scholarly journals Simuliidae and the transmission and control of human Onchocerciasis in Latin America

1991 ◽  
Vol 7 (3) ◽  
pp. 310-327 ◽  
Author(s):  
A. J. Shelley
Keyword(s):  
Latin America ◽  
Epidemiological Studies ◽  
Control Measures ◽  
Onchocerca Volvulus ◽  
Transmission Dynamics ◽  
Control Methods ◽  
Filarial Worm ◽  
And Control

Factors that affect the propensity of a simuliid species to act as a host to Onchocerca volvulus and to naturally transmit this filarial worm in nature are discussed. Presence or absence of a cibarial armature is believed to be a major factor that has been previously overlooked and this is considered in relation to the choice of control methods currently advocated for onchocerciasis. The current epidemiological studies, transmission dynamics and relevant control measures are discussed for each onchocerciasis focus in Latin America.

Principles and control methods

2015 ◽  
Author(s):  
Karen E Goldstone
Keyword(s):  
Radiation Protection ◽  
Control Measures ◽  
Risk Assessments ◽  
Control Methods ◽  
Alara Principle ◽  
Radiation Sources ◽  
Dose Limits ◽  
Dose Constraints ◽  
And Control ◽  
Dose Levels

Justification, optimization, and limitation are the three underlying principles of good radiation protection. This chapter considers how these principles apply in a variety of exposure situations. Risk-based application of the principles results in control methods comprising control over areas, control over people, and control over radiation sources. These are implemented through judgements based on the use of dose limits, dose constraints, and application of the ALARA principle. Potential dose levels and possible control measures appropriate to each situation are reviewed and evaluated in risk assessments prior to work being undertaken.

Molecular detection and epidemiology of chicken infectious anaemia virus in India

2013 ◽  
Vol 3 (4) ◽  
pp. 145-151
Author(s):  
M. Y. Wani ◽  
K. Dhama ◽  
R. Barathidasan ◽  
V. Gowthaman ◽  
R. Tiwari ◽  
...  
Keyword(s):  
Prevention And Control ◽  
Molecular Detection ◽  
Control Strategies ◽  
Age Groups ◽  
Epidemiological Studies ◽  
Control Measures ◽  
Economic Losses ◽  
Field Samples ◽  
And Control ◽  
Young Chicks

Chicken infectious anemia (CIA) is an economically important disease affecting poultry, especially young chicks, characterized by poor weight gain, anemia, immunosuppression and production losses. Recent reports indicate that the virus is emerging and re-emerging worldwide.  Also, scarce reports regarding the molecular detection and epidemiology of virus from India are available. The aim of this study was to determine the prevalence of the virus in the commercial poultry farms of the country employing polymerase chain reaction (PCR). Out of the suspected 424 field samples tested from 12 different states of the country during the last five years (2007-2012), 311 (73.3%) samples were found positive for CIAV-DNA indicating the wide prevalence of the virus in India. The age wise prevalence of the virus indicated high prevalence in young chicks of up to three weeks (80.3%) of age compared to 3-7 (66.6%) and 7-12 (25%) week age groups. Being an immunosuppressive emerging pathogen circulating among the poultry flocks of the country, suitable prevention and control measures need to be adopted timely. This is a first elaborative report on the molecular epidemiology of CIAV in poultry flocks of the country. Extensive epidemiological studies are suggested to know the magnitude of the virus affecting poultry industry of the country, and design and formulate effective disease prevention and control strategies to reduce economic losses being caused by emerging virus.

scholarly journals Behavior of the Avian Parasite Philornis downsi (Diptera: Muscidae) in and Near Host Nests in the Galapagos Islands

2021 ◽  
Author(s):  
Courtney L. Pike ◽  
Ismael E. Ramirez ◽  
David J. Anchundia ◽  
Birgit Fessl ◽  
George E. Heimpel ◽  
...  
Keyword(s):  
Life History ◽  
Mating Behavior ◽  
Galapagos Islands ◽  
Control Measures ◽  
Life History Strategies ◽  
Control Methods ◽  
Galápagos Islands ◽  
Nest Cavity ◽  
Philornis Downsi ◽  
And Control

