence of non-specific clinical signs as diagnostic criteria for visceral leishmaniasis in dogs living endemic areas to avoid misdiagnosis and subsequent elimination of dogs infected by L. braziliensis. Keywords: Leishmania braziliensis, dogs, Pernambuco, Brazil. Resumo A leishmaniose cutânea canina causada por Leishmania braziliensis é uma doença negligenciada, mas disseminada entre cães na America do Sul. Este artigo descreve alterações clÃnicas e hematológicas em 17 cães infectados por L. braziliensis do Brasil. As alterações hematológicas mais comuns foram trombocitopenia (82,4%), anemia (70,6%), baixo valor de hematócrito (52,9%) e eosinofilia (41,2%). Doze (70,6%) cães apresentaram pelo menos uma alteração fÃsica; 11 (64,7%) apresentaram lesões cutâneas, quatro (23,5%) perda de peso e dois (11,8%) onicogrifose. Cães infectados por L. braziliensis apresentaram alterações clÃnicas e hematológicas inespecÃficas que são comumente observadas em cães infectados por outros patógenos. Isso indica que veterinários e profissionais de saúde pública não deveriam considerar a presença de tais sinais clÃnicos como critério de diagnóstico para leishmaniose visceral em cães, em áreas endêmicas, no intuito de evitar um diagnóstico equivocado e a subsequente eliminação de cães infectados por L. braziliensis
Clinical and hematological findings in Leishmania braziliensis-infected dogs from Pernambuco, Brazil Achados clÃnicos e hematológicos em cães infectados por Leishmania braziliensis de Pernambuco, Brasil
Canine cutaneous leishmaniasis by Leishmania braziliensis is a neglected, but widespread disease of dogs in South America. This paper describes clinical and hematological alterations in 17 L. braziliensis-infected dogs from Brazil. The most common hematological findings were thrombocytopenia (82.4%), anemia (70.6%), low packed cell volume (52.9%) and eosinophilia (41.2%). Twelve (70.6%) dogs displayed at least one evident physical alteration; 11 dogs (64.7%) presented skin lesions, four (23.5%) had weight loss and two (11.8%) onychogryphosis. L. braziliensis-infected dogs present clinical and hematological signs often observed in dogs infected by other pathogens. This indicates that veterinarians and public health workers should not consider the presence of non-specific clinical signs as diagnostic criteria for visceral leishmaniasis in dogs living endemic areas to avoid misdiagnosis and subsequent elimination of dogs infected by L. braziliensis.A leishmaniose cutânea canina causada por Leishmania braziliensis é uma doença negligenciada, mas disseminada entre cães na America do Sul. Este artigo descreve alterações clÃnicas e hematológicas em 17 cães infectados por L. braziliensis do Brasil. As alterações hematológicas mais comuns foram trombocitopenia (82,4%), anemia (70,6%), baixo valor de hematócrito (52,9%) e eosinofilia (41,2%). Doze (70,6%) cães apresentaram pelo menos uma alteração fÃsica; 11 (64,7%) apresentaram lesões cutâneas, quatro (23,5%) perda de peso e dois (11,8%) onicogrifose. Cães infectados por L. braziliensis apresentaram alterações clÃnicas e hematológicas inespecÃficas que são comumente observadas em cães infectados por outros patógenos. Isso indica que veterinários e profissionais de saúde pública não deveriam considerar a presença de tais sinais clÃnicos como critério de diagnóstico para leishmaniose visceral em cães, em áreas endêmicas, no intuito de evitar um diagnóstico equivocado e a subsequente eliminação de cães infectados por L. braziliensis
Clinical and hematological findings in Leishmania braziliensis-infected dogs from Pernambuco, Brazil
Canine cutaneous leishmaniasis by Leishmania braziliensis is a neglected, but widespread disease of dogs in South America. This paper describes clinical and hematological alterations in 17 L. braziliensis-infected dogs from Brazil. The most common hematological findings were thrombocytopenia (82.4%), anemia (70.6%), low packed cell volume (52.9%) and eosinophilia (41.2%). Twelve (70.6%) dogs displayed at least one evident physical alteration; 11 dogs (64.7%) presented skin lesions, four (23.5%) had weight loss and two (11.8%) onychogryphosis. L. braziliensis-infected dogs present clinical and hematological signs often observed in dogs infected by other pathogens. This indicates that veterinarians and public health workers should not consider the presence of non-specific clinical signs as diagnostic criteria for visceral leishmaniasis in dogs living endemic areas to avoid misdiagnosis and subsequent elimination of dogs infected by L. braziliensis
