RESUMO
A population-based cross-sectional study was set up in Sabará country, Southeastern Brazil, to identify asymptomatic human visceral leishmaniasis in an urban area of low disease prevalence. Blood was collected on filter paper (n=1,604 inhabitants) and examined by indirect immunofluorescent test, enzyme-linked immunosorbent assay and immunochromatographic strip test. The prevalence rates of infection ranged from 2.4 to 5.6% depending on the test used. One year later, venous blood was collected in a subset of 226 participants (102 seropositive and 124 seronegative). The tests performed were IFAT, ELISA, rk39-ELISA, polymerase chain reaction and hybridization with Leishmania donovani complex probe. No clinical signs or symptoms of leishmaniasis were observed. Using hybridization as a reference test, the sensitivity and specificity of serology were respectively: 24.8 and 71% (ELISA); 26.3 and 76.3% (rk-39); 30.1 and 63.4% (IFAT). Due to disagreements, different criteria were tested to define the infection and hybridization should be considered in epidemiological studies.
Assuntos
Anticorpos Antiprotozoários/sangue , Leishmania donovani/genética , Leishmania donovani/imunologia , Leishmaniose Visceral/diagnóstico , Adolescente , Adulto , Animais , Brasil/epidemiologia , Estudos de Casos e Controles , Estudos Transversais , Sondas de DNA , Ensaio de Imunoadsorção Enzimática , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Leishmaniose Visceral/epidemiologia , Masculino , Reação em Cadeia da Polimerase , Prevalência , Fitas Reagentes , Sensibilidade e Especificidade , Fatores Socioeconômicos , População UrbanaRESUMO
A population-based cross-sectional study was set up in Sabará country, Southeastern Brazil, to identify asymptomatic human visceral leishmaniasis in an urban area of low disease prevalence. Blood was collected on filter paper (n=1,604 inhabitants) and examined by indirect immunofluorescent test, enzyme-linked immunosorbent assay and immunochromatographic strip test. The prevalence rates of infection ranged from 2.4 to 5.6 percent depending on the test used. One year later, venous blood was collected in a subset of 226 participants (102 seropositive and 124 seronegative). The tests performed were IFAT, ELISA, rk39-ELISA, polymerase chain reaction and hybridization with Leishmania donovani complex probe. No clinical signs or symptoms of leishmaniasis were observed. Using hybridization as a reference test, the sensitivity and specificity of serology were respectively: 24.8 and 71 percent (ELISA); 26.3 and 76.3 percent (rk-39); 30.1 and 63.4 percent (IFAT). Due to disagreements, different criteria were tested to define the infection and hybridization should be considered in epidemiological studies.
Um estudo seccional de base populacional foi desenvolvido no município de Sabará, região sudeste do Brasil, para identificar a leishmaniose visceral humana assintomática em uma área urbana de baixa prevalência da doença. Foi coletado sangue em papel filtro (n=1.604 moradores), sendo examinados pela reação de imunofluoresência indireta, ensaio imunoenzimático e teste imunocromatográfico (strip test). As taxas de prevalência da infecção variaram de 2,4 a 5,6 por cento, dependendo do teste utilizado. Um ano depois foi coletado sangue venoso de um subgrupo de 226 participantes (102 soropositivos e 124 soronegativos). Os testes realizados foram IFAT, ELISA, rk39-ELISA, reação em cadeia da polimerase e hibridização com sonda específica para o complexo Leishmania donovani. Não foi observado nenhum sinal clínico ou sintoma de leishmaniose. Usando a hibridização como teste de referência, a sensibilidade e especificidade dos testes sorológicos foram, respectivamente: 24.8 e 71 por cento (ELISA); 26,3 e 76,3 por cento (rk39-ELISA); 30,1 e 63,4 por cento (IFAT). Devido a discordâncias, diferentes critérios foram testados para definir a presença da infecção e a hibridização deveria ser considerada em estudos epidemiológicos.
