scholarly journals The impact of public health interventions in the Nordic countries during the first year of SARS-CoV-2 transmission and evolution

2021 ◽  
Vol 26 (44) ◽  
Author(s):  
Sebastian Duchene ◽  
Leo Featherstone ◽  
Birgitte Freiesleben de Blasio ◽  
Edward C Holmes ◽  
Jon Bohlin ◽  
...  

Background Many countries have attempted to mitigate and control COVID-19 through non-pharmaceutical interventions, particularly with the aim of reducing population movement and contact. However, it remains unclear how the different control strategies impacted the local phylodynamics of the causative SARS-CoV-2 virus. Aim We aimed to assess the duration of chains of virus transmission within individual countries and the extent to which countries exported viruses to their geographical neighbours. Methods We analysed complete SARS-CoV-2 genomes to infer the relative frequencies of virus importation and exportation, as well as virus transmission dynamics, in countries of northern Europe. We examined virus evolution and phylodynamics in Denmark, Finland, Iceland, Norway and Sweden during the first year of the COVID-19 pandemic. Results The Nordic countries differed markedly in the invasiveness of control strategies, which we found reflected in transmission chain dynamics. For example, Sweden, which compared with the other Nordic countries relied more on recommendation-based rather than legislation-based mitigation interventions, had transmission chains that were more numerous and tended to have more cases. This trend increased over the first 8 months of 2020. Together with Denmark, Sweden was a net exporter of SARS-CoV-2. Norway and Finland implemented legislation-based interventions; their transmission chain dynamics were in stark contrast to their neighbouring country Sweden. Conclusion Sweden constituted an epidemiological and evolutionary refugium that enabled the virus to maintain active transmission and spread to other geographical locations. Our analysis reveals the utility of genomic surveillance where monitoring of active transmission chains is a key metric.

2020 ◽  
Author(s):  
Sebastian Duchene ◽  
Leo Featherstone ◽  
Birgitte Freiesleben de Blasio ◽  
Edward C. Holmes ◽  
Jon Bohlin ◽  
...  

AbstractMany countries have attempted to control COVID-19 through the implementation of non-pharmaceutical interventions. However, it remains unclear how different control strategies have impacted SARS-CoV-2 virus transmission dynamics at the local level. Using complete SARS-CoV-2 genomes, we inferred the relative frequencies of virus importation and exportation, as well as virus transmission chain dynamics in Nordic countries - Denmark, Finland, Iceland, Norway and Sweden - during the first months of the pandemic. Our analyses revealed that Sweden experienced more numerous transmission chains, which tended to have more cases, and were of longer duration, a set of features that increased with time. Together with Denmark, Sweden was also a net exporter of SARS-CoV-2. Hence, Sweden effectively constituted an epidemiological and evolutionary ‘refugia’ that enabled the virus to maintain active transmission and spread to other geographic localities. This analysis highlights the utility of genomic surveillance where active transmission chain monitoring is a key metric.


Author(s):  
Sri Ariani ◽  
Tri Setianingsih

This research aims to find out Is there any significant differences between the impact of traditional teaching method and using Index Card Match in teaching English vocabulary at the First Year Students of SMA HANG TUAH 3 MATARAM and to find out does using Index Card Match have a positive effect on students’ vocabulary knowledge. The sample of this research is 40 students. The kind of this research is experimental research. The students are divided into two groups such as experimental group and control group. Then the research subjects are pre-tested to know their prior vocabulary mastery. After the treatment, the sample is post-tested to know their recent vocabulary mastery as the result of the treatment. The scores in both pre-test and post-test are taken as the main data of the research. The data is analyzed by using t-test.


2011 ◽  
Vol 3 (3) ◽  
pp. 35-48 ◽  
Author(s):  
Gregory J. Davis

Malaria is a vector-borne illness affecting millions of lives annually and imposes a heavy financial burden felt worldwide. Moreover, there is growing concern that global climate change, in particular, rising temperature, will increase this burden. As such, policy makers are in need of tools capable of informing them about the potential strengths and weaknesses of intervention and control strategies. A previously developed agent-based model of the Anopheles gambiae mosquito is extended, one of the primary vectors of malaria, to investigate how changes in temperature influence the dynamics of malaria transmission and the effectiveness of a common malaria intervention: insecticide-treated nets (ITNs). Results from the simulations suggest two important findings. Consistent with previous studies, an increase in mosquito abundance as temperature increases is observed. However, the increase in mosquito abundance reduces the effectiveness of ITNs at a given coverage level. The implications and limitations of these findings are discussed.


2020 ◽  
Author(s):  
Simon P. Kigozi ◽  
Ruth N. Kigozi ◽  
Adrienne Epstein ◽  
Arthur Mpimbaza ◽  
Asadu Sserwanga ◽  
...  

