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1.
Global Epidemiology ; JOUR: 100094,
Article in English | ScienceDirect | ID: covidwho-2104972

ABSTRACT

We simulate the impact of school reopening during the COVID-19 pandemic in three major urban centers in Brazil to identify the epidemiological indicators and the best timing for the return of in-school activities and the effect of contact tracing as a mitigation measure. Our goal is to offer guidelines for evidence-based policymaking. We implement an extended SEIR model stratified by age and considering contact networks in different settings – school, home, work, and community, in which the infection transmission rate is affected by various intervention measures. After fitting epidemiological and demographic data, we simulate scenarios with increasing school transmission due to school reopening, and also estimate the number of hospitalization and deaths averted by the implementation of contact tracing. Reopening schools results in a non-linear increase in reported COVID-19 cases and deaths, which is highly dependent on infection and disease incidence at the time of reopening. When contact tracing and quarantining are restricted to school and home settings, a large number of daily tests is required to produce significant effects in reducing the total number of hospitalizations and deaths. Policymakers should carefully consider the epidemiological context and timing regarding the implementation of school closure and return of in-person school activities. While contact tracing strategies prevent new infections within school environments, they alone are not sufficient to avoid significant impacts on community transmission.

2.
Int J Infect Dis ; 2022 Nov 07.
Article in English | MEDLINE | ID: covidwho-2105083

ABSTRACT

OBJECTIVES: This study assessed the concentration of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the air of hospital rooms occupied by coronavirus disease (COVID-19) patients who had viable SARS-CoV-2 in nasopharyngeal samples in early infection. METHODS: Between July and October 2021, nasopharyngeal swabs were collected from 20 inpatients with early SARS-CoV-2 infection admitted to a tertiary hospital in Japan. Air samples were collected from their rooms, tested for SARS-CoV-2 RNA, and cultured to determine potential infectivity. RESULTS: The nasopharyngeal swab samples of 18 patients were positive for viable SARS-CoV-2 (median concentration: 4.0×105 TCID50/mL). In the air samples, viral RNA (median concentration: 1.1×105 copies/m3) was detected in 12/18 (67%) patients and viable virus (median concentration: 8.9×102 TCID50/m3) was detected in 5/18 (28%) patients. The median time between illness onset and sampling was 3 days. The RNA concentration was significantly higher in samples wherein viable SARS-CoV-2 was detected than in samples in which viable virus was not detected (p = 0.027). CONCLUSIONS: Viable SARS-CoV-2 can be detected in the air surrounding patients with early SARS-CoV-2 infection. Healthcare workers should pay attention to infection control when caring for patients with early SARS-CoV-2 infection.

3.
Int J Infect Dis ; 2022 Nov 08.
Article in English | MEDLINE | ID: covidwho-2105082

ABSTRACT

OBJECTIVES: To assay the presence of SARS-CoV-2 genome in vaginal, rectal, and placental swabs among pregnant women, and in newborn nasopharyngeal swabs; and to investigate unvaccinated mothers' immunological response, and maternal antibodies transfer throughout umbilical cord blood and milk. METHODS: Vaginal, rectal, and placental specimens, maternal and neonatal serum, and milk were collected from a wide cohort of pregnant Italian women with confirmed SARS-CoV-2 infection admitted to hospital between February 25, 2020 and June 30, 2021. Samples were tested in selected reference laboratories according to a shared inter-laboratory protocol. RESULTS: Among 1,086 enrolled women, the SARS-CoV-2 positive rate detected in all specimens ranged from 0.7 to 8.4%. Respectively, 45.2% of maternal sera collected during pregnancy and 39.7% of those collected at birth tested positive for IgG, while 50.5% tested positive among neonates. Nasopharyngeal swabs were positive in 0.8% of the newborns, and IgG were detected in 3.0% of milk samples. The highest immunological response was recorded within 30 days during pregnancy and within 60 days at birth and in the neonatal population. CONCLUSIONS: Vertical transmission should be considered a rare event; while a good maternal immunological response and antibodies transfer throughout umbilical cord blood was detected.

