scholarly journals Non-invasive adapted N-95 mask sampling captures variation in viral particles expelled by COVID-19 patients: Implications in understanding SARS-CoV2 transmission

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249525
Author(s):  
Kalpana Sriraman ◽  
Ambreen Shaikh ◽  
Swapneil Parikh ◽  
Shreevatsa Udupa ◽  
Nirjhar Chatterjee ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Control Strategies ◽  
Secondary Infection ◽  
Transmission Risk ◽  
Nasopharyngeal Swab ◽  
Virus Particles ◽  
Patient Demographics ◽  
Non Invasive ◽  
Viral Particles ◽  
Key Driver

Infectious respiratory particles expelled by SARS-CoV-2 positive patients are attributed to be the key driver of COVID-19 transmission. Understanding how and by whom the virus is transmitted can help implement better disease control strategies. Here we have described the use of a noninvasive mask sampling method to detect and quantify SARS-CoV-2 RNA in respiratory particles expelled by COVID-19 patients and discussed its relationship to transmission risk. Respiratory particles of 31 symptomatic SARS-CoV-2 positive patients and 31 asymptomatic healthy volunteers were captured on N-95 masks layered with a gelatin membrane in a 30-minute process that involved talking/reading, coughing, and tidal breathing. SARS-CoV-2 viral RNA was detected and quantified using rRT-PCR in the mask and in concomitantly collected nasopharyngeal swab (NPS) samples. The data were analyzed with respect to patient demographics and clinical presentation. Thirteen of 31(41.9%) patients showed SARS-COV-2 positivity in both the mask and NPS samples, while 16 patients were mask negative but NPS positive. Two patients were both mask and NPS negative. All healthy volunteers except one were mask and NPS negative. The mask positive patients had significantly lower NPS Ct value (26) compared to mask negative patients (30.5) and were more likely to be rapid antigen test positive. The mask positive patients could be further grouped into low emitters (expelling <100 viral copies) and high emitters (expelling >1000 viral copies). The study presents evidence for variation in emission of SARS-CoV-2 virus particles by COVID-19 patients reflecting differences in infectivity and transmission risk among individuals. The results conform to reported secondary infection rates and transmission and also suggest that mask sampling could be explored as an effective tool to assess individual transmission risks, at different time points and during different activities.

Responses to External Emotions or their Transitions at Central to Peripheral Nervous System Levels: A Methodological Contribution to Mental Health

2020 ◽  
Vol 16 (2) ◽  
pp. 138-152
Author(s):  
Bingren Zhang ◽  
Chu Wang ◽  
Chanchan Shen ◽  
Wei Wang
Keyword(s):  
Healthy Volunteers ◽  
Psychiatric Patients ◽  
Event Related Potentials ◽  
Emotional Stimuli ◽  
Non Invasive ◽  
Related Potentials ◽  
Different Populations ◽  
Invasive Techniques ◽  
Psychiatric Problems ◽  
Different Levels

Background: Responses to external emotional-stimuli or their transitions might help to elucidate the scientific background and assist the clinical management of psychiatric problems, but pure emotional-materials and their utilization at different levels of neurophysiological processing are few. Objective: We aimed to describe the responses at central and peripheral levels in healthy volunteers and psychiatric patients when facing external emotions and their transitions. Methods: Using pictures and sounds with pure emotions of Disgust, Erotica, Fear, Happiness, Neutral, and Sadness or their transitions as stimuli, we have developed a series of non-invasive techniques, i.e., the event-related potentials, functional magnetic resonance imaging, excitatory and inhibitory brainstem reflexes, and polygraph, to assess different levels of neurophysiological responses in different populations. Results: Sample outcomes on various conditions were specific and distinguishable at cortical to peripheral levels in bipolar I and II disorder patients compared to healthy volunteers. Conclusions: Methodologically, designs with these pure emotions and their transitions are applicable, and results per se are specifically interpretable in patients with emotion-related problems.

