scholarly journals Why respiratory viruses or bacteria have the highest probability to be deposited in the respiratory tract in flu seasons

2016 ◽  
Author(s):  
Aleksandr N Ishmatov
Keyword(s):  
Mass Transfer ◽  
Respiratory Tract ◽  
Heat And Mass Transfer ◽  
Deposition Rate ◽  
Environmental Conditions ◽  
Respiratory Infections ◽  
Submicron Particles ◽  
Upper Respiratory Tract ◽  
Airborne Transmission ◽  
The Impact

Objective: The main aspects of influenza transmission via fine and ultrafine bioaerosols were considered. Here, we aimed to estimate the impact of the different environment conditions on the processes of heat and mass transfer in the upper respiratory tract and its role in the deposition rate of the infectious bioaerosols in the lungs. Background: The latest researches show the infected people generate the fine and ultrafine infectious bioaerosols with submicron particles/droplets (size below 1 µm). The airborne transmission of these particles/droplets is effective. It is considered the deposition of submicron particles in the respiratory tract (RT) has very low probability. But most studies examined the deposition of the particles in the lungs under normal environmental conditions and did not paid attention to the different environmental factors. Methods: We review the problems of epidemiology of respiratory infections and aspects of airborne transmission/spread of infectious agents. We contrast these approaches with known data from next area: inhalation toxicology, respiratory drug delivery and physics of heat and mass transfer in the airways. Results: On the basis of these analyses, we propose the next main concepts: 1 Breathing cool air leads to the supersaturation of air in RT; 2 the air supersaturation leads to the intensive condensational growth(CG) of inhaled viruses or bacteria in RT; 3 CG leads to the intensive and dramatically growth of deposition rate of viruses or bacteria in RT. We have shown: a) Under normal conditions of inhaled air (T>20˚C; Relatively Humidity (RH)=60%) there is no transition in supersaturated condition in RT and CG is insignificant and probability of virus deposition on epithelium of RT is low – no more than 20%. b) Breathing cool/cold air of T<+15˚C and RH of [30..60]% leads to the supersaturation in the airways and it can dramatically increase the deposition rate of inhaled bioaresols in the lungs (up to 97%). c) With an increase in RH of inhaled air the supersaturation in RT occurs even at warm temperature of inhaled air (for inhaled air of T<20°C and RH>70% ; T<25°C and RH>90%). It also indicates the high deposition rate of bioaerosols in the lungs. Conclusion: Under specific environmental conditions (when flu seasons) the processes of supersaturation in the RT can be observed. These results indicate the high probability of virus deposition on epithelium of RT and correspond to influenza and seasonal respiratory infections in temperate and tropical climates. We believe the effect of supersaturation in the lungs can be the key to understanding of ‘the age-old epidemiologic mystery of influenza seasonality in the different climatic conditions’.

scholarly journals Why respiratory viruses or bacteria have the highest probability to be deposited in the respiratory tract in flu seasons

2017 ◽  
Author(s):  
Aleksandr N Ishmatov
Keyword(s):  
Respiratory Tract ◽  
Deposition Rate ◽  
Environmental Conditions ◽  
Respiratory Infections ◽  
Aerosol Deposition ◽  
Climatic Conditions ◽  
Submicron Particles ◽  
Airborne Transmission ◽  
Infected People ◽  
The Impact

Objective: In this study the main aspects of influenza transmission via fine and ultrafine bioaerosols were considered. Here, we aimed to estimate the impact of the different environment conditions on the deposition rate of the infectious bioaerosols in the respiratory tract. Background: The latest researches show the infected people generate the fine and ultrafine infectious bioaerosols with submicron particles/droplets (size below 1 µm). The airborne transmission of these particles/droplets in the environment is effective. It is considered the deposition of submicron particles in the respiratory tract (RT) has very low probability. But most studies examined the aerosol deposition in RT under normal environmental conditions and did not paid attention to the affecting the different environmental factors. Methods: We review the problems of epidemiology of respiratory infections and aspects of airborne transmission/spread of infectious agents. We contrast these approaches with known data from next areas: inhalation toxicology, respiratory drug delivery and physics of heat and mass transfer in the airways. Results: Based on the conducted analysis, we propose the next main concepts: 1 Breathing cool air leads to the supersaturation of air in RT; 2 the air supersaturation leads to the intensive condensational growth(CG) of inhaled viruses or bacteria in RT; 3 CG leads to the intensive and dramatically growth of deposition rate of viruses or bacteria in RT. We have shown: a) Under normal conditions of inhaled air (T>20˚C; Relatively Humidity, RH=60%) there is no transition in supersaturated condition in RT and CG is insignificant and probability of virus deposition on epithelium of RT is low – no more than 20%. b) Breathing cool/cold air of T<+15˚C and RH of [30..60]% leads to the supersaturation in the airways and it can dramatically increase the deposition rate of inhaled bioaerosols in RT(up to 96%). c) With an increase in RH of inhaled air the supersaturation in RT occurs even at warm temperature of inhaled air (for inhaled air of T<20°C and RH>70% ; T<25°C and RH>90%). Which also indicates the deposition rate of bioaerosols in RT under these conditions is high. Conclusion: Under specific environmental conditions (when flu seasons) the processes of supersaturation in the RT can be observed. These results indicate the high probability of virus deposition on epithelium of RT and correspond to influenza and seasonal respiratory infections in temperate and tropical climates. We believe the effect of supersaturation in the airways can be the key to understanding of ‘the age-old epidemiologic mystery of influenza seasonality in the different climatic conditions’.

