scholarly journals Analysis of Strategies for Preventing and Controlling the Chikungunya Virus

2021 ◽  
Vol 16 (1) ◽  
pp. 57-68
Author(s):  
Julián Alejandro Olarte Garciá ◽  
Anibal Muñoz Loaiza
Keyword(s):  
Vector Control ◽  
Chikungunya Virus ◽  
Environmental Control ◽  
Integrated Control ◽  
Specific Treatment ◽  
Vector Model ◽  
Population Vector ◽  
Protection Measures ◽  
Preventive Vaccine ◽  
Gradual Process

Alternatives to stop chikungunya outbreaks are oriented to vector control and developing a specific treatment and a preventive vaccine. Environmental control and mosquito bite prevention are undoubtedly essential to decrease the disease burden, but Aedes vectors continue to expand geographically and re-emerge. So, vaccination is proposed to respond to this etiology and recognized as a pressing need for affected countries. A mathematical host-vector model, including asymptomatic population, vector control, and vaccination (assuming the existence of a safe protective vaccine against the chikungunya virus), is suggested to analyze the effects of these efforts. Poisson distribution is applied to interpret the basic reproduction number. Then vaccination and vector control thresholds are established to prescribe the most effective protection measures against exposure to the chikungunya virus. In conclusion, it is advisable to continue with integrated control to reduce the economic impact of relevant public health responses and mitigate other infections since Aedes is a transmitter of other arboviruses such as dengue, Zika, and Mayaro. Furthermore, vaccinating all individuals in a community could be a costly and gradual process.

scholarly journals Comparing sterile male releases and other methods for integrated control of the tiger mosquito in temperate and tropical climates

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Léa Douchet ◽  
Marion Haramboure ◽  
Thierry Baldet ◽  
Gregory L’Ambert ◽  
David Damiens ◽  
...  
Keyword(s):  
Vector Control ◽  
Mosquito Species ◽  
Integrated Control ◽  
Mass Trapping ◽  
Southwest Indian Ocean ◽  
Breeding Sites ◽  
Key Factor ◽  
Trapping Methods ◽  
Combination Of Methods ◽  
Tropical Climates

AbstractThe expansion of mosquito species worldwide is creating a powerful network for the spread of arboviruses. In addition to the destruction of breeding sites (prevention) and mass trapping, methods based on the sterile insect technique (SIT), the autodissemination of pyriproxyfen (ADT), and a fusion of elements from both of these known as boosted SIT (BSIT), are being developed to meet the urgent need for effective vector control. However, the comparative potential of these methods has yet to be explored in different environments. This is needed to propose and integrate informed guidelines into sustainable mosquito management plans. We extended a weather-dependent model of Aedes albopictus population dynamics to assess the effectiveness of these different vector control methods, alone or in combination, in a tropical (Reunion island, southwest Indian Ocean) and a temperate (Montpellier area, southern France) climate. Our results confirm the potential efficiency of SIT in temperate climates when performed early in the year (mid-March for northern hemisphere). In such a climate, the timing of the vector control action was the key factor in its success. In tropical climates, the potential of the combination of methods becomes more relevant. BSIT and the combination of ADT with SIT were twice as effective compared to the use of SIT alone.

scholarly journals Beyond members of the Flaviviridae family, sofosbuvir also inhibits chikungunya virus replication

2018 ◽  
Author(s):  
André C. Ferreira ◽  
Patrícia A. Reis ◽  
Caroline S. de Freitas ◽  
Carolina Q. Sacramento ◽  
Lucas Villas Bôas Hoelz ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Chikungunya Virus ◽  
Therapeutic Option ◽  
Antiviral Drug ◽  
Specific Treatment ◽  
Public Health Problem ◽  
Hepatoma Cells ◽  
Dependent Manner ◽  
Mice Model ◽  
Human Hepatoma Cells

AbstractChikungunya virus (CHIKV) causes a febrile disease associated with chronic arthralgia, which may progress to neurological impairment. Chikungunya fever (CF) is a consolidated public health problem, in tropical and subtropical regions of the world, where control of CHIKV vector, mosquitos of theAedesgenus, failed. Since there is no vaccine or specific treatment against CHIKV, infected patients receive only palliative care to alleviate pain and arthralgia. Thus, drug repurposing is necessary to identify antivirals against CHIKV. Recently, the structure and activity of CHIKV RNA polymerase was partially resolved, revealing similar aspects with the enzyme counterparner on other positive sense RNA viruses, such as members of the Flaviviridae family. We then evaluated if sofosbuvir, clinically approved against hepatitis C virus RNA polymerase, which also aims to dengue, Zika and yellow fever viruses replication, would inhibit CHIKV replication. Indeed, sofosbuvir was 5-times more selective in inhibiting CHIKV production in human hepatoma cells than ribavirin, a pan-antiviral drug. Although CHIKV replication in human induced pluripotent stem cell (iPS)-derived astrocytes was less sensitive to sofosbuvir’s, compared to hepatoma cells – this drug still impaired virus production and cell death in a MOI-dependent manner. Sofosbuvir also exhibited antiviral activityin vivo, by preventing CHIKV-induced paw oedeme in adult mice, at 20 mg/kg/day, and mortality on neonate mice model, at 40 and 80 mg/kg/day. Our data demonstrates that a prototypic alphavirus, CHIKV, is also susceptible to sofosbuvir. Since this is a clinically approved drug, it could pave the way to become a therapeutic option against CF.