4.
Ankara Universitesi Veteriner Fakultesi Dergisi ; JOUR(4):445-459, 69.
Article in English | Web of Science | ID: covidwho-2100994

ABSTRACT

Poxviruses have caused the most important diseases for humanity for a long time. An important triumph was achieved with the eradication of smallpox, defined by the World Health Organization in 1979. Poxviruses include significant agents that cause important animal diseases that are non-zoonotic and zoonotic. While humanity has been battling COVID-19, a new battle against monkeypox has recently emerged due to an increase in case numbers and the outbreak's global spread. The other points of the 2022 monkeypox outbreak that make it more serious than previous outbreaks are severe clinical outcomes such as encephalitis and death, and also the higher transmission rate, which occurs at approximately 99% in men, especially those who have sex with men. The 2022 monkeypox virus outbreak has focused public and scientific attention on poxviruses and potential bioterrorism risks posed by poxviruses. Therefore, it is aimed at writing a review that compiles information about monkeypox, cowpox, vaccinia, bovine papular stomatitis, orf, pseudocowpox, gray seal pox, and red deerpox viruses.

5.
Biomedica ; 42(Sp. 2): 48-58, 2022 10 31.
Article in English, Spanish | MEDLINE | ID: covidwho-2100347

ABSTRACT

Introducción. El síndrome respiratorio agudo grave causado por el nuevo coronavirus SARSCoV-2 es causa de la emergencia sanitaria por la pandemia de COVID-19. Si bien el humano es el el principal huésped vulnerable, en estudios experimentales y reportes de infección natural, se han encontrado casos de zoonosis inversa de SARS-CoV-2 en animales. OBJETIVO: Evaluar la infección natural por SARS-CoV-2 en gatos y perros de propietarios con diagnóstico de COVID-19 en el Valle de Aburrá, Antioquia, Colombia. Materiales y métodos. La circulación del SARS-CoV-2 se evaluó por RT-qPCR y RT-PCR en muestras de frotis nasofaríngeos y orofaríngeos de gatos y perros cuyos propietarios se encontraban dentro del periodo de los 14 días de aislamiento. Los casos positivos se verificaron amplificando fragmentos de los genes RdRp, N y E; se secuenció el gen RdRp y se analizó filogenéticamente. RESULTADOS: De 80 animales evaluados, seis gatos y tres perros fueron casos confirmados de infección natural por SARS-CoV-2. Los animales no presentaron signos clínicos y sus propietarios, que padecían la infección, reportaron únicamente signos leves de la enfermedad sin complicaciones clínicas. En el análisis de una de las secuencias, se encontró un polimorfismo de un solo nucleótido (SNP) con un cambio en la posición 647, con sustitución del aminoácido serina (S) por una isoleucina (I). Los casos se presentaron en los municipios de Caldas, Medellín y Envigado. CONCLUSIONES: Se infiere que la infección natural en los gatos y perros se asocia al contacto directo con un paciente con COVID-19. No obstante, no es posible determinar la virulencia del virus en este huésped, ni su capacidad de transmisión  zoonótica o entre especie.


