Search

Background: In Brazil, human visceral leishmaniasis (HVL) is caused by the protozoan parasite Leishmania infantum, primarily transmitted by the sand fly Lutzomyia longipalpis, with dogs acting as the main urban reservoir. This study aims to evaluate the effectiveness of 4% deltamethrin-impregnated dog collars (DMC) on HVL incidence. Methods: This is a community intervention study carried out from 2012 to 2015 in the municipalities of Araguaína, State of Tocantins, and Montes Claros, State of Minas Gerais, Brazil. Two areas in each were randomly allocated to either (1) culling seropositive dogs + residual insecticide spraying (control area—CA) or (2) culling seropositive dogs + residual insecticide spraying + DMC fitted to dogs every six months for two years (intervention area—IA). Cases of HVL (n = 1202) occurring from 2008 to 2020 were identified from the Brazilian Reportable Diseases Information System and georeferenced to the control and intervention areas. The HVL cases from 2008 to 2012 were considered as occurring in the "pre-intervention" period. Those cases from 2013 to 2016 and from 2017 to 2020 were regarded as occurring in the "intervention" and "post-intervention" periods, respectively. We used a mixed-effects Poisson regression model to estimate the effectiveness of the intervention, comparing the changes from the pre-intervention period to the intervention and post-intervention periods in the control and intervention areas. Results: In Araguaína, there was a statistically significant reduction in the incidence of HVL in both the control and intervention areas, comparing both the intervention and post-intervention periods with the pre-intervention period. The intervention with DMC was significantly associated with a reduction in HVL when comparing the intervention and pre-intervention periods, yielding an effectiveness estimate of the DMC of 27% (IC95% 1–46%, p = 0.045). No differences were observed when comparing the pre- and post-intervention periods (p = 0.827). In Montes Claros, cases reduced in both the control and intervention areas from the pre-intervention period to the intervention period (p = 0.913). In the post-intervention period, the incidence increased in the control area, while cases continued to decrease in the DMC area (p = 0.188). Conclusions: The use of DMC was associated with a reduction of 27% in the incidence of HVL during the period of DMC delivery, indicating that DMC is effective as an additional strategy for controlling visceral leishmaniasis in Brazil. However, no significant reduction associated with DMC was detected after the intervention period, suggesting that a control program based on the large-scale deployment of DMC might have to be maintained for more extended periods without interruption. [ABSTRACT FROM AUTHOR]

The detection of spatial clusters has been suggested as a potential tool for guiding the delivery of interventions against visceral leishmaniasis; however, little attention has been given to the consistency of results by using different spatial clustering methods. The present study aimed to assess the performance of three different techniques for identifying patterns in the spatial distribution of canine leishmaniasis in the city of Teresina, Brazil. This cross-sectional study was based on a serological survey for canine leishmaniasis in which each dog domicile was georeferenced to the exact location of each animal in space. The spatial analysis was performed using three methods: the Cuzick-Edwards statistic, the Hierarchical Nearest Neighbour analysis, and the Kulldorff Scan statistic. All techniques were able to identify clusters of high prevalences of canine leishmaniasis, but results were not consistent among techniques. The feasibility of the identification and location of clusters of cases in a restricted number of villages in neighborhoods might contribute to the optimization of control measures against visceral leishmaniasis. However, given the relative inconsistency of the results provided by the different methods, protocols for assessing clusters of diseases should always include more than one method of evaluation. [ABSTRACT FROM AUTHOR]

Vector-borne diseases (VBDs) are important contributors to the global disease burden and are a key factor in perpetuating economic inequality. Although environmental changes are often cited as drivers of VBDs, the link between deforestation and VBD occurrence remains unclear. Here, we examined this relationship in detail using the spread of visceral leishmaniasis (VL) in São Paulo state (Brazil) as the case study. We used a two-step approach to estimate the causal effects (overall, direct, and indirect) of deforestation on the occurrence of the VL vector, canine visceral leishmaniasis (CVL), and human visceral leishmaniasis (HVL). We first estimated the parameters via a double Metropolis–Hastings algorithm and then estimated the causal effects through a Gibbs sampler. We observed that the odds of vector, CVL, and HVL occurrence were 2.63-, 2.07-, and 3.18-fold higher, respectively, in deforested compared with forested municipalities. We also identified a significant influence of the presence of vector, CVL, and HVL in one municipality on disease occurrence in previously naive neighbouring municipalities. Lastly, we found that a hypothetical reduction in deforestation prevalence from 50 to 0% across the state would reduce vector, CVL, and HVL occurrence by 11%, 6.67%, and 29.87%, respectively. Our results suggest that implementing an eco-friendly development strategy that considers trade-offs between agriculture, urbanization, and conservation could be an effective mechanism of controlling VL. [ABSTRACT FROM AUTHOR]

