scholarly journals The Role of Vertical Transmission in the Control of Dengue Fever

2019 ◽  
Vol 16 (5) ◽  
pp. 803 ◽  
Author(s):  
David Murillo ◽  
Anarina Murillo ◽  
Sunmi Lee
Keyword(s):  
Dengue Fever ◽  
Vertical Transmission ◽  
Disease Transmission ◽  
Control Function ◽  
Infected Mosquito ◽  
Effective Control ◽  
Control Policies ◽  
Effective Interventions ◽  
Endemic Strain

In this work, a two-strain dengue model with vertical transmission in the mosquito population is considered. Although vertical transmission is often ignored in models of dengue fever, we show that effective control of an outbreak of dengue can depend on whether or not the vertical transmission is a significant mode of disease transmission. We model the effect of a control strategy aimed at reducing human-mosquito transmissions in an optimal control framework. As the likelihood of vertical transmission increases, outbreaks become more difficult and expensive to control. However, even for low levels of vertical transmission, the additional, uncontrolled, transmission from infected mosquito to eggs may undercut the effectiveness of any control function. This is of particular importance in regions where existing control policies may be effective and the endemic strain does not exhibit vertical transmission. If a novel strain that does exhibit vertical transmission invades, then existing, formerly effective, control policies may no longer be sufficient. Therefore, public health officials should pay more attention to the role of vertical transmission for more effective interventions and policy.

scholarly journals Arbovirus emergence in temperate climates: the case of Córdoba, Argentina, 2009-2018

2019 ◽  
Author(s):  
Michael A. Robert ◽  
Daniela Tatiana Tinunin ◽  
Elisabet Marina Benitez ◽  
Francisco Ludueña-Almeida ◽  
Moory Romero ◽  
...  
Keyword(s):  
Costa Rica ◽  
Dengue Virus ◽  
Dengue Fever ◽  
Disease Transmission ◽  
Human Movement ◽  
Denv Serotypes ◽  
Imported Cases ◽  
The Tropics ◽  
Zika Fever

AbstractThe distribution of arbovirus disease transmission is expanding from the tropics and subtropics into temperate regions worldwide. The aim of this study was to characterize the emergence of arboviruses in the temperate city of Córdoba, Argentina (2009-2018), including dengue virus (DENV) serotypes and origins of imported cases. The first cases of dengue fever were reported in 2009, followed by outbreaks in 2013, 2015, and 2016, each outbreak having greater incidence than the previous. DENV1 was the predominant serotype. Cases were imported from Venezuela, Brazil, Bolivia, Mexico, Costa Rica, and northern Argentina. The first imported cases of chikungunya were reported in 2014 and the first imported and autochthonous of Zika fever in 2016. Regional efforts are needed to strengthen surveillance, due to the key role of human movement in arbovirus introductions.

scholarly journals Inter-provincial disparity of COVID-19 transmission and control in Nepal

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Buddhi Pantha ◽  
Subas Acharya ◽  
Hem Raj Joshi ◽  
Naveen K. Vaidya
Keyword(s):  
Growth Rate ◽  
Disease Transmission ◽  
Reproduction Number ◽  
Control Strategies ◽  
National Level ◽  
Effective Control ◽  
Data Set ◽  
Control Policies ◽  
Local Spread ◽  
And Control

AbstractDespite the global efforts to mitigate the ongoing COVID-19 pandemic, the disease transmission and the effective controls still remain uncertain as the outcome of the epidemic varies from place to place. In this regard, the province-wise data from Nepal provides a unique opportunity to study the effective control strategies. This is because (a) some provinces of Nepal share an open-border with India, resulting in a significantly high inflow of COVID-19 cases from India; (b) despite the inflow of a considerable number of cases, the local spread was quite controlled until mid-June of 2020, presumably due to control policies implemented; and (c) the relaxation of policies caused a rapid surge of the COVID-19 cases, providing a multi-phasic trend of disease dynamics. In this study, we used this unique data set to explore the inter-provincial disparities of the important indicators, such as epidemic trend, epidemic growth rate, and reproduction numbers. Furthermore, we extended our analysis to identify prevention and control policies that are effective in altering these indicators. Our analysis identified a noticeable inter-province variation in the epidemic trend (3 per day to 104 per day linear increase during third surge period), the median daily growth rate (1 to 4% per day exponential growth), the basic reproduction number (0.71 to 1.21), and the effective reproduction number (maximum values ranging from 1.20 to 2.86). Importantly, results from our modeling show that the type and number of control strategies that are effective in altering the indicators vary among provinces, underscoring the need for province-focused strategies along with the national-level strategy in order to ensure the control of a local spread.