Introducción. El síndrome respiratorio agudo grave causado por el nuevo coronavirus SARSCoV-2 es causa de la emergencia sanitaria por la pandemia de COVID-19. Si bien el humano es el el principal huésped vulnerable, en estudios experimentales y reportes de infección natural, se han encontrado casos de zoonosis inversa de SARS-CoV-2 en animales. Objetivo. Evaluar la infección natural por SARS-CoV-2 en gatos y perros de propietarios con diagnóstico de COVID-19 en el Valle de Aburrá, Antioquia, Colombia. Materiales y métodos. La circulación del SARS-CoV-2 se evaluó por RT-qPCR y RT-PCR en muestras de frotis nasofaríngeos y orofaríngeos de gatos y perros cuyos propietarios se encontraban dentro del periodo de los 14 días de aislamiento. Los casos positivos se verificaron amplificando fragmentos de los genes RdRp, N y E; se secuenció el gen RdRp y se analizó filogenéticamente. Resultados. De 80 animales evaluados, seis gatos y tres perros fueron casos confirmados de infección natural por SARS-CoV-2. Los animales no presentaron signos clínicos y sus propietarios, que padecían la infección, reportaron únicamente signos leves de la enfermedad sin complicaciones clínicas. En el análisis de una de las secuencias, se encontró un polimorfismo de un solo nucleótido (SNP) con un cambio en la posición 647, con sustitución del aminoácido serina (S) por una isoleucina (I). Los casos se presentaron en los municipios de Caldas, Medellín y Envigado. Conclusiones. Se infiere que la infección natural en los gatos y perros se asocia al contacto directo con un paciente con COVID-19. No obstante, no es posible determinar la virulencia del virus en este huésped, ni su capacidad de transmisión zoonótica o entre especie.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , RNA-Dependent RNA Polymerase , Colombia/epidemiology , Retrospective Studies
6.
ASME 2022 41st International Conference on Ocean, Offshore and Arctic Engineering, OMAE 2022 ; JOUR, 5-A.
Article in English | Scopus | ID: covidwho-2097881

ABSTRACT

To investigate the operational improvements of vessels under the impact of COVID-19, this work has developed a Computational Fluid Dynamics model combined with Lagrangian particles to study the airborne transmission of COVID-19 viruses inside a ship. Initially a generic model was established to enable validation against experimental results for the diffusion of flu virus in an idealised room. Following this, the room geometry was replaced by the superstructure of a full-scale crew boat. Considering the boat advancing in open water, simulations were conducted to study the particulate flow due to a person coughing and speaking, with the boat’s forward door open and closed. The results have shown that, when the forward door is open, a significant airflow can carry the viruses to make extensive contacts with the passengers. This led to the suggestion of keeping the door closed. However, when the forward door is shut, face-to-face speaking can generate viruses that can float in the air for a long time, and it was found that the viruses mainly stay within a half-meter distance in front of the speaking person, before sinking to attach to the deck. Thus, a social-distancing suggestion on seat arrangement has been highlighted to minimise the risk of contagion. Overall, this work is expected to inform guidelines on hygienic and reconfiguring means for operators to counter COVID-19 and potentially the spread of similar viruses in the future. Copyright © 2022 by ASME.

7.
Emerg Infect Dis ; 28(12)2022 Nov 02.
Article in English | MEDLINE | ID: covidwho-2099065

ABSTRACT

We investigated a cluster of SARS-CoV-2 infections in a quarantine hotel in Taiwan in December 2021. The cluster involved 3 case patients who lived in nonadjacent rooms on different floors. They had no direct contact during their stay. By direct exploration of the space above the room ceilings, we found residual tunnels, wall defects, and truncated pipes between their rooms. We conducted a simplified tracer-gas experiment to assess the interconnection between rooms. Aerosol transmission through structural defects in floors and walls in this poorly ventilated hotel was the most likely route of virus transmission. This event demonstrates the high transmissibility of Omicron variants, even across rooms and floors, through structural defects. Our findings emphasize the importance of ventilation and integrity of building structure in quarantine facilities.

8.
Respir Res ; 23(1): 300, 2022 Oct 31.
Article in English | MEDLINE | ID: covidwho-2098347

ABSTRACT

Vaccines against SARS-CoV-2 protect from critical or severe pathogenesis also against new variants of concern (VOCs) such as BA.4 and BA.5, but immediate interventions to avoid viral transmission and subsequent inflammatory reactions are needed. Here we applied the ColdZyme® medical device mouth spray to fully differentiated, polarized human epithelium cultured at an air-liquid interphase (ALI). We found using VOCs BA.1 and BA.4/5 that this device effectively blocked respiratory tissue infection. While infection with these VOCs resulted in intracellular complement activation, thus enhanced inflammation, and drop of transepithelial resistance, these phenomena were prevented by a single administration of this medical device. Thus, ColdZyme® mouth spray significantly shields epithelial integrity, hinders virus infection and blocks in a secondary effect intrinsic complement activation within airway cultures also in terms of the highly contagious VOCs BA.4/5. Crucially, our in vitro data suggest that ColdZyme® mouth spray may have an impact to protect against SARS-CoV-2 transmission, also in case of the Omicron BA.1, BA.4 and BA.5 variants.