scholarly journals Vaccine and Therapeutic Options To Control Chikungunya Virus

2017 ◽  
Vol 31 (1) ◽  
Author(s):  
Ann M. Powers
Keyword(s):  
Vector Control ◽  
Future Development ◽  
Chikungunya Virus ◽  
Therapeutic Options ◽  
Protective Measures ◽  
Vector Borne Diseases ◽  
Advantages And Disadvantages ◽  
Vector Borne ◽  
And Control ◽  
Integrated Vector Control

SUMMARYBeginning in 2004, chikungunya virus (CHIKV) went from an endemic pathogen limited to Africa and Asia that caused periodic outbreaks to a global pathogen. Given that outbreaks caused by CHIKV have continued and expanded, serious consideration must be given to identifying potential options for vaccines and therapeutics. Currently, there are no licensed products in this realm, and control relies completely on the use of personal protective measures and integrated vector control, which are only minimally effective. Therefore, it is prudent to urgently examine further possibilities for control. Vaccines have been shown to be highly effective against vector-borne diseases. However, as CHIKV is known to rapidly spread and generate high attack rates, therapeutics would also be highly valuable. Several candidates are currently being developed; this review describes the multiple options under consideration for future development and assesses their relative advantages and disadvantages.

scholarly journals Presence of Autoimmune Antibody in Chikungunya Infection

2009 ◽  
Vol 2009 ◽  
pp. 1-4 ◽  
Author(s):  
Wirach Maek-a-nantawat ◽  
Udomsak Silachamroon
Keyword(s):  
Muscle Weakness ◽  
Antinuclear Antibody ◽  
Endemic Area ◽  
Chikungunya Virus ◽  
Specific Treatment ◽  
Close Monitoring ◽  
Southern Thailand ◽  
Arbovirus Infection

Chikungunya infection has recently re-emerged as an important arthropod-borne disease in Thailand. Recently, Southern Thailand was identified as a potentially endemic area for the chikungunya virus. Here, we report a case of severe musculoskeletal complication, presenting with muscle weakness and swelling of the limbs. During the investigation to exclude autoimmune muscular inflammation, high titers of antinuclear antibody were detected. This is the report of autoimmunity detection associated with an arbovirus infection. The symptoms can mimic autoimmune polymyositis disease, and the condition requires close monitoring before deciding to embark upon prolonged specific treatment with immunomodulators.

Modeling Reaching Impairment After Stroke Using a Population Vector Model of Movement Control That Incorporates Neural Firing-Rate Variability

2003 ◽  
Vol 15 (11) ◽  
pp. 2619-2642 ◽  
Author(s):  
David J. Reinkensmeyer ◽  
Mario G. Iobbi ◽  
Leonard E. Kahn ◽  
Derek G. Kamper ◽  
Craig D. Takahashi
Keyword(s):  
Cell Death ◽  
Standard Deviation ◽  
Firing Rate ◽  
Movement Control ◽  
Vector Model ◽  
Neural Firing ◽  
Population Vector ◽  
Directional Error ◽  
Wide Range ◽  
Impairment Severity

The directional control of reaching after stroke was simulated by including cell death and firing-rate noise in a population vector model of movement control. In this model, cortical activity was assumed to cause the hand to move in the direction of a population vector, defined by a summation of responses from neurons with cosine directional tuning. Two types of directional error were analyzed: the between-target variability, defined as the standard deviation of the directional error across a wide range of target directions, and the within-target variability, defined as the standard deviation of the directional error for many reaches to a single target. Both between and within-target variability increased with increasing cell death. The increase in between-target variability arose because cell death caused a nonuniform distribution of preferred directions. The increase in within-target variability arose because the magnitude of the population vector decreased more quickly than its standard deviation for increasing cell death, provided appropriate levels of firing-rate noise were present. Comparisons to reaching data from 29 stroke subjects revealed similar increases in between and within-target variability as clinical impairment severity increased. Relationships between simulated cell death and impairment severity were derived using the between and within-target variability results. For both relationships, impairment severity increased similarly with decreasing percentage of surviving cells, consistent with results from previous imaging studies. These results demonstrate that a population vector model of movement control that incorporates cosine tuning, linear summation of unitary responses, firing-rate noise, and random cell death can account for some features of impaired arm movement after stroke.

