Assessing coughing-induced influenza droplet transmission and implications for infection risk control

2015 ◽  
Vol 144 (2) ◽  
pp. 333-345 ◽  
Author(s):  
Y.-H. CHENG ◽  
C.-H. WANG ◽  
S.-H. YOU ◽  
N.-H. HSIEH ◽  
W.-Y. CHEN ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Risk Model ◽  
Control Measure ◽  
Influenza Infection ◽  
Infection Risk ◽  
Transmission Dynamics ◽  
Human Respiratory Tract ◽  
Host Interactions ◽  
And Control ◽  
Respiratory Droplets

SUMMARYIndoor transmission of respiratory droplets bearing influenza within humans poses high risks to respiratory function deterioration and death. Therefore, we aimed to develop a framework for quantifying the influenza infection risk based on the relationships between inhaled/exhaled respiratory droplets and airborne transmission dynamics in a ventilated airspace. An experiment was conducted to measure the size distribution of influenza-containing droplets produced by coughing for a better understanding of potential influenza spread. Here we integrated influenza population transmission dynamics, a human respiratory tract model, and a control measure approach to examine the indoor environment–virus–host interactions. A probabilistic risk model was implemented to assess size-specific infection risk for potentially transmissible influenza droplets indoors. Our results found that there was a 50% probability of the basic reproduction number (R0) exceeding 1 for small-size influenza droplets of 0·3–0·4 µm, implicating a potentially high indoor infection risk to humans. However, a combination of public health interventions with enhanced ventilation could substantially contain indoor influenza infection. Moreover, the present dynamic simulation and control measure assessment provide insights into why indoor transmissible influenza droplet-induced infection is occurring not only in upper lung regions but also in the lower respiratory tract, not normally considered at infection risk.

Assessing dengue infection risk in the southern region of Taiwan: implications for control

2014 ◽  
Vol 143 (5) ◽  
pp. 1059-1072 ◽  
Author(s):  
C.-M. LIAO ◽  
T.-L. HUANG ◽  
Y.-H. CHENG ◽  
W.-Y. CHEN ◽  
N.-H. HSIEH ◽  
...  
Keyword(s):  
Vector Control ◽  
Risk Model ◽  
Dengue Infection ◽  
Infection Risk ◽  
Incidence Rates ◽  
Human Infection ◽  
Health Concern ◽  
Biting Rate ◽  
And Control ◽  
The Impact

SUMMARYDengue, one of the most important mosquito-borne diseases, is a major international public health concern. This study aimed to assess potential dengue infection risk fromAedes aegyptiin Kaohsiung and the implications for vector control. Here we investigated the impact of dengue transmission on human infection risk using a well-established dengue–mosquito–human transmission dynamics model. A basic reproduction number (R0)-based probabilistic risk model was also developed to estimate dengue infection risk. Our findings confirm that the effect of biting rate plays a crucial role in shapingR0estimates. We demonstrated that there was 50% risk probability for increased dengue incidence rates exceeding 0·5–0·8 wk−1for temperatures ranging from 26°C to 32°C. We further demonstrated that the weekly increased dengue incidence rate can be decreased to zero if vector control efficiencies reach 30–80% at temperatures of 19–32°C. We conclude that our analysis on dengue infection risk and control implications in Kaohsiung provide crucial information for policy-making on disease control.

scholarly journals On the study of full transmission dynamics of COVID-19 in Wuhan

2020 ◽  
Author(s):  
Chong You ◽  
Xin Gai ◽  
Yuan Zhang ◽  
Xiao-Hua Zhou
Keyword(s):  
Transmission Rate ◽  
Control Measure ◽  
Transmission Mechanism ◽  
Control Measures ◽  
Transmission Dynamics ◽  
Modified Model ◽  
Pcr Screening ◽  
Active Virus ◽  
Current Outbreak ◽  
And Control

Abstract The current outbreak of coronavirus disease 2019 (COVID-19) has quickly spread across countries and become a global crisis. Understanding the transmission mechanism and effects of interventions is critical to the prevention and control of the COVID-19 pandemic. A recent study by Hao et al (2020) provided an interesting perspective on the transmission dynamics of COVID-19 in Wuhan and inferred that 87% of the infections before 8 March 2020 were not laboratory-confirmed. However we believe that there are a few major issues due to the vagueness in the definitions of compartments and inconsistence in the settings of parameters. In this paper, we clarify the definitions of the model compartments and raise questions in regard to the underlying homogenous assumption within compartments and settings of the parameters in the dynamic model by Hao et al (2020), and furthermore offer a modified model to resolve these potential limitations. Compared with the model in Hao et al (2020), the active virus carriers were predicted to persist for a longer period in our model which is well consistent with the active virus carriers detected in Wuhan in mid-May. Our model suggests that control measures cannot be easily lifted while continuous efforts are needed to contain the spread of the pandemic; a universal PT-PCR screening is essential to detect hidden cases before lifting control measure. In addition, we also provide a possible solution to solve the problem of heterogeneity transmission rate in disease courses.