Assuntos
Humanos , Animais , Masculino , Feminino , Adolescente , Adulto , Anticorpos Antiprotozoários/sangue , Leishmania donovani/genética , Leishmania donovani/imunologia , Leishmaniose Visceral/diagnóstico , Brasil/epidemiologia , Estudos de Casos e Controles , Estudos Transversais , Sondas de DNA , Ensaio de Imunoadsorção Enzimática , Técnica Indireta de Fluorescência para Anticorpo , Leishmaniose Visceral/epidemiologia , Reação em Cadeia da Polimerase , Prevalência , Fitas Reagentes , Sensibilidade e Especificidade , Fatores Socioeconômicos , População UrbanaRESUMO
The first choice of treatment for American cutaneous leishmaniasis is the pentavalent antimonial drug. Although it has been shown that this treatment is mostly effective and indicated, some disadvantages should be taken into account such as side effects, long term treatment inconveniences and counter-indication for patients suffering from cardiopathy, nephropathy; yet, aging, pregnancy and other conditions. With the advent of the vaccine anti-American cutaneous leishmaniasis as a prophylactic measure, studies on therapy using the vaccine associated or not with other drugs have been performed by many investigators and it is currently among the alternative treatments and prevention measures for American cutaneous leishmaniasis. In conclusion, the association between antimony and vaccine (immunochemotherapy) showed the same cure rate when compared with the standard treatment (100%) and it was also able to reduce the salt volume in 17.9% and treatment length from 87 to 62 days, decreasing side effects.
Assuntos
Imunoterapia/métodos , Leishmaniose Cutânea/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Antiprotozoários/administração & dosagem , Vacina BCG/administração & dosagem , Criança , Pré-Escolar , Quimioterapia Combinada , Feminino , Humanos , Leishmania/imunologia , Leishmaniose Cutânea/imunologia , Masculino , Meglumina/administração & dosagem , Antimoniato de Meglumina , Pessoa de Meia-Idade , Compostos Organometálicos/administração & dosagem , Vacinas Protozoárias/administração & dosagem , Fatores de Tempo , Resultado do TratamentoRESUMO
O tratamento de primeira escolha para leishmaniose tegumentar americana é o antimonial pentavalente. Embora este tratamento seja na maioria das vezes efetivo e indicado, devem ser consideradas as desvantagens tais como efeitos colaterais, longa duracão do tratamento e contra-indicacão para cardiopatas, nefropatas, idosos, grávidas e outras condicões. Com o advento da vacina antileishmaniose tegumentar americana para fins profiláticos e terapêuticos, associando-a ou não a outros fármacos, muitas pesquisas têm sido desenvolvidas, sendo a vacina a principal entre os atuais recursos no tratamento e prevencão da leishmaniose tegumentar americana. Em conclusão, a associacão do antimônio com a vacina (imunoquimioterapia) apresentou o mesmo índice de cura em relacão ao tratamento padrão (100%), e ainda reduziu o volume do sal em 17,9% e o tempo de cura significativamente, de 87 para 62 dias; conseqüentemente, reduzindo os efeitos colaterais.
Assuntos
Pré-Escolar , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso de 80 Anos ou mais , Animais , Humanos , Masculino , Feminino , Antiprotozoários/administração & dosagem , Vacina BCG/administração & dosagem , Leishmania/imunologia , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/terapia , Meglumina/administração & dosagem , Compostos Organometálicos/administração & dosagem , Vacinas Protozoárias/administração & dosagem , Quimioterapia Combinada , Fatores de Tempo , Resultado do TratamentoRESUMO
We have performed a detailed investigation in 40 dogs naturally infected with Leishmania infantum (syn. chagasi), subdivided into three groups: asymptomatic (AD = 12), oligosymptomatic (OD = 12) and symptomatic (SD = 16), based on their clinical features. Twenty non-infected dogs (CD) were included as control group. Serological analysis, performed by IFAT and ELISA, demonstrated higher antibodies titers in SD in comparison to the AD. A positive correlation was found between parasite density in the spleen and skin smears as well as the bone marrow parasitism with clinical status of the infection. We observed that the progression of the disease from asymptomatic to symptomatic clinical form was accompanied by intense parasitism in the bone marrow. It is likely that this led to the impaired biochemical/hematological status observed. Finally, we believe that the follow-up of these parameters could be a relevant approach to be used as markers during therapeutic and vaccine evaluations.