scholarly journals Evaluation of a home-based 7-day infection control strategy for healthcare workers following high-risk exposure to severe acute respiratory coronavirus virus 2 (SARS-CoV-2): A cohort study

2020 ◽  
pp. 1-4
Author(s):  
Carla Benea ◽  
Laura Rendon ◽  
Jesse Papenburg ◽  
Charles Frenette ◽  
Ahmed Imacoudene ◽  
...  
Keyword(s):  
High Risk ◽  
Infection Control ◽  
Control Strategy ◽  
Healthcare Workers ◽  
Control Strategies ◽  
Risk Exposure ◽  
Nasopharyngeal Swab ◽  
Home Based ◽  
Respiratory Coronavirus ◽  
Second Wave

Abstract Objective: Evidence-based infection control strategies are needed for healthcare workers (HCWs) following high-risk exposure to severe acute respiratory coronavirus virus 2 (SARS-CoV-2). In this study, we evaluated the negative predictive value (NPV) of a home-based 7-day infection control strategy. Methods: HCWs advised by their infection control or occupational health officer to self-isolate due to a high-risk SARS-CoV-2 exposure were enrolled between May and October 2020. The strategy consisted of symptom-triggered nasopharyngeal SARS-CoV-2 RNA testing from day 0 to day 7 after exposure and standardized home-based nasopharyngeal swab and saliva testing on day 7. The NPV of this strategy was calculated for (1) clinical coronavirus disease 2019 (COVID-19) diagnosis from day 8–14 after exposure, and for (2) asymptomatic SARS-CoV-2 detected by standardized nasopharyngeal swab and saliva specimens collected at days 9, 10, and 14 after exposure. Interim results are reported in the context of a second wave threatening this essential workforce. Results: Among 30 HCWs enrolled, the mean age was 31 years (SD, ±9), and 24 (80%) were female. Moreover, 3 were diagnosed with COVID-19 by day 14 after exposure (secondary attack rate, 10.0%), and all cases were detected using the 7-day infection control strategy: the NPV for subsequent clinical COVID-19 or asymptomatic SARS-CoV-2 detection by day 14 was 100.0% (95% CI, 93.1%–100.0%). Conclusions: Among HCWs with high-risk exposure to SARS-CoV-2, a home-based 7-day infection control strategy may have a high NPV for subsequent COVID-19 and asymptomatic SARS-CoV-2 detection. Ongoing data collection and data sharing are needed to improve the precision of the estimated NPV, and here we report interim results to inform infection control strategies in light of a second wave threatening this essential workforce.

scholarly journals Livestock movement informs the risk of disease spread in traditional production systems in East Africa

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Divine Ekwem ◽  
Thomas A. Morrison ◽  
Richard Reeve ◽  
Jessica Enright ◽  
Joram Buza ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Production Systems ◽  
Control Strategies ◽  
Herd Size ◽  
Transmission Risk ◽  
Disease Spread ◽  
Transmission Potential ◽  
Spatial And Temporal Scales ◽  
Transmission Distance ◽  
Risk Of Disease

AbstractIn Africa, livestock are important to local and national economies, but their productivity is constrained by infectious diseases. Comprehensive information on livestock movements and contacts is required to devise appropriate disease control strategies; yet, understanding contact risk in systems where herds mix extensively, and where different pathogens can be transmitted at different spatial and temporal scales, remains a major challenge. We deployed Global Positioning System collars on cattle in 52 herds in a traditional agropastoral system in western Serengeti, Tanzania, to understand fine-scale movements and between-herd contacts, and to identify locations of greatest interaction between herds. We examined contact across spatiotemporal scales relevant to different disease transmission scenarios. Daily cattle movements increased with herd size and rainfall. Generally, contact between herds was greatest away from households, during periods with low rainfall and in locations close to dipping points. We demonstrate how movements and contacts affect the risk of disease spread. For example, transmission risk is relatively sensitive to the survival time of different pathogens in the environment, and less sensitive to transmission distance, at least over the range of the spatiotemporal definitions of contacts that we explored. We identify times and locations of greatest disease transmission potential and that could be targeted through tailored control strategies.

