scholarly journals What We Are Learning from COVID-19 for Respiratory Protection: Contemporary and Emerging Issues

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4165
Author(s):  
Rui Li ◽  
Mengying Zhang ◽  
Yulin Wu ◽  
Peixin Tang ◽  
Gang Sun ◽  
...  
Keyword(s):  
Infectious Diseases ◽  
Transmission Rate ◽  
Social Activity ◽  
Medical Knowledge ◽  
Multiple Infection ◽  
Respiratory Protection ◽  
Standards Compliance ◽  
Recent Emergence ◽  
Respiratory Protective Devices ◽  
Emerging Issues

Infectious respiratory diseases such as the current COVID-19 have caused public health crises and interfered with social activity. Given the complexity of these novel infectious diseases, their dynamic nature, along with rapid changes in social and occupational environments, technology, and means of interpersonal interaction, respiratory protective devices (RPDs) play a crucial role in controlling infection, particularly for viruses like SARS-CoV-2 that have a high transmission rate, strong viability, multiple infection routes and mechanisms, and emerging new variants that could reduce the efficacy of existing vaccines. Evidence of asymptomatic and pre-symptomatic transmissions further highlights the importance of a universal adoption of RPDs. RPDs have substantially improved over the past 100 years due to advances in technology, materials, and medical knowledge. However, several issues still need to be addressed such as engineering performance, comfort, testing standards, compliance monitoring, and regulations, especially considering the recent emergence of pathogens with novel transmission characteristics. In this review, we summarize existing knowledge and understanding on respiratory infectious diseases and their protection, discuss the emerging issues that influence the resulting protective and comfort performance of the RPDs, and provide insights in the identified knowledge gaps and future directions with diverse perspectives.

scholarly journals Technological Advances in Ozone and Ozonized Water Spray Disinfection Devices

2021 ◽  
Vol 11 (7) ◽  
pp. 3081
Author(s):  
Luis Alberto Breda Mascarenhas ◽  
Fabricia Oliveira Oliveira ◽  
Eduardo Santos da Silva ◽  
Laerte Marlon Conceição dos Santos ◽  
Leticia de Alencar Pereira Rodrigues ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Infectious Diseases ◽  
Medical Devices ◽  
Transmission Rate ◽  
Database Search ◽  
Innovative Approach ◽  
Water Spray ◽  
Patent Classification ◽  
Technological Advances ◽  
Patent Documents

To control infectious diseases such as the severe acute respiratory syndrome coronavirus (Covid-19) that caused the current pandemic, disinfection measures are essential. Among building measures, disinfection chambers can help to decrease the transmission rate through the sanitizing capacity of the disinfectant used, which can thereby clean surfaces or humans. Out of existing biocides, ozone is considered one of the safest for humans, but one of the most powerful oxidizers, making the substance a better alternative as the biocidal solution in disinfection chambers. Analyses were carried out by using all patented documents related to disinfection chambers that used ozone as a disinfectant. A Derwent Innovation Index (DII) database search was undertaken to find these patents. Patent prospecting resulted in 620 patent documents that were divided into 134 patent families. There was no technology related to protective barriers for individuals, and the majority of patents in the retrieved data aimed at sterilizing medical devices and surfaces. Given that the specific Cooperative Patent Classification (CPC) code for ozone dissolved in liquid was used in the methodology search, but not included among the 10 most used codes in the patents, the use of ozonized water may be an innovative approach in the technology landscape of sterilization chambers.

scholarly journals The impact of temperature and absolute humidity on the coronavirus disease 2019 (COVID-19) outbreak - evidence from China

2020 ◽  
Author(s):  
Peng Shi ◽  
Yinqiao Dong ◽  
Huanchang Yan ◽  
Xiaoyang Li ◽  
Chenkai Zhao ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Infectious Diseases ◽  
Transmission Rate ◽  
Mainland China ◽  
Weather Condition ◽  
Absolute Humidity ◽  
List Type ◽  
Seir Model ◽  
Provincial Level ◽  
The Impact

