scholarly journals Natural malaria infection in anophelines vectors and their incrimination in local malaria transmission in Darién, Panama

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0250059
Author(s):  
Rolando Torres-Cosme ◽  
Chystrie Rigg ◽  
Ana María Santamaría ◽  
Vanessa Vásquez ◽  
Carlos Victoria ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Infection Rate ◽  
Control Strategies ◽  
Natural Infection ◽  
Transmission Dynamics ◽  
Baited Traps ◽  
New Information ◽  
Mosquito Pool ◽  
Species Being ◽  
Vector Diversity

Background More than 85% of the malaria cases in Panama occur in poor, rural and indigenous regions like Darien Province. Vector diversity, infection rate and spatial distribution are important entomological parameters of malaria transmission dynamics. Their understanding is crucial for the development of effective disease control strategies. The objective of this study was to determine the composition of Anopheles species, their natural infection rate and their geographic distribution to better understand the malaria transmission dynamics in Darién, Panama. Methods Anophelines mosquitoes were captured during the rainy and dry season of 2016. We selected five communities where adult anophelines were collected using CDC light-traps, and through protective human-baited traps. Detection of natural infection and Plasmodium genotype were detected via nested PCR through the amplification of ssrRNA and the circumsporozoite protein gene (csp), respectively. Results A total of 1,063 mosquitoes were collected mosquitoes were collected for the detection of natural infection with Plasmodium spp. Nine Anophelines species were identified, with the predominant species being: An. (Nys.) darlingi (45.0%) and An. (Nys.) albimanus (42.6%). Natural infection in An. (Nys.) albimanus with P. vivax was detected in one mosquito pool from the community Pueblo Tortuga (0.6%), three from Marraganti (1.7%), two from Bajo Chiquito (1.1%) and three pools from Alto Playona 3 (1.7%). For An. (Nys.) darlingi mosquitoes, we detected seven positive pools from the community Bajo Chiquito (4.0%), two pools from Marraganti (1.1%) and two pools from Alto Playona (1.1%). The P. vivax allelic variant VK210 was detected in infected mosquitoes. Conclusion The results from this study provide new information on the transmission dynamics associated with anophelines vectors in the Darién region. This is the first report of natural P. vivax infection in An. (Nys.) darlingi and its incrimination as a potential malaria vector in this region of Panama. Additional studies are necessary to expand our knowledge and determine crucial parameters in malaria transmission in Darién, which in turn will aid the National Malaria Program in attaining an adequate malaria control strategy towards malaria elimination.

scholarly journals Natural Malaria Infection in Anopheline Vectors and Their Incrimination in Local Malaria Transmission in Darién, Panama

2020 ◽  
Author(s):  
Rolando Torres-Cosme ◽  
Chystrie Rigg ◽  
Ana Maria Santamaria ◽  
Vanessa Vazquez ◽  
Carlos Victoria ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Infection Rate ◽  
Control Strategies ◽  
Natural Infection ◽  
Transmission Dynamics ◽  
Baited Traps ◽  
New Information ◽  
Mosquito Pool ◽  
Elevated Frequency ◽  
Species Being

Abstract BackgroundMore than 85% of the malaria cases in Panama occur in characteristically poor, rural and indigenous regions like Darien Province. Vector diversity, vector infection rate and spatial distribution are important entomological parameters of malaria transmission dynamics. Their understanding is crucial for the development of effective disease control strategies. The objective of this study was to determine the composition of Anopheles species, their natural infection rate and their geographic distribution to better understand the malaria transmission dynamics in Darién, Panama.MethodsAnopheline mosquitoes were captured during the rainy and dry season of 2016. We selected five communities where adult anophelines were collected using CDC light-traps, and through protective human-baited traps. Detection of natural infection and Plasmodium genotype in collected mosquitoes were detected via nested PCR through the amplification of Plasmodium 18s rRNA and the circumsporozoite protein gene, respectively.ResultsA total of 1,063 mosquitoes were collected, and nine Anopheline species were identified, with the predominant species being: An. (Nys.) darlingi (45.0%) and An. (Nys.) albimanus (42.6%). Among these mosquitoes, An. (Nys.) albimanus has historically presented an elevated frequency and abundance in all Panamanian regions. Natural infection with P. vivax was detected in a mosquito pool from the community Pueblo Tortuga (0.6%), three mosquito pools from Marraganti (1.7%), two pools from Bajo Chiquito (1.1%) and three pools from Alto Playona (1.7%). For An. (Nys.) darlingi mosquitoes, we detected seven positive pools from the community Bajo Chiquito (4.0%), two pools from Marraganti (1.1%) and two pools from Alto Playona (1.1%). This study was able to detect the P. vivax allelic variant VK210 in infected mosquitoes.ConclusionThe results from this study provide new information on the transmission dynamics associated with anopheline vectors in the Darién region. This is the first report of natural P. vivax infection in An. (Nys.) darlingi and its incrimination as a potential malaria vector in Panama. Additional studies are necessary to expand our knowledge and determine crucial parameters in malaria transmission in Darién, which in turn will aid the National Malaria Program in attaining an adequate malaria control strategy towards malaria elimination.

