scholarly journals Respiratory Virus Shedding in Exhaled Breath and Efficacy of Face Masks

2020 ◽  
Author(s):  
Nancy HL Leung ◽  
Daniel KW Chu ◽  
Eunice YC Shiu ◽  
Kwok-Hung Chan ◽  
James J McDevitt ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Respiratory Virus ◽  
Virus Transmission ◽  
Respiratory Illness ◽  
Source Control ◽  
Exhaled Breath ◽  
Virus Infections ◽  
Virus Shedding ◽  
Human Coronaviruses ◽  
Respiratory Droplets

Abstract There are few studies describing the presence of respiratory viruses in respiratory droplets and aerosols in the exhaled breath of infected persons, and the efficacy of facemasks as a source control to prevent respiratory virus transmission. Here, we recruited children and adults with acute respiratory illness and collected respiratory droplets and aerosols, with and without surgical facemasks. We identified human coronaviruses, influenza virus and rhinovirus from both respiratory droplets and aerosols. Surgical face masks reduced detection of coronavirus RNA in both respiratory droplets and aerosols, but only respiratory droplets and not aerosols for influenza virus RNA. Our results provide mechanistic evidence that surgical facemasks could prevent transmission of human coronavirus and influenza virus infections if worn by symptomatic individuals.Authors Donald K Milton and Benjamin J Cowling are joint senior authors.

scholarly journals Coe (Coxsackie A21) virus, para-influenza virus and other respiratory virus infections in the R.A.F., 1958–60

1962 ◽  
Vol 60 (2) ◽  
pp. 235-248 ◽  
Author(s):  
J. C. McDonald ◽  
D. L. Miller ◽  
A. J. Zuckerman ◽  
Marguerite S. Pereira ◽  
Ann Deacon ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Respiratory Virus ◽  
Influenza Virus Infection ◽  
Admission Rate ◽  
Respiratory Illness ◽  
Influenza Viruses ◽  
Influenza B ◽  
Virus Infections ◽  
Influenza Type

1. In two R.A.F. recruit stations between November 1958 and March 1959, there were 2603 admissions to Sick Quarters with respiratory illness. Throat swabs from 1129, and paired sera from 1197 were tested for certain respiratory viruses.2. From the serological results it was estimated that 19% of the admissions were associated with influenza A infection, 7% with influenza B, 26% with adenovirus, 1% with para-influenza Type 1, 1% with para-influenza Type 3 and 8% with Coe virus, but as 21% of the identified infections were multiple the proportion of illness associated with one or more of these infections was only 50%. Thirty-four per cent of the Coe virus infections and 56% of the para-influenza virus infections were multiple.3. Virus isolation test results led to a similar estimate of the frequency of adenovirus infection (23%) but to a lower estimate for Coe virus (3%) and for the para-influenza viruses, no systematic attempt was made to isolate influenza viruses. Reasons are given for thinking that most of the admissions associated with Coe virus infection in 1958, but few of those in 1959, were caused by this agent. The proportion of illnesses attributable to viruses of the para-influenza group was probably about 1%.4. The main symptoms associated with Coe virus infection were upper respiratory. Hoarseness was rather more prominent than in other infections but the height and duration of fever and the frequency of febrile symptoms were less. The few illnesses associated with para-influenza virus infection had no obvious distinguishing features.1960 survey1. Blood specimens were taken from 205 recruits on their arrival at a recruit camp in January 1960 and immediately before their departure in March; 764 men in ten operational stations were bled in January and a sample of 260 were bled again in March.2. The respiratory illness admission rate was 25% in the recruits and 4% in the trained men; 49% of the recruits showed a rise in antibody to one or more respiratory virus antigens compared with 2% in the other group. The high rate of infection in recruits was mainly due to adenovirus (36%) and Coe virus (20%).3. It was estimated that about a third of the adenovirus infections and an eighth of the Coe virus infections were responsible for illness requiring admission. There was no indication that either infection caused any appreciable number of less severe illnesses not requiring admission.4. Evidence from this survey and the earlier one suggests that the presence of neutralizing antibody to Coe virus does not prevent infection, though it appears to lower the probability of illness.

scholarly journals Sequential Seasonal H1N1 Influenza Virus Infections Protect Ferrets against Novel 2009 H1N1 Influenza Virus

2012 ◽  
Vol 87 (3) ◽  
pp. 1400-1410 ◽  
Author(s):  
Donald M. Carter ◽  
Chalise E. Bloom ◽  
Eduardo J. M. Nascimento ◽  
Ernesto T. A. Marques ◽  
Jodi K. Craigo ◽  
...  
Keyword(s):  
Influenza Virus ◽  
H1n1 Influenza ◽  
Cross Reactivity ◽  
Influenza Viruses ◽  
The Novel ◽  
Virus Infections ◽  
H1n1 Influenza Virus ◽  
Virus Shedding ◽  
2009 H1n1 ◽  
Novel H1n1 Influenza

