Forecasting temporal dynamics of cutaneous leishmaniasis in Northeast Brazil.
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ABSTRACT: Introduction
Cutaneous leishmaniasis (CL) is a vector-borne disease of increasing importance in northeastern Brazil. It is known that sandflies, which spread the causative parasites, have weather-dependent population dynamics. Routinely-gathered weather data may be useful for anticipating disease risk and planning interventions.Methodology/principal findings
We fit time series models using meteorological covariates to predict CL cases in a rural region of Bahía, Brazil from 1994 to 2004. We used the models to forecast CL cases for the period 2005 to 2008. Models accounting for meteorological predictors reduced mean squared error in one, two, and three month-ahead forecasts by up to 16% relative to forecasts from a null model accounting only for temporal autocorrelation.Significance
These outcomes suggest CL risk in northeastern Brazil might be partially dependent on weather. Responses to forecasted CL epidemics may include bolstering clinical capacity and disease surveillance in at-risk areas. Ecological mechanisms by which weather influences CL risk merit future research attention as public health intervention targets.
SUBMITTER: Lewnard JA
PROVIDER: S-EPMC4214672 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundCutaneous leishmaniasis (CL) is a vector-borne disease classified by the World Health Organization as one of the most neglected tropical diseases. Brazil has the highest incidence of CL in America and is one of the ten countries in the world with the highest number of cases. Understanding the spatiotemporal dynamics of CL is essential to provide guidelines for public health policies in Brazil. In the present study we used a spatial and temporal statistical approach to evaluate the dynamics of CL in Brazil.MethodsWe used data of cutaneous leishmaniasis cases provided by the Ministry of Health of Brazil from 2001 to 2017. We calculated incidence rates and used the Mann-Kendall trend test to evaluate the temporal trend of CL in each municipality. In addition, we used Kuldorff scan method to identify spatiotemporal clusters and emerging hotspots test to evaluate hotspot areas and their temporal trends.ResultsWe found a general decrease in the number of CL cases in Brazil (from 15.3 to 8.4 cases per 100 000 habitants), although 3.2% of municipalities still have an increasing tendency of CL incidence and 72.5% showed no tendency at all. The scan analysis identified a primary cluster in northern and central regions and 21 secondary clusters located mainly in south and southeast regions. The emerging hotspots analysis detected a high spatial and temporal variability of hotspots inside the main cluster area, diminishing hotspots in eastern Amazon and permanent, emerging, and new hotspots in the states of Amapá and parts of Pará, Roraima, Acre and Mato Grosso. The central coast the state of Bahia is one of the most critical areas due to the detection of a cluster of the highest rank in a secondary cluster, and because it is the only area identified as an intensifying hotspot.ConclusionsUsing a combination of statistical methods we were able to detect areas of higher incidence of CL and understand how it changed over time. We suggest that these areas, especially those identified as permanent, new, emerging and intensifying hotspots, should be targeted for future research, surveillance, and implementation of vector control measures.
| S-EPMC8207768 | biostudies-literature
Project description:Acre has reported the highest incidence of American cutaneous leishmaniasis (ACL) in Brazil in recent years. The present study seeks to identify high and low risk agglomerations of ACL in space and space-time during the period from 2007 to 2013 in Acre, and also to characterize the occurrence of the disease in time and according to sociodemographic variables.This is an ecological study, the study population of which consisted of autochthonous ACL cases notified in the municipalities of Acre by an epidemiological surveillance system. Scan statistics of SaTScan™ software were used to identify spatial and space-time clusters. In addition, the cases were characterized by sex, age, home situation (in a rural or urban area), and temporal tendency.Acre reported an incidence rate of 12.4 cases per 10 000 inhabitant-years in the study period, with the rates varied greatly (standard deviation of 21.8) among their 22 municipalities. One agglomeration of high risk and three of low risk were detected in space and space-time. Four of the five micro-regions of Acre presented a stationary temporal tendency. The profile of transmission varied according to the micro-region. Generally speaking, the disease occurred more often among young people, those of male gender, and those living in rural areas.Acre has stood out within the Brazilian national context due to its high rates of ACL incidence in the central region of the Acre Valley. The high rates in the micro-region of Brasiléia are related to the disease's intra/peridomiciliary occurrence, and it would seem that the municipality of Sena Madureira is approaching a transmission pattern similar to that of Brasiléia. In other micro-regions, the profile of the disease's transmission is mainly related to the forest/sylvatic cycle of ACL.