scholarly journals Why respiratory viruses or bacteria have the highest probability to be deposited in the respiratory tract in flu seasons

2017 ◽  
Author(s):  
Aleksandr N Ishmatov
Keyword(s):  
Respiratory Tract ◽  
Deposition Rate ◽  
Environmental Conditions ◽  
Respiratory Infections ◽  
Aerosol Deposition ◽  
Climatic Conditions ◽  
Submicron Particles ◽  
Airborne Transmission ◽  
Infected People ◽  
The Impact

Objective: In this study the main aspects of influenza transmission via fine and ultrafine bioaerosols were considered. Here, we aimed to estimate the impact of the different environment conditions on the deposition rate of the infectious bioaerosols in the respiratory tract. Background: The latest researches show the infected people generate the fine and ultrafine infectious bioaerosols with submicron particles/droplets (size below 1 µm). The airborne transmission of these particles/droplets in the environment is effective. It is considered the deposition of submicron particles in the respiratory tract (RT) has very low probability. But most studies examined the aerosol deposition in RT under normal environmental conditions and did not paid attention to the affecting the different environmental factors. Methods: We review the problems of epidemiology of respiratory infections and aspects of airborne transmission/spread of infectious agents. We contrast these approaches with known data from next areas: inhalation toxicology, respiratory drug delivery and physics of heat and mass transfer in the airways. Results: Based on the conducted analysis, we propose the next main concepts: 1 Breathing cool air leads to the supersaturation of air in RT; 2 the air supersaturation leads to the intensive condensational growth(CG) of inhaled viruses or bacteria in RT; 3 CG leads to the intensive and dramatically growth of deposition rate of viruses or bacteria in RT. We have shown: a) Under normal conditions of inhaled air (T>20˚C; Relatively Humidity, RH=60%) there is no transition in supersaturated condition in RT and CG is insignificant and probability of virus deposition on epithelium of RT is low – no more than 20%. b) Breathing cool/cold air of T<+15˚C and RH of [30..60]% leads to the supersaturation in the airways and it can dramatically increase the deposition rate of inhaled bioaerosols in RT(up to 96%). c) With an increase in RH of inhaled air the supersaturation in RT occurs even at warm temperature of inhaled air (for inhaled air of T<20°C and RH>70% ; T<25°C and RH>90%). Which also indicates the deposition rate of bioaerosols in RT under these conditions is high. Conclusion: Under specific environmental conditions (when flu seasons) the processes of supersaturation in the RT can be observed. These results indicate the high probability of virus deposition on epithelium of RT and correspond to influenza and seasonal respiratory infections in temperate and tropical climates. We believe the effect of supersaturation in the airways can be the key to understanding of ‘the age-old epidemiologic mystery of influenza seasonality in the different climatic conditions’.

scholarly journals Why respiratory viruses or bacteria have the highest probability to be deposited in the respiratory tract in flu seasons

2017 ◽  
Author(s):  
Aleksandr N Ishmatov
Keyword(s):  
Respiratory Tract ◽  
Deposition Rate ◽  
Environmental Conditions ◽  
Respiratory Infections ◽  
Aerosol Deposition ◽  
Climatic Conditions ◽  
Submicron Particles ◽  
Airborne Transmission ◽  
Infected People ◽  
The Impact

