Schistosoma mansoni: magnetic resonance analysis of liver fibrosis according to WHO patterns for ultrasound assessment of schistosomiasis-related morbidity.

For the last two decades, ultrasound (US) has been considered a surrogate for the gold standard in the evaluation of liver fibrosis in schistosomiasis. The use of magnetic resonance imaging (MRI) is not yet standardised for diagnosing and grading liver schistosomal fibrosis. The aim of this paper was to analyse MRI using an adaptation of World Health Organization (WHO) patterns for US assessment of schistosomiasis-related morbidity. US and MRI were independently performed in 60 patients (42.1 +/- 13.4 years old), including 37 men and 23 women with schistosomiasis. Liver involvement appraised by US and MRI was classified according to the WHO protocol from patterns A-F. Agreement between image methods was evaluated by kappa index (k). The correlation between US and MRI was poor using WHO patterns [k = 0.14; confidence interval (CI) 0.02; 0.26]. Even after grouping image patterns as "A-D", "Dc-E" and "Ec-F", the correlation between US and MRI remained weak (k = 0.39; CI 0.21; 0.58). The magnetic resonance adaptation used in our study did not confirm US classification of WHO patterns for liver fibrosis.

Correlation between ELISA and ML Flow assays applied to 60 Brazilian patients affected by leprosy.

Serological tests can be helpful in classifying leprosy patients as having either the paucibacillary or the multibacillary form. The aim of this study was to evaluate the concordance between two serological assays, i.e. ML Flow and ELISA, in a population of leprosy patients in Brazil. The investigation involved 60 patients with newly diagnosed leprosy. Together with the application of the serological assays, selected demographic, clinical and epidemiological data relating to the study population were recorded. ML Flow detected anti-PGL1 antibodies in 70% of the leprosy patients, while ELISA was positive in 53.3%. The degree of concordance between the tests was substantial (83.3%). A positive correlation was demonstrated between the results obtained in the semi-quantitative ML Flow test and ELISA absorbance values. We concluded that both serological assays were found to be efficient in detecting anti-PGL1 antibodies. The ML Flow test may be a cheaper and easier to perform alternative to ELISA in leprosy patients.

Efficacy of killed whole-parasite vaccines in the prevention of leishmaniasis: a meta-analysis.

Despite decades of investigation in countries on three continents, an efficacious vaccine against Leishmania infections has not been developed. Although some indication of protection was observed in some of the controlled trials conducted with "first-generation" whole, inactivated Leishmania parasite vaccines, convincing evidence of protection was lacking. After reviewing all previously published or unpublished randomized, controlled field efficacy clinical trials of prophylactic candidate vaccines, a meta-analysis of qualified trials was conducted to evaluate whether there was some evidence of protection revealed by considering the results of all trials together. The findings indicate that the whole-parasite vaccine candidates tested do not confer significant protection against human leishmaniasis.

First generation leishmaniasis vaccines: a review of field efficacy trials.

First generation candidate vaccines against leishmaniasis, prepared using inactivated whole parasites as their main ingredient, were considered as promising because of their relative ease of production and low cost. These vaccines have been the subject of many investigations over several decades and are the only leishmaniasis vaccine candidates which have undergone phase 3 clinical trial evaluation. Although the studies demonstrated the safety of the vaccines and several studies showed reasonable immunogenicity and some indication of protection, an efficacious prophylactic vaccine is yet to be identified. Despite this overall failure, these trials contributed significantly to increasing knowledge on human leishmaniasis immunology. To provide a collective view, this review discusses the methods and findings of field efficacy trials of first generation leishmaniasis vaccine clinical trials conducted in the Old and New Worlds.

Comparative study of the cutaneous sensation of leprosy-suspected lesions using Semmes-Weinstein monofilaments and quantitative thermal testing.

