scholarly journals Mask on, Mask off: An SEIAR Model to Evaluate the Role of Mask in Preventing Disease Transmission

2021 ◽  
Vol 120 (3) ◽  
pp. 263a
Author(s):  
Anthony J. Morciglio ◽  
Yi Jiang
Keyword(s):  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Steve J. Bickley ◽  
Ho Fai Chan ◽  
Ahmed Skali ◽  
David Stadelmann ◽  
Benno Torgler

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.


BMJ ◽  
2015 ◽  
Vol 350 (may11 1) ◽  
pp. h1314-h1314 ◽  
Author(s):  
V. Sintchenko ◽  
E. C. Holmes
Keyword(s):  

Author(s):  
V. P. Heluta

Abstract A description is provided for Arthrocladiella mougeotii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Powdery mildew of Lycium species only. The mycelium, conidiophores, conidia and ascomata form first white, then dirty-grey patches on damaged green parts of the host. Infected parts are deformed slightly and, in cases of high infection, plants can lose their ornamental qualities. Damaged leaves can fall prematurely. HOSTS: Lycium barbarum (= L. europaeum), L. chinense, L. dasystemum, L. halimifolium, L. ovatum, L. potaninii, L. rhombifolium, L. ruthenicum. [Type host - Lycium barbarum] GEOGRAPHICAL DISTRIBUTION: Africa: Canary Islands. Asia (temperate areas only): Armenia, Azerbaijan, China, Republic of Georgia, Israel, Japan, Kazakhstan, Kirghizistan, Korea, Russia (Russian far east), Tadzhikistan, Taiwan, Turkey, Turkmenistan, Uzbekistan. Australasia: New Zealand (introduced). Europe: Austria, Belgium, Bulgaria, Czech Republic, Estonia, France, Germany, Hungary, Italy, Netherlands, Norway, Poland, Rumania, Slovakia, Sweden, Switzerland, UK, Ukraine (southern), former Yugoslavia. North America: USA (introduced). TRANSMISSION: By wind-dispersed conidia. The rôle of ascospores in disease transmission is unknown, although it has been supposed that they can cause the initial stage of the disease.


Author(s):  
G. Hall

Abstract A description is provided for Peronospora oerteliana. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Primula acaulis, P. algida, P. elatior, P. juliae, P. officinalis, P. veris, P. vulgaris. DISEASE: Downy mildew of Primula species. GEOGRAPHICAL DISTRIBUTION: Asia-Temperate: Kazakhstan. Europe: Czechoslovakia, Denmark, Eire, France, Germany, Poland, Romania, Sweden, Switzerland, Yugoslavia, UK (England, Scotland). TRANSMISSION: By conidia which are dispersed by wind or rain-splash. The role of oospores in disease transmission is unknown, but they may have a perennating function.


Author(s):  
G. Hall

Abstract A description is provided for Peronospora sordida. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Scrophularia altaica, S. aquatica, S. auriculata, S. bosniaca, S. californica, S. heterophylla, S. lanceolata, S. marylandica, S. nodosa, S. scopolii, S. umbrosa (=S. alata), Verbascum banaticum, V. blattaria, V. densiflorum (=V. thapsiforme), V. glabratum subsp. glabratum, V. lychnitis, V. nigrum, V. phlomoides, V. phoenicum, V. speciosum, V. thapsus, V. thapsus subsp. crassifolium (=V. montanum), V. virgatum. DISEASE: Downy mildew of Scrophularia and Verbascum, some species of which may be cultivated commercially for their medicinal or ornamental value; an obligately necrotrophic plant pathogen. GEOGRAPHICAL DISTRIBUTION: Asia; USSR (Kirghizia, Turkmenia, Uzbekistan). Europe; Austria, Belgium, France, Czechoslovakia, Denmark, Eire, Finland, Germany, Hungary, Italy, Netherlands, Norway, Poland, Rumania, USSR (Byelorussia, Estonia, Latvia, Lithuania, RSFSR, Ukraine), Sweden, Switzerland, UK (England, Channel Islands, Northern Ireland, Scotland, Wales), Yugoslavia. North America; USA (California, Illinois, Indiana, Iowa, Kansas, Kentucky, Missouri, Nebraska, New York, Ohio, Wisconsin, Virginia). TRANSMISSION: By spores ('conidia') dispersed by wind or rain-splash. The role of oospores (if they are usually formed) in disease transmission is unknown.


