Relative efficacy of masks and respirators as source control for viral aerosol shedding from people infected with SARS-CoV-2: a controlled human exhaled breath aerosol experimental study.

BACKGROUND: Tight-fitting masks and respirators, in manikin studies, improved aerosol source control compared to loose-fitting masks. Whether this translates to humans is not known. METHODS: We compared efficacy of masks (cloth and surgical) and respirators (KN95 and N95) as source control for SARS-CoV-2 viral load in exhaled breath of volunteers with COVID-19 using a controlled human experimental study. Volunteers (N = 44, 43% female) provided paired unmasked and masked breath samples allowing computation of source-control factors. FINDINGS: All masks and respirators significantly reduced exhaled viral load, without fit tests or training. A duckbill N95 reduced exhaled viral load by 98% (95% CI: 97%-99%), and significantly outperformed a KN95 (p < 0.001) as well as cloth and surgical masks. Cloth masks outperformed a surgical mask (p = 0.027) and the tested KN95 (p = 0.014). INTERPRETATION: These results suggest that N95 respirators could be the standard of care in nursing homes and healthcare settings when respiratory viral infections are prevalent in the community and healthcare-associated transmission risk is elevated. FUNDING: Defense Advanced Research Projects Agency, National Institute of Allergy and Infectious Diseases, Centers for Disease Control and Prevention, the Bill & Melinda Gates Foundation, and The Flu Lab.

BBX24 Increases Saline and Osmotic Tolerance through ABA Signaling in Arabidopsis Seeds.

Seed germination is a critical stage for survival during the life cycle of an individual plant. Genetic and environmental cues are integrated by individual seeds to determine germination, mainly achieved through regulation of the metabolism and signaling of gibberellins (GA) and abscisic acid (ABA), two phytohormones with antagonistic roles. Saline and drought conditions can arrest the germination of seeds and limit the seedling emergence and homogeneity of crops. This work aimed to study the function of BBX24, a B-Box transcription factor, in the control of germination of Arabidopsis thaliana seeds imbibed in saline and osmotic conditions. Seeds of mutant and reporter GUS lines of BBX24 were incubated at different doses of NaCl and polyethylene-glycol (PEG) solutions and with ABA, GA and their inhibitors to evaluate the rate of germination. We found that BBX24 promotes seed germination under moderated stresses. The expression of BBX24 is inhibited by NaCl and PEG. In addition, ABA suppresses BBX24-induced seed germination. Additional experiments suggest that BBX24 reduces ABA sensitivity, improving NaCl tolerance, and increases GA sensitivity in seeds imbibed in ABA. In addition, BBX24 inhibits the expression of ABI3 and ABI5 and genetically interacts upstream of HY5 and ABI5. This study demonstrates the relevance of BBX24 to induce drought and salinity tolerance in seed germination to ensure seedling emergence in sub-optimal environments.

Exhaled Breath Aerosol Shedding of Highly Transmissible Versus Prior Severe Acute Respiratory Syndrome Coronavirus 2 Variants.

BACKGROUND: Aerosol inhalation is recognized as the dominant mode of severe acute respiratory syndrome coronavirus 2 (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: Individuals with coronavirus disease 2019 (COVID-19) (n = 93; 32 vaccinated and 20 boosted) were recruited to give samples, including 30-minute breath samples into a Gesundheit-II EBA sampler. Samples were quantified for viral RNA using reverse-transcription polymerase chain reaction and cultured for virus. RESULTS: Alpha (n = 4), Delta (n = 3), and Omicron (n = 29) cases shed significantly more viral RNA copies into EBAs 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 1 boosted and 3 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.

Acute pericarditis as a clinical manifestation in COVID-19 infection in a district hospital setting.

The global outbreak of coronavirus disease 2019(COVID-19) pandemic has heavily impacted the health service, leading to increased mortality and morbidity. Although known to manifest primarily as a respiratory illness, there are reports of cardiac involvement as extrapulmonary manifestation. We are reporting a case of pericarditis in a young patient who presented with only cardiac symptoms in COVID-19. He was admitted to the hospital for observation and treated with oral colchicine and oral ibuprofen. His conditions improved and subsequently discharged well. Acute pericarditis can present as part of the COVID-19 extrapulmonary spectrum. Therefore, it is important and challenging for clinicians to recognise the atypical presentations of COVID-19 to reduce morbidity and mortality.

Comparison of Saliva and Midturbinate Swabs for Detection of SARS-CoV-2.