Objective: In this study the main aspects of influenza transmission via fine and ultrafine bioaerosols were considered. Here, we aimed to estimate the impact of the different environment conditions on the deposition rate of the infectious bioaerosols in the respiratory tract. Background: The latest researches show the infected people generate the fine and ultrafine infectious bioaerosols with submicron particles/droplets (size below 1 µm). The airborne transmission of these particles/droplets in the environment is effective. It is considered the deposition of submicron particles in the respiratory tract (RT) has very low probability. But most studies examined the aerosol deposition in RT under normal environmental conditions and did not paid attention to the affecting the different environmental factors. Methods: We review the problems of epidemiology of respiratory infections and aspects of airborne transmission/spread of infectious agents. We contrast these approaches with known data from next areas: inhalation toxicology, respiratory drug delivery and physics of heat and mass transfer in the airways. Results: Based on the conducted analysis, we propose the next main concepts: 1 Breathing cool air leads to the supersaturation of air in RT; 2 the air supersaturation leads to the intensive condensational growth(CG) of inhaled viruses or bacteria in RT; 3 CG leads to the intensive and dramatically growth of deposition rate of viruses or bacteria in RT. We have shown: a) Under normal conditions of inhaled air (T>20˚C; Relatively Humidity, RH=60%) there is no transition in supersaturated condition in RT and CG is insignificant and probability of virus deposition on epithelium of RT is low – no more than 20%. b) Breathing cool/cold air of T<+15˚C and RH of [30..60]% leads to the supersaturation in the airways and it can dramatically increase the deposition rate of inhaled bioaerosols in RT(up to 96%). c) With an increase in RH of inhaled air the supersaturation in RT occurs even at warm temperature of inhaled air (for inhaled air of T<20°C and RH>70% ; T<25°C and RH>90%). Which also indicates the deposition rate of bioaerosols in RT under these conditions is high. Conclusion: Under specific environmental conditions (when flu seasons) the processes of supersaturation in the RT can be observed. These results indicate the high probability of virus deposition on epithelium of RT and correspond to influenza and seasonal respiratory infections in temperate and tropical climates. We believe the effect of supersaturation in the airways can be the key to understanding of ‘the age-old epidemiologic mystery of influenza seasonality in the different climatic conditions’.

scholarly journals Why respiratory viruses or bacteria have the highest probability to be deposited in the respiratory tract in flu seasons

2016 ◽  
Author(s):  
Aleksandr N Ishmatov
Keyword(s):  
Respiratory Tract ◽  
Deposition Rate ◽  
Environmental Conditions ◽  
Respiratory Infections ◽  
Climatic Conditions ◽  
Submicron Particles ◽  
High Deposition Rate ◽  
Airborne Transmission ◽  
Infected People ◽  
The Impact

Objective: In this study the main aspects of influenza transmission via fine and ultrafine bioaerosols were considered. Here, we aimed to estimate the impact of the different environment conditions on the deposition rate of the infectious bioaerosols in the respiratory tract (RT). Background: The latest researches show the infected people generate the fine and ultrafine infectious bioaerosols with submicron particles/droplets (size below 1 µm). The airborne transmission of these particles/droplets in the environment is effective. It is considered the deposition of submicron particles in RT has very low probability. But most studies examined the deposition of the particles in RT under normal environmental conditions and did not paid attention to the different environmental factors. Methods: We review the problems of epidemiology of respiratory infections and aspects of airborne transmission/spread of infectious agents. We contrast these approaches with known data from next area: inhalation toxicology, respiratory drug delivery and physics of heat and mass transfer in the airways. Results: On the basis of these analyses, we propose the next main concepts: 1 Breathing cool air leads to the supersaturation of air in RT; 2 the air supersaturation leads to the intensive condensational growth(CG) of inhaled viruses or bacteria in RT; 3 CG leads to the intensive and dramatically growth of deposition rate of viruses or bacteria in RT. We have shown: a) Under normal conditions of inhaled air (T>20˚C; Relatively Humidity, RH=60%) there is no transition in supersaturated condition in RT and CG is insignificant and probability of virus deposition on epithelium of RT is low – no more than 20%. b) Breathing cool/cold air of T<+15˚C and RH of [30..60]% leads to the supersaturation in the airways and it can dramatically increase the deposition rate of inhaled bioaerosols in RT(up to 96%). c) With an increase in RH of inhaled air the supersaturation in RT occurs even at warm temperature of inhaled air (for inhaled air of T<20°C and RH>70% ; T<25°C and RH>90%). It also indicates the high deposition rate of bioaerosols in RT. Conclusion: Under specific environmental conditions (when flu seasons) the processes of supersaturation in the RT can be observed. These results indicate the high probability of virus deposition on epithelium of RT and correspond to influenza and seasonal respiratory infections in temperate and tropical climates. We believe the effect of supersaturation in the lungs can be the key to understanding of ‘the age-old epidemiologic mystery of influenza seasonality in the different climatic conditions.’

