Navegando por Assunto "Leishmaniose visceral"

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Antibodies to Leishmania spp. in domestic felines
(Universidade Federal do Pará, 2015-12) OLIVEIRA, Gabriela Capriogli; PAIZ, Laís Moraes; MENOZZI, Benedito Donizete; LIMA, Michele de Souza; MORAES, Carla Cristina Guimarães de; LANGONI, Helio
Leishmaniasis is a vector-borne zoonotic disease caused by protozoa in the genus Leishmania, typical of rural and peri-urban environments. The causative agent of American visceral leishmaniasis is Leishmania (Leishmania) infantum chagasi and the main insect vector in Brazil is Lutzomyia longipalpis. Dogs (Canis familiaris) are important in the transmission of the disease, as a reservoir closely related to humans and an infection source for phlebotomine vectors. Since 1990, an increasing number of feline leishmaniasis cases have been reported, suggesting that domestic cats (Felis catus) might be involved in the epidemiology of the disease. The present study analyzed the prevalence of anti-Leishmania spp. antibodies in naturally infected domestic cats from various neighborhoods in the municipality of Belém, Pará, Brazil, using the indirect immunofluorescence assay (IFA) and the direct agglutination test (DAT). Among the 443 samples tested, 18 (4.06%) presented positive reactions in the IFA. The observed titers were 40 IU in 4.97% of the samples and 80 IU in 0.90%. In the DAT test, positive results were found in 25 (5.64%) of the samples. The observed titers were also 40 IU (4.97%) and 80 IU (0.68%). The agreement rate between the two tests was considered low (Kappa coefficient = 0.10).
Acesso aberto (Open Access)
Avaliação da susceptibilidade do primata Cebus apella (Primates: Cebidae) à infecção experimental com diferentes inóculos de Leishmania (Leishmania) chagasi
(Universidade Federal do Pará, 2005) SANTOS, Dirceu Costa dos; SILVEIRA, Fernando Tobias; http://lattes.cnpq.br/8106158306299969
In Brazil, the monkey Cebus apella has been successfully used as a model for studying cutaneous leishmaniasis. Thus, we decided to investigate its usefulness as a model for visceral leishmaniasis. For this purpose, we used 10 specimens of C. apella: 7 males and 3 females, juveniles. All were born and raised in captivity. In the first experiment was realize with 6 monkeys divided in 2 groups, in the first group with 3 monkeys was inoculated with 30 x 106 promastigotes of L. (L.) chagasi (MCAO/BR/1998/M18011, Maranhão State) from stationary phase of cultures, while in the second group with 3 monkeys was inoculated 5 doses successive with 30 x 106 promastigotes (150 x 106) of L. (L.) chagasi (MCAO/BR/1998/M18011, Maranhão State) from stationary phase of cultures. In the second experiment were used 4 monkeys, divided in 2 groups was also inoculated with five pairs of salivary glands of Lutzomyia longipalps together with parasites. In the first group with 2 monkeys was inoculated with 30 x 106 promastigotes of L. (L.) chagasi, second group with 2 monkeys was inoculated 5 doses successive with 30 x 106 promastigotes (150 x 106). The inoculations were, intradermaly, into the base of the tail of the animals. The evaluation of infections was monthly and included clinical examination, IgG antibody response (IFAT). In monkeys inoculated with promastigotes only or in those inoculated with promastigotes plus the salivary glands of the flebotominae sand fly we have till now found no clinical manifestations of infection all the experiment, neither have demonstrated parasites in the bone-marrow or specific antibody response. These results suggest that C. apella monkey is able to resist against to infection by L. (L.) chagasi.