Saliva is an attractive sample for detecting SARS-CoV-2. However, contradictory reports exist concerning the sensitivity of saliva versus nasal swabs. We followed close contacts of COVID-19 cases for up to 14 days from the last exposure and collected self-reported symptoms, midturbinate swabs (MTS), and saliva every 2 or 3 days. Ct values, viral load, and frequency of viral detection by MTS and saliva were compared. Fifty-eight contacts provided 200 saliva-MTS pairs, and 14 contacts (13 with symptoms) had one or more positive samples. Saliva and MTS had similar rates of viral detection (P = 0.78) and substantial agreement (κ = 0.83). However, sensitivity varied significantly with time since symptom onset. Early on (days -3 to 2), saliva had 12 times (95% CI: 1.2, 130) greater likelihood of viral detection and 3.2 times (95% CI: 2.8, 3.8) higher RNA copy numbers compared to MTS. After day 2 of symptoms, there was a nonsignificant trend toward greater sensitivity using MTS. Saliva and MTS demonstrated high agreement making saliva a suitable alternative to MTS for SARS-CoV-2 detection. Saliva was more sensitive early in the infection when the transmission was most likely to occur, suggesting that it may be a superior and cost-effective screening tool for COVID-19. IMPORTANCE The findings of this manuscript are increasingly important with new variants that appear to have shorter incubation periods emerging, which may be more prone to detection in saliva before detection in nasal swabs. Therefore, there is an urgent need to provide the science to support the use of a detection method that is highly sensitive and widely acceptable to the public to improve screening rates and early detection. The manuscript presents the first evidence that saliva-based RT-PCR is more sensitive than MTS-based RT-PCR in detecting SARS-CoV-2 during the presymptomatic period - the critical period for unwitting onward transmission. Considering other advantages of saliva samples, including the lower cost, greater acceptability within the general population, and less risk to health care workers, our findings further supported the use of saliva to identify presymptomatic infection and prevent transmission of the virus.

Infectious Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Exhaled Aerosols and Efficacy of Masks During Early Mild Infection.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemiology implicates airborne transmission; aerosol infectiousness and impacts of masks and variants on aerosol shedding are not well understood. METHODS: We recruited coronavirus disease 2019 (COVID-19) cases to give blood, saliva, mid-turbinate and fomite (phone) swabs, and 30-minute breath samples while vocalizing into a Gesundheit-II, with and without masks at up to 2 visits 2 days apart. We quantified and sequenced viral RNA, cultured virus, and assayed serum samples for anti-spike and anti-receptor binding domain antibodies. RESULTS: We enrolled 49 seronegative cases (mean days post onset 3.8 ±â€…2.1), May 2020 through April 2021. We detected SARS-CoV-2 RNA in 36% of fine (≤5 µm), 26% of coarse (>5 µm) aerosols, and 52% of fomite samples overall and in all samples from 4 alpha variant cases. Masks reduced viral RNA by 48% (95% confidence interval [CI], 3 to 72%) in fine and by 77% (95% CI, 51 to 89%) in coarse aerosols; cloth and surgical masks were not significantly different. The alpha variant was associated with a 43-fold (95% CI, 6.6- to 280-fold) increase in fine aerosol viral RNA, compared with earlier viruses, that remained a significant 18-fold (95% CI, 3.4- to 92-fold) increase adjusting for viral RNA in saliva, swabs, and other potential confounders. Two fine aerosol samples, collected while participants wore masks, were culture-positive. CONCLUSIONS: SARS-CoV-2 is evolving toward more efficient aerosol generation and loose-fitting masks provide significant but only modest source control. Therefore, until vaccination rates are very high, continued layered controls and tight-fitting masks and respirators will be necessary.

Marek's disease virus oncogene Meq expression in infected cells in vaccinated and unvaccinated hosts.

Marek's disease (MD) vaccines are unique in their capability to prevent MD lymphomas as early as a few days after vaccination, despite the fact that they do not eliminate virulent viruses from the host. To help understand the mechanism behind this unique MD vaccine effect, we compared the expression of MDV oncoprotein Meq among CD4+ T cells between vaccinated and unvaccinated birds. Chickens were vaccinated by an MD vaccine, herpesvirus of turkeys, and then challenged by a recombinant virulent MDV that expresses green fluorescent protein simultaneously with Meq. We found significantly fewer Meq-expressing CD4+ T cells appeared in peripheral blood mononuclear cells (PBMC) of the vaccinated birds compared to the unvaccinated birds as early as one week after the virulent virus challenge. In contrast, the quantity of virulent MDV genome remained similar in Meq- PBMC in both vaccinated and unvaccinated birds. Our results suggest that MD vaccination affects the dynamics of Meq-expressing, possibly transformed, cells while impact on the overall infection in the Meq- cells was not significant.