scholarly journals Evidence of activation of vagal afferents by non-invasive vagus nerve stimulation: An electrophysiological study in healthy volunteers

Cephalalgia ◽  
2017 ◽  
Vol 37 (13) ◽  
pp. 1285-1293 ◽  
Author(s):  
Romain Nonis ◽  
Kevin D’Ostilio ◽  
Jean Schoenen ◽  
Delphine Magis
Keyword(s):  
Vagus Nerve ◽  
Healthy Volunteers ◽  
Nerve Stimulation ◽  
Vagus Nerve Stimulation ◽  
Electrophysiological Study ◽  
Vagal Afferents ◽  
Response Analysis ◽  
Bipolar Electrode ◽  
Non Invasive ◽  
Vagal Afferent

Background Benefits of cervical non-invasive vagus nerve stimulation (nVNS) devices have been shown in episodic cluster headache and preliminarily suggested in migraine, but direct evidence of vagus nerve activation using such devices is lacking. Vagal somatosensory evoked potentials (vSEPs) associated with vagal afferent activation have been reported for invasive vagus nerve stimulation (iVNS) and non-invasive auricular vagal stimulation. Here, we aimed to show and characterise vSEPs for cervical nVNS. Methods vSEPs were recorded for 12 healthy volunteers who received nVNS over the cervical vagus nerve, bipolar electrode/DS7A stimulation over the inner tragus, and nVNS over the sternocleidomastoid (SCM) muscle. We measured peak-to-peak amplitudes (P1-N1), wave latencies, and N1 area under the curve. Results P1-N1 vSEPs were observed for cervical nVNS (11/12) and auricular stimulation (9/12), with latencies similar to those described previously, whereas SCM stimulation revealed only a muscle artefact with a much longer latency. A dose-response analysis showed that cervical nVNS elicited a clear vSEP response in more than 80% of the participants using an intensity of 15 V. Conclusion Cervical nVNS can activate vagal afferent fibres, as evidenced by the recording of far-field vSEPs similar to those seen with iVNS and non-invasive auricular stimulation.

A Spatiotemporal Analysis of Schistosomiasis in Hunan Province, China

2018 ◽  
Vol 30 (6) ◽  
pp. 521-531
Author(s):  
Enru Wang ◽  
Zhengyuan Zhao ◽  
Changhong Miao ◽  
Zhongcai Wu
Keyword(s):  
Schistosoma Japonicum ◽  
Hot Spots ◽  
Spatial Clustering ◽  
Control Strategies ◽  
Spatiotemporal Analysis ◽  
Hunan Province ◽  
Transmission Risk ◽  
Schistosomiasis Japonica ◽  
Health Studies ◽  
Risk Areas

Based on annual parasitological data recently collected at county and village levels, this article presents a multiscale spatiotemporal analysis of transmission risk of schistosomiasis japonica in Hunan Province during 2001 to 2015 in a geographic information system environment. The study shows that the incidence and prevalence rate of human Schistosoma japonicum infection in Hunan Province decreased after 2001. A spatial autocorrelation analysis reveals the existence of spatial clusters of human Schistosoma japonicum infection and a growing tendency of spatial clustering over time. The identification of high-risk areas (hot spots) helps find areas of priority for future implementation of control strategies. The research demonstrates the importance of spatial scale in public health studies.

scholarly journals Identification and Characterization of a Poliovirus Capsid Mutant with Enhanced Thermal Stability

