Continuously active disinfectant inactivates severe acute respiratory coronavirus virus 2 (SARS-CoV-2) and human coronavirus 229E two days after the disinfectant was applied and following wear exposures.

The surface environment in rooms of coronavirus disease 2019 (COVID-19) patients may be persistently contaminated despite disinfection. A continuously active disinfectant demonstrated excellent sustained antiviral activity following a 48-hour period of wear and abrasion exposures with reinoculations. Reductions of >4-log10 were achieved within a 1-minute contact time for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) and the human coronavirus, 229E.

Transfer efficiency of an enveloped virus, human coronavirus 229E, from various hard surface fomites to finger pads of the hands.

Respiratory viruses can be transmitted by fomite contact, but no data currently exist on the transfer of enveloped viruses. The transfer efficiency of human coronavirus from various hard surfaces ranged from 0.46% to 49.0%. This information can be used to model the fomite transmission of enveloped viruses.

Survival of SARS-CoV-2 in wastewater.

The ongoing pandemic of Coronavirus disease 2019 (COVID-19) has affected >600 million people with >6 million deaths. Although Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2), the etiologic agent of COVID-19, is transmitted via respiratory droplets or direct contact, isolation of viable SARS-CoV-2 in feces has been reported. Therefore, there is a need for understanding the persistence of SARS-CoV-2 and emerging variants in wastewater. In this study, the survival of SARS-CoV-2 isolate hCoV-19/USA-WA1/2020 was observed in three wastewater matrices - filtered and unfiltered raw wastewater, and secondary effluent. All experiments were conducted within a BSL-3 laboratory at room temperature. The time required for inactivation of 90 % (T90) of SARS-CoV-2 was 10.4, 10.8, and 18.3 h for unfiltered raw, filtered raw, and secondary effluent, respectively. Progressive decline in infectivity of the virus following first order kinetics was noted in these wastewater matrices. To the best of our knowledge, this is the first study to describe the survival of SARS-CoV-2 in secondary effluent.

In vitro antiviral effect of Mexican and Brazilian propolis and phenolic compounds against human coronavirus 229E.

Propolis is a resinous substance collected by bees (Apis mellifera). It is used for its biological properties. This natural product is available as a safe therapeutic option. Herein, we report the antiviral effects of brown propolis extract from Mexico and green and red propolis extracts from Brazil, as well as their phenolic compounds (quercetin, caffeic acid, and rutin) in preventing infection of MRC-5 cells by HCoV-229E. Normal human fibroblast lung cells (MRC-5) were used to determine the cytotoxicity of the compounds. All samples studied showed antiviral activity. Green and brown propolis extracts, and quercetin exhibited the best EC50 values with values of 19.080, 11.240, and 77.208 µg/mL against HCoV-229E, respectively, and with TC50 of 62.19, 29.192, and 298 µg/mL on MRC-5 cells, respectively. These results are the first in vitro study of the effects of propolis on HCoV-229E and provide the basis for the development of natural formulations against other coronavirus strains.

Efficacy of an antimicrobial surface coating against human coronavirus 229E and SARS-CoV-2.

The COVID-19 pandemic has accelerated the demand for alternatives to standard cleaning and disinfection practices. Antiviral coatingsmay provide an alternative to common surface treatments. A newly developed quaternary ammonium polymer coating was applied to stainless steel coupons and evaluated for efficacy against human coronavirus 229E and SARS-CoV-2. The polymer coating reduced levels of both test viruses by greater than 99.9% relative to non-coated stainless steel coupons during a 2-hour contact time.