The Control System Design of AC Servo PMSM Based on an EMCU

2013 ◽  
Vol 380-384 ◽  
pp. 309-312
Author(s):  
Xue Wen Wang ◽  
Zhou Hu Deng ◽  
Xiao Yun ◽  
Long Zhang ◽  
Yuan Zhang
Keyword(s):  
Control System ◽  
Vector Control ◽  
High Speed ◽  
Pulse Width Modulation ◽  
Control Method ◽  
Permanent Magnet Synchronous Motor ◽  
Control Process ◽  
Control Unit ◽  
Vector Model ◽  
Rotating Speed

The mathematical vector model of a permanent magnet synchronous motor (PMSM) has first been discussed in this paper, and a servo control system based on Space Vector Pulse Width Modulation (SVPWM) has been designed, in which a enhanced Microprogrammed Control Unit (EMCU) is combined with drive chips and the relevant control software to achieve the precise control of PMSM. In order to control the position, speed and current of the PMSM, six SVPWM signals are generated with the motor vector control method, and the vector control strategy with three closed loops is projected. According to the control principle, the circuits of the hardware modules are designed and built, and the program of the control process is compiled and downloaded the EMCU, and then the human-computer interaction interface of the system is implemented by LabVIEW. The results of the test show that the control system designed can control the rotating speed and the high-speed pendulum operation of PMSM precisely.

scholarly journals Chikungunya: vaccines and therapeutics

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 2114 ◽  
Author(s):  
Kothila Tharmarajah ◽  
Suresh Mahalingam ◽  
Ali Zaid
Keyword(s):  
Developing Countries ◽  
Indian Ocean ◽  
South America ◽  
Southeast Asia ◽  
Vector Control ◽  
Chikungunya Virus ◽  
Southern Indian Ocean ◽  
Emerging Pathogen ◽  
Transmission Cycle ◽  
The Caribbean

Chikungunya virus (CHIKV) has come to prominence as a global, re-emerging pathogen over the last two decades, progressing from sporadic, remote outbreaks to worldwide explosive epidemics. From contained, though considerable, outbreaks in the southern Indian Ocean, parts of South America and the Caribbean, CHIKV continues to be a significant pathogen in Southeast Asia and India. CHIKV circulates during epidemics through an urban mosquito-to-human transmission cycle, and with no available treatments or licensed vaccines to specifically target CHIKV disease, limiting transmission relies on vector control, which poses significant challenges, especially in developing countries. This review summarizes the current findings and progress in the development of safe, effective and affordable therapeutics and vaccines for CHIKV disease.

scholarly journals Mode-Dependent Antiviral Activity of Medicinal Plant Extracts against the Mosquito-Borne Chikungunya Virus

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1658
Author(s):  
Sze Mun Chan ◽  
Kong Soo Khoo ◽  
Shamala Devi Sekaran ◽  
Nam Weng Sit
Keyword(s):  
Viral Load ◽  
Medicinal Plants ◽  
Ethyl Acetate ◽  
Inhibitory Activity ◽  
Chikungunya Virus ◽  
Cytopathic Effect ◽  
Specific Treatment ◽  
Vero Cells ◽  
Sample Introduction ◽  
Medicinal Plant Extracts

The lack of specific treatment for chikungunya fever makes the need for anti-chikungunya virus agents more crucial. This study was conducted to evaluate 132 extracts obtained by sequential solvent extraction from 21 medicinal plants for cytopathic effect inhibitory activity using virus-infected Vero cells in two different sample introduction modes. Among the extracts, 42 extracts (31.8%) from 12 plants in the concurrent mode and three extracts (2.3%) from a plant in the non-concurrent mode displayed strong cytopathic effect inhibitory activity (cell viability ≥70%). Viral load quantification analysis unveiled that the extracts of Clinacanthus nutans (chloroform, ethyl acetate, and ethanol), Hydrocotyle sibthorpioides (ethanol), and Ocimum americanum (ethanol and methanol) hindered the release of viral progeny from the infected cells while the extracts of Ficus deltoidea (ethanol), Gynura bicolor (water), H. sibthorpioides (water), and O. americanum (chloroform and ethyl acetate) blocked the entry of virus into the cells. The extracts of Diodella sarmentosa (ethyl acetate), Diplazium esculentum (chloroform, ethyl acetate, and ethanol), and G. bicolor (ethanol) possessed virucidal effect and caused 5.41-log to 6.63-log reductions of viral load compared to the virus control. The results indicate that these medicinal plants are potential sources of anti-chikungunya virus agents that have varied modes of action.

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