Infection with Leishmania (Leishmania) infantum of 0 to 18-Month-old children living in a visceral leishmaniasis-endemic area in Brazil.

The diagnosis of Leishmania (Leishmania) infantum infection in children from birth may serve as a reference for the early identification of cases that would progress to classical visceral leishmaniasis (VL) in endemic areas. This study prospectively evaluated newborns of mothers living in the municipality of Paracatu, Minas Gerais, Brazil. The infants were followed up at 6-month intervals by clinical examination, serological tests (immunofluorescence [IIF] and enzyme-linked immunosorbent assay with rK39 [ELISA-rK39]) and polymerase chain reaction (PCR) until they had completed 18 months of age. A total of 166 pregnant women were included to evaluate the possible transfer of antibodies or even congenital transmission. Twenty-two of the women tested positive by IIF, four by ELISA-rK39, and one by PCR. Three infants of the 25 women with some positive test results were also positive in the first test (one by IIF, one by ELISA-rK39, and the third by ELISA-rK39 and PCR). One hundred and sixty infants were included in the study; of these, 43 had at least one positive sample over time. However, agreement between tests was low. Follow-up of children with a positive result in the tests studied revealed no progression to classical disease within a period of 18 months. In contrast, two children with negative IIF, PCR, and ELISA-rK39 results developed classical VL at 9 and 12 months of age. In conclusion, a positive test result was variable and sometimes temporary and agreement between tests was low. Therefore, the early diagnosis of Leishmania infection was not associated with the early identification of cases that would progress to classical VL in the endemic area studied.

Elevated dengue virus nonstructural protein 1 serum levels and altered toll-like receptor 4 expression, nitric oxide, and tumor necrosis factor alpha production in dengue hemorrhagic Fever patients.

Background. During dengue virus (DV) infection, monocytes produce tumor necrosis factor alpha (TNF-α) and nitric oxide (NO) which might be critical to immunopathogenesis. Since intensity of DV replication may determine clinical outcomes, it is important to know the effects of viral nonstructural protein 1 (NS1) on innate immune parameters of infected patients. The present study investigates the relationships between dengue virus nonstructural protein 1 (NS1) serum levels and innate immune response (TLR4 expression and TNF-α/NO production) of DV infected patients presenting different clinical outcomes. Methodology/Principal Findings. We evaluated NO, NS1 serum levels (ELISA), TNF-α production by peripheral blood mononuclear cells (PBMCs), and TLR4 expression on CD14(+) cells from 37 dengue patients and 20 healthy controls. Early in infection, increased expression of TLR4 in monocytes of patients with dengue fever (DF) was detected compared to patients with dengue hemorrhagic fever (DHF). Moreover, PBMCs of DHF patients showed higher NS1 and lower NO serum levels during the acute febrile phase and a reduced response to TLR4 stimulation by LPS (with a reduced TNF-α production) when compared to DF patients. Conclusions/Significance. During DV infection in humans, some innate immune parameters change, depending on the NS1 serum levels, and phase and severity of the disease which may contribute to development of different clinical outcomes.

Anti-leishmania infantum IgG antibody avidity in visceral leishmaniasis.

IgG avidity tests are used to discriminate acute from chronic infections. There are few reports on the IgG avidity profile of patients with visceral leishmaniasis (VL). This study investigated the anti-Leishmania IgG avidity in patients with classic VL (n = 10), patients showing clinical cure after treatment (n = 18), and asymptomatic subjects with at least one positive Leishmania test (n = 20). All subjects were from areas in Brazil where VL is endemic. Serum samples were collected from each subject on two different occasions. IgG avidity was evaluated by Western blotting. The proportion of high-avidity antibodies was higher in all samples from patients with classic VL. In contrast, low-avidity antibodies predominated in subjects with a history of VL, including 13 cases (72.2%) in the first assessment and 14 (77.8%) in the second. Fifteen (75%) of the asymptomatic subjects presented a predominance of low-avidity antibodies in the first assessment, and the frequency of high-avidity antibodies increased over time in seven subjects (35%) of this group. Antibodies against the 14- and/or 16-kDa antigen fraction were detected in the first assessment in all patients with classic VL, in 10 (55.5%) treated patients, and in 10 (50%) asymptomatic subjects. These were high-avidity antibodies in most cases. In the asymptomatic group, an increase in IgG avidity against the 14- and/or 16-kDa antigen fraction was observed in three cases (15%). The results indicate distinct responses in infected and asymptomatic subjects, probably associated with the length of time after infection. In this respect, IgG avidity tests represent a new approach to better characterize asymptomatic VL.