Subject(s)
COVID-19 , Respiratory Tract Infections , Humans , Epithelial Cells , COVID-19 Vaccines , SARS-CoV-2 , Epithelium , Respiratory Tract Infections/prevention & control
9.
Physics of Fluids ; JOUR(10), 34.
Article in English | Web of Science | ID: covidwho-2096933

ABSTRACT

Aerosolized droplets are produced en masse in dental practices;these aerosols disperse in the surrounding space, posing a health threat if the patient is infected with a transmittable disease, particularly COVID-19. Here, a viscoelastic polyacrylic acid (PAA) solution was used to minimize liquid aerosolization and limit the travel distance of aerosols. The PAA concentration was varied to evaluate its effect on aerosolization and droplet size resulting from procedures using dental handpieces, which include tooth cutting, grinding, and polishing. In addition, a thermocouple was inserted at the center of the model tooth to measure its temperature during a handpiece operation. The temperature data suggest that the cooling performance of the PAA solution is comparable to that of pure water in operations in the occlusal and facial directions. The PAA solution droplets splattered on the patient's facial area during the handpiece operation are markedly larger than those of pure water, which is evidence of the settling of the PAA droplets, preventing further transmission. Accordingly, the travel distance of the aerosolized PAA droplets was limited by viscoelastic resistance to droplet detachment. This comparison of the aerosol suppression capability between water and PAA solutions confirms the benefit of using viscoelastic solutions for various dental operations. Published under an exclusive license by AIP Publishing.

10.
Open Forum Infect Dis ; 9(10): ofac507, 2022 Oct.
Article in English | MEDLINE | ID: covidwho-2097433

ABSTRACT

Background: Estimates of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence in young children and risk factors for seropositivity are scarce. Using data from a prospective cohort study of households during the pre-coronavirus disease 2019 (COVID-19) vaccine period, we estimated SARS-CoV-2 seroprevalence by age and evaluated risk factors for SARS-CoV-2 seropositivity. Methods: The SARS-CoV-2 Epidemiology and Response in Children (SEARCh) study enrolled 175 Maryland households (690 participants) with ≥1 child aged 0-4 years during November 2020-March 2021; individuals vaccinated against COVID-19 were ineligible. At enrollment, participants completed questionnaires about sociodemographic and health status and work, school, and daycare attendance. Participants were tested for SARS-CoV-2 antibodies in sera. Logistic regression models with generalized estimating equations (GEE) to account for correlation within households assessed predictors of individual- and household-level SARS-CoV-2 seropositivity. Results: Of 681 (98.7%) participants with enrollment serology results, 55 (8.1%; 95% confidence interval [CI], 6.3%-10.4%) participants from 21 (12.0%) households were seropositive for SARS-CoV-2. Among seropositive participants, fewer children than adults reported being tested for SARS-CoV-2 infection before enrollment (odds ratio [OR] = 0.23; 95% CI, .06-.73). Seropositivity was similar by age (GEE OR vs 0-4 years: 1.19 for 5-17 years, 1.36 for adults; P = .16) and was significantly higher among adults working outside the home (GEE adjusted OR = 2.2; 95% CI, 1.1-4.4) but not among children attending daycare or school. Conclusions: Before study enrollment, children and adults in this cohort had similar rates of SARS-CoV-2 infection as measured by serology. An adult household member working outside the home increased a household's odds of SARS-CoV-2 infection, whereas a child attending daycare or school in person did not.