Cutaneous leishmaniasis in northeastern Brazil: a critical appraisal of studies conducted in State of Pernambuco Leishmaniose cutânea no nordeste do Brasil: uma avaliação crÃtica dos estudos realizados no Estado de Pernambuco
American cutaneous leishmaniasis (ACL) is a complex disease with clinical and epidemiological features that may vary from region to region. In fact, at least seven different Leishmania species, including Leishmania (Viannia) braziliensis, Leishmania (Viannia) guyanensis, Leishmania (Viannia) lainsoni, Leishmania (Viannia) naiffi, Leishmania (Viannia) shawi, Leishmania (Viannia) lindenbergi, and Leishmania (Leishmania) amazonensis, have been implicated in the etiology of ACL in Brazil, and numerous phlebotomine sandfly species of the genus Lutzomyia have been regarded as putative or proven vectors. Because ACL is a focal disease, understanding the disease dynamics at the local level is essential for the implementation of more effective control measures. The present paper is a narrative review about the ACL epidemiology in Pernambuco, northeastern Brazil. Furthermore, the need for more effective diagnosis, treatment, control and prevention strategies for the affected populations is highlighted. This paper will provide researchers with a critical appraisal of ACL in Pernambuco. Hopefully, it will also be helpful for public health authorities to improve current control strategies against ACL at the state and country levels.A leishmaniose cutânea americana (LCA) é uma doença complexa com caracterÃsticas clÃnicas e epidemiológicas que podem variar de região para região. De fato, pelo menos, sete diferentes espécies de Leishmania, incluindo Leishmania (Viannia) braziliensis, Leishmania (Viannia) guyanensis, Leishmania (Viannia) lainsoni, Leishmania (Viannia) naiffi, Leishmania (Viannia) shawi, Leishmania (Viannia) lindenbergi e Leishmania (Leishmania) amazonensis, têm sido incriminadas na etiologia da LCA no Brasil, e numerosas espécies de flebotomÃneos do gênero Lutzomyia, foram considerados vetores suspeitos ou comprovados. Devido ao seu caráter focal, a compreensão da dinâmica da LCA a nÃvel local é imprescindÃvel para a implementação de medidas de controle eficazes. Este trabalho consiste de uma revisão narrativa sobre a epidemiologia da LCA em Pernambuco, nordeste do Brasil. Além disso, se enfatiza a necessidade de maior efetividade no diagnóstico, tratamento, controle e estratégias de prevenção para as populações afetadas. Este artigo fornecerá aos pesquisadores uma avaliação crÃtica da LCA em Pernambuco. Espera-se também contribuir com as autoridades de saúde pública no aprimoramento das estratégias atuais de controle da LCA nos nÃveis estaduais e nacional
Transovarial passage of Leishmania infantum kDNA in artificially infected Rhipicephalus sanguineus
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Previous issue date: 2010Università degli Studi di Bari. Dipartimento di Sanità Pubblica e Zootecnia. Valenzano, BA, Italy.Universidade de São Paulo. Departamento de Medicina Veterinária Preventiva e Saúde Animal. São Paulo, SP, Brazil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Imunologia. Recife, PE, Brasil.Università degli Studi di Bari. Dipartimento di Sanità Pubblica e Zootecnia. Valenzano, BA, Italy.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Imunologia. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Imunologia. Recife, PE, Brasil.Phlebotomine sand flies are the only proven biological vectors of Leishmania parasites. However, Rhipicephalus sanguineus ticks have long been suspected to transmit Leishmania infantum in studies carried out in laboratory and natural conditions. In the present study, 5 microl of L. infantum promastigotes (1x10(6) cells per ml) was injected into the hemocel through the coxa I of four engorged females (F1, F2, F3 and F4). Control ticks (F5 and F6) were injected with sterile phosphate-buffered saline (PBS) using the same procedure. Then, these females, their eggs, and the originated larvae were tested by real time polymerase chain reaction (real-time PCR) for the presence of L. infantum kinetoplast DNA (kDNA). Females and eggs were tested after the end of the oviposition period (about 5 weeks post-inoculation) whereas larvae were tested about 4 months after the inoculation of females. All artificially infected females were positive for L. infantum kDNA. In addition, two pools of eggs (one from F2 and other from F4) and four pools of larvae (one from each F1 and F4 and two from F2) were positive for L. infantum kDNA. These results showed, for the first time, the transovarial passage of L. infantum kDNA in R. sanguineus ticks, thus suggesting that the transovarial transmission of L. infantum protozoa in ticks is worth to be investigated
