31 research outputs found
Epidemiological aspects of visceral leishmaniasis (kala-azar) in Ceará in the period 2007 to 2011
Genetic Control of Canine Leishmaniasis: Genome-Wide Association Study and Genomic Selection Analysis
Background: the current disease model for leishmaniasis suggests that only a proportion of infected individuals develop clinical disease, while others are asymptomatically infected due to immune control of infection. The factors that determine whether individuals progress to clinical disease following Leishmania infection are unclear, although previous studies suggest a role for host genetics. Our hypothesis was that canine leishmaniasis is a complex disease with multiple loci responsible for the progression of the disease from Leishmania infection. Methodology/Principal Findings: genome-wide association and genomic selection approaches were applied to a population-based case-control dataset of 219 dogs from a single breed (Boxer) genotyped for ~170,000 SNPs. Firstly, we aimed to identify individual disease loci; secondly, we quantified the genetic component of the observed phenotypic variance; and thirdly, we tested whether genome-wide SNP data could accurately predict the disease. Conclusions/Significance: we estimated that a substantial proportion of the genome is affecting the trait and that its heritability could be as high as 60%. Using the genome-wide association approach, the strongest associations were on chromosomes 1, 4 and 20, although none of these were statistically significant at a genome-wide level and after correcting for genetic stratification and lifestyle. Amongst these associations, chromosome 4: 61.2-76.9 Mb maps to a locus that has previously been associated with host susceptibility to human and murine leishmaniasis, and genomic selection estimated markers in this region to have the greatest effect on the phenotype. We therefore propose these regions as candidates for replication studies. An important finding of this study was the significant predictive value from using the genomic information. We found that the phenotype could be predicted with an accuracy of ~0.29 in new samples and that the affection status was correctly predicted in 60% of dogs, significantly higher than expected by chance, and with satisfactory sensitivity-specificity values (AUC = 0.63)
Of cattle, sand flies and men : a systematic review of risk factor analyses for South Asian visceral leishmaniasis and implications for elimination
Background: Studies performed over the past decade have identified fairly consistent epidemiological patterns of risk
factors for visceral leishmaniasis (VL) in the Indian subcontinent.
Methods and Principal Findings: To inform the current regional VL elimination effort and identify key gaps in knowledge,
we performed a systematic review of the literature, with a special emphasis on data regarding the role of cattle because
primary risk factor studies have yielded apparently contradictory results. Because humans form the sole infection reservoir,
clustering of kala-azar cases is a prominent epidemiological feature, both at the household level and on a larger scale.
Subclinical infection also tends to show clustering around kala-azar cases. Within villages, areas become saturated over a
period of several years; kala-azar incidence then decreases while neighboring areas see increases. More recently, post kalaazar
dermal leishmaniasis (PKDL) cases have followed kala-azar peaks. Mud walls, palpable dampness in houses, and peridomestic
vegetation may increase infection risk through enhanced density and prolonged survival of the sand fly vector.
Bed net use, sleeping on a cot and indoor residual spraying are generally associated with decreased risk. Poor micronutrient
status increases the risk of progression to kala-azar. The presence of cattle is associated with increased risk in some studies
and decreased risk in others, reflecting the complexity of the effect of bovines on sand fly abundance, aggregation, feeding
behavior and leishmanial infection rates. Poverty is an overarching theme, interacting with individual risk factors on multiple
levels.
Conclusions: Carefully designed demonstration projects, taking into account the complex web of interconnected risk
factors, are needed to provide direct proof of principle for elimination and to identify the most effective maintenance
activities to prevent a rapid resurgence when interventions are scaled back. More effective, short-course treatment
regimens for PKDL are urgently needed to enable the elimination initiative to succeed
Complexities of Assessing the Disease Burden Attributable to Leishmaniasis
Among parasitic diseases, morbidity and mortality caused by leishmaniasis are surpassed only by malaria and lymphatic filariasis. However, estimation of the leishmaniasis disease burden is challenging, due to clinical and epidemiological diversity, marked geographic clustering, and lack of reliable data on incidence, duration, and impact of the various disease syndromes. Non-health effects such as impoverishment, disfigurement, and stigma add to the burden, and introduce further complexities. Leishmaniasis occurs globally, but has disproportionate impact in the Horn of Africa, South Asia and Brazil (for visceral leishmaniasis), and Latin America, Central Asia, and southwestern Asia (for cutaneous leishmaniasis). Disease characteristics and challenges for control are reviewed for each of these foci. We recommend review of reliable secondary data sources and collection of baseline active survey data to improve current disease burden estimates, plus the improvement or establishment of effective surveillance systems to monitor the impact of control efforts
Profile and geographic distribution of reported cases of visceral leishmaniasis in Campo Grande, State of Mato Grosso do Sul, Brazil, from 2002 to 2009
Diagnosing human asymptomatic visceral leishmaniasis in an urban area of the State of Minas Gerais, using serological and molecular biology techniques
STRUCTURE of SULFATED GLYCOSAMINOGLYCANS SYNTHESIZED DURING the ONTOGENY of the MOLLUSK POMACEA SP
ESCOLA PAULISTA MED SCH,DEPT BIOQUIM,BR-04034 São Paulo,SP,BRAZILESCOLA PAULISTA MED SCH,DEPT BIOQUIM,BR-04034 São Paulo,SP,BRAZILWeb of Scienc
BIOSYNTHESIS of AN ACIDIC GALACTAN and SULFATED GLYCOSAMINOGLYCANS DURING EMBRYONIC-DEVELOPMENT of the MOLLUSK POMACEA SP
ESCOLA PAULISTA MED,DEPT BIOQUIM,CP 20372,BR-04023 São Paulo,SP,BRAZILUNIV FED RIO GRANDE NORTE,DEPT BIOQUIM,NATAL,RN,BRAZILESCOLA PAULISTA MED,DEPT BIOQUIM,CP 20372,BR-04023 São Paulo,SP,BRAZILWeb of Scienc
CHARACTERISTIC DISTRIBUTION of HEPARAN SULFATES and CHONDROITIN SULFATES in TISSUES and ORGANS of the AMPULARIDAE-POMACEA SP
ESCOLA PAULISTA MED,DEPT BIOQUIM,BR-01000 São Paulo,SP,BRAZILESCOLA PAULISTA MED,DEPT BIOQUIM,BR-01000 São Paulo,SP,BRAZILWeb of Scienc