The objective of the present study was to compare the warm cold perception thresholds (WPT), cold perception thresholds (CPT) and the warm and cold perception interval (WCPI) determined in our previous study with the touch-pressure thresholds, in leprosy-suspected skin lesions ('patch'). Thermal testing was conducted using a thermal sensory analyser TSA-2001 (Medoc Ltd., Israel) and the method of levels. The touch-pressure thresholds were measured using Semmes-Weinstein monofilament (SWM) of 0-05 g, 0.2 g, 2 g, 4 g, 10 g and 300 g. A cross-sectional study of 112 patients presenting with leprosy-suspected skin lesions, with no clinical evidence of peripheral nerve damage, was conducted. Leprosy diagnoses were based on clinical dermato-neurological examinations. One-hundred-and-eight subjects (45 males, 63 females; average age 37.7 years) completed the tests: 82 were positively diagnosed with leprosy and 26 with diseases of different aetiologies. The SWM test showed a sensitivity of 81.7% and a specificity of 96.1%, while the warm and cold perception thresholds presented sensitivity of 90.2% and 92-2%, respectively (both with 100% specificity). In leprosy patients, lesions that exhibited pressure thresholds of 0.05 g typically showed significantly different WPT, CPT and WCPI values when compared with skin lesions of different aetiologies. Within the leprosy group, the mean values of WPT, CPT and WCPI increased according to the increase in touch-pressure thresholds. Some of the patients exhibiting leprosy lesions with touch-pressure thresholds of 0-05 and 0-2 g presented normal WPT or CPT values. However, all patients with SWM equal or above 2.0 g presented altered WPT and CPT. All patients with leprosy, including those that exhibited pressure thresholds of 0.05 g, presented altered WCPI in the skin lesions. Despite a higher sensitivity to thermal tests, the SWM has adequate validity as a screening tool in the diagnosis of cutaneous forms of leprosy and in the selection of patients who should be submitted to a more detailed examination.

Disagreement between ultrasound and magnetic resonance imaging in the identification of schistosomal periportal fibrosis

Abdominal ultrasound (US) has been widely used in the evaluation of patients with schistosomiasis mansoni. It represents an important indirect method of diagnosis and classification of the disease, and it has also been used as a tool in the evaluation of therapeutic response and regression of fibrosis. We describe the case of a man in whom US showed solid evidence of schistosomal periportal fibrosis and magnetic resonance imaging revealed that periportal signal alteration corresponded to adipose tissue which entered the liver togheter with the portal vein.

Disagreement between ultrasound and magnetic resonance imaging in the identification of schistosomal periportal fibrosis.

Abdominal ultrasound (US) has been widely used in the evaluation of patients with schistosomiasis mansoni. It represents an important indirect method of diagnosis and classification of the disease, and it has also been used as a tool in the evaluation of therapeutic response and regression of fibrosis. We describe the case of a man in whom US showed solid evidence of schistosomal periportal fibrosis and magnetic resonance imaging revealed that periportal signal alteration corresponded to adipose tissue which entered the liver together with the portal vein.

Setting priorities for environmental sanitation interventions based on epidemiological criteria: a Brazilian study.

The present study addresses the use of analytical epidemiologic approaches to subsidize the establishment of priorities in environmental sanitation interventions. An epidemiological investigation was carried out in 1993 in the urban area of Betim, a southeast Brazilian City of 160,000 inhabitants. The case-control 'inclusive' (or case-cohort) design, with a sample of 997 cases and 999 controls, was employed. Cases were defined as children of less than five years of age presenting diarrhoea episodes, while controls were randomly selected among children of the same age, living in the study area. After logistic regression adjustment, 11 of several exposure variables analysed were significantly associated with diarrhoea. Four different criteria, using as risk measures the relative risk, the attributable risk, the standardized coefficient of the logistic regression and the cost standardized coefficient, were used in order to define intervention priorities.

Lessons from a national survey of Chagas disease transmission risk in Colombia.

In recent years, there has been a revitalization of large-scale programmes to control parasitic disease in developing countries. In 1997, the Governments of Colombia, Venezuela, Ecuador and Peru committed themselves to replicate the cost-effective elimination of Trypanosoma cruzi transmission achieved in the Southern Cone by using insecticides against the domestic triatomine vectors (in combination with blood-bank screening). Central American Governments launched a complementary initiative. All plan to interrupt vectorial transmission throughout the region by 2010 but specific targets are decided nationally. In this article, we highlight the novel approach taken by the Colombian Government for determining the geographic distribution of Chagas disease risk to select where to intervene first.