Background: The study presents estimates for the burden of visceral leishmaniasis (VL) and cutaneous and mucocutaneous leishmaniasis (CML) in Brazil and its 27 federated units using data from the Global Burden of Disease Study (GBD) 2016. Methodology: We report the incidence, years of life lost (YLL), years lived with disability (YLD), and disability-adjusted life years (DALY) for leishmaniasis in Brazil from 1990 to 2016. The metrics are presented as age-standardized rates per 100,000 inhabitants with their respective uncertainty intervals (95%UI) and relative percentages of change. Principal findings: The age-standardized incidence rate of leishmaniasis decreased 48.5% from 1990 (71.0, 95%UI 24.3–150.7) to 2016 (36.5, 95%UI 24.7–50.9), whereas the age-standardized DALY increased 83.6% over the studied period from 12.2 (95%UI 7.9–18.8) to 22.4 (95%UI 13.3–36.2). The age-standardized incidence rate and YLL for VL increased by 52.9% and 108% from 1990 to 2016, respectively. Considering CML, the age-standardized incidence rate and YLD decreased by 51% and 31.8% respectively for the same period. For VL, similar profiles for male and female were observed, with YLL and DALY increasing over time; with males presenting slightly higher values. The highest YLL rates were among "under 1-year old" children, which increased 131.2% from 1990 to 2016. Regarding CML, the highest values of YLD and DALY were verified among males, and YLD values showed a similar profile, with rates increasing with age. The VL burden increased in some states in the Northeast and Southeast regions and decreased for CML in some Northern states. Conclusion: The increase of VL burden over the study period might be associated with the difficulties in controlling the disease spread. Information regarding the weight of VL and CML, including the death and disability tolls that they cause, highlights the impact of these neglected diseases on public health and the importance of effective prevention and treatment. [ABSTRACT FROM AUTHOR]

Background: Neglected Tropical Diseases (NTDs) are important causes of morbidity, disability, and mortality among poor and vulnerable populations in several countries worldwide, including Brazil. We present the burden of NTDs in Brazil from 1990 to 2016 based on findings from the Global Burden of Diseases, Injuries, and Risk Factors Study 2016 (GBD 2016). Methodology: We extracted data from GBD 2016 to assess years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) for NTDs by sex, age group, causes, and Brazilian states, from 1990 to 2016. We included all NTDs that were part of the priority list of the World Health Organization (WHO) in 2016 and that are endemic/autochthonous in Brazil. YLDs were calculated by multiplying the prevalence of sequelae multiplied by its disability weight. YLLs were estimated by multiplying each death by the reference life expectancy at each age. DALYs were computed as the sum of YLDs and YLLs. Principal findings: In 2016, there were 475,410 DALYs (95% uncertainty interval [UI]: 337,334–679,482; age-standardized rate of 232.0 DALYs/100,000 population) from the 12 selected NTDs, accounting for 0.8% of national all-cause DALYs. Chagas disease was the leading cause of DALYs among all NTDs, followed by schistosomiasis and dengue. The sex-age-specific NTD burden was higher among males and in the youngest and eldest (children <1 year and those aged ≥70 years). The highest age-standardized DALY rates due to all NTDs combined at the state level were observed in Goiás (614.4 DALYs/100,000), Minas Gerais (433.7 DALYs/100,000), and Distrito Federal (430.0 DALYs/100,000). Between 1990 and 2016, the national age-standardized DALY rates from all NTDs decreased by 45.7%, with different patterns among NTD causes and Brazilian states. Most NTDs decreased in the period, with more pronounced reduction in DALY rates for onchocerciasis, lymphatic filariasis, and rabies. By contrast, age-standardized DALY rates due to dengue, visceral leishmaniasis, and trichuriasis increased substantially. Age-standardized DALY rates decreased for most Brazilian states, increasing only in the states of Amapá, Ceará, Rio Grande do Norte, and Sergipe. Conclusions/Significance: GBD 2016 findings show that, despite the reduction in disease burden, NTDs are still important and preventable causes of disability and premature death in Brazil. The data call for renewed and comprehensive efforts to control and prevent the NTD burden in Brazil through evidence-informed and efficient and affordable interventions. Multi-sectoral and integrated control and surveillance measures should be prioritized, considering the population groups and geographic areas with the greatest morbidity, disability, and most premature deaths due to NTDs in the country. [ABSTRACT FROM AUTHOR]

