Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
LanguageLanguage
-
SubjectSubject
-
Item TypeItem Type
-
DisciplineDiscipline
-
YearFrom:-To:
-
More FiltersMore FiltersIs Peer Reviewed
Done
Filters
Reset
598
result(s) for
"Leandro, André S."
Sort by:
Citywide Integrated Aedes aegypti Mosquito Surveillance as Early Warning System for Arbovirus Transmission, Brazil
2022
Arbovirus epidemiology lacks efficient and timely surveillance systems with accurate outbreak alert signals. We devised a citywide integrated surveillance system combining entomologic, epidemiologic, and entomo-virologic data gathered during 2017-2020 in Foz do Iguaçu, Brazil. We installed 3,476 adult mosquito traps across the city and inspected traps every 2 months. We compared 5 entomologic indices: traditional house and Breteau indices for larval surveys and trap positivity, adult density, and mosquitoes per inhabitant indices for adult trapping. We screened for dengue, Zika, and chikungunya viruses in live adult Aedes aegypti mosquitoes collected from traps. Indices based on adult mosquito sampling had higher outbreak predictive values than larval indices, and we were able to build choropleth maps of infestation levels <36 h after each round of trap inspection. Locating naturally infected vectors provides a timely support tool for local public health managers to prioritize areas for intervention response to prevent virus outbreaks.
Journal Article
Spatial analysis of dengue transmission in an endemic city in Brazil reveals high spatial structuring on local dengue transmission dynamics
by
Garey, Michel Varajão
,
Chiba de Castro, Wagner A.
,
Maciel-de-Freitas, Rafael
in
631/326/417
,
631/326/421
,
692/699/255
2024
In the last decades, dengue has become one of the most widespread mosquito-borne arboviruses in the world, with an increasing incidence in tropical and temperate regions. The mosquito
Aedes aegypti
is the dengue primary vector and is more abundant in highly urbanized areas. Traditional vector control methods have showing limited efficacy in sustaining mosquito population at low levels to prevent dengue virus outbreaks. Considering disease transmission is not evenly distributed in the territory, one perspective to enhance vector control efficacy relies on identifying the areas that concentrate arbovirus transmission within an endemic city, i.e., the hotspots. Herein, we used a 13-month timescale during the SARS-Cov-2 pandemic and its forced reduction in human mobility and social isolation to investigate the spatiotemporal association between dengue transmission in children and entomological indexes based on adult
Ae. aegypti
trapping. Dengue cases and the indexes Trap Positive Index (TPI) and Adult Density Index (ADI) varied seasonally, as expected: more than 51% of cases were notified on the first 2 months of the study, and higher infestation was observed in warmer months. The Moran's Eigenvector Maps (MEM) and Generalized Linear Models (GLM) revealed a strong large-scale spatial structuring in the positive dengue cases, with an unexpected negative correlation between dengue transmission and ADI. Overall, the global model and the purely spatial model presented a better fit to data. Our results show high spatial structure and low correlation between entomological and epidemiological data in Foz do Iguaçu dengue transmission dynamics, suggesting the role of human mobility might be overestimated and that other factors not evaluated herein could be playing a significant role in governing dengue transmission.
Journal Article
Assessing mosquito dynamics and dengue transmission in Foz do Iguaçu, Brazil through an enhanced temperature-dependent mathematical model
2025
Dengue fever remains a major public health concern, requiring continuous efforts to mitigate its impact. This study investigates the influence of key temperature-dependent parameters on dengue transmission dynamics in Foz do Iguaçu, a tri-border municipality in southern Brazil, using a mathematical model based on a system of ordinary differential equations. The fitted model aligns well with observed data. To track changes in dengue transmission over time and detect epidemic onset, we calculated the effective reproduction number. Additionally, we explored the potential effects of climate variability on dengue dynamics. Our findings highlight the importance of vector population dynamics, climate, and incidence, offering insights into dengue transmission in Foz do Iguaçu. This research provides a foundation for optimizing intervention strategies in other cities, improving outbreak prediction, and supporting public health efforts in dengue control.
Journal Article
What is the optimal In2Care stations density to achieve Aedes aegypti population reduction in a dengue endemic setting?
by
Chiba de Castro, Wagner A.
,
Pires-Vieira, Lara H.
,
Reis, Murilo
in
Aedes - growth & development
,
Aedes - physiology
,
Animals
2025
Autodissemination traps are among the most innovative strategies for suppressing mosquito vector populations. These traps are particularly effective against Aedes aegypti due to the species' skip oviposition behavior, where eggs from a single clutch are distributed across multiple breeding sites. Evaluating the efficacy of different densities of In2Care stations under large-scale field conditions is crucial for understanding their potential impact on Ae. aegypti populations.
