No abstract

Background 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 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 two visits two days apart. We quantified and sequenced viral RNA, cultured virus, and assayed sera for anti-spike and anti-receptor binding domain antibodies. Results We enrolled 49 seronegative cases (mean days post onset 3.8 ±2.1), May 2020 through April 2021. We detected SARS-CoV-2 RNA in 45% of fine (≤5 µm), 31% of coarse (>5 µm) aerosols, and 65% of fomite samples overall and in all samples from four 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. Conclusion 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.

Background: SARS-CoV-2 epidemiology implicates airborne transmission; mask source-control efficacy for, variant impact on, and infectiousness of aerosols are not well understood. Methods: We recruited 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 two visits two days apart. We quantified and sequenced viral RNA, cultured virus, and assayed sera for anti-spike and anti-receptor binding domain antibodies. Results: We enrolled 61 participants with active infection, May 2020 through April 2021. Among 49 seronegative cases (mean days post onset 3.8 ±2.1), we detected SARS-CoV-2 RNA in 45% of fine (≥5 μm), 31% of coarse (>5 μm) aerosols, and 65% of fomite samples overall and in all samples from four 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. The alpha variant was associated with a 43-fold (95% CI, 6.6 to 280-fold) increase in fine aerosol viral RNA that remained a significant 18-fold (95% CI, 3.4 to 92-fold) increase adjusting for viral RNA in saliva, in mid-turbinate swabs, and other potential confounders. Two fine aerosol samples, collected days 2-3 post illness onset, while participants wore masks, were culture-positive. Conclusion: SARS-CoV-2 is evolving toward more efficient airborne transmission 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.

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.

Magnetic stimulation (MS) is a novel approach for treating urinary incontinence (UI), but its applicability remains unclear. This systematic review and meta-analysis were conducted to evaluate the effects of MS treatment on UI. A literature search was performed in EMBASE, PubMed and Cochrane Library (from May 2018 to August 2018), and all randomized control trials (RCTs) published in English were screened to determine whether they met the inclusion criteria. A manual search of the reference lists of the retrieved studies was also performed. Eleven studies involving 612 patients were included in this review. According to the results of the meta-analysis, MS therapy relieved UI symptoms evaluated using the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) score (mean difference [MD] −3.03, 95% CI −3.27 to −2.79). In addition, the frequency of UI in the MS treatment group was also alleviated compared with sham group (MD −1.42, 95% CI −2.15 to −0.69). Finally, MS treatment improved the quality of life of patients with UI (standardized mean difference [SMD] −1.00, 95% CI −1.24 to −0.76). Our meta-analysis preliminarily indicates that MS treatment is an effective therapeutic modality for patients with UI. Nevertheless, additional large, high quality RCTs with a longer follow-up period that use consistent stimulation methods and analyse comparable outcomes are required to validate the efficacy.