AbstractThe Avian Vampire Fly, Philornis downsi, has invaded the Galapagos Islands, where it causes high mortality of endemic and native landbird species, including most species of Darwin’s finches. Control methods are under development, but key information is missing about the reproductive biology of P. downsi and the behavior of flies in and near nests of their hosts. We used external and internal nest cameras to record the behavior of P. downsi adults within and outside nests of the Galapagos Flycatcher, Myiarchus magnirostris, throughout all stages of the nesting cycle. These recordings showed that P. downsi visited flycatcher nests throughout the day with higher fly activity during the nestling phase during vespertine hours. The observations also revealed that multiple P. downsi individuals can visit nests concurrently, and that there are some interactions among these flies within the nest. Fly visitation to nests occurred significantly more often while parent birds were away from the nest than in the nest, and this timing appears to be a strategy to avoid predation by parent birds. We report fly mating behavior outside the nest but not in the nest cavity. We discuss the relevance of these findings for the adaptive forces shaping P. downsi life history strategies as well as rearing and control measures.

scholarly journals TOXOPLASMOSIS IN MEXICO: EPIDEMIOLOGICAL SITUATION IN HUMANS AND ANIMALS

2015 ◽  
Vol 57 (2) ◽  
pp. 93-103 ◽  
Author(s):  
Ivonne HERNÁNDEZ-CORTAZAR ◽  
Karla Y. ACOSTA-VIANA ◽  
Antonio ORTEGA-PACHECO ◽  
Eugenia del S. GUZMAN-MARIN ◽  
Armando J. AGUILAR-CABALLERO ◽  
...  
Keyword(s):  
Epidemiological Studies ◽  
Wide Distribution ◽  
Control Measures ◽  
Meat Production ◽  
Human Consumption ◽  
Feral Cat ◽  
Animal Populations ◽  
Tropical Areas ◽  
And Control ◽  
Treatment Alternatives

Toxoplasmosis is a parasitic disease widely distributed throughout the world, infecting a wide variety of animal species including humans. In Mexico, this parasite has been detected in different parts of the country, particularly in the tropical areas where the parasite can remain infective for long periods of time due to the environmental conditions (i.e. high temperature and humidity over the whole year). Several epidemiological studies have been conducted in both human and animal populations, but despite the wide distribution of the agent in the country, there is a significant lack of knowledge on the parasite transmission, treatment alternatives and control measures. The lack of feral cat populations and control measures in sites of meat production for human consumption are playing a role that has led to the wide spread of the disease in the country, particularly in tropical areas of Southeastern Mexico. For these reasons, this manuscript aims to review the published information on relevant epidemiological aspects of infection with T. gondii in humans and animals from Mexico.

scholarly journals Assessing the effects of time-dependent restrictions and control actions to flatten the curve of COVID-19 in Kazakhstan

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10806
Author(s):  
Ton Duc Do ◽  
Meei Mei Gui ◽  
Kok Yew Ng
Keyword(s):  
Ad Hoc ◽  
Reproduction Number ◽  
National Level ◽  
Control Measures ◽  
Time Dependent ◽  
Transmission Dynamics ◽  
Model Parameters ◽  
Real World Data ◽  
Control Actions ◽  
And Control