scholarly journals The current role of cattle in transmission of hydatidosis in an endemic area of central Iran

2019 ◽  
Vol 21 (4) ◽  
pp. 153-156
Author(s):  
Maryam Rahmani-Dehaghani ◽  
Mohammadreza Haghighi-Broujeni ◽  
Zahra Ghayour-Najafabadi
Keyword(s):  
Disease Transmission ◽  
Laboratory Data ◽  
Effective Control ◽  
Sufficient Information ◽  
Intermediate Hosts ◽  
Current Role ◽  
Lung Cysts ◽  
Worldwide Distribution ◽  
Age Range

Background and aims: Hydatidosis is considered as one of the most important zoonotic parasitic diseases, which has a worldwide distribution with endemic regions in many countries including Iran. The disease has public health and economic importance and its effective control requires sufficient information on the patterns of disease transmission. This study aimed to assess the current role of the cattle as the intermediate host in transmission of the disease and maintain the evolution of hydatidosis. Methods: The study was conducted at Isfahan Fasaran abattoir. From among 129 cattle infected with hydatid cyst, 134 liver and lung cysts were transferred to parasitology laboratory. Data including age, sex, the infected organ, the type of cyst (e.g., fertile, sterile, and calcified), and the severity of infection were evaluated for each of the cattle. Results: Based on the data, 99 (76.7%) of the cases were females and the remaining 30 (23.3%) cases were males, who were in the age range of 5-10 and 2-5 years, respectively. In addition, 385 cysts were found out of the total 134 examined infected livers and lungs and the number of the cysts in infected organs varied between 1 and 14. A significantly higher infection was detected in older cattle (P<0.05) compared to the younger and female ones. Finally, out of the total of 385 collected cysts, 1%, 59.8%, and 39.2% were fertile, sterile, and calcified cysts, respectively. Conclusion: In general, the total rate of cyst fertility was estimated at 1% and it seems that the role of cattle led to a reduction in the transmission of the disease. However, due to the species differences in various areas and the better adaptation of the parasite to some intermediate hosts, further studies including more samples are necessary in different regions.

scholarly journals Implications of asymptomatic carriers for infectious disease transmission and control

2018 ◽  
Vol 5 (2) ◽  
pp. 172341 ◽  
Author(s):  
Rebecca H. Chisholm ◽  
Patricia T. Campbell ◽  
Yue Wu ◽  
Steven Y. C. Tong ◽  
Jodie McVernon ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Model Parameters ◽  
Model Structure ◽  
Infectious Disease Transmission ◽  
Asymptomatic Carriers ◽  
Effective Interventions ◽  
History Of ◽  
And Control ◽  
Selection Of

For infectious pathogens such as Staphylococcus aureus and Streptococcus pneumoniae , some hosts may carry the pathogen and transmit it to others, yet display no symptoms themselves. These asymptomatic carriers contribute to the spread of disease but go largely undetected and can therefore undermine efforts to control transmission. Understanding the natural history of carriage and its relationship to disease is important for the design of effective interventions to control transmission. Mathematical models of infectious diseases are frequently used to inform decisions about control and should therefore accurately capture the role played by asymptomatic carriers. In practice, incorporating asymptomatic carriers into models is challenging due to the sparsity of direct evidence. This absence of data leads to uncertainty in estimates of model parameters and, more fundamentally, in the selection of an appropriate model structure. To assess the implications of this uncertainty, we systematically reviewed published models of carriage and propose a new model of disease transmission with asymptomatic carriage. Analysis of our model shows how different assumptions about the role of asymptomatic carriers can lead to different conclusions about the transmission and control of disease. Critically, selecting an inappropriate model structure, even when parameters are correctly estimated, may lead to over- or under-estimates of intervention effectiveness. Our results provide a more complete understanding of the role of asymptomatic carriers in transmission and highlight the importance of accurately incorporating carriers into models used to make decisions about disease control.