| S-EPMC5461694 | biostudies-other
Project description:BackgroundZoonotic cutaneous leishmaniasis (ZCL) is a neglected tropical disease worldwide, especially the Middle East. Although previous works attempt to model the ZCL spread using various environmental factors, the interactions between vectors (Phlebotomus papatasi), reservoir hosts, humans, and the environment can affect its spread. Considering all of these aspects is not a trivial task.MethodsAn agent-based model (ABM) is a relatively new approach that provides a framework for analyzing the heterogeneity of the interactions, along with biological and environmental factors in such complex systems. The objective of this research is to design and develop an ABM that uses Geospatial Information System (GIS) capabilities, biological behaviors of vectors and reservoir hosts, and an improved Susceptible-Exposed-Infected-Recovered (SEIR) epidemic model to explore the spread of ZCL. Various scenarios were implemented to analyze the future ZCL spreads in different parts of Maraveh Tappeh County, in the northeast region of Golestan Province in northeastern Iran, with alternative socio-ecological conditions.ResultsThe results confirmed that the spread of the disease arises principally in the desert, low altitude areas, and riverside population centers. The outcomes also showed that the restricting movement of humans reduces the severity of the transmission. Moreover, the spread of ZCL has a particular temporal pattern, since the most prevalent cases occurred in the fall. The evaluation test also showed the similarity between the results and the reported spatiotemporal trends.ConclusionsThis study demonstrates the capability and efficiency of ABM to model and predict the spread of ZCL. The results of the presented approach can be considered as a guide for public health management and controlling the vector population .
| S-EPMC7659076 | biostudies-literature
Project description:Mapping murine genes controlling cutaneous leishmaniasis (CL) identified Fli1 as a candidate influencing resistance to L. major and enhanced wound healing. We examine FLI1 as a gene controlling CL and mucosal leishmaniasis (ML) caused by L. braziliensis in humans. Intron 1 single nucleotide polymorphisms tagging promoter and enhancer elements were analysed in 168 nuclear families (250 CL; 87 ML cases) and replicated in 157 families (402 CL; 39 ML cases). Robust case-pseudocontrol logistic regression analysis showed association between allele C (odds ratio (OR) 1.65; 95% confidence interval 1.18-2.29; P=0.003) of FLI1_rs7930515 and CL in the primary sample that was confirmed (OR 1.60; 95% confidence interval 1.10-2.33; P=0.014) in the replication set (combined P=1.8 × 10(-4)). FLI1_rs7930515 is in linkage disequilibrium with the functional GAn microsatellite in the proximal promoter. Haplotype associations extended across the enhancer, which was not polymorphic. ML associated with inverse haplotypes compared with CL. Wound healing is therefore important in CL, providing potential for therapies modulating FLI1.
| S-EPMC3297968 | biostudies-literature
Project description:Leishmania braziliensis causes cutaneous (CL) and mucosal (ML) leishmaniasis. In the mouse, Fli1 was identified as a gene influencing enhanced wound healing and resistance to CL caused by Leishmania major. Polymorphism at FLI1 is associated with CL caused by L. braziliensis in humans, with an inverse association observed for ML disease. Here we extend the analysis to look at other wound healing genes, including CTGF, TGFB1, TGFBR1/2, SMADS 2/3/4/7 and FLII, all functionally linked along with FLI1 in the TGF beta pathway. Haplotype tagging single nucleotide polymorphisms (tag-SNPs) were genotyped using Taqman technology in 325 nuclear families (652 CL cases; 126 ML cases) from Brazil. Robust case-pseudocontrol (CPC) conditional logistic regression analysis showed associations between CL and SNPs at CTGF (SNP rs6918698; CC genotype; OR 1.67; 95%CI 1.10-2.54; P=0.016), TGFBR2 (rs1962859; OR 1.50; 95%CI 1.12-1.99; P=0.005), SMAD2 (rs1792658; OR 1.57; 95%CI 1.04-2.38; P=0.03), SMAD7 (rs4464148; AA genotype; OR 2.80; 95%CI 1.00-7.87; P=0.05) and FLII (rs2071242; OR 1.60; 95%CI 1.14-2.24; P=0.005), and between ML and SNPs at SMAD3 (rs1465841; OR 2.15; 95%CI 1.13-4.07; P=0.018) and SMAD7 (rs2337107; TT genotype; OR 3.70; 95%CI 1.27-10.7; P=0.016). Stepwise logistic regression analysis showed that all SNPs associated with CL at FLI1, CTGF, TGFBR2, and FLII showed independent effects from each other, but SNPs at SMAD2 and SMAD7 did not add independent effects to SNPs from other genes. These results suggest that TGF? signalling via SMAD2 is important in directing events that contribute to CL, whereas signalling via SMAD3 is important in ML. Both are modulated by the inhibitory SMAD7 that acts upstream of SMAD2 and SMAD3 in this signalling pathway. Along with the published FLI1 association, these data further contribute to the hypothesis that wound healing processes are important determinants of pathology associated with cutaneous forms of leishmaniasis.