ABSTRACTOBJECTIVETo investigate the impact of temperature and absolute humidity on the coronavirus disease 2019 (COVID-19) outbreak.DESIGNEcological study.SETTING31 provincial-level regions in mainland China.MAIN OUTCOME MEASURESData on COVID-19 incidence and climate between Jan 20 and Feb 29, 2020.RESULTSThe number of new confirm COVID-19 cases in mainland China peaked on Feb 1, 2020. COVID-19 daily incidence were lowest at -10 °C and highest at 10 °C, while the maximum incidence was observed at the absolute humidity of approximately 7 g/m3. COVID-19 incidence changed with temperature as daily incidence decreased when the temperature rose. No significant association between COVID-19 incidence and absolute humidity was observed in distributed lag nonlinear models. Additionally, A modified susceptible-exposed-infectious-recovered (M-SEIR) model confirmed that transmission rate decreased with the increase of temperature, leading to further decrease of infection rate and outbreak scale.CONCLUSIONTemperature is an environmental driver of the COVID-19 outbreak in China. Lower and higher temperatures might be positive to decrease the COVID-19 incidence. M-SEIR models help to better evaluate environmental and social impacts on COVID-19.What is already known on this topicMany infectious diseases present an environmental pattern in their incidence.Environmental factors, such as climate and weather condition, could drive the space and time correlations of infectious diseases, including influenza.Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be transmitted through aerosols, large droplets, or direct contact with secretions (or fomites) as influenza virus can.Little is known about environmental pattern in COVID-19 incidence.What this study addsThe significant association between COVID-19 daily incidence and temperature was confirmed, using 3 methods, based on the data on COVID-19 and weather from 31 provincial-level regions in mainland China.Environmental factors were considered on the basis of SEIR model, and a modified susceptible-exposed-infectious-recovered (M-SEIR) model was developed.Simulations of the COVID-19 outbreak in Wuhan presented similar effects of temperature on incidence as the incidence decrease with the increase of temperature.

scholarly journals What is the mechanism for persistent coexistence of drug-susceptible and drug-resistant strains of Streptococcus pneumoniae ?

2009 ◽  
Vol 7 (47) ◽  
pp. 905-919 ◽  
Author(s):  
Caroline Colijn ◽  
Ted Cohen ◽  
Christophe Fraser ◽  
William Hanage ◽  
Edward Goldstein ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Infectious Diseases ◽  
Multiple Infection ◽  
Drug Resistant ◽  
Host Interactions ◽  
Resistant Strains ◽  
Neutral Models ◽  
Drug Resistant Strains ◽  
And Control

The rise of antimicrobial resistance in many pathogens presents a major challenge to the treatment and control of infectious diseases. Furthermore, the observation that drug-resistant strains have risen to substantial prevalence but have not replaced drug-susceptible strains despite continuing (and even growing) selective pressure by antimicrobial use presents an important problem for those who study the dynamics of infectious diseases. While simple competition models predict the exclusion of one strain in favour of whichever is ‘fitter’, or has a higher reproduction number, we argue that in the case of Streptococcus pneumoniae there has been persistent coexistence of drug-sensitive and drug-resistant strains, with neither approaching 100 per cent prevalence. We have previously proposed that models seeking to understand the origins of coexistence should not incorporate implicit mechanisms that build in stable coexistence ‘for free’. Here, we construct a series of such ‘structurally neutral’ models that incorporate various features of bacterial spread and host heterogeneity that have been proposed as mechanisms that may promote coexistence. We ask to what extent coexistence is a typical outcome in each. We find that while coexistence is possible in each of the models we consider, it is relatively rare, with two exceptions: (i) allowing simultaneous dual transmission of sensitive and resistant strains lets coexistence become a typical outcome, as does (ii) modelling each strain as competing more strongly with itself than with the other strain, i.e. self-immunity greater than cross-immunity. We conclude that while treatment and contact heterogeneity can promote coexistence to some extent, the in-host interactions between strains, particularly the interplay between coinfection, multiple infection and immunity, play a crucial role in the long-term population dynamics of pathogens with drug resistance.

scholarly journals Mongolian Buddhist Scholars’ Works on Infectious Diseases (Late 17th Century to the Beginning of the 20th Century)

Religions ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 229 ◽  
Author(s):  
Batsaikhan Norov
Keyword(s):  
Infectious Diseases ◽  
20Th Century ◽  
Critical Period ◽  
Medical Knowledge ◽  
17Th Century ◽  
Political Control ◽  
Tibetan Buddhist ◽  
Medical Practices ◽  
Political Milieu ◽  
Preventive Methods

The Qing period saw both the flowering of Buddhism in Mongolia as well as the arrival of new infectious diseases such as smallpox and syphilis which had reached epidemic levels by the 17th to early 20th centuries. During that critical period, a considerable number of Mongolian Buddhist scholars produced a substantial amount of works dedicated to the ways of fighting epidemics. This paper explores the efforts of Mongolian Buddhist scholars in countering this new threat, within the unique social and political milieu of the time. Smallpox spread severely reduced the Mongolian population and could have influenced the change of political control in the region, as several prominent Mongolian leaders who fought against Qing domination were themselves victims of smallpox epidemics. Similarly, at the beginning of the 20th century, around half the Mongolian population was infected by syphilis and, as a result, the population further declined in numbers. Tibetan Buddhist medicine, which was introduced to Mongolia from Tibet, was enriched by Mongolian traditional medical practices and fused with traditional Mongolian and Chinese medical knowledge during Mongolian scholars’ search for preventive methods against infectious diseases. This article examines the works of three renowned Mongolian Buddhist scholars who dealt with issues of infectious diseases: Ye shes dpal ‘byor, Chakhar Géshé Lobsang Tsültim, and Lobsang chos ‘phel.