Copyright of Cadernos de Saude Publica is the property of Escola Nacional de Saude Publica Sergio Arouca and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: The urbanization of visceral leishmaniasis (VL) and the concurrent movement of the HIV infection to rural areas in Brazil are possible mechanisms associated with an increased number of Leishmania/HIV coinfected people. This study aimed to describe the clinical and epidemiological profile of VL/HIV coinfected patients and compare this profile to non-coinfected VL patients. Methods: Cases of VL/HIV coinfection were obtained through a probabilistic record linkage of databases of VL and AIDS cases from the Brazilian Ministry of Health. Results: We retrieved 760 cases of VL/HIV coinfection, most prevalent in adult males, with incidence ranging from 0.01 to 0.07 cases, per 100.000 population, in 2001 and 2010, respectively. Case-fatality rates were 27.3% in 2001 and 23.2% in 2010. Weakness, weight loss, cough, other associated infections and haemorrhagic phenomena were more commonly found among coinfected patients, which had a fatality rate three times higher as compared to the non-coinfected group. The relapse proportion was two times greater among coinfected (6.3%) than non-coinfected (3.1%). Conclusions: The results found herein contribute to the increase of knowledge of the epidemiological situation of VL/HIV coinfection in Brazil and reinforce the necessity of implementing specific strategies to improve early case detection and efficacious and less toxic treatment in order to achieve lower case-fatality rates. [ABSTRACT FROM AUTHOR]

Background: In the current context of high fatality rates associated with American visceral leishmaniasis (VL), the appropriate use of prognostic factors to identify patients at higher risk of unfavorable outcomes represents a potential tool for clinical practice. This systematic review brings together information reported in studies conducted in Latin America, on the potential predictors of adverse prognosis (continued evolution of the initial clinical conditions of the patient despite the implementation of treatment, independent of the occurrence of death) and death from VL. The limitations of the existing knowledge, the advances achieved and the approaches to be used in future research are presented. Methods/Principal Findings: The full texts of 14 studies conforming to the inclusion criteria were analyzed and their methodological quality examined by means of a tool developed in the light of current research tools. Information regarding prognostic variables was synthesized using meta-analysis. Variables were grouped according to the strength of evidence considering summary measures, patterns and heterogeneity of effect-sizes, and the results of multivariate analyses. The strongest predictors identified in this review were jaundice, thrombocytopenia, hemorrhage, HIV coinfection, diarrhea, age <5 and age >40–50 years, severe neutropenia, dyspnoea and bacterial infections. Edema and low hemoglobin concentration were also associated with unfavorable outcomes. The main limitation identified was the absence of validation procedures for the few prognostic models developed so far. Conclusions/Significance: Integration of the results from different investigations conducted over the last 10 years enabled the identification of consistent prognostic variables that could be useful in recognizing and handling VL patients at higher risk of unfavorable outcomes. The development of externally validated prognostic models must be prioritized in future investigations. Author Summary: In contrast to other clinical presentations of leishmaniasis in Latin America, American visceral leishmaniasis (VL) can lead to death in 5-10% of patients under treatment. The fatality rates associated with this disease have remained stable at a high level over the years in Brazil and are neither recorded in under-treatment patients from endemic countries of the Old World nor from non-endemic countries where such cases are imported. Since VL-induced lethality can occur even after the implementation of recommended therapy, the understanding of individual, clinical and laboratory factors that predispose to an unfavorable outcome might represent an important feature for informing better practice in the clinical management of cases. The present systematic review with meta-analysis brings together information on various prognostic variables associated with the severity of VL. Potential predictors identified in the studies surveyed were grouped according to the strength of evidence available, and 13 were considered to be of significant relevance. The gaps in the existing knowledge and the need for the development of externally validated prognostic models were also discussed. The results presented herein could be useful in identifying patients at higher risk of unfavorable evolution or death from VL, and might provide an aid in decision-making regarding the clinical management of VL cases. [ABSTRACT FROM AUTHOR]