scholarly journals Differential attraction in mosquito–human interactions and implications for disease control

2020 ◽  
Vol 376 (1818) ◽  
pp. 20190811 ◽  
Author(s):  
Julien Martinez ◽  
Alicia Showering ◽  
Catherine Oke ◽  
Robert T. Jones ◽  
James G. Logan
Keyword(s):  
Vector Control ◽  
Disease Transmission ◽  
Control Strategies ◽  
Effective Control ◽  
Skin Microbiome ◽  
Human Interactions ◽  
Relative Contribution ◽  
Body Odour ◽  
Host Parasite

Mosquito-borne diseases are a major burden on human health worldwide and their eradication through vector control methods remains challenging. In particular, the success of vector control interventions for targeting diseases such as malaria is under threat, in part due to the evolution of insecticide resistance, while for other diseases effective control solutions are still lacking. The rate at which mosquitoes encounter and bite humans is a key determinant of their capacity for disease transmission. Future progress is strongly reliant on improving our understanding of the mechanisms leading to a mosquito bite. Here, we review the biological factors known to influence the attractiveness of mosquitoes to humans, such as body odour, the skin microbiome, genetics and infection by parasites. We identify the knowledge gaps around the relative contribution of each factor, and the potential links between them, as well as the role of natural selection in shaping vector–host–parasite interactions. Finally, we argue that addressing these questions will contribute to improving current tools and the development of novel interventions for the future. This article is part of the theme issue ‘Novel control strategies for mosquito-borne diseases'.

Youngistan-Discussion on Models for Working with Youth

2015 ◽  
Vol 1 (2) ◽  
Author(s):  
Praveen Varghese Thomas ◽  
Sojin P. Varghese
Keyword(s):  
Essential Element ◽  
Youth Work ◽  
Effective Interventions ◽  
The World ◽  
Agents Of Change ◽  
Support Policy ◽  
Youth Bulge ◽  
Conducive Environment ◽  
Age Category

Youth is always considered as the dynamic section of society which stands inevitable both as age category and social status. There is a strong tendency among politicians, researchers to see youth bulge as a problem to be solved or as a threat which must be treated. However youth are underestimated as positive agents of change and key actors in development and harmony of the nation. But then more importantly, providing a conducive environment for youth is crucial and remains as the biggest challenge in India as the nation is going to be the youngest nation in the world demographically and will remain the same for next couple of decades. This paper explores the role of youth in development and various models and approaches by which the society and professionals working with youth can address those queries and anxieties associated with the youth bulge. Further the paper explores the scope of youth work in India as the nation is going to be the youngest nation in couple of years. Further research and debates on youth work as a profession in India is an essential element to develop specific guidance to support policy and commissioning processes in understanding how youth work contributes to effective interventions and improves the lives of young people.

Perceived Risks and Normative Beliefs as Explanatory Models for College Student Alcohol Involvement: An Assessment of a Campus with Conventional Alcohol Control Policies and Enforcement Practices

NASPA Journal ◽  
2005 ◽  
Vol 42 (2) ◽  
Author(s):  
Todd F. Lewis ◽  
Dennis L Thombs
Keyword(s):  
College Student ◽  
Explanatory Models ◽  
Normative Beliefs ◽  
Control Policies ◽  
Perceptions Of Risk ◽  
Student Drinking ◽  
Alcohol Control ◽  
Effective Interventions ◽  
Alcohol Involvement ◽  
University Communities

The aim of this study was to conduct a multivariate assessment of college student drinking motivations at a campus with conventional alcohol control policies and enforcement practices, including the establishment and dissemination of alcohol policies and the use of warnings to arouse fear of sanctions. Two explanatory models were compared: perceptions of risk and normative beliefs. An anonymous questionnaire was administered to 1,396 students at a large Midwestern university. Data analyses were conducted on the subsample of participants who had reported using alcohol within the past 12 months (n = 1,322). Overall, the results from a canonical correlation analysis indicated that alcohol involvement was best explained by normative beliefs about the drinking practices of one’s closest friends. Perceptions of drinking risk were less important to the explanation of alcohol involvement, and some of these measures unexpectedly had positive associations with indicators of alcohol risk behavior. The findings call into question the conventional deterrence strategies used in many university communities (i.e., belief that students who perceive there to be a low risk of receiving sanctions are those most likely to engage in alcohol related misbehavior). Furthermore, the findings suggest that effective interventions will need to impact students' normative beliefs about the drinking practices of proximal peer groups.

