scholarly journals Dynamic Model for the Epidemiology of Diarrhea and Simulation Considering Multiple Disease Carriers

2020 ◽  
Vol 17 (16) ◽  
pp. 5692 ◽  
Author(s):  
Firda Rahmadani ◽  
Hyunsoo Lee
Keyword(s):  
Uv Light ◽  
Control Strategies ◽  
Light Trap ◽  
Breeding Site ◽  
Compartment Model ◽  
Effective Control ◽  
Control Parameters ◽  
Food Hygiene ◽  
Compartmental System ◽  
Epidemic Dynamics

Diarrhea is responsible for killing around 525,000 children every year, even though it is preventable and treatable. This research focuses on both houseflies’ roles and humans’ roles in carrying pathogens causing diarrhea as multiple disease carriers. Both human and fly compartmental models are simulated with five diseases control strategies in order to identify the epidemic dynamics. The framework considers the life cycle of flies modeled into eggs, larvae, pupae, susceptible flies, and carrier flies, while the human system follows a compartment model as susceptible, infected, recovered, and back to susceptible again (SIRS). The relationships are modeled into an ordinary differential equation-based compartmental system. Then, the control parameters of the compartmental framework are analyzed. In order to propose effective control methods, five control strategies are considered: (1) elimination of flies’ breeding site, (2) sanitation, (3) installation of UV light trap, (4) good personal and food hygiene, and (5) water purification. Then, overall, ten control scenarios using the five control strategies are analyzed. Among them, effective control solutions considering various dynamic epidemiology are provided with the simulations and analyses. The proposed framework contributes to an effective control strategy in reducing the number of both flies and infected humans, since it minimizes the spread of the disease and considers cost-effectiveness.

scholarly journals Phylogenetic Complexity of Morphologically Identified Anopheles squamosus in Southern Zambia

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 146
Author(s):  
Jordan Hoffman ◽  
Ilinca Ciubotariu ◽  
Limonty Simubali ◽  
Twig Mudenda ◽  
William Moss ◽  
...  
Keyword(s):  
Phylogenetic Relationships ◽  
Catchment Area ◽  
Control Strategies ◽  
Light Trap ◽  
Current Control ◽  
Control Measures ◽  
Morphological Identification ◽  
The Past ◽  
Blood Meal Source ◽  
Residual Malaria Transmission

Despite dramatic reductions in malaria cases in the catchment area of Macha Hospital, Choma District, Southern Province in Zambia, prevalence has remained near 1–2% by RDT for the past several years. To investigate residual malaria transmission in the area, this study focuses on the relative abundance, foraging behavior, and phylogenetic relationships of Anopheles squamosus specimens. In 2011, higher than expected rates of anthropophily were observed among “zoophilic” An. squamosus, a species that had sporadically been found to contain Plasmodium falciparum sporozoites. The importance of An. squamosus in the region was reaffirmed in 2016 when P. falciparum sporozoites were detected in numerous An. squamosus specimens. This study analyzed Centers for Disease Control (CDC) light trap collections of adult mosquitoes from two collection schemes: one performed as part of a reactive-test-and-treat program and the second performed along a geographical transect. Morphological identification, molecular verification of anopheline species, and blood meal source were determined on individual samples. Data from these collections supported earlier studies demonstrating An. squamosus to be primarily exophagic and zoophilic, allowing them to evade current control measures. The phylogenetic relationships generated from the specimens in this study illustrate the existence of well supported clade structure among An. squamosus specimens, which further emphasizes the importance of molecular identification of vectors. The primarily exophagic behavior of An. squamosus in these collections also highlights that indoor vector control strategies will not be sufficient for elimination of malaria in southern Zambia.

scholarly journals Marine Organisms for the Sustainable Management of Plant Parasitic Nematodes

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 369
Author(s):  
Pasqua Veronico ◽  
Maria Teresa Melillo
Keyword(s):  
Crop Production ◽  
Control Strategies ◽  
Marine Organisms ◽  
New Drugs ◽  
Effective Control ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Wide Range ◽  
Plant Growth Stimulants ◽  
Plant Parasitic