11.
J Aerosol Med Pulm Drug Deliv ; 2022 Nov 01.
Article in English | MEDLINE | ID: covidwho-2097255

ABSTRACT

Background: As the COVID-19 pandemic has progressed, numerous variants of SARS-CoV-2 have arisen, with several displaying increased transmissibility. Methods: The present study compared dose-response relationships and disease presentation in nonhuman primates infected with aerosols containing an isolate of the Gamma variant of SARS-CoV-2 to the results of our previous study with the earlier WA-1 isolate of SARS-CoV-2. Results: Disease in Gamma-infected animals was mild, characterized by dose-dependent fever and oronasal shedding of virus. Differences were observed in shedding in the upper respiratory tract between Gamma- and WA-1-infected animals that have the potential to influence disease transmission. Specifically, the estimated median doses for shedding of viral RNA or infectious virus in nasal swabs were approximately 10-fold lower for the Gamma variant than the WA-1 isolate. Given that the median doses for fever were similar, this suggests that there is a greater difference between the median doses for viral shedding and fever for Gamma than for WA-1 and potentially an increased range of doses for Gamma over which asymptomatic shedding and disease transmission are possible. Conclusions: These results complement those of previous studies, which suggested that differences in exposure dose may help to explain the range of clinical disease presentations observed in individuals with COVID-19, highlighting the importance of public health measures designed to limit exposure dose, such as masking and social distancing. The dose-response data provided by this study are important to inform disease transmission and hazard modeling, as well as to inform dose selection in future studies examining the efficacy of therapeutics and vaccines in animal models of inhalational COVID-19.

12.
Physica A ; 608: 128284, 2022 Dec 15.
Article in English | MEDLINE | ID: covidwho-2095891

ABSTRACT

In the post-epidemic era, people's lives are gradually returning to normal, and travel is gradually resuming. The safe evacuation of cross-regional travelers in railway station has also attracted more and more attention, especially the evacuation behavior of college students in railway station. In this paper, considering the pedestrian dynamics mechanism in the emergency evacuation process during the COVID-19 normalized epidemic prevention and control, an Agent-based social force model was established to simulate the activities of college students in railway station. Combined with the virus infection transmission model, Monte Carlo simulation was used to calculate the total exposure time and the number of high-risk exposed people in the railway station evacuation process. In addition, sensitivity analysis was conducted on the total exposure time and the number of high-risk exposed people under 180 combinations of the number of initial infections, social distance, and the proportion of people wearing masks incorrectly. The results show that with the increase of social distances, the total exposure time and the number of high-risk exposures do not always decrease, but increase in some cases. The presence or absence of obstacles in the evacuation scene has no significant difference in the effects on total exposure time and the number of high-risk exposures. During the evacuation behavior of college students in railway station, choosing the appropriate number of lines can effectively reduce the total exposure time and the number of high-risk exposures. Finally, some policy suggestions are proposed to reduce the risk of virus transmission in the railway station evacuation process, such as choosing dynamic and reasonable social distance and the number of queues, and reducing obstacles.

13.
J Theor Biol ; 557: 111335, 2022 Nov 02.
Article in English | MEDLINE | ID: covidwho-2095714

ABSTRACT

Repeat asymptomatic testing in order to identify and quarantine infectious individuals has become a widely-used intervention to control SARS-CoV-2 transmission. In some workplaces, and in particular health and social care settings with vulnerable patients, regular asymptomatic testing has been deployed to staff to reduce the likelihood of workplace outbreaks. We have developed a model based on data available in the literature to predict the potential impact of repeat asymptomatic testing on SARS-CoV-2 transmission. The results highlight features that are important to consider when modelling testing interventions, including population heterogeneity of infectiousness and correlation with test-positive probability, as well as adherence behaviours in response to policy. Furthermore, the model based on the reduction in transmission potential presented here can be used to parameterise existing epidemiological models without them having to explicitly simulate the testing process. Overall, we find that even with different model paramterisations, in theory, regular asymptomatic testing is likely to be a highly effective measure to reduce transmission in workplaces, subject to adherence. This manuscript was submitted as part of a theme issue on "Modelling COVID-19 and Preparedness for Future Pandemics".