In visceral leishmaniasis (VL) endemic areas, a minority of infected individuals progress to disease since most of them develop protective immunity.Therefore, we investigated the riskmarkers of VL within nonimmune sector. Analyzing infected symptomatic and, asymptomatic, and noninfected individuals, VL patients presented with reduced high-density lipoprotein cholesterol (HDLC), elevated triacylglycerol (TAG), and elevated very-low-density lipoprotein cholesterol (VLDL-C) levels. A polymorphism analysis of the lipoprotein lipase (LPL) gene using HindIII restriction digestion (N = 156 samples) (H+ = the presence and H- = the absence of mutation) revealed an increased adjusted odds ratio (OR) of VL versus noninfected individuals when the H+/H+ was compared with the H-/H- genotype (OR = 21.3; 95% CI = 2.32-3335.3; P = 0.003).The H+/H+ genotype and the H+ allele were associated with elevated VLDL-C and TAG levels (P < 0.05) and reduced HDL-C levels (P < 0.05). An analysis of the L162V polymorphism in the peroxisome proliferator-activated receptor alpha (PPARα) gene (n = 248) revealed an increased adjusted OR when the Leu/Val was compared with the Leu/Leu genotype (OR = 8.77; 95% CI = 1.41-78.70; P = 0.014). High TAG (P = 0.021) and VLDL-C (P = 0.023) levels were associated with susceptibility to VL, whereas low HDL (P = 0.006) levels with resistance to infection.The mutated LPL and the PPARα Leu/Val genotypes may be considered risk markers for the development of VL. [ABSTRACT FROM AUTHOR]

Background: Still today, more than 30 years after the beginning of the process of visceral leishmaniasis' urbanization, there is little knowledge about the risk factors for its occurrence, despite their relevance to the control and understanding of disease dynamics. The present study is the first systematic review with meta-analysis about factors associated with Leishmania infantum infection in humans in the Americas. Methods and Findings: After searching different databases, consultations to the reference lists of articles and to experts in the field, 51 studies were reviewed. Theoretical discussions or meta-analysis of p-values or of effect sizes were used to pool information about each variable. The Q test and the I2 statistic were used to assess heterogeneities among the studies. Male sex was associated with visceral leishmaniasis in studies which used the leishmanin skin test for diagnosis and in those where the outcome was the clinical disease; the opposite occurred when serological diagnosis was applied. Younger individuals were less frequently infected than adults, but were more prone to illness. Although with different levels of evidence and of heterogeneity, the presence of dogs at home, higher dog seropositivity in nearby areas, lower socioeconomic status and highly vegetated areas were associated with L. infantum infection. This was not noticed for the presence of chickens in the house and with nutritional status. Susceptibilities to bias and limitations in the analysis and in the description of results were often identified in the studies analyzed. Conclusions: Results showed the existence of consistent patterns for some of the factors analyzed and should be taken into account in developing more effective and well-targeted control measures. Studies must be conducted in new areas of the continent, with improved methodological quality and prioritizing the investigation of the patterns identified and their causes, as well as variables for which knowledge is poor. Author Summary: Visceral leishmaniasis (VL) is the most severe clinical form of leishmaniasis. In the Americas, VL is a zoonosis caused by the protozoan parasite Leishmania infantum, an intracellular micro-organism transmitted to humans through the bite of female phlebotomine sand flies. The domestic dog is considered the main reservoir and human beings are dead-end hosts. The disease occurs in 12 countries of the New World and Brazil accounts for 90% of the reported cases. The factors associated with infection are only partially understood, making harder understanding the disease dynamics and the development of effective and well-targeted control measures. Our work is the first systematic review with meta-analysis about factors associated with human visceral leishmaniasis in the Americas. It provides an organization of the available information, the description of more accurate data on the role of each of the factors studied, the evaluation of possible causes of heterogeneity in the results of the studies as well as the analysis of the quality of publications and limitations in the existing knowledge. The results of this study might be useful in the definition of which and where target interventions should be delivered, and for guiding researchers towards the development of future studies of better methodological quality. [ABSTRACT FROM AUTHOR]

Copyright of Tropical Medicine & International Health is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Cadernos de Saude Publica is the property of Escola Nacional de Saude Publica Sergio Arouca and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)