[Comparison of heart failure and COVID-19 in chest CT features and clinical characteristics].

Objective: To identify the characteristics including clinical features and pulmonary computed tomography (CT) features of heart failure and COVID-19. Methods: This study was a retrospective study. A total of 7 patients with heart failure and 12 patients with COVID-19 in the Second Xiangya Hospital of Central South University between December 1, 2019 and February 15, 2020 were enrolled. The baseline clinical and imaging features of the two groups were statistically analyzed. Results: There was no significant difference in age and sex between the two groups(both P>0.05), but the incidence of epidemiological contact history, fever or respiratory symptoms in the COVID-19 group was significantly higher than that in the heart failure group (12/12 vs. 0, P<0.001; 12/12 vs. 4/7, P=0.013). While the proportion of cardiovascular diseases and impaired cardiac function was significantly less than that of the heart failure group(2/12 vs.7/7, P<0.001；0 vs.7/7, P<0.001). For imaging features, both groups had ground-glass opacity and thickening of interlobular septum, but the ratio of central and gradient distribution was higher in patients with heart failure than that in patients with COVID-19 (4/7 vs. 1/12, P=0.04). In heart failure group, the ratio of the expansion of pulmonary veins was also higher (3/7 vs. 0，P=0.013), and the lung lesions can be significantly improved after effective anti-heart failure treatment. Besides, there were more cases with rounded morphology in COVID-19 group（9/12 vs. 2/7, P=0.048）. Conclusions: More patients with COVID-19 have epidemiological history and fever or respiratory symptoms. There are significant differences in chest CT features, such as enlargement of pulmonary veins, lesions distribution and morphology between heart failure and COVID-19.

Viral replication and innate immunity of feline herpesvirus-1 virulence-associated genes in feline respiratory epithelial cells.

Feline herpesvirus-1 (FHV-1) infection occurs worldwide and is a leading cause of respiratory and ocular diseases in cats. Current vaccines reduce the severity of symptoms but do not prevent infection and, therefore, do not provide defense against an establishment of latency and reactivation. We hypothesize that immunomodulation of FHV-1 is the cause of lack in protection and that deletion of virulence/immune modulatory genes of FHV-1 will enhance safety and immunogenicity. Our objective was to use feline respiratory epithelial cell (FREC) cultures to define in vitro growth characteristics and immunomodulation resulting from infection of FRECs with the virulent FHV-1 strain C27 (WT) and glycoprotein C-deletion (gC-), glycoprotein E-deletion (gE-), serine/threonine protein kinase-deletion (PK-), as well as gE and thymidine kinase-double-deletion (gE-TK-) mutants generated by bacterial artificial chromosome mutagenesis. Differentiated FRECs were mock inoculated or inoculated with WT, gC-, gE-, PK-, or gE-TK- mutants. Virus titration and real-time quantitative PCR assays were performed on samples collected at 1 hpi followed by 24 h intervals between 24 and 96 hpi to determine growth kinetics. Real-time PCR was used to quantitate IFNα, TNFα, IL-1ß, IL-10, and TGFß-specific mRNA levels. Immunoassays were performed to measure the protein levels of subsets of cytokines/chemokines secreted by FRECs. Inoculation of FRECs with gE-TK- resulted in significantly lower end-point titers than inoculation with WT or gE-. Both PK- and gC- inoculated FRECs also produced significantly lower end-point titers at 96 hpi than WT. Overall, intracellular virus titers were higher than those of extracellular virus. PCR results for viral DNA paralleled the virus titration results. Further, in contrast to WT inoculation, an increase in IFNα and IL-10 mRNA expression was not observed following inoculation with gE-TK- and PK-, but inoculation with gE-TK- and PK- did result in increased TGFß expression in FRECs compared to responses following infection with WT. Moreover, gE-TK- and PK- blocked the inhibition of IL-8 and neutrophil chemoattractant (KC), which was observed following inoculation with WT. In summary, the results obtained in FRECs may be used to predict the safety and immunogenicity characteristics of these mutants in vivo. Our study highlights the value of the FREC system for studying replication kinetics/immune modulation factors of FHV-1 and screening prospective vaccine candidates before their use in experimental cats.

[Risk factors for early death in acute myocardial infarction patients complicating with ventricular septal rupture].