scholarly journals Respiratory protective devices for the healthcare workers (literature review)

2021 ◽  
Vol 100 (3) ◽  
pp. 240-245
Author(s):  
Valery A. Kaptsov ◽  
Alexander V. Chirkin
Keyword(s):  
Carbon Dioxide Concentration ◽  
Risk Level ◽  
Respiratory Protection ◽  
Risk Of Infection ◽  
Human Welfare ◽  
Oxford University ◽  
Care Workers ◽  
Increased Risk ◽  
Respiratory Protective Devices ◽  
Certification Requirements

Introduction. Healthcare practitioners are at increased risk of infection with infectious diseases, including the inhalation route. Healthcare practitioners use respirators of various designs providing different efficiency of protection. The purpose of the study was to improve efficiency of the respiratory protection of the healthcare practitioners in Russian Federation. There were analyzed available NIOSH publications, articles in journals Taylor & Francis, Oxford University Press, published materials of Federal Service for Supervision of Consumer Rights Protection and Human Welfare (Rospotrebnadzor), and western training manuals. Differences in the requirements of the legislation were identified that increase the risk of infection in healthcare practitioners. There are no methods for assessing the risk level, and there are no specific requirements for selecting the respirator’s type that corresponds to the risk level. The employer is not obliged to provide the fit test for all employees. The respirator must be used timely, so it should not negatively affect the worker. But the average carbon dioxide concentration can exceed the STEL by more than two times. The certification requirements for respirators do not correspond to the conditions of their use in the hospitals. Respirators were not certified as means of protection against bioaerosols. Conclusions. Identified shortcomings in the respiratory safety of health care workers show possible ways to improve their protection by harmonizing national legislation with the best of existing Western requirements.

scholarly journals Reconstructing contact network structure and cross-immunity patterns from multiple infection histories

2021 ◽  
Vol 17 (9) ◽  
pp. e1009375
Author(s):  
Christian Selinger ◽  
Samuel Alizon
Keyword(s):  
Infectious Diseases ◽  
Multiple Infection ◽  
Contact Network ◽  
Multiple Infections ◽  
Similarity Metrics ◽  
Summary Statistics ◽  
Transmission Networks ◽  
Contact Patterns ◽  
Network Properties ◽  
Cross Immunity

Interactions within a population shape the spread of infectious diseases but contact patterns between individuals are difficult to access. We hypothesised that key properties of these patterns can be inferred from multiple infection data in longitudinal follow-ups. We developed a simulator for epidemics with multiple infections on networks and analysed the resulting individual infection time series by introducing similarity metrics between hosts based on their multiple infection histories. We find that, depending on infection multiplicity and network sampling, multiple infection summary statistics can recover network properties such as degree distribution. Furthermore, we show that by mining simulation outputs for multiple infection patterns, one can detect immunological interference between pathogens (i.e. the fact that past infections in a host condition future probability of infection). The combination of individual-based simulations and analysis of multiple infection histories opens promising perspectives to infer and validate transmission networks and immunological interference for infectious diseases from longitudinal cohort data.

scholarly journals Modelling infectious diseases with herd immunity in a randomly mixed population

2021 ◽  
Author(s):  
Kian Boon Law ◽  
Kalaiarasu M. Peariasamy ◽  
Hishamshah Mohd. Ibrahim ◽  
Noor Hisham Abdullah
Keyword(s):  
Infectious Disease ◽  
Infectious Diseases ◽  
Transmission Rate ◽  
Herd Immunity ◽  
Sir Model ◽  
Mixed Population ◽  
Transmission Dynamics ◽  
Transmission Model ◽  
Infection Model ◽  
Vaccination Rates