A model for deposition of stable and unstable aerosols in the human respiratory tract

AIHAJ ◽  
1979 ◽  
Vol 40 (12) ◽  
pp. 1055-1066 ◽  
Author(s):  
E. AUSTIN ◽  
J. BROCK ◽  
E. WISSLER
Keyword(s):  
Respiratory Tract ◽  
Human Respiratory Tract

Numerical assessment of natural respiration and particles deposition in the computed tomography scan airway with a glomus tumour

2021 ◽  
pp. 095440892110240
Author(s):  
Digamber Singh
Keyword(s):  
Computed Tomography ◽  
Respiratory Tract ◽  
Particle Deposition ◽  
Flow Characteristics ◽  
Glomus Tumour ◽  
Computed Tomography Scan ◽  
Human Respiratory Tract ◽  
Airflow Pattern ◽  
Human Airways ◽  
Tomography Scan

The human respiratory tract has a complex airflow pattern. If any obstruction is present in the airways, it will change the airflow pattern and deposit particles inside the airways. This is the concern of breath quality (inspired air), and it is decreasing due to the unplanned production of material goods. This is a primary cause of respiratory illness (asthma, cancer, etc.). Therefore, it is important to identify the flow characteristics in the human airways and airways with a glomus tumour with particle deposition. A numerical diagnosis is presented with an asymmetric unsteady-state light breathing condition (10 l/min). An in vitro human respiratory tract model has been reconstructed using computed tomography scan techniques and an artificial glomus tumour developed 2 cm above a carina on the posterior wall of the trachea. The transient flow characteristics are numerically simulated with a realizable (low Reynolds number) k–ɛ turbulence model. The flow disturbance is captured around the tumour, which influenced the upstream and downstream of the flow. The flow velocity pattern, wall shear stress and probable area of inflammation (hotspot) due to suspended particle deposition are determined, which may assist doctors more effectively in aerosol therapy and prosthetics of human airways illness.

scholarly journals Establishment and lineage dynamics of the SARS-CoV-2 epidemic in the UK

Science ◽  
2021 ◽  
pp. eabf2946
Author(s):  
Louis du Plessis ◽  
John T. McCrone ◽  
Alexander E. Zarebski ◽  
Verity Hill ◽  
Christopher Ruis ◽  
...  
Keyword(s):  
Large Scale ◽  
Phylogenetic Analyses ◽  
Transmission Dynamics ◽  
Genetic Lineage ◽  
Size Dependent ◽  
Spatio Temporal ◽  
The Uk ◽  
Lineage Structure ◽  
And Control ◽  
Lineage Diversity

The UK’s COVID-19 epidemic during early 2020 was one of world’s largest and unusually well represented by virus genomic sampling. Here we reveal the fine-scale genetic lineage structure of this epidemic through analysis of 50,887 SARS-CoV-2 genomes, including 26,181 from the UK sampled throughout the country’s first wave of infection. Using large-scale phylogenetic analyses, combined with epidemiological and travel data, we quantify the size, spatio-temporal origins and persistence of genetically-distinct UK transmission lineages. Rapid fluctuations in virus importation rates resulted in >1000 lineages; those introduced prior to national lockdown tended to be larger and more dispersed. Lineage importation and regional lineage diversity declined after lockdown, while lineage elimination was size-dependent. We discuss the implications of our genetic perspective on transmission dynamics for COVID-19 epidemiology and control.

scholarly journals Correction to Patchy Amphiphilic Dendrimers Bind Adenovirus and Control Its Host Interactions and in Vivo Distribution

ACS Nano ◽  
2021 ◽  
Author(s):  
Yuzhou Wu ◽  
Longjie Li ◽  
Larissa Frank ◽  
Jessica Wagner ◽  
Patrizia Andreozzi ◽  
...  
Keyword(s):  
Host Interactions ◽  
In Vivo Distribution ◽  
Amphiphilic Dendrimers ◽  
And Control

Design and Application Research of Audit Risk Control Program

2013 ◽  
Vol 310 ◽  
pp. 718-721
Author(s):  
Li Ya Ma ◽  
Shu Feng Wang
Keyword(s):  
Risk Model ◽  
Risk Control ◽  
Control Program ◽  
Audit Report ◽  
Audit Risk ◽  
Specific Content ◽  
Auditing Standards ◽  
Audit Reports ◽  
Independent Auditing ◽  
And Control

Strict procedures for prevention and control of audit risk is one of the most effective measures, so the research on design of audit risk control standardization program has very great practical application value. Combined with the research needs, the CPA practices respectively utilize means of summarizing method, for example, analysis method and enumeration method. The CPA practice also revealing the audit risk and audit report risk associated with different basis, combining with the traditional audit risk model. The specific content concludes the report of audit risk and then designs including audit reports preparation, audit draft, final review report to track a feedback of visit to the control standard operating requirements, and then puts forward the independent auditing standards. The auditing standards should be added to the proposal of audit report program.

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