A total of 3,250 In2Care stations were deployed in Goiânia, the 10th largest city in Brazil, with an estimated population of 1.45 million. The field study lasted 14 months, with each station serviced bi-monthly. To assess the impact of In2Care, ovitraps were installed and inspected weekly to measure changes in the number of positive ovitraps and the average number of eggs laid by Ae. aegypti females in intervention areas compared to control neighborhoods. Over the course of the study, 666,204 eggs were sampled. The density of In2Care stations varied across neighborhoods, ranging from 220 to 555 stations per km2. In the high-density area (~555 stations per km2), the Ovitrap Positivity Index (OPI) decreased from 56.9% to 31.5%, while the average number of eggs per positive paddle dropped from 41.2 to 18.1-representing a 56% reduction in egg counts. Conversely, in the low- and medium-density, no significant effect was observed.
The recommended density of In2Care is about 2500 stations per Km2. Our results demonstrated stations density 4.5 times lower than the recommended density is able to reduce the frequency of positive ovitraps and the number of eggs collected on them. entomological indexes. Additional fieldwork in other entomological and epidemiological settings are needed to evaluate whether the In2Care density of ~555 units/Km2 observed for Goiânia was site-dependent or if it has borader applicability. Our results show that In2Care stations can effectively suppress Ae. aegypti populations over large geographic areas, with efficacy likely influenced by trap density.
Journal Article
Mosquitoes infected with dengue viruses in Brazil
by
de Figueiredo, Mario LG
,
de C Gomes, Almério
,
de S Leandro, André
in
Aedes albopictus
,
Animals
,
Biomedical and Life Sciences
2010
Dengue epidemics have been reported in Brazil since 1985. The scenery has worsened in the last decade because several serotypes are circulating and producing a hyper-endemic situation, with an increase of DHF/DSS cases as well as the number of fatalities. Herein, we report dengue virus surveillance in mosquitoes using a
Flavivirus
genus-specific RT-Hemi-Nested-PCR assay. The mosquitoes (
Culicidae
, n = 1700) collected in the Northeast, Southeast and South of Brazil, between 1999 and 2005, were grouped into 154 pools. Putative genomes of DENV-1, -2 and -3 were detected in 6 mosquito pools (3.8%). One amplicon of putative DENV-1 was detected in a pool of
Haemagogus leucocelaenus
suggesting that this virus could be involved in a sylvatic cycle. DENV-3 was found infecting 3 pools of larvae of
Aedes albopictus
and the nucleotide sequence of one of these viruses was identified as DENV-3 of genotype III, phylogenetically related to other DENV-3 isolated in Brazil. This is the first report of a nucleotide sequence of DENV-3 from larvae of
Aedes albopictus
.
Journal Article
Genetic profile and molecular resistance of Aedes (Stegomyia) aegypti (Diptera: Culicidae) in Foz do Iguaçu (Brazil), at the border with Argentina and Paraguay
by
Piccoli, Carla F.
,
Kafka, Rosinei
,
Navarro-Silva, Mário A.
in
Aquatic insects
,
Bioassays
,
Cypermethrin
2012
The genetic variability of populations of Aedes (Stegomyia) aegypti (Linnaeus, 1762) is often low due to the intense selection pressure caused by chemical control measures. In this study, we evaluated the susceptibility of larvae and adults of this mosquito to chemical insecticides, the frequency of the Val1016IIe mutation, and the genetic variability of the mitochondrial ND4 gene fragment in the urban area of Foz do Iguaçu, Paraná. The populations of A. aegypti in the southern and central regions of the city were resistant to the diagnostic dose of temephos 0.0162 ppm. Additionally, we detected difference in susceptibility in the northern population. The resistance ratios (RR95) were 3.8, 4.1, and 4.6 for the populations in the north, central, and south of the city, respectively. The entire population of A. aegypti in Foz do Iguaçu is resistant to pyrethroids. The mortality rates are as follows: 72.2% for cypermethrin (CD: 146 mg i.a./m²) and 57% for deltamethrin (CD: 18 mg i.a./m²). These results corroborate the hypothesis that the mutated 1016Ile allele is present in all analyzed strata. Out of the 234 samples genotyped for the Val1016Ile mutation, 15% were homozygous dominant for the wild allele (Val/Val), 62% were heterozygous (Va/Ile) and 23% were homozygous for the recessive mutation (Ile/Ile). With respect to the genetic variability of the mitochondrial ND4 gene fragment, 93% of the sequences analyzed belonged to haplotype 1, and 7% belonged to haplotype 2. The genetic diversity was low, the fixation index was not significant, and gene flow was high. The control of A. aegypti in Foz do Iguaçu using temephos and pyrethroids may be compromised because of the reduced vector susceptibility. Populations of A. aegypti, that undergoes a sudden reduction in effective population size and become resistant to pyrethroids may differ from the original population in vector capacity.