This article presents the assessment of time-dependent national-level restrictions and control actions and their effects in fighting the COVID-19 pandemic. By analysing the transmission dynamics during the first wave of COVID-19 in the country, the effectiveness of the various levels of control actions taken to flatten the curve can be better quantified and understood. This in turn can help the relevant authorities to better plan for and control the subsequent waves of the pandemic. To achieve this, a deterministic population model for the pandemic is firstly developed to take into consideration the time-dependent characteristics of the model parameters, especially on the ever-evolving value of the reproduction number, which is one of the critical measures used to describe the transmission dynamics of this pandemic. The reproduction number alongside other key parameters of the model can then be estimated by fitting the model to real-world data using numerical optimisation techniques or by inducing ad-hoc control actions as recorded in the news platforms. In this article, the model is verified using a case study based on the data from the first wave of COVID-19 in the Republic of Kazakhstan. The model is fitted to provide estimates for two settings in simulations; time-invariant and time-varying (with bounded constraints) parameters. Finally, some forecasts are made using four scenarios with time-dependent control measures so as to determine which would reflect on the actual situations better.

scholarly journals Reconstruction of the transmission dynamics of the first COVID-19 epidemic wave in Thailand

2021 ◽  
Author(s):  
Chaiwat Wilasang ◽  
Natcha Jitsuk ◽  
Chayanin Sararat ◽  
Charin Modchang
Keyword(s):  
Disease Transmission ◽  
Infected Individual ◽  
Mainland China ◽  
Stochastic Modelling ◽  
Epidemiological Data ◽  
Control Measures ◽  
Transmission Dynamics ◽  
Thai Government ◽  
And Control ◽  
Epidemic Wave

Abstract Thailand was the first country reporting the first Coronavirus disease 2019 (COVID-19) infected individual outside mainland China. Here we delineated the course of the COVID-19 outbreak together with the timeline of the control measures and public health policies employed by the Thai government during the first wave of the COVID-19 outbreak in Thailand. Based on the comprehensive epidemiological data, we reconstructed the dynamics of COVID-19 transmission in Thailand using a stochastic modelling approach. Our stochastic model incorporated effects of individual heterogeneity in infectiousness on the disease transmission, which allows us to capture relevant features of superspreading events. We found that our model could accurately capture the transmission dynamics of the first COVID-19 epidemic wave in Thailand. The model predicted that at the end of the first wave, the number of cumulative confirmed cases was 3,091 (95%CI: 2,782 - 3,400). We also estimated the time-varying reproduction number (Rt) during the first epidemic wave. We found that after implementing the nationwide interventions, the Rt in Thailand decreased from the peak value of 5.67 to a value below one in less than one month, indicating that the control measures employed by the Thai government during the first COVID-19 epidemic wave were effective. Finally, effects of transmission heterogeneity and control measures on the likelihood of outbreak extinction were also investigated.

Prospects of Pesticide Contamination and Control Measures in Aquatic Systems

2019 ◽  
pp. 369-386
Author(s):  
Roopa Rani ◽  
Prem Kishore Patnala ◽  
Vinayak V. Pathak
Keyword(s):  
Surface Water ◽  
Chemical Control ◽  
Cost Effective ◽  
Control Measures ◽  
Aquatic Systems ◽  
Control Methods ◽  
Relative Toxicity ◽  
Water Reservoirs ◽  
Pesticide Pollution ◽  
And Control

In this chapter, up-to-date knowledge on extenuation strategies to diminish pesticide accumulation in aquatic systems, which has remained a major concern for ground water as well as surface water, adversely affecting aquatic ecosystems and humans through bio-magnification, are included. Several factors affect the toxicity of pesticides like dosage of concentration, relative toxicity, and chemical interactions. The best approach to decrease pesticide pollution in environment is to use safer, non-chemical control methods, and industrial or sewage superfluous should not be dumped into water reservoirs without proper pretreatment. Biological and chemical methods used for the control measures of pesticides pollution in aquatic systems. Thus, a greener approach for remedy of pesticide-contaminated aquatic system could be more cost-effective and sustainable.

scholarly journals Knowledge of malaria prevention and control methods and associated factors among rural households in West Belesa district, North West Ethiopia, 2019.