ABSTRACTIndividuals <60 years of age had the lowest incidence of infection, with ∼25% of these people having preexisting, cross-reactive antibodies to novel 2009 H1N1 influenza. Many people >60 years old also had preexisting antibodies to novel H1N1. These observations are puzzling because the seasonal H1N1 viruses circulating during the last 60 years were not antigenically similar to novel H1N1. We therefore hypothesized that a sequence of exposures to antigenically different seasonal H1N1 viruses can elicit an antibody response that protects against novel 2009 H1N1. Ferrets were preinfected with seasonal H1N1 viruses and assessed for cross-reactive antibodies to novel H1N1. Serum from infected ferrets was assayed for cross-reactivity to both seasonal and novel 2009 H1N1 strains. These results were compared to those of ferrets that were sequentially infected with H1N1 viruses isolated prior to 1957 or more-recently isolated viruses. Following seroconversion, ferrets were challenged with novel H1N1 influenza virus and assessed for viral titers in the nasal wash, morbidity, and mortality. There was no hemagglutination inhibition (HAI) cross-reactivity in ferrets infected with any single seasonal H1N1 influenza viruses, with limited protection to challenge. However, sequential H1N1 influenza infections reduced the incidence of disease and elicited cross-reactive antibodies to novel H1N1 isolates. The amount and duration of virus shedding and the frequency of transmission following novel H1N1 challenge were reduced. Exposure to multiple seasonal H1N1 influenza viruses, and not to any single H1N1 influenza virus, elicits a breadth of antibodies that neutralize novel H1N1 even though the host was never exposed to the novel H1N1 influenza viruses.

Breast-feeding and Respiratory Virus Infection

PEDIATRICS ◽  
1982 ◽  
Vol 70 (2) ◽  
pp. 239-245 ◽  
Author(s):  
Arthur L. Frank ◽  
Larry H. Taber ◽  
W. P. Glezen ◽  
Gary L. Kasel ◽  
Christine R. Wells ◽  
...  
Keyword(s):  
Virus Infection ◽  
Respiratory Tract ◽  
Breast Feeding ◽  
Lower Respiratory Tract ◽  
Respiratory Virus ◽  
Respiratory Illness ◽  
Severe Illness ◽  
Virus Infections ◽  
Respiratory Virus Infections ◽  
Breast Fed

Thirty-nine breast-fed and 42 bottle-fed infants were followed up from birth over a four-year period. Virus infection was documented by culture and serologic testing, and history and physical examination were recorded for all episodes of respiratory illness. There were no statistically significant differences in rates or distributions of infection with individual viruses or with all viruses over the first three or six months or during the second six months of life in the two groups, nor were there statistically significant differences in rates or distributions of disease of the upper and lower respiratory tract or total respiratory disease, except for decreased disease of the lower respiratory tract in bottle-fed infants in the second six months. There were trends to decreased morbidity in breast-fed infants in the first three and six months and more episodes of pneumonia and bronchiolitis in bottle-fed infants in the first six months (P &lt; .05) but similar use of medical care by both groups. High cord blood titers to two viruses were not associated with evidence of breast-feeding protection from infection with those two agents. Breast-fed babies do not have fewer respiratory virus infections or illnesses but may experience less severe illness.

scholarly journals Toll-Like Receptor 4-Mediated Activation of p38 Mitogen-Activated Protein Kinase Is a Determinant of Respiratory Virus Entry and Tropism

2010 ◽  
Vol 84 (21) ◽  
pp. 11359-11373 ◽  
Author(s):  
David Marchant ◽  
Gurpreet K. Singhera ◽  
Soraya Utokaparch ◽  
Tillie L. Hackett ◽  
John H. Boyd ◽  
...  
Keyword(s):  
Influenza Virus ◽  
P38 Mapk ◽  
Respiratory Virus ◽  
Respiratory Viruses ◽  
Mitogen Activated Protein Kinase ◽  
Toll Like Receptor ◽  
Virus Infections ◽  
Toll Like Receptor 4 ◽  
Mitogen Activated Protein ◽  
Respiratory Virus Infections

ABSTRACT Respiratory viruses exert a heavy toll of morbidity and mortality worldwide. Despite this burden there are few specific treatments available for respiratory virus infections. Since many viruses utilize host cell enzymatic machinery such as protein kinases for replication, we determined whether pharmacological inhibition of kinases could, in principle, be used as a broad antiviral strategy for common human respiratory virus infections. A panel of green fluorescent protein (GFP)-expressing recombinant respiratory viruses, including an isolate of H1N1 influenza virus (H1N1/Weiss/43), was used to represent a broad range of virus families responsible for common respiratory infections (Adenoviridae, Paramyxoviridae, Picornaviridae, and Orthomyxoviridae). Kinase inhibitors were screened in a high-throughput assay that detected virus infection in human airway epithelial cells (1HAEo-) using a fluorescent plate reader. Inhibition of p38 mitogen-activated protein kinase (MAPK) signaling was able to significantly inhibit replication by all viruses tested. Therefore, the pathways involved in virus-mediated p38 and extracellular signal-regulated kinase (ERK) MAPK activation were investigated using bronchial epithelial cells and primary fibroblasts derived from MyD88 knockout mouse lungs. Influenza virus, which activated p38 MAPK to approximately 10-fold-greater levels than did respiratory syncytial virus (RSV) in 1HAEo- cells, was internalized about 8-fold faster and more completely than RSV. We show for the first time that p38 MAPK is a determinant of virus infection that is dependent upon MyD88 expression and Toll-like receptor 4 (TLR4) ligation. Imaging of virus-TLR4 interactions showed significant clustering of TLR4 at the site of virus-cell interaction, triggering phosphorylation of downstream targets of p38 MAPK, suggesting the need for a signaling receptor to activate virus internalization.