Failure of a killed Leishmania amazonensis vaccine against American cutaneous leishmaniasis in Colombia.

We report the results of a double-blind, randomized, placebo-controlled clinical trial of a killed whole-cell Leishmania amazonensis candidate vaccine against American cutaneous leishmaniasis (CL) in Colombia. The trial subjects were 2597 healthy volunteers with negative leishmanin skin test (LST) selected from rural Colombian soldiers who were going to patrol endemic areas. They were randomized to receive either three doses of vaccine (n=1295) or placebo (n=1302) given at 20-day intervals. An active and passive case detection system was established to follow-up volunteers for 1 year after vaccination. Safety and efficacy of the vaccine were determined by comparing local and systemic adverse reactions after each dose and the incidence of parasitologically confirmed CL. In the vaccine and placebo groups 101 (7.7%) and 88 (6.8%) volunteers developed CL respectively. The vaccine was shown to be safe but offered no protection against CL caused by L. panamensis in the proposed vaccination schedule.

Filariose bancroftiana em áreas urbanas do Estado de Alagoas, nordeste do Brasil: estudo em populaçäo geral / Bancroftian filariasis in urban areas of Alagoas State, Northeast Brazil: study in general population

Com objetivo de estudar a situaçäo da filariose linfática em Alagoas, foi realizado um inquérito hemoscópico na populaçäo geral de áreas urbanas das três diferentes regiöes fisiográficas do estado. Dos 101 municípios, foram pesquisados aleatoriamente 10, sendo a bancroftose detectada somente na capital, Maceió. Em um estudo seccional feito com a populaçäo geral de 4 bairros desta cidade foram examinados 10.973 indivíduos sendo detectados 226 microfilarêmicos, com prevalências nos bairros variando de O a 5,4 por cento. Tanto a prevalência de microfilarêmicos como a microfilaremia média foram significativamente maiores em indivíduos do sexo masculino. Entre os examinados näo nascidos em Maceió, o tempo de residência na área endêmica foi significativamente maior entre microfilarêmicos que entre amicrofilarêmicos. Baseado nestes dados, medidas de controle já foram implementadas visando a eliminaçäo da filariose linfática na regiäo

Epidemiological and clinical aspects of snakebite in Belo Horizonte, Southeast Brazil

Um estudo clinico-epidemiologico, comparando 310 pacientes hospitalizados por acidentes ofidicos (casos) e 310 pacientes hospitalizados por outras causas (controles), pareados por idade e sexo, durante um periodo de sete anos, foi conduzido em um hospital de emergencias em Belo Horizonte, MG. O diagnostico dos casos foi baseado no quadro clinico ou na identificacao do ofidio

Avaliaçäo de eficácia do programa de controle da Doença de Chagas: aspectos metodológicos / Evaluation of the efficacy of the Chagas'Disease control program: methodological aspects

A eficácia do Programa de Controle da Doença de Chagas (PCDCh) foi estimada em um estudo conduzido em Minas Gerais. Areas com diferentes tempos de intervençäo (cinco e 10 anos) e sem intervençäo (controle) foram comparadas para verificar possível reduçäo na incidência da infecçäo pelo Trypanosoma cruzi nos habitantes nascidos após a implantaçäo do PCDCh. A eficácia do PCDCh foi estimada pela comparaçäo dos resultados da infecçäo pelo T. cruzi, com resultados obtidos pelo Inquérito Sorológico Nacional (1975-1980), realizado antes do início do Programa. A comparaçäo seccional para a faixa etária de 2-6 anos indicou reduçäo nos índices de infecçäo de 94,7 por cento (área de 10 anos), 63,2 por cento (área de cinco anos) e 65,2 por cento (área sem intervençäo). Entretanto, a análise de coorte, para as faixas etárias de 2-6 anos e 7-14 anos, mostrou que a reduçäo observada (52,6 por cento) ocorreu somente na área com 10 anos de intervençäo. Os resultados encontrados mostraram associaçäo entre as açoes do PCDCh e a reduçäo da infecçäo pelo T. cruzi, estimada por testes sorológicos.