| S-EPMC3372530 | biostudies-literature
Project description:BackgroundVisceral leishmaniasis (VL) caused by Leishmania infantum became a disease of urban areas in Brazil in the last 30 years and there has been an increase in asymptomatic L. infantum infection with these areas.Methodology/principal findingsA retrospective study of human VL was performed in the state of Rio Grande do Norte, Brazil, for the period of 1990-2014. The data were divided into five-time periods. For all VL cases, data on sex, age, nutritional status and childhood vaccination were collected. Geographic information system tools and statistical models were used to analyze the dispersion of human VL. The mean annual incidence of VL was 4.6 cases/100,000 inhabitants, with total 3,252 cases reported. The lethality rate was 6.4%. Over time the annual incidence of VL decreased in the 0-4 years (p<0.0001) and 5-9 (p <0.0001) age groups, but increased in ages 20-39 (p<0.001) and >40 years (p<0.0001). VL occurred more often in males (?2 = 2.5; p<0.0001). The decreased incidence of VL in children was associated with improved nutritional status and childhood immunizations including measles, poliomyelitis, BCG, and hepatitis B. Human VL correlated temporally and geographically with canine L. infantum infection (p = 0.002, R2 = 0.438), with rainfall and with Lutzomyia longipalpis density (r = 0.762). Overall, the incidence of VL decreased, while VL-AIDS increased, especially between 2010-2014. VL was more frequently found in areas that lacked urban infrastructure, detected by lack of garbage collection and sewers, whereas HIV infection was associated with higher levels of schooling and evidence of higher socioeconomic status.Conclusion/significanceThe demographics of VL in northeastern Brazil have changed. Disease incidence has decreased in children and increased in adults. They were associated with improvements in nutrition, socioeconomic status and immunization rates. Concurrent VL-AIDS poses a serious challenge for the future.
| S-EPMC5839541 | biostudies-literature
Project description:Our goal was to identify genetic risk factors for cutaneous leishmaniasis (CL) caused by Leishmania braziliensis. Genotyping 2066 CL cases and 2046 controls using Illumina HumanCoreExomeBeadChips provided data for 4,498,586 imputed single nucleotide variants (SNVs). Genome-wide association testing using linear mixed models took account of genetic diversity/ethnicity/admixture. Post-GWAS positional, expression quantitative trait locus (eQTL), and chromatin interaction mapping was performed in FUMA. Transcriptional data were compared between lesions and normal skin, and cytokines measured using flow cytometry and Bioplex assay.
| EGAS00001004596 | EGA
Project description:The contribution of this paper is twofold. First, a new data driven approach for predicting the Covid-19 pandemic dynamics is introduced. The second contribution consists in reporting and discussing the results that were obtained with this approach for the Brazilian states, with predictions starting as of 4 May 2020. As a preliminary study, we first used an Long Short Term Memory for Data Training-SAE (LSTM-SAE) network model. Although this first approach led to somewhat disappointing results, it served as a good baseline for testing other ANN types. Subsequently, in order to identify relevant countries and regions to be used for training ANN models, we conduct a clustering of the world's regions where the pandemic is at an advanced stage. This clustering is based on manually engineered features representing a country's response to the early spread of the pandemic, and the different clusters obtained are used to select the relevant countries for training the models. The final models retained are Modified Auto-Encoder networks, that are trained on these clusters and learn to predict future data for Brazilian states. These predictions are used to estimate important statistics about the disease, such as peaks and number of confirmed cases. Finally, curve fitting is carried out to find the distribution that best fits the outputs of the MAE, and to refine the estimates of the peaks of the pandemic. Predicted numbers reach a total of more than one million infected Brazilians, distributed among the different states, with São Paulo leading with about 150 thousand confirmed cases predicted. The results indicate that the pandemic is still growing in Brazil, with most states peaks of infection estimated in the second half of May 2020. The estimated end of the pandemics (97% of cases reaching an outcome) spread between June and the end of August 2020, depending on the states.