scholarly journals Influenza virus-flow from insects to humans as causative for influenza seasonality

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Albrecht Pfäfflin
Keyword(s):  
Influenza Virus ◽  
Seasonal Influenza ◽  
Respiratory Virus ◽  
Temperate Climate ◽  
Virus Infections ◽  
Tropical Conditions ◽  
Respiratory Virus Infections ◽  
Influenza Seasonality ◽  
Temperate Climates

Abstract Virus biomass outweighs human biomass, and insects biomass outweighs human biomass. Insects are regularly habited by viruses as well as humans, humans are further inhabited via insects. A model of viral flow is described and specified to explain influenza virus seasonality, which, in temperate climate, usually evolves when insects have mostly disappeared. With this hypothesis a coherent description of regular seasonal influenza and other seasonal respiratory virus infections in temperate climates is possible. The incidence of influenza under different circumstances e.g. temperature, humidity, or tropical conditions and different aspects like synchronicity of infections or in respect to evolutionary conditions do sustain this hypothesis if the behaviour of insects is considered.

Protecting the Frontline: Designing an Infection Prevention Platform for Preventing Emerging Respiratory Viral Illnesses in Healthcare Personnel

2015 ◽  
Vol 36 (3) ◽  
pp. 336-345 ◽  
Author(s):  
Westyn Branch-Elliman ◽  
Connie Savor Price ◽  
Allison McGeer ◽  
Trish M. Perl
Keyword(s):  
Prevention Program ◽  
Infection Prevention ◽  
Respiratory Virus ◽  
Virus Transmission ◽  
Respiratory Illness ◽  
Healthcare Personnel ◽  
Respiratory Protection ◽  
Modes Of Transmission ◽  
Illness Prevention ◽  
The Cost

Healthcare personnel often find themselves on the frontlines of any epidemic, and may be at particularly high risk of acquiring respiratory viral illnesses when compared to the general population. Many aspects dictate how respiratory viruses spread both inside the hospital and out: Elements to consider include the specific type of virus being targeted for prevention, as well as environmental conditions and host factors, such as age and immune status. Due to the diverse nature of these agents, multiple modes of transmission, including contact, droplet, aerosol, and transocular, must be considered when designing an effective infection prevention program. In this review, we examine the data behind current theories of respiratory virus transmission and key elements of any respiratory illness prevention program. We also highlight other influences that may come into play, such as the cost-effectiveness of choosing one respiratory protection strategy over another.Infect Control Hosp Epidemiol 2014;00(0): 1–10

scholarly journals The Disappearance of Respiratory Viruses in Children during the COVID-19 Pandemic

2021 ◽  
Vol 18 (18) ◽  
pp. 9550
Author(s):  
Anna Chiara Vittucci ◽  
Livia Piccioni ◽  
Luana Coltella ◽  
Claudia Ciarlitto ◽  
Livia Antilici ◽  
...  
Keyword(s):  
Respiratory Virus ◽  
Respiratory Infections ◽  
Virus Transmission ◽  
Tertiary Hospital ◽  
Virus Infections ◽  
Epidemic Period ◽  
Syncytial Virus ◽  
Viral Respiratory Infections ◽  
Respiratory Virus Infections ◽  
The Impact

Background: Social distancing measures are used to reduce the spreading of COVID-19. The aim of this study was to assess the impact of local restrictions on the transmission of respiratory virus infections. Methods: we retrospectively analyzed the nasopharyngeal samples of all patients (0–18 years old) admitted with respiratory symptoms in a large Italian tertiary hospital during the last three seasons from 2018 to 2021. Results: A strong reduction in all viral respiratory infections was observed in the last season (2020–2021) compared to the two previous seasons (−79.69% and −80.66%, respectively). In particular, we found that during the epidemic period 2018–2019 and 2019–2020, the total number of Respiratory Syncytial Virus (RSV) cases was, respectively 726 and 689, while in the last season a total of five cases was detected. In the first months of 2018–2019 and 2019–2020, the total flu infections were 240 and 354, respectively, while in the last season we did not detect any influenza virus. As other viruses, the presence of Rhinovirus declined, but to a lesser extent: a total of 488 cases were assessed compared to the 1030 and 1165 cases of the two previous respective epidemic seasons. Conclusions: Public health interventions and distancing (including continuous use of face masks) settled to counter the pandemic spread of COVID-19 had a macroscopic impact on all respiratory virus transmission and related diseases, with a partial exception of Rhinovirus. The absence of viruses’ circulation could result in a lack of immunity and increased susceptibility to serious infections in the next seasons.

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