2019 ◽  
Author(s):  
Tsigie Baye Aragie
Keyword(s):  
Prevention And Control ◽  
Associated Factors ◽  
Malaria Prevention ◽  
Control Measures ◽  
Control Methods ◽  
Binary Logistic Regression Model ◽  
North West ◽  
North West Ethiopia ◽  
And Control ◽  
Structured Questionnaire

Abstract Introduction: In Ethiopia malaria is one of the top ten leading causes of morbidity and mortality.The two major malaria prevention services implemented in Ethiopia are targeted Indoor Residual Spray (IRS) with insecticides and distribution of Long Lasting Insecticidal Nets (LLIN). Community knowledge towards prevention and control methods had been proven to play important role for the implementation of effective and sustainable interventions against malaria. This information is limited in the study area regarding to knowledge and practice on malaria prevention and control. This study aimed to assess knowledge towards malaria prevention and control methods and its associated factors among households in West Bellessa district, 2019. Methods: Community based cross-sectional mixed quantitative and qualitative study was conducted from April to June 2019 in West Bellessa district, Amhara region, North West Ethiopia. Multistage sampling was used to select an estimated sample size of 770. Pretested structured questionnaire was used for the quantitative component and semi-structured questionnaire for qualitative one. Quantitative data were coded and entered using Epi info software version 7 and exported to SPSS version 20 for analysis. Binary logistic regression model was fitted to identify the associated factors. Odds Ratio (OR) with 95 % Confidence Interval (CI) was used to assess the strength of association. The qualitative data transcribed manually in thematic approach. Result: A total of 770 subjects were included in this study with 99.5% response rate. Of the total respondents 75.6% had good compressive knowledge about malaria prevention measures. Poorest wealth quintiles [AOR= 0.40, 95% CI: 0.23, 0.73], poor wealth quintiles [AOR= 0.38, 95% CI: 0.21, 0.70], and medium wealth quintiles [AOR= 0.41, 95% CI: 0.22, 0.75], living in Menti Kebele [AOR= 3.01, 95% CI 1.87, 5.15], living in Abay tera kebele [AOR= 2.03, 95% CI 1.23, 3.34] were significantly associated with compressive knowledge about malaria prevention control.Conclusion: In overall there was relatively high knowledge of malaria prevention and control measures. There was decrement in the effect of LLIN and IRS as compared with the previous brands. Wealth index and respondents living kebele are predictors for malaria prevention knowledge of malaria.

scholarly journals Management of Rhynchophorus ferrugineus Olivier in the Gulf and Mediterranean region

CORD ◽  
2005 ◽  
Vol 21 (02) ◽  
pp. 34 ◽  
Author(s):  
C.P. Ramachandran
Keyword(s):  
Hybrid Sterility ◽  
Climatic Conditions ◽  
Control Measures ◽  
Control Methods ◽  
Rhynchophorus Ferrugineus ◽  
Jordan Valley ◽  
Pheromone Trapping ◽  
Wide Range ◽  
Palm Species ◽  
And Control

The red palm weevil Rhynchophorus ferrugineus Olivier is the most deadly and dangerous pest of coconut, date, oil, sago and other palms. R. ferrugineus is distributed in over 33 countries over a wide range of area under different agro-climatic conditions and attacks more than two dozen palm species. In the Middle East the weevil is the most destructive pest of the date palms. The hidden nature of the pest attack makes timely detection of the infestation and control measures difficult.  The earlier reviews provide details of biology and control methods viz. phyto-sanitary and preventive, curative, biological, baiting and trapping etc. Different combinations of above mentioned control methods have also been tried with varying degrees of success. Results of two major IPM programmes carried out in the gulf countries, the first during 1993-1998 mainly based on chemical and pheromone trapping and the second from 1998-2002 using bio-agents and pheromone trapping are discussed.  In Jordan valley intensive pheromone trapping and incorporation of systemic insecticide in irrigation water could not control the pest even after three years. Development of ecofriendly pest control strategies like hybrid sterility, incompatibility and disruption of tolerance to high temperatures in Gulf and Mediterranean regions is suggested to combat the pest.

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