Plant parasitic nematodes are annually responsible for the loss of 10%–25% of worldwide crop production, most of which is attributable to root-knot nematodes (RKNs) that infest a wide range of agricultural crops throughout the world. Current nematode control tools are not enough to ensure the effective management of these parasites, mainly due to the severe restrictions imposed on the use of chemical pesticides. Therefore, it is important to discover new potential nematicidal sources that are suitable for the development of additional safe and effective control strategies. In the last few decades, there has been an explosion of information about the use of seaweeds as plant growth stimulants and potential nematicides. Novel bioactive compounds have been isolated from marine cyanobacteria and sponges in an effort to find their application outside marine ecosystems and in the discovery of new drugs. Their potential as antihelmintics could also be exploited to find applicability against plant parasitic nematodes. The present review focuses on the activity of marine organisms on RKNs and their potential application as safe nematicidal agents.

scholarly journals Label-Free Comparative Proteomics of Differentially Expressed Mycobacterium tuberculosis Protein in Rifampicin-Related Drug-Resistant Strains

Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 607
Author(s):  
Nadeem Ullah ◽  
Ling Hao ◽  
Jo-Lewis Banga Ndzouboukou ◽  
Shiyun Chen ◽  
Yaqi Wu ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Drug Targets ◽  
Control Strategies ◽  
Multidrug Resistant ◽  
Differentially Expressed ◽  
Effective Control ◽  
Drug Resistant ◽  
Differentially Expressed Proteins ◽  
Label Free ◽  
Candidate Target

Rifampicin (RIF) is one of the most important first-line anti-tuberculosis (TB) drugs, and more than 90% of RIF-resistant (RR) Mycobacterium tuberculosis clinical isolates belong to multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB. In order to identify specific candidate target proteins as diagnostic markers or drug targets, differential protein expression between drug-sensitive (DS) and drug-resistant (DR) strains remains to be investigated. In the present study, a label-free, quantitative proteomics technique was performed to compare the proteome of DS, RR, MDR, and XDR clinical strains. We found iniC, Rv2141c, folB, and Rv2561 were up-regulated in both RR and MDR strains, while fadE9, espB, espL, esxK, and Rv3175 were down-regulated in the three DR strains when compared to the DS strain. In addition, lprF, mce2R, mce2B, and Rv2627c were specifically expressed in the three DR strains, and 41 proteins were not detected in the DS strain. Functional category showed that these differentially expressed proteins were mainly involved in the cell wall and cell processes. When compared to the RR strain, Rv2272, smtB, lpqB, icd1, and folK were up-regulated, while esxK, PPE19, Rv1534, rpmI, ureA, tpx, mpt64, frr, Rv3678c, esxB, esxA, and espL were down-regulated in both MDR and XDR strains. Additionally, nrp, PPE3, mntH, Rv1188, Rv1473, nadB, PPE36, and sseA were specifically expressed in both MDR and XDR strains, whereas 292 proteins were not identified when compared to the RR strain. When compared between MDR and XDR strains, 52 proteins were up-regulated, while 45 proteins were down-regulated in the XDR strain. 316 proteins were especially expressed in the XDR strain, while 92 proteins were especially detected in the MDR strain. Protein interaction networks further revealed the mechanism of their involvement in virulence and drug resistance. Therefore, these differentially expressed proteins are of great significance for exploring effective control strategies of DR-TB.

scholarly journals The use of light spectrum blocking films to reduce populations of Drosophila suzukii Matsumura in fruit crops

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Michelle T. Fountain ◽  
Amir Badiee ◽  
Sebastian Hemer ◽  
Alvaro Delgado ◽  
Michael Mangan ◽  
...  
Keyword(s):  
Control Strategies ◽  
Field Trials ◽  
Biological Data ◽  
Insect Vision ◽  
Invasive Pest ◽  
Effective Control ◽  
Fruit Crops ◽  
Light Spectrum ◽  
Drosophila Suzukii ◽  
The Impact