Objective: To assess the clinical characteristics and identify the risk factors in the acute myocardial infarction (AMI) patients complicating with ventricular septal rupture (VSR). Methods: A retrospective study was performed on 96 AMI patients complicating with VSR, who were hospitalized in the Second Xiangya Hospital of Central South University, Hunan Provincial Peoples' Hospital, the First Affiliated Hospital of University of South China, the Second Affiliated hospital of University of south China, Xiangtan Central Hospital from December 2007 to May 2017. There were 46 females and the age was (66.2±10.7) years (from 43 to 90 years). Patients were divided into in-hospital survival group (n=64) and in-hospital death group (n=32). The 96 patients were also divided into the early death group (survived ≤2 weeks after admission, n=50) and non-early death group (survived>2 weeks after admission, n=46). Multivariate logistic regression was used to analyze the independent risk factors of the early death. Results: Location of VSR was available in 71 patients, VSR was located at the apical or anterior septum near the apical region in 64.0% (32/50) patients with the anterior AMI, VSR was located at the posterior wall and basal inferior segment in 57.1% (12/21) patients with non-anterior AMI. Compared to the in-hospital survival group, patients in the in-hospital death group were older ((69.6±11.3) years vs. (64.6±10.1) years, P=0.031), incidence of non-ventricular aneurysm (71.9% (23/32) vs. 37.5% (24/64), P=0.001) and anterior AMI (84.4%(27/32) vs. 62.5%(40/64), P=0.028) was significantly higher in the in-hospital death group than in the in-hospital survival group. The comparison between the early death group and non-early death group showed that older age, female, no history of angina or myocardial infarction, Killip grade>Ⅲ, and non-ventricular aneurysm were related to increased risk of the early mortality in this patient cohort. Logistic regression analysis revealed that female (OR=5.109,95%CI 1.19-22.00, P=0.012), no history of angina or myocardial infarction (OR=23.34, 95%CI 3.44-158.37, P=0.001), Killip grade>Ⅲ(OR=5.35, 95%CI 1.26-22.66, P=0.019) and non-ventricular aneurysm (OR=6.30,95%CI 1.67-23.73, P=0.005) were independent risk factors for early death in this patient cohort. Conclusion: The risk factors of in-hospital death include older age, non-ventricular aneurysm and anterior AMI. Female, no history of angina or myocardial infarction, Killip grade>Ⅲ and non-ventricular aneurysm are independent risk factors for the early death of AMI patients complicating VSR.

[Clinical evaluation of dry chemical enzyme method for detecting Neisseria gonorrhoeae and analysis of external quality assessment results].

Objective:Neisseria gonorrhoeae in female cervix sample was detected by dry chemical enzymatic method and culture method. The detection effects of two detection methods were analyzed to provide reference for clinical detection. At the same time, strains were separated and identified to evaluate reliability of different methods. Methods: During October 2015 to December 2017, 8 860 samples of female cervix from the Third Affiliated Hospital of Zhengzhou University and Henan Provincial Peoples Hospital were detected by dry chemical enzymatic method and culture method. Because of the possible leak detection by culture method, the inconsistent results were supplemented by real-time PCR assay. The data were analyzed by SPSS 19.0. Fifteen strains of external quality assessment of Neisseria gonorrhoeae identification and validation during 2015 to 2017 years were identified by latex chromatography, culture method, dry chemical enzyme method and PCR- fluorescent probe method. Results: The positive rates of dry chemical enzymatic method and culture method for detection of Neisseria gonorrhoeae were 0.88% (78/8 860) and 0.41% (36/8 860), respectively. Among these, 26 samples were tested positive by dry chemical enzymatic method which were consistent with real-time PCR assay. Meanwhile, the culture method was negative. Dry chemistry enzyme method external quality assessment results of 3 years were accurate. Conclusion: The positive rate of dry chemical enzymatic method was markedly higher than that of culture method (P<0.05). The dry chemical enzymatic method, while exhibiting a high specificity, had high detection rate compared to culture method. And external quality assessment results are accurate. The clinical coincidence rate of dry chemical enzymatic detection was higher.

Expression of Marek's Disease Virus Oncoprotein Meq During Infection in the Natural Host.

Gallid herpesvirus 2 (Marek's disease virus, MDV) causes lymphoproliferative Marek's disease (MD), and is unique among alphaherpesviruses as the viral genome encodes an oncoprotein, Meq. To elucidate the temporal relationship between Meq expression and the development of MD lymphomas in infected chickens, we generated a virulent recombinant MDV that expresses GFP simultaneously with Meq. By using this virus, we monitored the dynamics of Meq expression in vivo throughout the course of infection. In peripheral blood mononuclear cells, the percentage of Meq-expressing cells dramatically increased in the early latent phase but decreased thereafter. Furthermore, we discovered evidences that indicate some of the infected lymphocytes did not express Meq during the latent phase of MDV pathogenesis. These findings provide the first insight into the temporal relationship between Meq expression and MD progression, and new clues to refine the current MD pathogenesis model.