Toxoplasmosisand mental retardation: report of a case; control study

A case-control study evaluating the association between mental retardation and toxoplasmosis was conducted among 845 school children in Belo Horizonte, MG, Brazil. Cases (450) were mentally retarded children attending a public school for special education. Controls (395) were children from the regular public school system. Clinical and anthropometric examinations and interviews were carried out to determine risk factors for toxoplasmosis and mental retardation. Diagnosis of Toxoplasma gondii infection was based upon an indirect immunofluorescent test (IFA); 55% of cases and 29% of controls were positive. The Relative Odds of mental retardation in children with positive serology was 3.0 (95% CI 2.2-4.0). Maternal exposure to cats and contact with soil were associated with an increased risk of mental retardation. Retinochoroiditis was fourfold more prevalent among cases than controls and was only diagnosed in T. gondii IFA positive participants. Congenital toxoplasmosis, in its subclinical form, appears to be an important component in the etiology of mental retardation, especially in high risk (lower socio-economic) groups. The population attributable risk was estimated as 6.0 - 9.0%, suggesting the amount of mental retardation associated with this infection

Exposure to acellular blood products and risk of HIV infection in hemophiliacs from Belo Horizonte, Brazil

Results of a HIV prevalence study conducted in hemophiliacs from Belo Horizonte, Brazil are presented. History of exposure to acellular blood components was determined for the five year period prior to entry in the study, which occurred during 1986 and 1987. Patients with coagulations disorders (hemophilia A = 132, hemophilia B = 16 and coagulation disorders other than hemophilia = 16) were transfused with liquid cryoprecipitate, locally produced, lyophilized cryoprecipitate, imported from Säo Paulo (Brazil) and factor VIII and IX, imported from Rio de Janeiro (Brazil), Europe, and United States. Thirty six (22%) tested HIV seropositive. The univariate and multivariate analysis (logistic model) demonstrated that the risk of HIV infection during the study period was associated with the total units of acellular blood components transfused. In addition, the proportional contribution of the individual components to the total acellular units transfused, namely a increase in factor VIII/IX and lyophilized cryoprecipitate proportions, were found to be associated with HIV seropositivity. This analysis suggest that not only the total amount of units was an important determinant of HIV infection, but that the risk was also associated with the specific component of blood transfused

Comparison on the performance of Leishmania major-like and Leishmania braziliensis braziliensis as antigen for new world leishmaniasis IgG-immunofluorescence test

O desempenho de um antigeno de promastigotas de L. major-like para o diagnostico sorologico de leishmaniose mucocutanea pelo teste de imunofluorescencia-IgG foi comparado com o desempenho de um antigeno de L. braziliensis braziliensis. Cada antigeno foi usado para testar 224 soros de etiologias como leishmaniose mucocutanea, micoses profundas, toxoplasmose, malaria, doenca de Chagas, leishmaniose visceral, fator anti-nucleo, esquistossomose mansonica, fator reumatoide e controles normais. A concordancia entre as respostas de cada antigeno foi grande: 77,2 por cento dos soros de leishmaniose mostraram resultado positivo para ambos os antigenos ou negativo, assim como 91,1 por cento dos soros controle negativos. Reacoes cruzadas ficaram restritas a doenca de Chagas, leishmaniose visceral, fator anti-nucleo e paracoccidioidomicose. A resposta quantitativa dos soros de leishmaniose e doenca de Chagas foi avaliada pelo metodo de regressao linear; embora a interseccao com o eixo y e o "slope" fossem diferentes para cada antigeno nenhum deles se mostrou melhor na evidenciacao de anticorpos anti-Leishmania. O antigeno de L. major-like mostrou-se melhor que o de L.b. braziliensis na evidenciacao de anticorpos em soros de doenca de Chagas.