Abstract Spotted wing drosophila, Drosophila suzukii, is a serious invasive pest impacting the production of multiple fruit crops, including soft and stone fruits such as strawberries, raspberries and cherries. Effective control is challenging and reliant on integrated pest management which includes the use of an ever decreasing number of approved insecticides. New means to reduce the impact of this pest that can be integrated into control strategies are urgently required. In many production regions, including the UK, soft fruit are typically grown inside tunnels clad with polyethylene based materials. These can be modified to filter specific wavebands of light. We investigated whether targeted spectral modifications to cladding materials that disrupt insect vision could reduce the incidence of D. suzukii. We present a novel approach that starts from a neuroscientific investigation of insect sensory systems and ends with infield testing of new cladding materials inspired by the biological data. We show D. suzukii are predominantly sensitive to wavelengths below 405 nm (ultraviolet) and above 565 nm (orange & red) and that targeted blocking of lower wavebands (up to 430 nm) using light restricting materials reduces pest populations up to 73% in field trials.

Surveillance-based estimation of the malaria disease burden in a low endemic state of Punjab, India, targeted for malaria elimination

2021 ◽  
Author(s):  
Jaspreet Kaur ◽  
Taruna Kaura ◽  
Ayush Sharma ◽  
Ashish Kumar ◽  
M K Pangotra ◽  
...  
Keyword(s):  
Malaria Elimination ◽  
Control Strategies ◽  
The State ◽  
Primary Data ◽  
Effective Control ◽  
Malaria Surveillance ◽  
Weighted Estimates ◽  
Malaria Burden ◽  
Routine Surveillance ◽  
Malaria Trends

Abstract Background The state of Punjab in India qualifies for malaria elimination because the number of cases reported through routine surveillance is in decline. However, surveillance system prevalence mainly provides malaria trends. Therefore, a prospective epidemiological study was designed to estimate the malaria burden in the state. Methods District-wise annual parasite incidence (API) was used for identification of three strata, representing high, moderate and low API zones. A total of 0.9 million people from nine districts was under malaria surveillance for 1 y. The weighted estimates of API for the three regions was calculated and combined to give an estimate of API for the total population of the state. Results Based upon the primary data generated, malaria cases from high, moderate and low malaria-endemic areas were estimated to be 3727, 904 and 106, respectively. Further, the total number of malaria cases in the state was estimated to be 4737 (95% CI 4006 to 5469) cases per annum. Conclusion Actual burden of malaria in the state of Punjab, India, is about seven to eight times higher than that reported by routine surveillance activities. However, the state still qualifies for malaria elimination but needs vigorous efforts to strengthen the active surveillance and reporting system along with implementation of effective control strategies to achieve malaria elimination.

Molecular Subtyping and Characterization of Psychrotolerant Endospore-Forming Bacteria in Two New York State Fluid Milk Processing Systems

2007 ◽  
Vol 70 (10) ◽  
pp. 2354-2364 ◽  
Author(s):  
JASON R. HUCK ◽  
NICOLE H. WOODCOCK ◽  
ROBERT D. RALYEA ◽  
KATHRYN J. BOOR
Keyword(s):  
Control Strategies ◽  
New York State ◽  
Raw Milk ◽  
Effective Control ◽  
Processing Plant ◽  
Milk Processing ◽  
High Temperature Short Time ◽  
Processing Plants ◽  
Processing Continuum ◽  
Fluid Milk