Analysis of the IGS rRNA Region and Applicability for Leishmania (V.) braziliensis Characterization
The causative species is an important factor influencing the evolution of American cutaneous leishmaniasis (ACL). Due to its wide distribution in endemic areas, Leishmania (V.) braziliensis is considered one of the most important species in circulation in Brazil. Molecular targets derived from ribosomal RNA (rRNA) were used in studies to identify Leishmania spp.; however, the Intergenic Spacer (IGS) region has not yet been explored in parasite species differentiation. Besides, there is a shortage of sequences deposited in public repositories for this region. Thus, it was proposed to analyze and provide sequences of the IGS rRNA region from different Leishmania spp. and to evaluate their potential as biomarkers to characterize L. braziliensis. A set of primers was designed for complete amplification of the IGS rRNA region of Leishmania spp. PCR products were submitted to Sanger sequencing. The sequences obtained were aligned and analyzed for size and similarity, as well as deposited in GenBank. Characteristics of the repetitive elements (IGSRE) present in the IGS rRNA were also verified. In addition, a set of primers for L. braziliensis identification for qPCR was developed and optimized. Sensitivity (S), specificity (σ), and efficiency (ε) tests were applied. It was found that the mean size for the IGS rRNA region is 3 kb, and the similarity analysis of the sequences obtained demonstrated high conservation among the species. It was observed that the size for the IGSRE repetitive region varies between 61 and 71 bp, and there is a high identity between some species. Fifteen sequences generated for the IGS rRNA partial region of nine different species were deposited in GenBank so far. The specific primer system for L. braziliensis showed S=10 fg, ε=98.08%, and logσ=103 for Leishmania naiffi; logσ=104 for Leishmania guyanensis; and logσ=105 for Leishmania shawi. This protocol system can be used for diagnosis, identification, and quantification of a patient’s parasite load, aiding in the direction of a more appropriate therapeutic management to the cases of infection by this etiological agent. Besides that, the unpublished sequences deposited in databases can be used for multiple analyses in different contexts
Identification of phlebotomine sand fly blood meals by real-time PCR
Background: Phlebotomine sand flies are blood-feeding insects of great medical and veterinary significance acting as vectors of Leishmania parasites. Studying the blood-feeding pattern of these insects may help in the understanding of their interactions with potential reservoir hosts of Leishmania parasites. In this study, we developed real time PCR assays for the identification of sand fly blood meal. Methods: Six pairs of primers were designed based on cytochrome b gene sequences available in GenBank of the following potential hosts: dog, cat, horse, chicken, black rat, and human. Firstly, SYBR Green-based real time PCR assays were conducted using a standard curve with eight different concentrations (i.e., 10 ng, 1 ng, 100 pg, 10 pg, 1 pg, 100 fg, 10 fg and 1 fg per 2 μl) of DNA samples extracted from EDTA blood samples from each target animal. Then, DNA samples extracted from field-collected engorged female sand flies belonging to three species (i.e., Lutzomyia longipalpis, L. migonei and L. lenti) were tested by the protocols standardized herein. Additionally, female sand flies were experimentally fed on a black rat (Rattus rattus) and used for evaluating the time course of the detection of the protocol targeting this species. Results: The protocols performed well with detection limits of 10 pg to 100 fg. Field-collected female sand flies were fed on blood from humans (73%), chickens (23%), dogs (22%), horses (15%), black rats (11%) and cats (2%). Interestingly, 76.1% of the L. longipalpis females were positive for human blood. In total, 48% of the tested females were fed on single sources, 31% on two and 12% on three. The analysis of the time course showed that the real time PCR protocol targeting the black rat DNA was able to detect small amounts of the host DNA up to 5 days after the blood meal. Conclusions: The real time PCR assays standardized herein successfully detected small amounts of host DNA in female sand flies fed on different vertebrate species and, specifically for the black rats, up to 5 days after the blood meal. These assays represent promising tools for the identification of blood meal in field-collected female sand flies