2018 ◽  
Vol 93 (6) ◽  
Author(s):  
Y Nguyen ◽  
Palmy R. Jesudhasan ◽  
Elizabeth R. Aguilera ◽  
Julie K. Pfeiffer
Keyword(s):  
Thermal Stability ◽  
High Temperatures ◽  
Oral Route ◽  
Mutant Virus ◽  
Single Amino Acid ◽  
Bacterial Surface ◽  
Virus Particles ◽  
Heat Resistant ◽  
Viral Particles ◽  
Very High

ABSTRACTEnteric viruses, including poliovirus, are spread by the fecal-oral route. In order to persist and transmit to a new host, enteric virus particles must remain stable once they are in the environment. Environmental stressors such as heat and disinfectants can inactivate virus particles and prevent viral transmission. It has been previously demonstrated that bacteria or bacterial surface glycans can enhance poliovirus virion stability and limit inactivation from heat or bleach. While investigating the mechanisms underlying bacterially enhanced virion thermal stability, we identified and characterized a poliovirus (PV) mutant with increased resistance to heat inactivation. The M132V mutant harbors a single amino acid change in the VP1 capsid coding that is sufficient to confer heat resistance but not bleach resistance. Although the M132V virus was stable in the absence of bacteria or feces at most temperatures, M132V virus was stabilized by feces at very high temperatures. M132V PV had reduced specific infectivity and RNA uncoating compared with those of wild-type (WT) PV, but viral yields in HeLa cells were similar. In orally inoculated mice, M132V had a slight fitness cost since fecal titers were lower and 12.5% of fecal viruses reverted to the WT. Overall, this work sheds light on factors that influence virion stability and fitness.IMPORTANCEViruses spread by the fecal-oral route need to maintain viability in the environment to ensure transmission. Previous work indicated that bacteria and bacterial surface polysaccharides can stabilize viral particles and enhance transmission. To explore factors that influence viral particle stability, we isolated a mutant poliovirus that is heat resistant. This mutant virus does not require feces for stability at most temperatures but can be stabilized by feces at very high temperatures. Even though the mutant virus is heat resistant, it is susceptible to inactivation by treatment with bleach. This work provides insight into how viral particles maintain infectivity in the environment.

scholarly journals Abundant Defective Viral Particles Budding from Microglia in the Course of Retroviral Spongiform Encephalopathy

2000 ◽  
Vol 74 (4) ◽  
pp. 1775-1780 ◽  
Author(s):  
Regine Hansen ◽  
Stefanie Czub ◽  
Evi Werder ◽  
Jens Herold ◽  
Georg Gosztonyi ◽  
...  
Keyword(s):  
Infectious Virus ◽  
Protein Translocation ◽  
Neuronal Damage ◽  
Ex Vivo ◽  
Spongiform Encephalopathy ◽  
Microglia Cell ◽  
Virus Particles ◽  
Viral Particles ◽  
Type C ◽  
Retroviral Infections

ABSTRACT A pathogenetic hallmark of retroviral neurodegeneration is the affinity of neurovirulent retroviruses for microglia cells, while degenerating neurons are excluded from retroviral infections. Microglia isolated ex vivo from rats peripherally infected with a neurovirulent retrovirus released abundant mature type C virions; however, infectivity associated with microglia was very low. In microglia, viral transcription was unaffected but envelope proteins were insufficiently cleaved into mature viral proteins and were not detected on the microglia cell surface. These microglia-specific defects in envelope protein translocation and processing not only may have prevented formation of infectious virus particles but also may have caused further cellular defects in microglia with the consequence of indirect neuronal damage. It is conceivable that similar events play a role in neuro-AIDS.

scholarly journals What is in a Viral Stock: Perspectives and Current Limitations of Flow Virometry

2020 ◽  
Author(s):  
Timothy K. Soh ◽  
Jens B. Bosse
Keyword(s):  
Flow Cytometry ◽  
Full Potential ◽  
Multiple Objects ◽  
Virus Particles ◽  
Viral Particles ◽  
Viral Stock ◽  
Infected Cells ◽  
A Minor ◽  
Unique Capability