scholarly journals Boll Weevil Control Strategies: Regional Benefits and Costs

1977 ◽  
Vol 9 (1) ◽  
pp. 129-135 ◽  
Author(s):  
C. Robert Taylor ◽  
Ronald D. Lacewell
Keyword(s):  
Insect Pests ◽  
Control Strategies ◽  
Boll Weevil ◽  
Early Season ◽  
Trap Crops ◽  
Southern States ◽  
Baited Traps ◽  
Mexico Border ◽  
Benefits And Costs ◽  
The U.S

Throughout the southern states and at the federal level, much attention is being focused on the appropriate strategy for controlling cotton insect pests, particularly the boll weevil. This paper presents estimated economic impacts to farmers, regions and consumers of implementing three alternative boll weevil control strategies. One strategy evaluated is a proposed boll weevil eradication program which involves integrating many controls including insecticides, reproduction-diapause control by early season stalk destruction, pheromone-baited traps, trap crops, early season control with insecticide, and massive releases of sterile boll weevils. The plan is to eradicate the boll weevil in the U.S., and then indefinitely maintain a barrier at the U.S.-Mexico border to prevent future weevil immigration to the U.S.

scholarly journals Modeling the spread of porcine reproductive and respiratory syndrome virus (PRRSV) in a swine population: transmission dynamics, immunity information, and optimal control strategies

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Phithakdet Phoo-ngurn ◽  
Chanakarn Kiataramkul ◽  
Farida Chamchod
Keyword(s):  
Mathematical Model ◽  
Vaccination Coverage ◽  
Control Strategies ◽  
Vaccination Rate ◽  
Transmission Dynamics ◽  
Respiratory Syndrome Virus ◽  
Respiratory Problems ◽  
Prrs Virus ◽  
Swine Population ◽  
Swine Disease

Abstract Porcine reproductive and respiratory syndrome (PRRS) is an important swine disease that affects many swine industries worldwide. The disease can cause reproductive failure and respiratory problems in a swine population. As vaccination is an important tool to control the spread of PRRS virus (PRRSV), we employ a mathematical model to investigate the transmission dynamics of PRRSV and the effects of immunity information, as well as vaccination control strategies. We also explore optimal vaccination coverage and vaccination rate to minimize the number of infected swines and vaccination efforts. Our results suggest that: (i) higher vaccination coverage and vaccination rate together with prior knowledge about immunity may help reduce the prevalence of PRRSV, and (ii) longer maximum vaccination efforts are required when swines stay longer in a population and it takes them longer time to recover from PRRS infections.

scholarly journals Anopheles ecology, genetics and malaria transmission in northern Cambodia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amélie Vantaux ◽  
Michelle M. Riehle ◽  
Eakpor Piv ◽  
Elise J. Farley ◽  
Sophy Chy ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Mosquito Species ◽  
Rubber Tree ◽  
Amplicon Sequencing ◽  
Forest Sites ◽  
Baited Traps ◽  
Residual Malaria Transmission ◽  
Mosquito Ecology ◽  
Forested Areas ◽  
Greater Mekong Subregion

AbstractIn the Greater Mekong Subregion, malaria cases have significantly decreased but little is known about the vectors or mechanisms responsible for residual malaria transmission. We analysed a total of 3920 Anopheles mosquitoes collected during the rainy and dry seasons from four ecological settings in Cambodia (villages, forested areas near villages, rubber tree plantations and forest sites). Using odor-baited traps, 81% of the total samples across all sites were collected in cow baited traps, although 67% of the samples attracted by human baited traps were collected in forest sites. Overall, 20% of collected Anopheles were active during the day, with increased day biting during the dry season. 3131 samples were identified morphologically as 14 different species, and a subset was also identified by DNA amplicon sequencing allowing determination of 29 Anopheles species. The investigation of well characterized insecticide mutations (ace-1, kdr, and rdl genes) indicated that individuals carried mutations associated with response to all the different classes of insecticides. There also appeared to be a non-random association between mosquito species and insecticide resistance with Anopheles peditaeniatus exhibiting nearly fixed mutations. Molecular screening for Plasmodium sp. presence indicated that 3.6% of collected Anopheles were positive, most for P. vivax followed by P. falciparum. These results highlight some of the key mechanisms driving residual human malaria transmission in Cambodia, and illustrate the importance of diverse collection methods, sites and seasons to avoid bias and better characterize Anopheles mosquito ecology in Southeast Asia.