| S-EPMC7400194 | biostudies-literature
Project description:Background and aimsLeishmaniasis is a neglected tropical disease which causes significant morbidity and mortality, particularly in developing countries. Cutaneous leishmaniasis (CL) is the main form of leishmaniasis that affects the skin. Knowledge and perception of people about leishmaniasis has a great impact to prevent the disease in endemic areas. Hence, the aim of this study was to assess the knowledge, attitude and preventive measures of Wegeltena secondary school students towards CL in Delanta district, one of the endemic areas in Northeast Ethiopia.MethodsA facility-based cross-sectional study was conducted from January 4 to 20, 2021 at Wegeltena secondary school in Delanta district, Northeast Ethiopia. A pre-tested, interviewer administered structured questionnaire was used to collect the data. Multivariable logistic regression analysis was utilized to measure the degree of association between outcome and independent variables. Statistically significant association with the outcome variables was declared at a p-value of <0.05.ResultsA total of 388 students were participated in the study. In overall, 27.6% and 34.5% of participants had good knowledge and favorable attitude towards CL, respectively. Being grade 12 (AOR = 2.56; 95% CI: 1.23-5.29) and dwelling in urban areas (AOR = 1.78; 95% CI: 1.09-2.89) were determinants of good knowledge. However, female sex (AOR = 1.96; 95% CI: 1.21-3.18) and had good knowledge about CL (AOR = 3.75; 95% CI: 2.26-6.21) were significantly associated with favorable attitude of respondents towards the disease.ConclusionIn this study, nearly three-fourth of participants had poor knowledge about CL and two-third of them had unfavorable attitude towards the disease. Level of education and residence were determinants of respondents' knowledge about CL. Moreover, sex and level of knowledge about CL were determinants of respondents' attitude towards the disease. Therefore, an intensified health education program shall be implemented in schools that are found in endemic areas.
| S-EPMC8818578 | biostudies-literature
Project description:BACKGROUND:The aim of this study was to compare cases of Visceral Leishmaniasis (VL) with and without HIV in a state in northeastern Brazil. METHODOLOGY:We performed a comparative study in the state's referral hospital for infectious/parasitic diseases located in Northeast Brazil between January 2007 and July 2017. The data obtained using this protocol were analyzed with SPSS. PRINCIPAL FINDINGS:In total, 252 patients were evaluated, including 126 with coincident VL/HIV and 126 with VL alone. Both groups primarily consisted of male patients. The most commonly affected ages were 30-39 years in the coinfected group and 19-29 years in the VL group (p < 0.001). Fever and anorexia (p = 0.001), which were more common in those with VL alone, were frequently observed, while diarrhea, vomiting, bleeding and dyspnea were more common in patients with VL/HIV coinfection (p<0.005). According to the hemogram results, leukocyte levels were lower in the VL group (p < 0.0001). Additionally, AST (aspartate aminotransferase) and ALT (alanine aminotransferase) levels differed between the groups, with higher levels in patients with VL (p < 0.001). On average, HIV was diagnosed 2.6 years before VL (p < 0.001), and VL relapse was observed only in the coinfection group (36.5% of cases). Fever (? = +0.17; p = 0.032) in the first VL/HIV episode was identified as a risk factor for relapse (R2 = 0.18). More deaths occurred in the VL/HIV group (11.1%) than in the VL group (2.4%). CONCLUSION/SIGNIFICANCE:VL/HIV was found to be prevalent among young adults, although the median patient age was higher in the VL/HIV group. The classic symptomatology of VL was more common in patients not coinfected with HIV; therefore, attention is needed in patients with HIV who present with any symptoms that suggest the presence of VL, especially in endemic areas. No cases of VL relapse occurred in patients without HIV, and death was more common in the VL/HIV co-infected group.
| S-EPMC6894860 | biostudies-literature