Assuntos
Doenças do Cão/parasitologia , Leishmaniose Visceral/metabolismo , Leishmaniose Visceral/veterinária , Animais , Anticorpos Antiprotozoários/análise , Medula Óssea/parasitologia , Estudos de Casos e Controles , Progressão da Doença , Doenças do Cão/sangue , Doenças do Cão/metabolismo , Doenças do Cão/patologia , Cães , Ensaio de Imunoadsorção Enzimática , Feminino , Leishmaniose Visceral/sangue , Leishmaniose Visceral/parasitologia , Masculino , Densidade Demográfica , Índice de Gravidade de DoençaRESUMO
An evaluation of 5 laboratory methods for diagnosing American cutaneous leishmaniasis (ACL) was carried out on patients from an endemic area of Brazil. From 164 patients presenting cutaneous lesions, and suspected to have ACL, 133 (81.1%) were confirmed for the disease by Montenegro skin test (MST) and/or parasitologic examination (PE). In both groups of patients, the positivity of polymerase chain reaction (PCR) was similar to that of immunofluorescence assay and enzyme-linked immunosorbent assay, and higher than that of MST and PE (P < .05). In the group of patients suspected to have ACL, PCR presented the same positivity as PE and MST together. No correlation between positivity of the laboratory methods and clinical or epidemiologic aspects was observed. Our data confirmed the value of PCR as an alternative laboratory method for diagnosing ACL, especially for those patients with negative PE and MST.
Assuntos
DNA de Protozoário/análise , Leishmania/isolamento & purificação , Leishmaniose Cutânea/diagnóstico , Animais , Anticorpos Antiprotozoários/sangue , Brasil , Primers do DNA , Humanos , Leishmania/genética , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/patologia , Reação em Cadeia da PolimeraseRESUMO
Com o objetivo de identificar os determinantes da infeccão humana por Leishmania chagasi em uma área urbana, foi realizado um estudo seccional de base populacional utilizando-se métodos moleculares e sorológicos para identificar a infeccão. Os participantes foram entrevistados utilizando-se questionário pré-codificado. Dois critérios foram testados para identificar os fatores de risco: Modelo 1- incluindo todos os participantes positivos na hibridizacão com sonda para o complexo Leishmania donovani; Modelo 2- incluindo todos os participantes positivos na hibridizacão e em pelo menos um teste sorológico. No Modelo 1, as variáveis associadas à infeccão foram: criar pássaros, encontrar-se fora de casa entre 18:00-22:00h e não ter o lixo coletado. No Modelo 2, as variáveis associadas à infeccão foram: família conhecer o vetor, não ter o lixo coletado, lixo não removido ou queimado, criar pássaros, proximidade de áreas erodidas. Os fatores de risco identificados foram associados às condicões das moradias, presenca de animais e probabilidade de contato com flebotomíneos.
Assuntos
Lactente , Pré-Escolar , Criança , Adolescente , Adulto , Cães , Animais , Humanos , Masculino , Feminino , Leishmania infantum , Leishmaniose Visceral/epidemiologia , Aves , Brasil/epidemiologia , Estudos Transversais , Leishmaniose Visceral/diagnóstico , Fatores de Risco , População UrbanaRESUMO
An evaluation of the microbiota present in cutaneous ulcers from 31 patients with a clinical and parasitological diagnosis of American tegumentary leishmaniasis (ATL) was carried out by the standard filter paper disc technique, including antimicrobial susceptibility of the bacterial isolates. Microbial examination indicated that 21 patients (67.7%) were contaminated with one to four bacteria and some of them also with yeast. A total of 142 micro-organisms were isolated. Staphylococcus aureus was the most frequently recovered bacterium (95.2% of positive patients) and was found to produce type B (70% of the staphylococcal isolates) and type C (50%) enterotoxins as well as toxic shock syndrome toxin (60%). Proteus mirabilis (33.3% of the positive patients), Streptococcus pyogenes (19.0 %), H(2)S-negative Proteus species (19.0%), Klebsiella oxytoca (14.3%), Enterobacter species (9.5%), Peptostreptococcus species (9.5%), Pseudomonas species (4.8%), Prevotella bivia (4.8%), Escherichia coli (4.8%), Streptococcus agalactiae (4.8%), Bacteroides fragilis (4.8%), Candida albicans (9.5%) and Candida tropicalis (4.8%) were also isolated. Surprisingly, Staph. aureus isolates were susceptible to almost all tested drugs, although some of them were resistant to penicillin (69%) and ampicillin + sulbactam (68%). Concerning obligate anaerobes, all the Gram-negative isolates (25% of the total) were resistant to metronidazole. The results of the present study show that microbial secondary contaminants, particularly Staph. aureus, should be considered in the diagnosis and treatment of ATL lesions.