scholarly journals Integrative biology defines novel biomarkers of resistance to strongylid infection in horses

2021 ◽  
Author(s):  
Guillaume Sallé ◽  
Cécile Canlet ◽  
Jacques Cortet ◽  
Christine Koch ◽  
Joshua Malsa ◽  
...  
Keyword(s):  
Time Window ◽  
Control Strategies ◽  
Natural Infection ◽  
Nutritional Intervention ◽  
Plasma Metabolites ◽  
Selective Treatment ◽  
Phenylalanine Level ◽  
Acid Producing Bacteria ◽  
New Biomarkers ◽  
Beta Hydroxybutyrate

AbstractThe widespread failure of anthelmintic drugs against nematodes of veterinary interest requires novel control strategies. Selective treatment of the most susceptible individuals could reduce drug selection pressure but requires appropriate biomarkers of the intrinsic susceptibility potential. To date, this has been missing in livestock species. Here, we selected Welsh ponies with divergent intrinsic susceptibility to cyathostomin infection and found that their potential was sustained across a 10-year time window. Using this unique set of individuals, we monitored variations in their blood cell populations, plasma metabolites and faecal microbiota over a grazing season to isolate core differences between their respective responses under worm-free or natural infection conditions. Our analyses identified the concomitant rise in plasmatic phenylalanine level and faecal Prevotella abundance and the reduction in circulating monocyte counts as biomarkers of the need for drug treatment. This biological signal was replicated in other independent populations. We also unravelled an immunometabolic network encompassing plasmatic beta-hydroxybutyrate level, short-chain fatty acid producing bacteria and circulating neutrophils that forms the discriminant baseline between susceptible and resistant individuals. Altogether our observations open new perspectives on the susceptibility of equids to cyathostomin infection and leave scope for both new biomarkers of infection and nutritional intervention.

scholarly journals TRANSMISSION DYNAMICS OF DENGUE IN COSTA RICA: THE ROLE OF HOSPITALIZATIONS

2019 ◽  
Vol 27 (1) ◽  
pp. 241-266
Author(s):  
FABIO SANCHEZ ◽  
JORGE ARROYO-ESQUIVEL ◽  
PAOLA VÁSQUEZ
Keyword(s):  
Costa Rica ◽  
Compartmental Model ◽  
Control Strategies ◽  
Transmission Dynamics ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Specific Parameter ◽  
Public Health Officials ◽  
Disease Free

For decades, dengue virus has caused major problems for public health officials in tropical and subtropical countries around the world. We construct a compartmental model that includes the role of hospitalized individuals in the transmission dynamics of dengue in Costa Rica. The basic reproductive number, R0, is computed, as well as a sensitivity analysis on R0 parameters. The global stability of the disease-free equilibrium is established. Numerical simulations under specific parameter scenarios are performed to determine optimal prevention/control strategies.

scholarly journals Global Stability of Malaria Transmission Dynamics Model with Logistic Growth

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Abadi Abay Gebremeskel
Keyword(s):  
Sensitivity Analysis ◽  
Global Stability ◽  
Malaria Transmission ◽  
Equilibrium Points ◽  
Transmission Dynamics ◽  
Logistic Growth ◽  
Asymptotically Stable ◽  
Dynamics Model ◽  
Globally Asymptotically Stable ◽  
The Impact

Mathematical models become an important and popular tools to understand the dynamics of the disease and give an insight to reduce the impact of malaria burden within the community. Thus, this paper aims to apply a mathematical model to study global stability of malaria transmission dynamics model with logistic growth. Analysis of the model applies scaling and sensitivity analysis and sensitivity analysis of the model applied to understand the important parameters in transmission and prevalence of malaria disease. We derive the equilibrium points of the model and investigated their stabilities. The results of our analysis have shown that if R0≤1, then the disease-free equilibrium is globally asymptotically stable, and the disease dies out; if R0>1, then the unique endemic equilibrium point is globally asymptotically stable and the disease persists within the population. Furthermore, numerical simulations in the application of the model showed the abrupt and periodic variations.

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