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Severe Acute Respiratory Syndrome Coronavirus 1 (SARS-CoV-1) infections almost always caused overt symptoms, so effective case and contact management enabled its effective eradication within months. However, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) usually causes only mild symptoms, so transmission chains may grow to include several individuals before at least one index case becomes ill enough to self-report for diagnosis and care. Here, simple mathematical models were developed to evaluate the implications of delayed index case detection for retrospective contact tracing and management responses. Specifically, these simulations illustrate how: (1) Contact tracing and management may effectively contain most but not all large SARS-CoV-2 clusters arising at foci with high reproduction numbers because rapidly expanding transmission chains ensure at least one overtly symptomatic index case occurs within two viral generations a week or less apart. (2) However, lower reproduction numbers give rise to thinner transmission chains extending through longer sequences of non-reporting asymptomatic and paucisymptomatic individuals, often spanning three or more viral generations (≥2 weeks of transmission) before an overtly symptomatic index case occurs. (3) Consequently, it is not always possible to fully trace and contain such long, thin transmission chains, so the community transmission they give rise to is underrepresented in surveillance data. (4) Wherever surveillance systems are weak and/or transmission proceeds within population groups with lower rates of overt clinical symptoms and/or self-reporting, case and contact management effectiveness may be more severely limited, even at the higher reproduction numbers associated with larger outbreaks. (5) Because passive surveillance platforms may be especially slow to detect the thinner transmission chains that occur at low reproduction numbers, establishing satisfactory confidence of elimination may require that no confirmed cases are detected for two full months, throughout which presumptive preventative measures must be maintained to ensure complete collapse of undetected residual transmission. (6) Greater scope exists for overcoming these limitations by enhancing field surveillance for new suspected cases than by improving diagnostic test sensitivity. (7) While population-wide active surveillance may enable complete traceability and containment, this goal may also be achievable through enhanced passive surveillance for paucisymptomatic infections, combining readily accessible decentralized testing with population hypersensitization to self-reporting with mild symptoms. Containment and elimination of SARS-CoV-2 will rely far more upon presumptive, population-wide prevention measures than was necessary for SARS-CoV-1, necessitating greater ambition, political will, investment, public support, persistence and patience. Nevertheless, case and contact management may be invaluable for at least partially containing SARS-CoV-2 transmission, especially larger outbreaks, but only if enabled by sufficiently sensitive surveillance. Furthermore, consistently complete transmission chain containment may be enabled by focally enhanced surveillance around manageably small numbers of outbreaks in the end stages of successful elimination campaigns, so that their endpoints may be accelerated and sustained.

Aim and Objective: One of the challenges we are currently facing is the COVID-19 pandemic. With its rapid spread around the world, it has become an unprecedented major health, human, and financial crisis. The saliva of COVID-19 patients contains the virus that can be transmitted. Various studies have shown the effect of mouthwashes in reducing the rate of transmission of the virus and, consequently, reducing the likelihood of infection. Therefore, we considered it important to examine the effect of using different mouthwashes by studying the existing data and articles. Materials and Methods: The study was conducted by the review method. The keywords “coronavirus, SARS-CoV-2, COVID-19, mouthwash, hydrogen Peroxide, chlorhexidine, povidone- iodine, cetylpyridinium chloride” were searched in articles and protocols in the following databases: PubMed, Scopus, Embase, Dimensions. The searched articles were submitted from January 2019 to April 2021. Only the articles in English were studied. Results: Among 23 reviewed studies, there were 15 review study, 4 in vitro study, two clinical trial, one letter to the editor in chief, and two studies that are, in fact, instructions of Australian and American dental community. 4 studies were published in 2021, 18 articles in 2020, and 1 article in 2019. By investigating 16 reports, Povidone-Iodine mouth wash was the most effective mouthwash ever mentioned. Hydrogen peroxide mouth rinse with nine mentions, chlorohexidine with seven mentions, cetylpyridinium chloride with four mentions, Essential oils with three mentions, and mouth rinses contains Citrox and beta-cyclodextrin, and Methylene blue with one mention was ranked next. Generally, most of the studies have recommended mouth rinses use in patients in dental clinics (or other recipients of health care services). They have emphasized their effectiveness in reducing the viral load in saliva and oral secretions. Conclusion: The results of the review showed that povidone-iodine mouthwash and hydrogen peroxide mouthwash can be the first and the second candidates to reduce viral load and, consequently, reduce disease transmission. However, more clinical studies are needed to confirm the results. Keywords: Coronavirus; Covid 2019; SARS2, SARS-CoV-2; Severe acute respiratory syndrome coronavirus 2; Coronavirus infection; Covid-19, 2019 novel coronavirus disease; SARS-CoV-2 infection; COVID-19 virus disease; 2019 novel coronavirus infection; 2019-nCoV infection; Coronavirus disease 2019; Coronavirus disease-19, 2019-nCoV; SARS-CoV-2; Novel cov; Sars cov2; Mouthwash; Mouth rinse; Hydrogen peroxide; Chlorhexidine; Povidone-iodine; Cetylpyridinium chloride.