Training, Supervising, and Supporting Students With Emotional–Behavioral Disorders as Cross-Age Tutors

2021 ◽  
pp. 105345122110148
Author(s):  
Gavin W. Watts ◽  
John W. McKenna
Keyword(s):  
Behavioral Disorders ◽  
Special Educators ◽  
Skills Training ◽  
Instructional Delivery ◽  
Behavioral Skills ◽  
Intervention Models ◽  
Effective Interventions ◽  
Effective Procedures ◽  
Students With Ebd

Students with emotional and behavioral disorders (EBD) are frequently on the receiving end of intervention models (e.g., social skills training) in which targeted skills are modeled and practiced in unnatural arrangements (i.e., teacher-lead). Special educators consistently report a need for effective interventions and instructional arrangements that promote social-behavioral skills of students with EBD in natural learning environments (i.e., with peers). When students with EBD are provided the opportunity to serve in the role of tutor (i.e., on the instructional delivery end of the model), increases in academic and behavioral skills have been found for both tutors and tutees. This article provides an overview of effective procedures and considerations for training, supervising, and supporting students with EBD as cross-age tutors.

scholarly journals How does globalization affect COVID-19 responses?

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Steve J. Bickley ◽  
Ho Fai Chan ◽  
Ahmed Skali ◽  
David Stadelmann ◽  
Benno Torgler
Keyword(s):  
Infectious Disease ◽  
Disease Transmission ◽  
State Capacity ◽  
International Travel ◽  
Health Crisis ◽  
Government Effectiveness ◽  
Policy Responses ◽  
Travel Restrictions ◽  
High Government

Abstract Background The ongoing COVID-19 pandemic has highlighted the vast differences in approaches to the control and containment of coronavirus across the world and has demonstrated the varied success of such approaches in minimizing the transmission of coronavirus. While previous studies have demonstrated high predictive power of incorporating air travel data and governmental policy responses in global disease transmission modelling, factors influencing the decision to implement travel and border restriction policies have attracted relatively less attention. This paper examines the role of globalization on the pace of adoption of international travel-related non-pharmaceutical interventions (NPIs) during the coronavirus pandemic. This study aims to offer advice on how to improve the global planning, preparation, and coordination of actions and policy responses during future infectious disease outbreaks with empirical evidence. Methods and data We analyzed data on international travel restrictions in response to COVID-19 of 185 countries from January to October 2020. We applied time-to-event analysis to examine the relationship between globalization and the timing of travel restrictions implementation. Results The results of our survival analysis suggest that, in general, more globalized countries, accounting for the country-specific timing of the virus outbreak and other factors, are more likely to adopt international travel restrictions policies. However, countries with high government effectiveness and globalization were more cautious in implementing travel restrictions, particularly if through formal political and trade policy integration. This finding is supported by a placebo analysis of domestic NPIs, where such a relationship is absent. Additionally, we find that globalized countries with high state capacity are more likely to have higher numbers of confirmed cases by the time a first restriction policy measure was taken. Conclusions The findings highlight the dynamic relationship between globalization and protectionism when governments respond to significant global events such as a public health crisis. We suggest that the observed caution of policy implementation by countries with high government efficiency and globalization is a by-product of commitment to existing trade agreements, a greater desire to ‘learn from others’ and also perhaps of ‘confidence’ in a government’s ability to deal with a pandemic through its health system and state capacity. Our results suggest further research is warranted to explore whether global infectious disease forecasting could be improved by including the globalization index and in particular, the de jure economic and political, and de facto social dimensions of globalization, while accounting for the mediating role of government effectiveness. By acting as proxies for a countries’ likelihood and speed of implementation for international travel restriction policies, such measures may predict the likely time delays in disease emergence and transmission across national borders.

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