Psychrotolerant endospore-forming bacteria Bacillus and Paenibacillus spp. are important spoilage organisms in fluid milk. A recently developed rpoB subtyping method was applied to characterize the diversity and phylogenetic relationships among Bacillus and related sporeformers associated with milk processing systems. Milk samples representing the processing continuum from raw milk to pasteurized products were collected from two fluid milk processing plants, held at 6°C uptothe code date that had been established by each processing plant (i.e., either 18 or 21 days), and plated for bacterial enumeration throughout storage. Bacterial colonies selected to represent the visible diversity in colony morphology on enumeration plates were examined further. Among 385 bacterial isolates characterized, 35% were Bacillus spp., and 65% were Paenibacillus spp. A total of 92 rpoB allelic types were identified among these isolates, indicating considerable diversity among endospore-forming spoilage organisms present in fluid milk systems. Of the 92 allelic types identified, 19 were isolated from samples collected from both processing plants. The same rpoB allelic types were frequently identified in paired raw milk and packaged product samples, indicating that Bacillus and Paenibacillus spp. can enter dairy processing systems through raw milk. Certain subtypes were found exclusively in pasteurized samples, including those that were temporally independent, suggesting the possibility of in-plant sources for these spoilage organisms, including through the persistence of selected subtypes in processing plants. Development of effective control strategies for the diverse array of psychrotolerant endospore-forming organisms that currently limit the shelf lives of high-temperature short-time fluid milk products will require comprehensive, integrated efforts along the entire milk processing continuum.

scholarly journals Photodegradation of Trace Trichloronitromethane in Water under UV Irradiation

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Lin Deng ◽  
Zhiren Wu ◽  
Caiqian Yang ◽  
Yung-Li Wang
Keyword(s):  
Humic Acid ◽  
Light Intensity ◽  
Uv Light ◽  
Control Strategies ◽  
Chloride Ions ◽  
Source Control ◽  
Photochemical Degradation ◽  
Nitrate Ions ◽  
Photodegradation Rate ◽  
Water And Wastewater

This study’s objective was to study the photodegradation of TCNM (trichloronitromethane) in water under UV light. The effects of light intensity, nitrate ions, chloride ions, humic acid, and pH on the photochemical degradation of TCNM were investigated under the irradiation of low pressure mercury lamp (λ= 254 nm, 12 W). The photodegradation rate of TCNM was found to increase with increasing the concentration of nitrate ions, chloride ions, humic acid, pH, and light intensity. The photodegradation of TCNM was examined at pH 6.0 with initial concentrations (C0) of TCNM at 10.0–200.0 µg/L. The overall rate of degradation of TCNM was modeled using a pseudofirst-order rate law. Finally, the proposed mechanism involved in the photodegradation of TCNM was also discussed by analysis. Results of this study can contribute to the development of new source control strategies for minimization of TCNM risk at drinking water and wastewater utilities.

scholarly journals Strategies for control of the redlegged earth mite in Australia

2008 ◽  
Vol 48 (12) ◽  
pp. 1506 ◽  
Author(s):  
T. J. Ridsdill-Smith ◽  
A. A. Hoffmann ◽  
G. P. Mangano ◽  
J. M. Gower ◽  
C. C. Pavri ◽  
...  
Keyword(s):  
Control Strategies ◽  
Field Trials ◽  
Effective Control ◽  
Synthetic Pyrethroids ◽  
Halotydeus Destructor ◽  
Mite Control ◽  
Redlegged Earth Mite ◽  
Single Well ◽  
Plant Seedlings ◽  
Control Package

The redlegged earth mite, Halotydeus destructor, continues to be an intractable pest causing damage to most crop and pasture species in southern Australia. H. destructor feed on all stages of plants, but particularly damage seedlings in autumn. Research has aimed to develop new controls based on a better understanding of the biology and ecology of this pest. Chemicals remain the key tool to control H. destructor, despite the recent appearance of resistance to synthetic pyrethroids. A control package, Timerite, has been developed by which a single well-timed spray in spring can prevent H. destructor from developing diapause eggs. Field trials show this strategy provides effective control of H. destructor the following autumn, and protects plant seedlings, although mite populations build up again during winter. Non-chemical control strategies include grazing, the use of tolerant plants such as cereals, resistant legume cultivars and avoiding rotations where favourable host plants are available in the year before growing susceptible crops such as canola. Natural enemies can assist in mite control, and their numbers can be enhanced by methods including increasing landscape features like shelterbelts. Interspecific competition can occur between H. destructor and other pest mites, but the extent to which these interactions influence the structure of pest communities under different management regimes remains to be investigated.