Abstract Background The conventional susceptible-infectious-recovered (SIR) model tends to overestimate the transmission dynamics of infectious diseases and ends up with total infections and total immunized population exceeding the threshold required for control and eradication of infectious diseases. The study aims to overcome the limitation by allowing the transmission rate of infectious disease to decline along with the reducing risk of contact infection. Methods Two new SIR models were developed to mimic the declining transmission rate of infectious diseases at different stages of transmission. Model A mimicked the declining transmission rate along with the reducing risk of transmission following infection, while Model B mimicked the declining transmission rate following recovery. Then, the conventional SIR model, Model A and Model B were used to simulate an infectious disease with a basic reproduction number (r0) of 3.0 and a herd immunity threshold (HIT) of 0.667 with and without vaccination. The infectious disease was expected to be controlled or eradicated when the total immunized population either through infection or vaccination reached the level predicted by the HIT. Outcomes of simulations were assessed at the time when the total immunized population reached the level predicted by the HIT, and at the end of simulations. Findings All three models performed likewise at the beginning of the transmission when sizes of infectious and recovered were relatively small as compared with the population size. The infectious disease modelled using the conventional SIR model appeared completely out of control even when the HIT was achieved in all scenarios with and without vaccination. The infectious disease modelled using Model A appeared to be controlled at the level predicted by the HIT in all scenarios with and without vaccination. Model B projected the infectious disease to be controlled at the level predicted by the HIT only at high vaccination rates. At lower vaccination rates or without vaccination, the level at which the infectious disease was controlled cannot be accurately predicted by the HIT. Conclusion Transmission dynamics of infectious diseases with herd immunity can accurately be modelled by allowing the transmission rate of infectious disease to decline along with the combined risk of contact infection. Model B provides a more credible framework for modelling infectious diseases with herd immunity in a randomly mixed population.

scholarly journals Social mobility and gonorrhoea in Germany during 2020

2021 ◽  
pp. sextrans-2021-055159
Author(s):  
Mihály Sulyok ◽  
Mark Walker
Keyword(s):  
Time Series ◽  
Health Services ◽  
Infectious Diseases ◽  
Social Mobility ◽  
Social Factors ◽  
Moving Average ◽  
Social Activity ◽  
Autoregressive Integrated Moving Average ◽  
Time Series Modelling ◽  
The Relationship

ObjectivesThe incidence of STIs is likely to be related to levels of social activity and mobility. Novel datasets detailing levels of social activity were made widely available during the COVID-19 pandemic. These allow the relationship between activity and STI incidence to be examined.MethodsThe correlation between social activities and the reported number of gonorrhoea cases between March and December 2020 in Germany was studied. Regression through Autoregressive Integrated Moving Average (ARIMA) time series modelling identified those activities associated with case numbers.ResultsARIMA regression identified a significant association with ‘transit’ activity within the Apple data and ‘parks’ within Google.ConclusionsThis study illustrates the potential newly available measures of social activity provided for STI research. Reductions in STI incidence are likely to have occurred due to COVID-19 social restrictions. Although other studies report reductions in infectious diseases during this period, few examine the potential social factors mediating this. The results illustrate the continual need for sexual health services throughout the pandemic.

scholarly journals Agent-Based Modeling for Super-Spreading Events: A Case Study of MERS-CoV Transmission Dynamics in the Republic of Korea

2018 ◽  
Vol 15 (11) ◽  
pp. 2369 ◽  
Author(s):  
Yunhwan Kim ◽  
Hohyung Ryu ◽  
Sunmi Lee
Keyword(s):  
Infectious Diseases ◽  
Transmission Rate ◽  
Emerging Infectious Diseases ◽  
Epidemiological Data ◽  
Agent Based Modeling ◽  
Transmission Dynamics ◽  
Republic Of Korea ◽  
Agent Based ◽  
The Republic ◽  
High Level

Super-spreading events have been observed in the transmission dynamics of many infectious diseases. The 2015 MERS-CoV outbreak in the Republic of Korea has also shown super-spreading events with a significantly high level of heterogeneity in generating secondary cases. It becomes critical to understand the mechanism for this high level of heterogeneity to develop effective intervention strategies and preventive plans for future emerging infectious diseases. In this regard, agent-based modeling is a useful tool for incorporating individual heterogeneity into the epidemic model. In the present work, a stochastic agent-based framework is developed in order to understand the underlying mechanism of heterogeneity. Clinical (i.e., an infectivity level) and social or environmental (i.e., a contact level) heterogeneity are modeled. These factors are incorporated in the transmission rate functions under assumptions that super-spreaders have stronger transmission and/or higher links. Our agent-based model has employed real MERS-CoV epidemic features based on the 2015 MERS-CoV epidemiological data. Monte Carlo simulations are carried out under various epidemic scenarios. Our findings highlight the roles of super-spreaders in a high level of heterogeneity, underscoring that the number of contacts combined with a higher level of infectivity are the most critical factors for substantial heterogeneity in generating secondary cases of the 2015 MERS-CoV transmission.

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