scholarly journals Why respiratory viruses or bacteria have the highest probability to be deposited in the respiratory tract in flu seasons

2016 ◽  
Author(s):  
Aleksandr N Ishmatov
Keyword(s):  
Respiratory Tract ◽  
Deposition Rate ◽  
Liquid Water ◽  
Population Biology ◽  
Respiratory Infections ◽  
Climatic Conditions ◽  
Submicron Particles ◽  
Cold Air ◽  
Infected People ◽  
Inhaled Particles

Marc Lipsitch and Cécile Viboud (2009) (Lipsitch and Viboud, 2009): “Seasonal variation in the incidence of communicable diseases is among the oldest observations in population biology, dating back at least to ancient Greece, yet our understanding of the mechanisms underlying this phenomenon remains hazy at best.” The latest researches show the infected people when breathing generate the infectious aerosols with particles below 1 µm. The airborne transmission of these particles is effective but the deposition of submicron particles in the respiratory tract (RT) has very low probability. Here I investigated the processes in RT when breathing cold air and its role in the delivery of viruses and bacteria of submicron and ultrafine sizes in RT. The original hypothesis of the highest probability of delivery and deposition of viruses or bacteria from inhaled air in the respiratory tract during flu seasons in different climatic conditions was investigated. On the basis of estimation I have originally shown: Breathing cool air leads to the supersaturation of air in RT; the air supersaturation leads to the intensive condensational growth(CG) of inhaled viruses or bacteria in RT; CG leads to the intensive and dramatically growth of deposition rate of viruses or bacteria in RT. Under normal conditions of inhaled air (T>20˚C; RH=60%) there is no transition in oversaturated condition in RT (CG is insignificant and probability of virus deposition on epithelium of RT is low – no more than 20%). But with an increase in RH of inhaled air the oversaturation in RT occurs even at warm temperature of inhaled air. For inhaled air of T=20°C, RH>70% the local supersaturation in the airways occurs: the concentration of liquid water in the mixed air in RT (СLiq) is СLiq<2·4g/kg and for T=25°C; RH>90% СLiq<1·2g/kg. The estimation also shown that for conditions of breathing cold air of T [-15..+15]˚C and Relatively Humidity (RH) of [30..60]% the supersaturation in the airways occurs: the concentration of liquid water in the mixed air in RT (СLiq) is [0·2..12·1]g/kg. Under these conditions the growth of inhaled particles by condensation in RT is significant. It lead to the dramatically growth of deposition rate of the viruses and bacteria in RT (up to 97%). These results correspond to influenza and seasonal respiratory infections in temperate and tropical climates and indicate the high probability of virus deposition on epithelium of RT. It may be the key to ‘the age-old epidemiologic mystery of influenza seasonality in the different climatic conditions’.

scholarly journals Viral etiology and epidemiology of pediatric patients hospitalized for acute respiratory tract infections in Macao: a retrospective study from 2014 to 2017

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Cheng Lei ◽  
Lisong Yang ◽  
Cheong Tat Lou ◽  
Fan Yang ◽  
Kin Ian SiTou ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Lower Respiratory Tract ◽  
Respiratory Tract Infections ◽  
Pediatric Patients ◽  
Respiratory Infections ◽  
Upper Respiratory Tract ◽  
Viral Etiology ◽  
Upper Respiratory ◽  
Syncytial Virus ◽  
Tract Infections