Acesso aberto (Open Access)
A comparison of molecular markers to detect Lutzomyia longipalpis naturally infected with Leishmania (Leishmania) infantum
(2014-07) LIDANI, Kárita Cláudia Freitas; REASON, Iara José de Messias; ISHIKAWA, Edna Aoba Yassui
The aim of the present study was to detect natural infection by Leishmania (Leishmania) infantum in Lutzomyia longipalpis captured in Barcarena, state of Pará, Brazil, through the use of three primer sets. With this approach, it is unnecessary to previously dissect the sandfly specimens. DNA of 280 Lu. longipalpis female specimens were extracted from the whole insects. PCR primers for kinetoplast minicircle DNA (kDNA), the mini-exon gene and the small subunit ribosomal RNA (SSU-rRNA) gene of Leishmania were used, generating fragments of 400 bp, 780 bp and 603 bp, respectively. Infection by the parasite was found with the kDNA primer in 8.6% of the cases, with the mini-exon gene primer in 7.1% of the cases and with the SSU-rRNA gene primer in 5.3% of the cases. These data show the importance of polymerase chain reaction as a tool for investigating the molecular epidemiology of visceral leishmaniasis by estimating the risk of disease transmission in endemic areas, with the kDNA primer representing the most reliable marker for the parasite.
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Diagnóstico molecular e frequência de anticorpos anti-Leishmania infantum chagasi em cães do município de Belém, Pará
(2014-03) SCHWANKE, Katiane; SILVA, Aryane Maximina Melo da; OLIVEIRA, Adlilton Pacheco de; SILVA, Michele Bahia do Vale; SILVEIRA, Fernando Tobias; SCOFIELD, Alessandra; CAVALCANTE, Gustavo Góes
Visceral leishmaniasis is a disease whose etiological agent in Brazil is Leishmania infantum chagasi. Dogs are considered urban reservoirs of the disease, being an indicator of the human cases occurrence. The present study aimed to diagnose L. infantum chagasi infection in stray and owned dogs in Belém, Pará State, by polymerase chain reaction (PCR) and indirect immunofluorescence assay (IFA) using two different antigens. Venous blood samples from adult dogs, regardless of gender or breed, of different neighborhoods in Belém-PA, were collected in tubes with and without anticoagulant to obtain DNA and serum, respectively. These animals were divided into two groups: stray dogs captured by the Center for Zoonosis Control (Group A) and owned dogs (Group B). Sera were analyzed by IFA testing for IgG using two different antigens: 1) Bio-Manguinhos/Fiocruz antigen kit (Ag-PRO) containing promastigotes of Leishmania sp. (Complex Major-Like), 2) Instituto Evandro Chagas Antigen (Ag-AMA) consisting of amastigotes of L. infantum chagasi. The evaluation of the two antigens was performed considering positive the reactions above the 1:80 dilution. Already PCR was performed with DNA isolated from whole blood of animals and amplified with the primers RV1 and RV2. Of the 335 samples analyzed, 10.4% (35/335) were positive by IFA (Ag-PRO) and 0.9% (3/335) with the Ag-AMA. The distribution of positive samples is given as follows: Group A 14.8% (25/169) with Ag-PRO and 1.2% (2/169) with Ag-AMA; Group B 6% (10/166) with Ag-PRO and 0.6% (1/166) with Ag-AMA, being that all samples positive by IFA with Ag-AMA also reacted with Ag-PRO, and none of the samples detected DNA of L. infantum chagasi. The findings of this study indicate that Belém can still be considered non-endemic area for canine visceral leishmaniasis and the nature of the antigen influences the result of the IFA for the detection of anti-L. infantum chagasi antibodies in dogs, and the IFA using promastigotes of Leishmania major-like antigen should be used with caution as a confirmatory diagnostic on epidemiological studies in non-endemic areas.
Acesso aberto (Open Access)
Distribution of phlebotomine fauna (Diptera: Psychodidae) across an urban-rural gradient in an area of endemic visceral leishmaniasis in northern Brazil
(2011-12) OLIVEIRA, Davi Marcos Souza de; HABIB, Elvira Maria Saraiva Chequer Bou; ISHIKAWA, Edna Aoba Yassui; SOUSA, Adelson Alcimar Almeida de; SILVA, Edilene Oliveira da; SILVA, Ivoneide Maria da
The number of visceral leishmaniasis (VL) cases has increased over the past 10 years in Brazil, especially in the North and Northeast regions of the country. The aim of this study was to evaluate the urbanisation of VL vectors in Barcarena, Pará, an area in northern Brazil where VL is endemic. Sandflies were captured using Centers for Disease Control (CDC) light traps along an urban-rural gradient. The CDC traps were installed inside hen houses at a height of 150 cm. A total of 5,089 sandflies were collected and 11 species were identified. The predominant species was Lutzomyia longipalpis (rate of 95.15%), which suggests its participation in the transmission of VL. A total of 1,451 Lu. longipalpis females were dissected and no Leishmania infections were detected. Most of the sandflies were captured at the border of a forest (88.25%) and no flies were captured in the urban area, which suggests that transmission is still restricted to rural sites. However, the fact that a specimen was collected in an intermediate area indicates that urbanisation is a real possibility and that vector monitoring is important.