14.
Lancet Digital Health ; JOUR(8):E573-E583, 4.
Article in English | Web of Science | ID: covidwho-2092794

ABSTRACT

Background Real-time prediction is key to prevention and control of infections associated with health-care settings. Contacts enable spread of many infections, yet most risk prediction frameworks fail to account for their dynamics. We developed, tested, and internationally validated a real-time machine-learning framework, incorporating dynamic patient-contact networks to predict hospital-onset COVID-19 infections (HOCIs) at the individual level. Methods We report an international retrospective cohort study of our framework, which extracted patient-contact networks from routine hospital data and combined network-derived variables with clinical and contextual information to predict individual infection risk. We trained and tested the framework on HOCIs using the data from 51 157 hospital inpatients admitted to a UK National Health Service hospital group (Imperial College Healthcare NHS Trust) between April 1, 2020, and April 1, 2021, intersecting the first two COVID-19 surges. We validated the framework using data from a Swiss hospital group (Department of Rehabilitation, Geneva University Hospitals) during a COVID-19 surge (from March 1 to May 31, 2020;40 057 inpatients) and from the same UK group after COVID-19 surges (from April 2 to Aug 13, 2021;43 375 inpatients). All inpatients with a bed allocation during the study periods were included in the computation of network-derived and contextual variables. In predicting patient-level HOCI risk, only inpatients spending 3 or more days in hospital during the study period were examined for HOCI acquisition risk. Findings The framework was highly predictive across test data with all variable types (area under the curve [AUC]-receiver operating characteristic curve [ROC] 0.89 [95% CI 0.88-0.90]) and similarly predictive using only contact-network variables (0.88 [0.86-0.90]). Prediction was reduced when using only hospital contextual (AUC-ROC 0.82 [95% CI 0.80-0.84]) or patient clinical (0.64 [0.62-0.66]) variables. A model with only three variables (ie, network closeness, direct contacts with infectious patients [network derived], and hospital COVID-19 prevalence [hospital contextual]) achieved AUC-ROC 0.85 (95% CI 0.82-0.88). Incorporating contact-network variables improved performance across both validation datasets (AUC-ROC in the Geneva dataset increased from 0.84 [95% CI 0.82-0.86] to 0.88 [0.86-0.90];AUC-ROC in the UK post-surge dataset increased from 0.49 [0.46-0.52] to 0.68 [0.64-0.70]). Interpretation Dynamic contact networks are robust predictors of individual patient risk of HOCIs. Their integration in clinical care could enhance individualised infection prevention and early diagnosis of COVID-19 and other nosocomial infections. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.

15.
Emerg Infect Dis ; 28(12)2022 Oct 26.
Article in English | MEDLINE | ID: covidwho-2089724

ABSTRACT

SARS-CoV-2 likely emerged from an animal reservoir. However, the frequency of and risk factors for interspecies transmission remain unclear. We conducted a community-based study in Idaho, USA, of pets in households that had >1 confirmed SARS-CoV-2 infections in humans. Among 119 dogs and 57 cats, clinical signs consistent with SARS-CoV-2 were reported for 20 dogs (21%) and 19 cats (39%). Of 81 dogs and 32 cats sampled, 40% of dogs and 43% of cats were seropositive, and 5% of dogs and 8% of cats were PCR positive. This discordance might be caused by delays in sampling. Respondents commonly reported close human‒animal contact and willingness to take measures to prevent transmission to their pets. Reported preventive measures showed a slightly protective but nonsignificant trend for both illness and seropositivity in pets. Sharing of beds and bowls had slight harmful effects, reaching statistical significance for sharing bowls and seropositivity.