Abstract Background Acute respiratory infections (ARIs) are among the leading causes of hospitalization in children. Understanding the local dominant viral etiologies is important to inform infection control practices and clinical management. This study aimed to investigate the viral etiology and epidemiology of respiratory infections among pediatric inpatients in Macao. Methods A retrospective study using electronic health records between 2014 and 2017 at Kiang Wu Hospital was performed. Nasopharyngeal swab specimens were obtained from hospitalized children aged 13 years or younger with respiratory tract diseases. xMAP multiplex assays were employed to detect respiratory agents including 10 respiratory viruses. Data were analyzed to describe the frequency and seasonality. Results Of the 4880 children enrolled in the study, 3767 (77.1%) were positive for at least one of the 13 viral pathogens tested, of which 2707 (55.5%) being male and 2635 (70.0%) under 2 years old. Among the positive results, there were 3091 (82.0%) single infections and 676 (18.0%) multiple infections. The predominant viruses included human rhinovirus/enterovirus (HRV/EV 27.4%), adenovirus (ADV, 15.8%), respiratory syncytial virus B (RSVB, 7.8%) and respiratory syncytial virus A (RSVA, 7.8%). The detection of viral infection was the most prevalent in autumn (960/1176, 81.6%), followed by spring (1095/1406, 77.9%), winter (768/992, 77.4%), and summer (944/1306, 72.3%), with HRV/EV and ADV being most commonly detected throughout the 4 years of study period. The detection rate of viral infection was highest among ARI patients presented with croup (123/141, 87.2%), followed by lower respiratory tract infection (1924/2356, 81.7%) and upper respiratory tract infection (1720/2383, 72.2%). FluA, FluB and ADV were positive factors for upper respiratory tract infections. On the other hand, infection with RSVA, RSVB, PIV3, PIV4, HMPV, and EV/RHV were positively associated with lower respiratory tract infections; and PIV1, PIV2, and PIV3 were positively associated with croup. Conclusions This is the first study in Macao to determine the viral etiology and epidemiology of pediatric patients hospitalized for ARIs. The study findings can contribute to the awareness of pathogen, appropriate preventative measure, accurate diagnosis, and proper clinical management of respiratory viral infections among children in Macao.

Principles of Judicious Use of Antimicrobial Agents for Pediatric Upper Respiratory Tract Infections

PEDIATRICS ◽  
1998 ◽  
Vol 101 (Supplement_1) ◽  
pp. 163-165 ◽  
Author(s):  
Scott F. Dowell ◽  
S. Michael Marcy ◽  
William R. Phillips ◽  
Michael A. Gerber ◽  
Benjamin Schwartz
Keyword(s):  
Respiratory Tract ◽  
Antimicrobial Agents ◽  
Respiratory Infections ◽  
The United States ◽  
Antimicrobial Treatment ◽  
Antimicrobial Use ◽  
Upper Respiratory Tract ◽  
Oral Agents ◽  
Upper Respiratory ◽  
Tract Infections

This article introduces a set of principles to define judicious antimicrobial use for five conditions that account for the majority of outpatient antimicrobial use in the United States. Data from the National Center for Health Statistics indicate that in recent years, approximately three fourths of all outpatient antibiotics have been prescribed for otitis media, sinusitis, bronchitis, pharyngitis, or nonspecific upper respiratory tract infection.1Antimicrobial drug use rates are highest for children1; therefore, the pediatric age group represents the focus for the present guidelines. The evidence-based principles presented here are focused on situations in which antimicrobial therapy could be curtailed without compromising patient care. They are not formulated as comprehensive management strategies. For most upper respiratory infections that require antimicrobial treatment, there are several appropriate oral agents from which to choose. Although the general principles of selecting narrow-spectrum agents with the fewest side effects and lowest cost are important, the principles that follow include few specific antibiotic selection recommendations.

Bacterial Infections of the Adult Upper Respiratory Tract

2019 ◽  
Author(s):  
Laura K Certain ◽  
Miriam B Barshak
Keyword(s):  
Respiratory Tract ◽  
Bacterial Infections ◽  
Respiratory Tract Infections ◽  
Respiratory Infections ◽  
Group A Streptococcus ◽  
The United States ◽  
Controlled Study ◽  
Upper Respiratory Tract ◽  
Upper Respiratory ◽  
Tract Infections

Upper respiratory tract infections are the most common maladies experienced by humankind.1 The majority are caused by respiratory viruses. A Dutch case-controlled study of primary care patients with acute respiratory tract infections found that viruses accounted for 58% of cases; rhinovirus was the most common (24%), followed by influenza virus type A (11%) and corona­viruses (7%). Group A streptococcus (GAS) was responsible for 11%, and 3% of patients had mixed infections. Potential pathogens were detected in 30% of control patients who were free of acute respiratory symptoms; rhinovirus was the most common.2 Given the increasing problem of antibiotic resistance and the increasing awareness of the importance of a healthy microbiome, antibiotic use for upper respiratory infections should be reserved for those patients with clear indications for treatment. A recent study of adult outpatient visits in the United States found that respiratory complaints accounted for 150 antibiotic prescriptions per 1,000 population annually, yet the expected “appropriate” rate would be 45.3 In other words, most antibiotic prescriptions for these complaints are unnecessary. Similarly, a study in the United Kingdom found that general practitioners prescribed antibiotics to about half of all patients presenting with an upper respiratory infection, even though most of these infections are viral.4 This review contains 5 figures, 16 tables, and 82 references. Keywords: infection, airway, sinusitis, otitis media, otitis externa, pharyngitis, epiglottitis, abscess

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