Assuntos
Antibacterianos/farmacologia , Bactérias/classificação , Candida/classificação , Candidíase Cutânea/microbiologia , Leishmaniose Cutânea/complicações , Dermatopatias Bacterianas/microbiologia , Úlcera Cutânea/microbiologia , Adolescente , Adulto , Idoso , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Toxinas Bacterianas/análise , Brasil , Candida/efeitos dos fármacos , Candida/isolamento & purificação , Candidíase Cutânea/complicações , Criança , Enterotoxinas/análise , Feminino , Humanos , Leishmaniose Cutânea/microbiologia , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Dermatopatias Bacterianas/complicações , Superantígenos/análise , Resistência beta-LactâmicaRESUMO
Control of canine visceral leishmaniasis (VL) remains a difficult and serious problem mostly because there is no reliable and effective vaccine available to prevent this disease. A mixture of three recombinant leishmanial antigens (TSA, LeIF and LmSTI1) encoded by three genes highly conserved in the Leishmania genus have been shown to induce excellent protection against infection in both murine and simian models of cutaneous leishmaniasis. A human clinical trial with these antigens is currently underway. Because of the high degree of conservation, these antigens might be useful vaccine candidates for VL as well. In the present study, using the dog model of the visceral disease, we evaluated the immunogenicity of these three antigens formulated with two different adjuvants, MPL-SE and AdjuPrime. The results were compared with a whole parasite vaccine formulated with BCG as the adjuvant. In order to investigate if sensitization with the recombinant antigens would result in recognition of the corresponding native parasite antigens upon infection, the animals were exposed for four weeks after the termination of the immunization protocol with the recombinant antigens to a low number of L. chagasi promastigotes, an etiological agent of VL. Immune response was evaluated by quantitative ELISA in the animal sera before and after exposure to the viable parasites. Both antigen specific IgG1 and IgG2 antibody levels were measured. Immunization of dogs with the recombinant antigens formulated in either MPL-SE or AdjuPrime resulted in high antibody levels particularly to LmSTI1. In addition, this immunization although to low levels, resulted in the development of antibody response to the whole parasite lysate. Importantly, experimental exposure with low numbers of culture forms of L. chagasi promastigotes caused a clear boost in the immune response to both the recombinant antigens and the corresponding native molecules. The boost response was predominantly of the IgG2 isotype in animals primed with the recombinant antigens plus MPL-SE. In contrast, animals primed with the recombinant antigens formulated in AdjuPrime as well as animals vaccinated with crude antigen preparation responded with mixed IgG1/IgG2 isotypes. These results point to the possible use of this antigen cocktail formulated with the adjuvant MPL-SE in efficacy field trials against canine VL.
Assuntos
Antígenos de Protozoários/imunologia , Doenças do Cão/imunologia , Leishmaniose Visceral/veterinária , Vacinas Protozoárias/imunologia , Animais , Anticorpos Antiprotozoários/biossíntese , Doenças do Cão/parasitologia , Cães , Leishmaniose Visceral/imunologia , Vacinas Sintéticas/imunologiaRESUMO
The performances of ELISA assays with different antigen preparations, such as Leishmania amazonensis or L. chagasi lysates and the recombinant antigens rK-39 and rK-26, were compared using sera or eluates from dried blood collected on filter paper to detect anti-Leishmania antibodies in dogs from a visceral leishmaniasis-endemic area in Brazil. Of 115 IFAT-reactive dogs at 1:40 titre, 106 (92.2%) were positive in parasitological exams (skin and/or spleen). These animals were compared to healthy animals (n = 25), negative for IFAT at a titre of 1:40 and parasitological exams. The sensitivities of crude and recombinant antigens were similar and remarkably high for both sera and eluates (97-100%). Specificity was higher than 96% for sera and eluates for different antigens, except for L. chagasi antigen using eluates (88%). Concordance values among the tests were higher either for sera or eluates (J = 0.95-1.00). High concordances were observed between sera and eluates tested with different antigens (kappa = 0.93-0.97). Crude and recombinant antigens identified different clinical phases of canine leishmaniasis. These results show that eluates could be used in canine surveys to identify L. chagasi infection. Recombinant antigens added little when compared to crude antigen in identifying positive dogs. Cross-reactivity with other diseases whose distribution often overlaps VL-endemic areas is a limitation of crude antigen use however.