Journal Article
Methane emissions, performance and carcass characteristics of different lines of beef steers reared on pasture and finished in feedlot
by
MÉO FILHO, P
,
SAKAMOTO, L. S
,
PEDROSO, A. de F
in
Agricultural research
,
Animal feeding and feeds
,
beef
2020
The present study aimed to investigate whether different lines of a composite breed (5/8 Charolais × 3/8 Zebu), formed at different times, and genetically improved, would result in differences in animal performance, enteric methane emissions, and carcass traits. Forty?six Canchim steers (15 months, 280 ± 33 kg liveweight) from three different lines were used: old, new, and their cross. These three breed lines were considered the treatments (arranged in four randomized blocks based on initial liveweight) and were evaluated under grazing and feedlot conditions in relation to the performance and emission of enteric methane. During the grazing period, the new line was found to be superior to the old only in relation to the average daily liveweight gain (0.692 vs. 0.547 kg/day), and with no differences in relation to the cross line (0.692 vs. 0.620). In the feedlot finishing phase, only the average daily liveweight gain was significantly higher in the new line compared to the cross and old line (1.44 vs. 1.32 and 1.23 kg/day). The new and cross lines demonstrated higher dry matter intake when compared to the old line (10.25 and 10.42 vs. 9.11 kg/day), with the crossline Animals 2020, 10, 303 2 of 15 animals demonstrating the best feed conversion. The new line showed higher enteric methane emissions compared to the old line (178 vs. 156 g/day). The line had an effect on the carcass dressing of the animals, with greater fat thickness in carcasses from the new and cross lines than the old line (4.4 and 3.8 vs. 3.2 mm). Canchim cattle selected for improved productive performance characteristics does not guarantee animals with lower methane emissions under grazing conditions; while in feedlots, can lead to increased daily feed consumption, and hence, to higher emissions of methane.
Journal Article
Azospirillum brasilense promotes increases in growth and nitrogen use efficiency of maize genotypes
by
Silva, Mayara Barbosa
,
Perini, Luiz Júnior
,
Scapim, Carlos Alberto
in
Agricultural chemicals
,
Agricultural production
,
Agronomy
2019
The development of cultivars with an improved nitrogen use efficiency (NUE) together with the application of plant growth-promoting bacteria is considered one of the main strategies for reduction of fertilizers use. In this sense, this study: i) evaluated the effect of Azospirillum brasilense on the initial development of maize genotypes; ii) investigated the influence of A. brasilense inoculation on NUE under nitrogen deficit; and iii) sought for more NUE genotypes with higher responsiveness to A. brasilense inoculation. Twenty-seven maize genotypes were evaluated in three independent experiments. The first evaluated the initial development of maize genotypes with and without A. brasilense (strain Ab-V5) inoculation of seeds on germination paper in a growth chamber. The second and third experiments were carried out in a greenhouse using Leonard pots and pots with substrate, respectively, and the genotypes were evaluated at high nitrogen, low nitrogen and low nitrogen plus A. brasilense Ab-V5 inoculation. The inoculation of seeds with A. brasilense Ab-V5 intensified plant growth, improved biochemical traits and raised NUE under nitrogen deficit. The inoculation of seeds with A. brasilense can be considered an economically viable and environmentally sustainable strategy for maize cultivation.
Journal Article
Effects of plant growth-promoting rhizobacteria on co-inoculation with Bradyrhizobium in soybean crop: a meta-analysis of studies from 1987 to 2018
by
de Oliveira, André L.M.
,
Koltun, Alessandra
,
Canteri, Marcelo G.
in
Abiotic stress
,
Agricultural production
,
Agricultural Science
2020
The co-inoculation of soybean with
and other plant growth-promoting rhizobacteria (PGPR) is considered a promising technology. However, there has been little quantitative analysis of the effects of this technique on yield variables. In this context, the present study aiming to provide a quantification of the effects of the co-inoculation of
and PGPR on the soybean crop using a meta-analysis approach.
A total of 42 published articles were examined, all of which considered the effects of co-inoculation of PGPR and
on the number of nodules, nodule biomass, root biomass, shoot biomass, shoot nitrogen content, and grain yield of soybean. We also determined whether the genus of the PGPR used as co-inoculant, as well as the experimental conditions, altered the effect size of the PGPR.
The co-inoculation technology resulted in a significant increase in nodule number (11.40%), nodule biomass (6.47%), root biomass (12.84%), and shoot biomass (6.53%). Despite these positive results, no significant increase was observed in shoot nitrogen content and grain yield. The response of the co-inoculation varied according to the PGPR genus used as co-inoculant, as well as with the experimental conditions. In general, the genera
,
, and
were more effective than
. Overall, the observed increments were more pronounced under pot than that of field conditions. Collectively, this study summarize that co-inoculation improves plant development and increases nodulation, which may be important in overcoming nutritional limitations and potential stresses during the plant growth cycle, even though significant increases in grain yield have not been evidenced by this data meta-analysis.
Journal Article