Abstract Background: Malaria control using long-lasting insecticidal nets (LLINs) and indoor residual spraying of insecticide (IRS) has been associated with reduced transmission throughout Africa. However, the impact of transmission reduction on the age distribution of malaria cases remains unclear. Methods: Over a 10-year period (January, 2009 to July, 2018), outpatient surveillance data from four health facilities in Uganda were used to estimate the impact of control interventions on temporal changes in the age distribution of malaria cases using multinomial regression. Interventions included mass distribution of LLINs at all sites and IRS at two sites. Results: Overall, 896,550 patient visits were included in the study; 211,632 aged <5 years, 171,166 aged 5-15 years, and 513,752 >15 years. Over time, the age distribution of patients not suspected of malaria and those malaria negative either declined or remained the same across all sites. In contrast, the age distribution of suspected and confirmed malaria cases increased across all four sites. In the two LLINs-only sites, the proportion of malaria cases in <5 years decreased from 31% to 16% and 35% to 25%, respectively. In the two sites receiving LLINs plus IRS, these proportions decreased from 58% to 30% and 64% to 47%, respectively. Similarly, in the LLINs-only sites, the proportion of malaria cases >15 years increased from 40% to 61% and 29% to 39%, respectively. In the sites receiving LLINs plus IRS, these proportions increased from 19% to 44% and 18% to 31%, respectively. Discussion: These findings demonstrate a shift in the burden of malaria from younger to older individuals following implementation of successful control interventions, which has important implications for malaria prevention, surveillance, case management and control strategies.


2018 ◽  
Vol 12 ◽  
pp. 56-62
Author(s):  
PRAGYA SINGH LODHI ◽  
DEEPAK SINGH ◽  
GUNJAN SHARMA

This study has been conducted to study the impact of diary writing on mental health of adolescent girls. A sample of 100 girlsfrom Shri Ram Collage Muzaffernagar (U.P.), who are studying in first year of graduation, was selected from accidental sampling method.Sample was divided into two groups, 50 in experimental group and 50 in control group. Diary writing was selected as the independent variable, which was appliedfor 3 months where girls used to write down their thoughts and feelings; independently 30 minutes each for 5 days a week. Mental health of girls was assessed using the ‘Mental Health Inventory’. Statistical analysis of the data was performed using the SPSS software (version 18) the result indicated that there was a significant difference between experimental and control group on the level of mental health of adolescent girls. The findings of this study indicate that the practice of diary writing significantly improved the level of mental health of adolescent girls.


2021 ◽  
Vol 15 (5) ◽  
pp. e0009449
Author(s):  
Maylis Layan ◽  
Simon Dellicour ◽  
Guy Baele ◽  
Simon Cauchemez ◽  
Hervé Bourhy

Background Rabies is a fatal yet vaccine-preventable disease. In the last two decades, domestic dog populations have been shown to constitute the predominant reservoir of rabies in developing countries, causing 99% of human rabies cases. Despite substantial control efforts, dog rabies is still widely endemic and is spreading across previously rabies-free areas. Developing a detailed understanding of dog rabies dynamics and the impact of vaccination is essential to optimize existing control strategies and developing new ones. In this scoping review, we aimed at disentangling the respective contributions of mathematical models and phylodynamic approaches to advancing the understanding of rabies dynamics and control in domestic dog populations. We also addressed the methodological limitations of both approaches and the remaining issues related to studying rabies spread and how this could be applied to rabies control. Methodology/principal findings We reviewed how mathematical modelling of disease dynamics and phylodynamics have been developed and used to characterize dog rabies dynamics and control. Through a detailed search of the PubMed, Web of Science, and Scopus databases, we identified a total of n = 59 relevant studies using mathematical models (n = 30), phylodynamic inference (n = 22) and interdisciplinary approaches (n = 7). We found that despite often relying on scarce rabies epidemiological data, mathematical models investigated multiple aspects of rabies dynamics and control. These models confirmed the overwhelming efficacy of massive dog vaccination campaigns in all settings and unraveled the role of dog population structure and frequent introductions in dog rabies maintenance. Phylodynamic approaches successfully disentangled the evolutionary and environmental determinants of rabies dispersal and consistently reported support for the role of reintroduction events and human-mediated transportation over long distances in the maintenance of rabies in endemic areas. Potential biases in data collection still need to be properly accounted for in most of these analyses. Finally, interdisciplinary studies were determined to provide the most comprehensive assessments through hypothesis generation and testing. They also represent new avenues, especially concerning the reconstruction of local transmission chains or clusters through data integration. Conclusions/significance Despite advances in rabies knowledge, substantial uncertainty remains regarding the mechanisms of local spread, the role of wildlife in dog rabies maintenance, and the impact of community behavior on the efficacy of control strategies including vaccination of dogs. Future integrative approaches that use phylodynamic analyses and mechanistic models within a single framework could take full advantage of not only viral sequences but also additional epidemiological information as well as dog ecology data to refine our understanding of rabies spread and control. This would represent a significant improvement on past studies and a promising opportunity for canine rabies research in the frame of the One Health concept that aims to achieve better public health outcomes through cross-sector collaboration.