As every country in the world struggles with the ongoing COVID-19 pandemic, it is essential that as many people as possible understand the epidemic containment, elimination and exclusion strategies required to tackle it. Simplified arithmetic models of COVID-19 transmission, control and elimination are presented in user-friendly Shiny and Excel formats that allow non-specialists to explore, query, critique and understand the containment decisions facing their country and the world at large. Although the predictive model is broadly applicable, the simulations presented are based on parameter values representative of the United Republic of Tanzania, which is still early enough in its epidemic cycle and response to avert a national catastrophe. The predictions of these models illustrate (1) why ambitious lock-down interventions to crush the curve represent the only realistic way for individual countries to contain their national-level epidemics before they turn into outright catastrophes, (2) why these need to be implemented so early, so stringently and for such extended periods, (3) why high prevalence of other pathogens causing similar symptoms to mild COVID-19 precludes the use of contact tracing as a substitute for lock down interventions to contain and eliminate epidemics, (4) why partial containment strategies intended to merely flatten the curve, by maintaining epidemics at manageably low levels, are grossly unrealistic, and (5) why local elimination may only be sustained after lock down ends if imported cases are comprehensively excluded, so international co-operation to conditionally re-open trade and travel between countries certified as free of COVID-19 represents the best strategy for motivating progress towards pandemic eradication at global level. The three sequential goals that every country needs to emphatically embrace are contain, eliminate and exclude. As recently emphasized by the World Health Organization, success will require widespread genuine national unity and unprecedented global solidarity.

Countries with ambitious national strategies to crush the curve of their Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) epidemic trajectories include China, Korea, Japan, Taiwan, New Zealand and Australia. However, the United States and many hard-hit European countries, like Ireland, Italy, Spain, France and the United Kingdom, currently appear content to merely flatten the curve of their epidemic trajectories so that transmission persists at rates their critical care services can cope with. Here I present a simple set of arithmetic modelling analyses that are accessible to non-specialists and explain why preferable crush the curve strategies, to eliminate transmission within months, would require only a modest amount of additional containment effort relative to the tipping point targeted by flatten the curve strategies, which allow epidemics to persist at supposedly steady, manageable levels for years, decades or even indefinitely.

There is an urgent need for antivirals to treat the newly emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To identify new candidates, we screen a repurposing library of ∼3,000 drugs. Screening in Vero cells finds few antivirals, while screening in human Huh7.5 cells validates 23 diverse antiviral drugs. Extending our studies to lung epithelial cells, we find that there are major differences in drug sensitivity and entry pathways used by SARS-CoV-2 in these cells. Entry in lung epithelial Calu-3 cells is pH independent and requires TMPRSS2, while entry in Vero and Huh7.5 cells requires low pH and triggering by acid-dependent endosomal proteases. Moreover, we find nine drugs are antiviral in respiratory cells, seven of which have been used in humans, and three are US Food and Drug Administration (FDA) approved, including cyclosporine. We find that the antiviral activity of cyclosporine is targeting Cyclophilin rather than calcineurin, revealing essential host targets that have the potential for rapid clinical implementation. [Display omitted] • 3,000 compounds screened in two cell types against SARS-CoV-2 • Entry pathways are distinct in hepatocyte Huh7.5 and respiratory Calu-3 cells • Only nine compounds that are active in Huh7.5 cells are active in Calu-3 cells • Cyclosporin and cyclophilin inhibitors block SARS-CoV-2 infection in diverse cells There is an urgent need for antivirals to treat the newly emerged SARS-CoV-2. Dittmar et al. find nine host-directed drugs are antiviral in respiratory cells, seven of which have been given to humans, and three are FDA approved. We show host targets that have the potential for rapid clinical implementation. [ABSTRACT FROM AUTHOR]