16.
Indoor Air ; 32(10): e13121, 2022 Oct.
Article in English | MEDLINE | ID: covidwho-2088232

ABSTRACT

Experiments were conducted in an UK inter-city train carriage with the aim of evaluating the risk of infection to the SARS-CoV-2 virus via airborne transmission. The experiments included in-service CO2 measurements and the measurement of salt aerosol concentrations released within the carriage. Computational fluid dynamics simulations of the carriage airflow were also used to visualise the airflow patterns, and the efficacy of the HVAC filter material was tested in a laboratory. Assuming an infectious person is present, the risk of infection for a 1-h train journey was estimated to be 6 times lower than for a full day in a well-ventilated office, or 10-12 times lower than a full day in a poorly ventilated office. While the absolute risk for a typical journey is likely low, in the case where a particularly infectious individual is on-board, there is the potential for a number of secondary infections to occur during a 1-h journey. Every effort should therefore be made to minimize the risk of airborne infection within these carriages. Recommendations are also given for the use of CO2 sensors for the evaluation of the risk of airborne transmission on train carriages.


Subject(s)
Air Pollution, Indoor , COVID-19 , Humans , SARS-CoV-2 , Carbon Dioxide , Respiratory Aerosols and Droplets
17.
Clin Infect Dis ; 2022 Oct 26.
Article in English | MEDLINE | ID: covidwho-2087752

ABSTRACT

BACKGROUND: Aerosol inhalation is recognized as the dominant mode of SARS-CoV-2 transmission. Three highly transmissible lineages evolved during the pandemic. One hypothesis to explain increased transmissibility is that natural selection favors variants with higher rates of viral aerosol shedding. However, the extent of aerosol shedding of successive SARS-CoV-2 variants is unknown. We aimed to measure the infectivity and rate of SARS-CoV-2 shedding into exhaled breath aerosol (EBA) by individuals during the Delta and Omicron waves and compared those rates with those of prior SARS-CoV-2 variants from our previously published work. METHODS: COVID-19 cases (n = 93, 32 vaccinated and 20 boosted) were recruited to give samples, including 30-minute breath samples into a Gesundheit-II exhaled breath aerosol sampler. Samples were quantified for viral RNA using RT-PCR and cultured for virus. RESULTS: Alpha (n = 4), Delta (n = 3), and Omicron (n = 29) cases shed significantly more viral RNA copies into exhaled breath aerosols than cases infected with ancestral strains and variants not associated with increased transmissibility (n = 57). All Delta and Omicron cases were fully vaccinated and most Omicron cases were boosted. We cultured virus from the EBA of one boosted and three fully vaccinated cases. CONCLUSIONS: Alpha, Delta, and Omicron independently evolved high viral aerosol shedding phenotypes, demonstrating convergent evolution. Vaccinated and boosted cases can shed infectious SARS-CoV-2 via EBA. These findings support a dominant role of infectious aerosols in transmission of SARS-CoV-2. Monitoring aerosol shedding from new variants and emerging pathogens can be an important component of future threat assessments and guide interventions to prevent transmission.

18.
J Adolesc ; 2022 Oct 25.
Article in English | MEDLINE | ID: covidwho-2085045

ABSTRACT

INTRODUCTION: Theoretical and empirical evidence suggests that the effect of parental verbal threat information on the offspring's fear acquisition of novel stimuli may be causal. The current study investigated this verbal fear acquisition pathway from parents to children in the unique context of Covid-19 as a novel environmental threat for parents and children. METHODS: Using an online cross-sectional survey, we collected data about fear of Covid-19, parent-child communication, parental anxiety, and child temperament, in the period between June 11th 2020 and May 28th 2021. Participants were 8 to 18-year-old children (N = 195; Mage = 14.23; 113 girls) and their parents (N = 193; Mage = 47.82; 146 mothers) living in the Netherlands. RESULTS: Children of parents with stronger Covid-19 fears also reported stronger Covid-19 fears. Moreover, parents who were more fearful of Covid-19 provided more threat-related information about the virus to their children. More parental threat information in turn was related to stronger fear of Covid-19 in their children, and partly mediated the link between parent and child fear of the virus. The link between parental threat information and children's fear of Covid-19 was not moderated by child temperament or parental anxiety. CONCLUSIONS: Parental communication about Covid-19 may play a role in children's fear acquisition of Covid-19. The lack of moderation of this link by parental anxiety and child temperament may reflect the potentially adaptive nature of verbal fear transmission during the first year of the pandemic and the nonclinical levels of fear in this community sample.

