Identification of priority areas for surveillance of cutaneous leishmaniasis using spatial analysis approaches in Southeastern Brazil.

BACKGROUND: Cutaneous leishmaniasis (CL) is an important public health problem in Brazil and in several tropical regions of the world. In the Americas, Brazil is the country with the highest number of registered cases. In Brazil, the state of Minas Gerais has the highest number of cases in the southeastern region. In the present study, we used spatial analysis in the State of Minas Gerais to identify municipalities of priority during a nine-year period (2007-2015), which might be used to guide surveillance and control measures. METHODS: An ecological study with spatial analysis of autochthonous cases of CL was performed in the state of Minas Gerais between 2007 and 2015. We calculated incidence rates, used Empirical Bayesian smoothing for each municipality, and divided the analyses into three-year intervals. In order to analyze the existence of spatial autocorrelation, and to define priority areas, Moran's Global Index and Local Indicators of Spatial Association (LISA) were used. RESULTS: The mean incidence rate for the entire state was 6.1/100,000 inhabitants. For Minas Gerais, analysis of CL cases over time revealed a successive increase of indicated mesoregions with high priority municipalities. Eight of the designated mesoregions contained municipalities classified as high priority areas in any of the three evaluated trienniums, and four mesoregions had high priority municipalities throughout the entire investigation. CONCLUSIONS: Within the southeastern region of Brazil, Minas Gerais State stands out, with highest CL incidence rates. Using spatial analysis, we identified an increasing numbers of cases in the municipalities classified as high priority areas in different mesoregions of the state. This information might be of value to direct surveillance and control measures against CL and to understand the dynamics of the expansion of CL in Minas Gerais. Similar approaches might be used to map CL in other regions throughout Brazil, or in any other country, where national notification and control programs exist

Perfil de citocinas e quimiocinas no sangue periférico de indivíduos com carga parasitaria baixa na infecção pelo Schistosoma mansoni

Exportado OPUSMade available in DSpace on 2019-08-13T06:37:58Z (GMT). No. of bitstreams: 1 disserta__o_flu_vanessa_corre__o_13_11.pdf: 3080547 bytes, checksum: 966016789023c88df29be4043ee8a749 (MD5) Previous issue date: 21A esquistossomose mansônica é uma doença de curso crônico, sendo seu causador o parasito Schistosoma mansoni, e a exposição contínua e prolongada aos antígenos de Schistosoma mansoni, resulta em um desvio da resposta imune. O diagnóstico é realizado por meio do método de Kato-Katz, porém, o método apresenta pouca acurácia em áreas de baixa endêmicidade. Levando-se em conta tais fatores, o objetivo do presente trabalho é caracterizar o perfil de citocinas e quimiocinas e buscar marcadores imunológicos da infecção, que indiquem a presença do Schistosoma mansoni em indivíduos com carga parasitária extremamente baixa, que obtiveram positividade para esquistossomose nos métodos de Gradiente Salino e/ou Helmintex®, comparando-os com indivíduos positivos no método de Kato-Katz e indivíduos, que por vezes foram diagnosticados, negativos nos testes parasitológicos de fezes. No Norte de Minas Gerais, Município de Januária, 197 moradores da zona rural de Brejo do Amparo foram examinados por diferentes métodos parasitológicos. Dentre esses indivíduos, foram obtidas amostras de sangue de 174 moradores para a avaliação de marcadores imunológicos. Foram dosados por ELISA, marcadores imunológicos tipo 1 (IL-1, IL-6, TNF-, IL-27, CXCL10), marcadores tipo 2 (CCL11, CCL17, IL-5 e IL-13) marcadores Th17 (IL-17) e de regulação ( IL-10). Os resultados mostraram que no pré-tratamento, indivíduos com carga parasitária extremamente baixa apresentaram concentrações elevadas do marcador tipo 1, IL-6 no sangue periférico, mostrando que o grupo possui um processo inflamatório ativo. Quimiocinas como marcadores de resposta imune do tipo 1 (CXCL10) ou do tipo 2 (CCL11 e CCL17), foram detectadas indiferentemente nos quatro grupos analisados, indicando que não há explícita modulação da resposta no sangue periférico. O marcador regulatório IL-10 apresentou concentração mínima e indiferença entre os grupos. Em relação ao póstratamento, observou-se apenas o aumento da quimiocina CCL11, com diferença significativa, em todos os grupos analisados. Em geral, indivíduos infectados apresentaram uma tendência de diminuição de marcadores de inflamação do tipo 1 e um aumento de marcadores do tipo 2, que poderiam ser benéficos em caso de reinfecção.Schistosomiasis mansoni is a chronic disease and the prolonged and continuous exposure to Schistosoma mansoni antigens results in a deviation of the immune response. For the diagnosis in low endemicity areas, the Kato-Katz method is commonly applied, however, this method has low accuracy. This study aimed to characterize the cytokine and chemokine profile in individuals with extremely low parasite load, who were diagnosed positive with the saline gradient and/or Helmintex® methods, and compare the immunological profile with individuals diagnosed by the Kato-Katz method and with individuals repetitively negative by different stool exams. In the Municipality of Januária, Northern Minas Gerais, 197 residents from the rural area of Brejo do Amparo were examined by different parasitological methods. Among these individuals, blood samples of 174 residents were obtained for assessment of immunological markers, using commercially available sandwich ELISAs for the following markers: type 1 immune response (IL-1, IL-6, TNF-, IL-27, CXCL10), type 2 (CCL11, CCL17, IL-5 and IL-13), inflammatory Th17 (IL-17) and regulatory response (IL-10). The results showed that before treatment, individuals with extremely low parasitic load exhibited elevated concentrations of the type 1 marker IL-6 in the peripheral blood, indicating an active inflammatory process in this group. Chemokines, such as type 1 (CXCL10) or type 2 (CCL11 and CCL17) immune response markers were detected indifferently in the four analyzed groups. Therefore, an explicit immune modulation was not observed in the peripheral blood. Also, the concentrations of IL-10 as a regulatory marker were minimal and indifferent among groups. At post-treatment, an increase in CCL11 chemokine concentration was observed in all groups, when compared with pre-treatment levels. In general, infected individuals presented a tendency to decrease the type 1 inflammation markers after treatment and increase type 2 markers, which could be beneficial in case of reinfection