Comparative study of serologic tests for the diagnosis of asymptomatic visceral leishmaniasis in an endemic area.

Serologic tests have been widely used for the diagnosis of asymptomatic visceral leishmaniasis. This study evaluated five serologic tests used for the diagnosis of asymptomatic infection: enzyme-linked immunosorbent assay (ELISA) using promastigote antigen (ELISAp), ELISA using recombinant K39 (ELISA rK39), and K26 (ELISA rK26) antigens, an indirect immunofluorescence test using Leishmania (Leishmania) amazonensis promastigote antigen (IIFT), and an immunochromatographic test using rK39 antigen (TRALd). As a reference regarding the performance of the tests, patients with classic visceral leishmaniasis originating from Minas Gerais, Brazil (N = 36), were defined as the positive group and samples of healthy individuals from nonendemic areas (Argentina) (N = 127) were used as negative controls. Patients with other diseases such as cutaneous leishmaniasis (N = 53) and malaria (N = 56) were also studied to evaluate the chance of cross-reactivity in these tests. Finally, subjects from an area endemic for visceral leishmaniasis in Brazil (Porteirinha, northern Minas Gerais) (N = 1241) were screened for asymptomatic infection with Leishmania and Chagas disease. The sensitivity of the serologic tests was 50% (18/36), 66.7% (24/36), 69.4% (25/36), 83.3% (30/36), and 88.9% (32/36) for ELISAp, ELISA rK26, ELISA rK39, IIFT, and TRALd, respectively. Specificity, calculated using the truly negative group, was 96% (122/127) for TRALd, 97.6% (124/127) for ELISAp and IIFT, and 100% (127/127) for ELISA rK39 and rK26. Positivity in at least one test employing recombinant antigen was observed in 24 (45%) patients with cutaneous leishmaniasis and 47 (82.4%) with malaria. In the visceral leishmaniasis-endemic area, the positivity of the serologic tests ranged from 3.9% to 37.5%. The enzyme-linked immunosorbent assay (ELISA) tests using recombinant antigens were more frequently positive in subjects with a history of exposure to human or canine visceral leishmaniasis (ELISArK39: 14.6% [149/1017] versus 37.5% [84/224]; ELISA rK26: 12.7% [129/1017] versus 21.4% [48/224], P < 0.001 for both). Kappa agreement was low, with a maximum value of 0.449 between ELISAp and IIFT. In addition, among the 112 IIFT-positive subjects, 75 (67%) also presented positive serology for Chagas disease. In conclusion, IIFT and TRALd presented the best performance to diagnose classic cases of visceral leishmaniasis in an endemic area. Cross-reactivity of the tests with Chagas disease, cutaneous leishmaniasis, and malaria should be taken into account. However, the differences in the positivity of the tests used, together with the low agreement between results, do not permit to select the best test for the diagnosis of asymptomatic Leishmania infection.

Comparação de dois antígenos para intradermorreação de Montenegro / A comparison of two antigens for Montenegro skin test

Foram feitas reações intradérmicas em 399 indivíduos usando-se, simultaneamente, o antígeno fabricado pela Universidade Federal de Minas Gerais e pela Fundação Instituto Oswaldo Cruz. Ambos antígenos manufaturados com promastigotas de Leishmania (L) amazonensis (IFLA/BR/67/PH8). O antígeno da Fundação Oswaldo Cruz produziu maior número de reações positivas. Houve 22 por cento de reações discordantes.

Azithromycin in the treatment of mucosal leishmaniasis.