Herpesviruses produce a plethora of pleomorphic and heterogeneous particle populations. The composition and biological role of these is not understood. Detailed analysis has been challenging due to the lack of multidimensional identification and purification methodologies. Fluorescence-activated cell sorting (FACS), originally developed to sort objects with at least ten thousand-fold larger volumes, has recently been applied to cellular exosomes as well as viral particles and has been dubbed nanoscale flow cytometry or &ldquo;flow virometry&rdquo;. In comparison to other nanoparticles, herpesvirus concentrations can be measured with high precision using simple culturing methods. Here, we used this unique capability to evaluate a standard FACS sorter. We demonstrate that detection and separation capabilities were insufficient to distinguish infectious fluorescent viral populations from populations lacking fluorescence and infectivity. Moreover, fluorescent populations did not contain single virus particles but mostly aggregates. On top, analysis of viral samples by flow cytometry was confounded by swarm detection, as multiple objects are measured simultaneously and interpreted as a single object. Despite these technical difficulties, comparison of crude supernatant to gradient purified HCMV revealed that infectious virus is a minor proportion of the particles released from infected cells. Our data stress the need for a set of standardized controls and protocols when applying FACS to biological nanoparticles and highlights technical challenges that need to be solved before flow virometry can achieve its full potential.

scholarly journals Broncho-alveolar inflammation in COVID-19 patients: a correlation with clinical outcome

2020 ◽  
Author(s):  
laura pandolfi ◽  
Fossali Tommaso ◽  
Frangipane Vanessa ◽  
Bozzini Sara ◽  
Morosini Monica ◽  
...  
Keyword(s):  
Clinical Outcome ◽  
Mononuclear Cells ◽  
Severe Pneumonia ◽  
Nasopharyngeal Swab ◽  
Icu Patients ◽  
Transmission Microscopy ◽  
Inflammatory Status ◽  
Viral Particles ◽  
A Prospective Study ◽  
Electron Transmission Microscopy

Abstract Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly reached pandemic proportions. Given that the main target of SARS-CoV-2 are lungs leading to severe pneumonia with hyperactivation of the inflammatory cascade, we conducted a prospective study to assess alveolar inflammatory status in patients with moderate to severe COVID-19. Methods: Diagnostic bronchoalveolar lavage (BAL) was performed in 33 adult patients with SARS-CoV-2 infection by real-time PCR on nasopharyngeal swab admitted to the Intensive care unit (ICU) (n=28) and to the Intermediate Medicine Ward (IMW) (n=5). We analyze the differential cell count, ultrastructure of cells and Interleukin(IL)6, 8 and 10 levels.Results: ICU patients showed a marked increase in neutrophils (1.24 x 105 ml-1 , 0.85-2.07), lower lymphocyte (0.97 x 105 ml-1, 0.024-0.34) and macrophages fractions (0.43 x 105 ml-1, 0.34-1.62) compared to IMW patients (0.095 x 105 ml-1, 0.05-0.73; 0.47 x 105 ml-1, 0.28-1.01 and 2.14 x 105 ml-1, 1.17-3.01, respectively) (p<0.01). Study of ICU patients BAL by electron transmission microscopy showed viral particles inside mononuclear cells confirmed by immunostaining with anti-viral capsid and spike antibodies. IL6 and IL8 were significantly higher in ICU patients than in IMW (IL6 p<0.01, IL8 p<0.0001), and also in patients who did not survive (IL6 p < 0.05, IL8 p = 0.05 vs. survivors). IL10 did not show a significant variation between groups. Dividing patients by treatment received, lower BAL concentrations of IL6 were found in patients treated with steroids as compared to those treated with tocilizumab (p<0.1) or antivirals (p<0.05). Conclusions: Alveolitis, associated with COVID-19, is mainly sustained by innate effectors which showed features of extensive activation. The burden of pro-inflammatory cytokines IL6 and IL8 in the broncho-alveolar environment is associated with clinical outcome.

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