2019 ◽  
Author(s):  
Simon P. Kigozi ◽  
Ruth N. Kigozi ◽  
Adrienne Epstein ◽  
Arthur Mpimbaza ◽  
Asadu Sserwanga ◽  
...  

Abstract Background: Malaria control using long-lasting insecticidal nets (LLINs) and indoor residual spraying of insecticide (IRS) has been associated with reduced transmission throughout Africa. However, the impact of transmission reduction on the age distribution of malaria cases remains unclear. Methods: Over a 10-year period (January, 2009 to July, 2018), outpatient surveillance data from four health facilities in Uganda were used to estimate the impact of control interventions on temporal changes in the age distribution of malaria cases using multinomial regression. Interventions included mass distribution of LLINs at all sites and IRS at two sites. Results: Overall, 896,550 patient visits were included in the study; 211,632 aged <5 years, 171,166 aged 5-15 years, and 513,752 >15 years. Over time, the age distribution of patients not suspected of malaria and those malaria negative either declined or remained the same across all sites. In contrast, the age distribution of suspected and confirmed malaria cases increased across all four sites for. In the two LLINs-only sites, the proportion of malaria cases in <5 years decreased from 31% to 16% and 35% to 25%, respectively. In the two sites receiving LLINs plus IRS, these proportions decreased from 58% to 30% and 64% to 47%, respectively. Similarly, in the LLINs-only sites, the proportion of malaria cases >15 years of age increased from 40% to 61% and 29% to 39%, respectively. In the sites receiving LLINs plus IRS, these proportions increased from 19% to 44% and 18% to 31%, respectively. Discussion: These findings demonstrate a shift in the burden of malaria from younger to older individuals following implementation of successful control interventions, which has important implications for malaria prevention, surveillance, case management and control strategies.


2019 ◽  
Vol 188 (6) ◽  
pp. 987-990
Author(s):  
Nicole E Basta ◽  
M Elizabeth Halloran

Abstract The regression discontinuity design (RDD), first proposed in the educational psychology literature and popularized in econometrics in the 1960s, has only recently been applied to epidemiologic research. A critical aim of infectious disease epidemiologists and global health researchers is to evaluate disease prevention and control strategies, including the impact of vaccines and vaccination programs. RDDs have very rarely been used in this context. This quasi-experimental approach using observational data is designed to quantify the effect of an intervention when eligibility for the intervention is based on a defined cutoff such as age or grade in school, making it ideally suited to estimating vaccine effects given that many vaccination programs and mass-vaccination campaigns define eligibility in this way. Here, we describe key features of RDDs in general, then specific scenarios, with examples, to illustrate that RDDs are an important tool for advancing our understanding of vaccine effects. We argue that epidemiologic researchers should consider RDDs when evaluating interventions designed to prevent and control diseases. This approach can address a wide range of research questions, especially those for which randomized clinical trials would present major challenges or be infeasible. Finally, we propose specific ways in which RDDs could advance future vaccine research.


2021 ◽  
pp. injuryprev-2021-044247
Author(s):  
Johnathon P Ehsani ◽  
Rebecca Weast ◽  
Theresa Chirles ◽  
Andrew Hellinger ◽  
Wendy Shields ◽  
...  

BackgroundThe learner stage of graduated driver licensing (GDL), when teenagers are supervised by an adult driver, represents an opportunity to develop skills that could confer a safety benefit during their years of independent driving. This paper describes the design of a teenage driving study, which aims to evaluate the impact of a smartphone application, the ‘DrivingApp,’ to increase the quantity and improve the quality of supervised practice driving.MethodsThis longitudinal intervention study of teenage drivers and a parent/guardian spans the final 6 months of the learner licence and the first year of independent driving. Participants will be assigned to experimental or control groups using block allocation. Parent–teenage dyads assigned to the intervention arm will receive information about their practice driving via a smartphone application, including miles driven and total drive time. Baseline and monthly surveys will be administered to both experimental and control participants to measure the outcome measures during the learner stage: (1) practice driving amount, (2) consistency and (3) variety. Outcomes during independent driving are (1) self-reported number of attempts at the driving test and (2) number of crashes during the first year of independent driving.DiscussionImproving the quality of teenagers’ supervised practice driving is an unmet research need. This study will contribute to the evidence about what can be done during the learner period of GDL to maximise teenage drivers’ safety during the first years of independent driving, when crash risk is highest.


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