Evaluation of diagnostic methods for the detection of intestinal schistosomiasis in endemic areas with low parasite loads: Saline gradient, Helmintex, Kato-Katz and rapid urine test

<div><p>Background</p><p>In some tropical countries, such as Brazil, schistosomiasis control programs have led to a significant reduction in the prevalence and parasite burden of endemic populations. In this setting, the Kato-Katz technique, as the standard diagnostic method for the diagnosis of <i>Schistosoma mansoni</i> infections, which involves the analysis of two slides from one fecal sample, loses its sensitivity. As a result, a significant number of infected individuals are not detected. The objective of this study was to perform extensive parasitological testing of up to three fecal samples and include a rapid urine test (POC-CCA) in a moderate prevalence area in Northern Minas Gerais, Brazil, and evaluate the performance of each test separately and in combination.</p><p>Methods and findings</p><p>A total of 254 individuals were examined with variants of the standard Kato-Katz technique (up to18 Kato-Katz slides prepared from three fecal samples), a modified Helmintex (30 g of feces), the saline gradient (500 mg of feces), and the POC-CCA methods. We established a reference standard taking into consideration all the positive results in any of the parasitological exams. Evaluation of the parasite burden by two Kato-Katz slides confirmed that most of the individuals harbored a light infection. When additional slides and different parasitological methods were included, the estimated prevalence rose 2.3 times, from 20.4% to 45.9%. The best sensitivity was obtained with the Helmintex method (84%). All parasitological methods readily detected a high or moderate intensity of infection; however, all lost their high sensitivity in the case of low or very low intensity infections. The overall sensitivity of POC-CCA (64.9%) was similar to the six Kato-Katz slides from three fecal samples. However, POC-CCA showed low concordance (κ = 0.34) when compared with the reference standard.</p><p>Conclusions</p><p>The recommended Kato-Katz method largely underestimated the prevalence of <i>S</i>. <i>mansoni</i> infection. Because the best performance was achieved with a modified Helmintex method, this technique might serve as a more precise reference standard. An extended number of Kato-Katz slides in combination with other parasitological methods or with POC-CCA was able to detect more than 80% of egg-positive individuals; however, the rapid urine test (POC-CCA) produced a considerable percentage of false positive results.</p></div

Prevalence profile of intestinal schistosomiasis in an endemic population divided by different age groups according to the different parasitological methods.

<p>Black circles indicate the prevalence profile in the population considering the sum of all parasitological methods used (reference standard: 18 Kato-Katz slides, saline gradient, and Helmintex); grey squares indicate the prevalence profile considering the recommended two KK slides from one fecal sample. Prevalence values (%) for each age group are indicated.</p

Flowchart describing the workflow for the diagnosis of intestinal schistosomiasis in an endemic population within the district of Brejo do Amparo, Januária, Minas Gerais, Brazil.

<p>Fecal samples were examined with the Kato-Katz technique with one fecal sample and two (SPL1 K1-K2), six (SPL1 K1-K6), 12 (SPL1 K1-K12), and 14 thick-smears (SPL1 K1-K14), or with three fecal samples with two slides each (SPL1-3 K1-K2), saline gradient, Helmintex and spontaneous sedimentation technique (HPJ). Further, individual urine samples were analyzed with the point-of-care rapid urine test (POC-CCA) that detects the circulating cathodic antigen of <i>Schistosoma mansoni</i>. The numbers in brackets indicate the number of individuals tested with each method.</p

Sensitivity of different diagnostic methods for the detection of intestinal schistosomiasis considering the parasite load, as defined by egg counts of two Kato-Katz slides.

<p>Sensitivity of different diagnostic methods for the detection of intestinal schistosomiasis considering the parasite load, as defined by egg counts of two Kato-Katz slides.</p

Prevalence of <i>Schistosoma mansoni</i> infection and other intestinal parasites in a rural community of the Municipality of Januária, Minas Gerais, Brazil.

<p>Prevalence of <i>Schistosoma mansoni</i> infection and other intestinal parasites in a rural community of the Municipality of Januária, Minas Gerais, Brazil.</p

Performance of the rapid urine test (POC-CCA) for the diagnosis of <i>Schistosoma mansoni</i> infection.

<p><b>A:</b> Photograph showing the different reactions possible with the POC-CCA: negative, trace, weak (+), medium (++) and strong (+++). <b>B:</b> Distribution of the POC-CCA results in individuals from an endemic area classified as negative (n = 116) or positive (n = 112) for <i>S</i>. <i>mansoni</i> infection by extensive parasitological testing (Reference standard: 18 Kato-Katz slides, saline gradient, and Helmintex); total n = 228). Data indicate the percentages of POC-CCA reactivities in each group of parasitologically negative or positive individuals. Red circles indicate discordant results in comparison with the reference standard (false positive: 28 and 2%; or false negative: 35%).</p

Prevalence, sensitivity and specificity of different diagnostic tests when combined with the Kato-Katz method, as compared with the reference standard (18 Kato-Katz slides, saline gradient, and Helmintex).

<p>Prevalence, sensitivity and specificity of different diagnostic tests when combined with the Kato-Katz method, as compared with the reference standard (18 Kato-Katz slides, saline gradient, and Helmintex).</p