19.
Pathogenic Coronaviruses of Humans and Animals ; CHAP: 53-124,
Article in English | ScienceDirect | ID: covidwho-2083144

ABSTRACT

In 2002, a severe-to-fatal respiratory disease began in China and was named severe acute respiratory syndrome (SARS). The causative agent was soon found to be a coronavirus and was named SARS-coronavirus (SARS-CoV). Infection was traced to contact with live palm civet cats or raccoon dogs in live animal food markets (“wet markets”) and later, person-to-person. Visiting these markets or restaurants housing these animals before preparing them for customer consumption were among the risk factors for infection in addition to frequent use of taxis and comorbidities. After its initial appearance, SARS spread rapidly through parts of Asia and then to countries around the world before almost completely disappearing in 2003. It caused 8096 cases and 774 deaths. SARS-CoV is a betacoronavirus linage B. The single-stranded RNA genome of coronaviruses is the largest among RNA viruses. The size of the genome, the inaccuracy of replication in most coronaviruses, and homogenous and heterogenous genetic recombination contribute to the high frequency of mutation. The viral spike (S) protein binds to angiotensin-converting enzyme 2 on the host cell before entry. Mutations in the S protein make a substantial contribution to viral transmission to additional host species and cell types in addition to viral virulence as the virus adapted to its new hosts. Interestingly, SARS-CoV isolates from the initial stages of the 2002–2003 epidemic were more virulent than those isolated later and are associated with a 29-nucleotide deletion in the S protein gene. Several insectivorous Chinese bats appear to serve as reservoir hosts for the ancestorial coronavirus. New forms of protection against infection were implemented in China and some other countries and include wearing face masks, thermal screening, and avoiding travel in taxis and public transportation. Their effectiveness in decreasing transmission and the rapid end of the epidemic is unknown.

20.
Pathogenic Coronaviruses of Humans and Animals ; CHAP: 125-172,
Article in English | ScienceDirect | ID: covidwho-2082962

ABSTRACT

Middle East respiratory virus syndrome (MERS) is a viral disease that primarily affects the respiratory system, but also has a major impact on the kidneys and nervous system and, to a lesser extent, on the intestines, liver, and heart. Over 2500 cases and 850 deaths have been confirmed as of 2019. The fatality rate is approximately 35%, more than that caused by severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2 (that causes COVID-19). The first known case of MERS in humans was reported in 2012 in Saudi Arabia but the virus was present in stored serum samples from dromedary (one-humped) camels from Africa and the Middle East for decades before that time. Since then, it spread to at least 27 countries around the world, most of which are related to travel to the Arabian Peninsula. The coronavirus that causes MERS, MERS-CoV, is related to several other human coronaviruses that typically cause cold-like illness as well as to SARS-CoV and SARS-CoV-2. MERS-CoV is from the subgenus Merbecovirus, while SARS-CoV and SARS-CoV-2 are in Sarbecovirus. MERS-CoV also uses dipeptidyl peptidase 4 as its host cell receptor, while SARS-CoV and SARS-CoV-2 use angiotensin-converting enzyme 2. While MERS-CoV is transmittable between people in close contact with an infected person, many infections are zoonotic and are due to inhaling infectious respiratory droplets from dromedaries or consuming their raw milk or urine. Many cases are nosocomial (acquired in healthcare facilities). Fortunately, MERS-CoV only can pass through several rounds of human-to-human transmission, unlike SARS-CoV-2. Much of the pathology is due to an excessive inflammatory type of immune response caused by cytokines and chemokines, abnormal blood coagulation, and virus-induced apoptosis (programmed cell death). Bats appear to be the reservoir hosts and should be monitored for possible zoonotic transmission outside of the Middle East, in line with the One Health approach.

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