Acesso aberto (Open Access)
Genes that encodes NAGT, MIF1 and MIF2 are not virulence factors for kala-azar caused by Leishmania infantum
(Universidade Federal do Pará, 2014-10) AGUIAR, Bruno Guedes Alcoforado; COELHO, Daniela Lemos; COSTA, Dorcas Lamounier; DRUMOND, Betânia Paiva; COELHO, Luiz Felipe Leomil; FIGUEIREDO, Lívio Carvalho; ZACARIAS, Danielle Alves; SILVA, Jailthon Carlos da; ALONSO, Diego Peres; RIBOLLA, Paulo Eduardo Martins; ISHIKAWA, Edna Aoba Yassui; GAÍDO, Samara Belchior; COSTA, Carlos Henrique Nery
Introduction: Kala-azar is a disease resulting from infection by Leishmania donovani and Leishmania infantum. Most patients with the disease exhibit prolonged fever, wasting, anemia and hepatosplenomegaly without complications. However, some patients develop severe disease with hemorrhagic manifestations, bacterial infections, jaundice, and edema dyspnea, among other symptoms, followed by death. Among the parasite molecules that might influence the disease severity are the macrophage migration inhibitory factor-like proteins (MIF1 and MIF2) and N-acetylglucosamine-1-phosphotransferase (NAGT), which act in the first step of protein N-glycosylation. This study aimed to determine whether MIF1, MIF2 and NAGT are virulence factors for severe kala-azar. Methods: To determine the parasite genotype in kala-azar patients from Northeastern Brazil, we sequenced the NAGT genes of L. infantum from 68 patients as well as the MIF1 and MIF2 genes from 76 different subjects with diverse clinical manifestations. After polymerase chain reaction (PCR), the fragments were sequenced, followed by polymorphism identification. Results: The nucleotide sequencing of the 144 amplicons revealed the absence of genetic variability of the NAGT, MIF1 and MIF2 genes between the isolates. The conservation of these genes suggests that the clinical variability of kala-azar does not depend upon these genes. Additionally, this conservation suggests that these genes may be critical for parasite survival. Conclusions: NAGT, MIF1 and MIF2 do not alter the severity of kala-azar. NAGT, MIF1 and MIF2 are highly conserved among different isolates of identical species and exhibit potential for use in phylogenetic inferences or molecular diagnosis.
Acesso aberto (Open Access)
Leishmaniose visceral no município de Barcarena, Pará: importância do comportamento da enzootia canina por Leishmania (Leishmania) chagasi e de outros fatores para a infecção humana
(Universidade Federal do Pará, 2005) PEREIRA, Elza Alves; SILVEIRA, Fernando Tobias; http://lattes.cnpq.br/8106158306299969
The leishmaniasis is an infectious disease no contagious of chronic evolution with high mortality rate, and Brazil notifies about 90% of the cases of the American continent. His importance in the context of the public health has been increasing in function of the crescent number of cases that is happening not only in the rural area as well as in the periphery of great urban centers. The epidemiology of LV in Brazil is based on the occurrence of clinical cases. In this sense the present study intended to study the behavior of the canine infection and of other factors for the human infection. Because little it is known on the determinant of the infection and his importance in the maintenance of the disease. For that a place municipal district of Barcarena was defined, where the population is stable, happening the disease in an endemic way. The study accompanied during one year two cohorts, being one for canine teeth, with 172 dogs, and one for humans, with 1064 people of which only 1012 participated in the material collection, because 52 people were out of the strip of compatible age for the accomplishment of the procedures. The accomplishment of the test serology through the Reaction of Indirect Imunofluorescência (RIFI), she had as purpose the determination of the initial prevalence of infection and the incidences in two moments of the study, so much of the population human as canine. It was also accomplished in the human population Montenegro's Intradermo Reação (IDRM) with the same purpose, to check the prevalence and infection incidence through this method. Other factors were also analyzed and they can be associated to the risk for the infection. The statistical analysis of the data was accomplished with of the programs EPI INFO version 6.04 and BIOESTAT version 3.0 and the applied tests were Qui - Square and the prevalence calculation and incidence. In