Quantitative Risk Assessment of Listeriosis-Associated Deaths Due to Listeria monocytogenes Contamination of Deli Meats Originating from Manufacture and Retail

2010 ◽  
Vol 73 (4) ◽  
pp. 620-630 ◽  
Author(s):  
ABANI K. PRADHAN ◽  
RENATA IVANEK ◽  
YRJÖ T. GRÖHN ◽  
ROBERT BUKOWSKI ◽  
IFIGENIA GEORNARAS ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Listeria Monocytogenes ◽  
Relative Risk ◽  
Storage Temperature ◽  
Control Strategies ◽  
Quantitative Risk Assessment ◽  
Sensitivity Analyses ◽  
Effective Control ◽  
Lag Phase ◽  
Reported Data

The objective of this study was to estimate the relative risk of listeriosis-associated deaths attributable to Listeria monocytogenes contamination in ham and turkey formulated without and with growth inhibitors (GIs). Two contamination scenarios were investigated: (i) prepackaged deli meats with contamination originating solely from manufacture at a frequency of 0.4% (based on reported data) and (ii) retail-sliced deli meats with contamination originating solely from retail at a frequency of 2.3% (based on reported data). Using a manufacture-to-consumption risk assessment with product-specific growth kinetic parameters (i.e., lag phase and exponential growth rate), reformulation with GIs was estimated to reduce human listeriosis deaths linked to ham and turkey by 2.8- and 9-fold, respectively, when contamination originated at manufacture and by 1.9- and 2.8-fold, respectively, for products contaminated at retail. Contamination originating at retail was estimated to account for 76 and 63% of listeriosis deaths caused by ham and turkey, respectively, when all products were formulated without GIs and for 83 and 84% of listeriosis deaths caused by ham and turkey, respectively, when all products were formulated with GIs. Sensitivity analyses indicated that storage temperature was the most important factor affecting the estimation of per annum relative risk. Scenario analyses suggested that reducing storage temperature in home refrigerators to consistently below 7°C would greatly reduce the risk of human listeriosis deaths, whereas reducing storage time appeared to be less effective. Overall, our data indicate a critical need for further development and implementation of effective control strategies to reduce L. monocytogenes contamination at the retail level.

scholarly journals Global Stability and Optimal Control of Dengue with Two Coexisting Virus Serotypes

MATEMATIKA ◽  
2019 ◽  
Vol 35 (4) ◽  
pp. 149-170
Author(s):  
Afeez Abidemi ◽  
Rohanin Ahmad ◽  
Nur Arina Bazilah Aziz
Keyword(s):  
Optimal Control ◽  
Global Stability ◽  
Disease Transmission ◽  
Deterministic Model ◽  
Control Strategies ◽  
Equilibrium Points ◽  
Effective Control ◽  
Asymptotically Stable ◽  
Globally Asymptotically Stable ◽  
Boundary Equilibrium

This study presents a two-strain deterministic model which incorporates Dengvaxia vaccine and insecticide (adulticide) control strategies to forecast the dynamics of transmission and control of dengue in Madeira Island if there is a new outbreak with a different virus serotypes after the first outbreak in 2012. We construct suitable Lyapunov functions to investigate the global stability of the disease-free and boundary equilibrium points. Qualitative analysis of the model which incorporates time-varying controls with the specific goal of minimizing dengue disease transmission and the costs related to the control implementation by employing the optimal control theory is carried out. Three strategies, namely the use of Dengvaxia vaccine only, application of adulticide only, and the combination of Dengvaxia vaccine and adulticide are considered for the controls implementation. The necessary conditions are derived for the optimal control of dengue. We examine the impacts of the control strategies on the dynamics of infected humans and mosquito population by simulating the optimality system. The disease-freeequilibrium is found to be globally asymptotically stable whenever the basic reproduction numbers associated with virus serotypes 1 and j (j 2 {2, 3, 4}), respectively, satisfy R01,R0j 1, and the boundary equilibrium is globally asymptotically stable when the related R0i (i = 1, j) is above one. It is shown that the strategy based on the combination of Dengvaxia vaccine and adulticide helps in an effective control of dengue spread in the Island.

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