Urban Health ◽  
2019 ◽  
pp. 248-255
Author(s):  
Abby E. Rudolph

One of the distinguishing features of urban environments is the close proximity of their residents. There is ample evidence that our social networks influence how we think, feel, and behave and, through doing so, shape our health. Therefore, the challenge and opportunity for urban areas is how to foster social relationships and interactions that promote healthier behaviors, reduce the risk of disease transmission, and remove or serve as buffers against existing barriers to health service utilization. This chapter provides a theoretical framework for thinking about the role of social networks in public health and provides two examples how social network analysis has been used to better understand two major public health concerns in urban settings.


Author(s):  
David Murillo ◽  
Anarina Murillo ◽  
Sunmi Lee

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.


2018 ◽  
Vol 11 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Emily R. Vana ◽  
Elizabeth R. Wrobel ◽  
Travis E. Wilcoxen

Congregation of individuals at high densities is known to increase disease transmission and bird-feeding activities are specifically aimed at attracting many birds to a single location. We surveyed nine potential host species for evidence of infection by each Mycoplasma gallisepticum (MG) and Avipoxvirus, or avian pox. We also examined differences in pathogen exposure at sites with bird feeders and sites without bird feeders. Finally, we compared prevalence of birds with antibodies against MG and avian pox to those that showed physical signs of infection. To test for pathogen exposure, we used indirect enzyme-linked immunosorbent assays. We found species-specific disease dynamics, as House Finches Haemorhous mexicanus had a significantly greater likelihood of having antibodies against MG than any other species. Birds at sites with feeders were more likely to have antibodies against MG. Birds at sites with feeders were no more likely to have antibodies against avian pox, but seroprevalence of avian pox did differ significantly among species. Overall, our findings suggest differential exposure and immune responses to each pathogen among species and that feeders increase the exposure of individuals to MG but not to avian pox, offering valuable new insights into the role of bird feeding activities in disease transmission among birds.


2020 ◽  
Vol 117 (41) ◽  
pp. 25237-25245 ◽  
Author(s):  
Manouk Abkarian ◽  
Simon Mendez ◽  
Nan Xue ◽  
Fan Yang ◽  
Howard A. Stone

Many scientific reports document that asymptomatic and presymptomatic individuals contribute to the spread of COVID-19, probably during conversations in social interactions. Droplet emission occurs during speech, yet few studies document the flow to provide the transport mechanism. This lack of understanding prevents informed public health guidance for risk reduction and mitigation strategies, e.g., the “6-foot rule.” Here we analyze flows during breathing and speaking, including phonetic features, using orders-of-magnitude estimates, numerical simulations, and laboratory experiments. We document the spatiotemporal structure of the expelled airflow. Phonetic characteristics of plosive sounds like “P” lead to enhanced directed transport, including jet-like flows that entrain the surrounding air. We highlight three distinct temporal scaling laws for the transport distance of exhaled material including 1) transport over a short distance (<0.5 m) in a fraction of a second, with large angular variations due to the complexity of speech; 2) a longer distance, ∼1 m, where directed transport is driven by individual vortical puffs corresponding to plosive sounds; and 3) a distance out to about 2 m, or even farther, where sequential plosives in a sentence, corresponding effectively to a train of puffs, create conical, jet-like flows. The latter dictates the long-time transport in a conversation. We believe that this work will inform thinking about the role of ventilation, aerosol transport in disease transmission for humans and other animals, and yield a better understanding of linguistic aerodynamics, i.e., aerophonetics.


Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1984
Author(s):  
Jacqueline Poldy

Many arthropod pests of humans and other animals select their preferred hosts by recognising volatile odour compounds contained in the hosts’ ‘volatilome’. Although there is prolific literature on chemical emissions from humans, published data on volatiles and vector attraction in other species are more sporadic. Despite several decades since the identification of a small number of critical volatiles underpinning specific host–vector relationships, synthetic chemicals or mixtures still largely fail to reproduce the attractiveness of natural hosts to their disease vectors. This review documents allelochemicals from non-human terrestrial animals and considers where challenges in collection and analysis have left shortfalls in animal volatilome research. A total of 1287 volatile organic compounds were identified from 141 species. Despite comparable diversity of entities in each compound class, no specific chemical is ubiquitous in all species reviewed, and over half are reported as unique to a single species. This review provides a rationale for future enquiries by highlighting research gaps, such as disregard for the contribution of breath volatiles to the whole animal volatilome and evaluating the role of allomones as vector deterrents. New opportunities to improve vector surveillance and disrupt disease transmission may be unveiled by understanding the host-associated stimuli that drive vector-host interactions.


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