the inquiry canine serology it was observed a prevalence of canine infection of 37,2% and the incidence six months after, it was of 29,2%. In the interval of second for the third collection the euthanasia of the dogs positive serology was accomplished, in a total of 70 dogs, because 15 had died before the intervention. The incidence made calculations after the intervention showed a tax of 14,6%, what characterizes a reduction of about 50%. As for the titulation, in all of the stages titles were observed considered high. It is worth to stand out that of the 54 animals that didn't present clinical signs, 30 were infected (55,5%). When accomplished the inquiry human serology it was observed a prevalence of human infection of 5,25%, and the incidence six months after it was of 1,69% and in the it finishes evaluation 6,52%, with increase about 300% for RIFI, while for IDRM the initial prevalence was respectively of 10,78% and the incidences of 4,75% and 7,30% to the six and twelve months of the study. In relation to the characteristics of the population it was observed that she enters them infected there was not prevalence of any age group. The variable sex was not significant for the infection occurrence. On them infected so much by RIFI, as IDRM, stands out the statistical significance of the variable occupation, and in this context, the category farmer was the one that came with larger proportion. The variables time residence in the place, residence proximity with the forest, destiny of the garbage and dejections also showed - if significant. Although in the variable age group, the distribution of the infected by RIFI was not predominant in any strip; in IDRM, it was observed that as it increases the age also increases the proportion of having infected. Other results were observed of great relevance for the association to the infection risk, but the observation as to have infected for RIFI and IDRM it was the one that deserved prominence in function of the statistical significance. The study was shown appropriate goes the knowledge of the prevalences and incidences of canine and human infection in the place, the well the behavior of adds factors that associated they can be constituted in risk goes infection and that the elimination of dogs seropositives reduces the incidence of canine infection mean while no doesn't alter the course of the human infection, could have other wild reservoirs involved in the transmission.
Acesso aberto (Open Access)
Severe visceral leishmaniasis in children: the relationship between cytokine patterns and clinical features
(Universidade Federal do Pará, 2013-12) GAMA, Mônica Elinor Alves; GOMES, Claudia Maria de Castro; SILVEIRA, Fernando Tobias; AURENTI, Márcia Dalastra; GONÇALVES, Eloisa da Graça do Rosario; SILVA, Antônio Rafael da; CORBETT, Carlos Eduardo Pereira
Introduction: The relationship between severe clinical manifestations of visceral leishmaniasis (VL) and immune response profi les has not yet been clarifi ed, despite numerous studies on the subject. This study aimed to investigate the relationship between cytokine profi les and the presence of immunological markers associated with clinical manifestations and, particularly, signs of severity, as defi ned in a protocol drafted by the Ministry of Health (Brazil). Methods: We conducted a prospective, descriptive study between May 2008 and December 2009. This study was based on an assessment of all pediatric patients with VL who were observed in a reference hospital in Maranhão. Results: Among 27 children, 55.5% presented with more than one sign of severity or warning sign. Patients without signs of severity or warning signs and patients with only one warning sign had the highest interferon-gamma (IFN-γ) levels, although their interleukin 10 (IL-10) levels were also elevated. In contrast, patients with the features of severe disease had the lowest IFN-γ levels. Three patients who presented with more than two signs of severe disease died; these patients had undetectable interleukin 2 (IL-2) and IFN-γ levels and low IL-10 levels, which varied between 0 and 36.8pg/mL. Conclusions: Our results showed that disease severity was associated with low IFN-γ levels and elevated IL-10 levels. However, further studies with larger samples are needed to better characterize the relationship between disease severity and cytokine levels, with the aim of identifying immunological markers of active-disease severity.