This report describes three elderly patients with mucosal form of American tegumentary leishmaniasis associated with chronic cardiopathy. Due to the known toxicity of classical drugs with activity against Leishmania sp., the patients received three oral courses of azithromycin therapy in single 500 mg daily dose during ten days, every other month. All lesions healed after the third series. One of the patients relapsed and a new series of azithromycin was prescribed. Azithromycin may be an alternative drug for the treatment of leishmaniasis in special situations due to its optimal mucosal and intraphagocyte concentration, single daily posology, high tolerance and oral administration. The mechanism of this drug on Leishmania sp. is unknown at present.

Azithromycin in the treatment of mucosal leishmaniasis

O presente relato descreve três pacientes idosos com leishmaniose mucosa de longa evolução, os quais eram portadores de cardiopatia crônica. Pela alta freqüência de efeitos secundários e tóxicos dos medicamentos utilizados no tratamento clássico, esses pacientes receberam azitromicina. Este medicamento foi administrado pela via oral, em dose única diária de 500 mg, durante dez dias, em três séries com intervalo de um mês. Em todos, houve cicatrização das lesões depois da terceira série. Um dos pacientes apresentou recidiva após seis meses e uma nova série de azitromicina fez regredir novamente o quadro. Azitromicina pode ser uma alternativa para o tratamento das leishmanioses, principalmente pela concentração adequada em mucosas e nos fagócitos, posologia única diária, boa tolerância e administração oral.

[A comparison of two antigens for Montenegro skin test]. / Comparação de dois antígenos para intradermorreação de Montenegro.

Intradermal reactions were performed in 399 individuals by using, simultaneously, the antigen produced by both the Universidade Federal de Minas Gerais and Fundação Instituto Oswaldo Cruz. Each of these antigens was manufactured with promastigotes of Leishmania (L) amazonensis (IFLA/BR/67/PH8). The Fundação Oswaldo Cruz antigen caused a larger number of positive reactions. Discordant reactions occurred in 22% of the individuals.

[Montenegro intradermoreaction after the test sequential repetitions in Porteirinha, Minas Gerais State, Brazil]. / Intradermorreação de Montenegro após sucessivas repetições do teste em Porteirinha, MG.

With the purpose of evaluating the response of sequential applications of Montenegro intradermoreaction (IDRM), we have repeated four times the test in the inhabitants of an endemic area for kala-azar, that resulted negative 3-4 years ago. Firstly, we have repeated three IDRM in those who remained negative, with a 60-day interval among them. In the second stage, we have performed a last reaction in all participants of the study. From the total of 49 individuals with prior negative IDRM, 19 (38.8%) have positivated the test in some of the times, 17 (34.7%) have given up the study and 13 (26.5%) remained with a negative result in all the applications. In the second stage, the repetition of IDRM has shown that from the 14 positive in some of the tests, 8 remained like this and 6 have become negative. Our results confirm the possibility of late hypersensitivity induction in some individuals as a consequence of IDRM application.

Intradermorreação de Montenegro após sucessivas repetições do teste em Porteirinha, MG / Montenegro intradermoreaction after the test sequential repetitions in Porteirinha, Minas Gerais State, Brazil

Para avaliar a resposta a sucessivas aplicaçöes da intradermorreaçäo de Montenegro (IDRM), repetimos quatro vezes o teste em moradores de uma área endêmica de calazar que tiveram o exame negativo há 3-4 anos. Inicialmente, repetimos três IDRM nos que permaneceram negativos, com intervalo de 60 dias entre elas. Na segunda etapa, realizamos uma última reaçäo em todos participantes do estudo. Do total de 49 indivíduos com IDRM prévia negativa, 19 (38,8 por cento) positivaram o teste em alguma das vezes, 17 (34,7 por cento) abandonaram o estudo e 13 (26,5 por cento) permaneceram com resultado negativo em todas as aplicaçöes. Na segunda etapa, a repetiçäo da IDRM mostrou que dos 14 que eram positivos em algum dos testes, 8 assim permaneceram e 6 tornaram-se negativos. Nossos resultados confirmam a possibilidade de induçäo de hipersensibilidade tardia em alguns indivíduos pela aplicaçäo da IDRM