The advent of severe acute respiratory syndrome and its potential environmental transmission indicates the need for more information on the survival of coronavirus in water and wastewater. The survival of representative coronaviruses, feline infectious peritonitis virus, and human coronavirus 229E was determined in filtered and unfiltered tap water (4 and 23°C) and wastewater (23°C). This was compared to poliovirus 1 under the same test conditions. Inactivation of coronaviruses in the test water was highly dependent on temperature, level of organic matter, and presence of antagonistic bacteria. The time required for the virus titer to decrease 99.9% (T 99.9 ) shows that in tap water, coronaviruses are inactivated faster in water at 23°C (10 days) than in water at 4°C ([100 days). Coronaviruses die off rapidly in wastewater, with T 99.9 values of between 2 and 4 days. Poliovirus survived longer than coronaviruses in all test waters, except the 4°C tap water.
Effective disinfection technology to combat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can help reduce viral transmissions during the on-going COVID-19 global pandemic and in the future. Ultraviolet (UV) devices emitting UVC irradiation (200-280 nm) have proven to be effective for virus disinfection, but limited information is available for SARS-CoV-2 due to the safety requirements of testing, which is limited to biosafety level (BSL) 3 laboratories. In this study, inactivation of SARS-CoV-2 in thin-film buffered aqueous solution (pH 7.4) was determined across UVC irradiation wavelengths (222 nm to 282 nm) from krypton chloride (KrCl*) excimers, a low-pressure mercury-vapor lamp, and two UVC light emitting diodes. Our results show that all tested UVC devices can effectively inactivate SARS-CoV-2, among which the KrCl* excimer had the best disinfection performance (i.e., highest inactivation rate). The inactivation rate constants of SARS-CoV-2 across wavelengths are similar to those for murine hepatitis virus (MHV) from our previous investigation, suggesting that MHV can serve as a reliable surrogate of SARS-CoV-2 with a lower BSL requirement (BSL-2) during UV disinfection tests. This study provides fundamental information for UVC action on SARS-CoV-2 and guidance for achieving reliable disinfection performance of UVC devices. IMPORTANCE UV light is an effective tool to help stem the spread of respiratory viruses and protect public health in commercial, transportation and healthcare settings. For effective use of UV, there is a need to determine the efficiency of different UV wavelengths in killing pathogens, specifically SARS-CoV-2, to support efforts to control the on-going COVID-19 global pandemic and future coronavirus-caused respiratory virus pandemics. We found that SARS-CoV-2 can be inactivated effectively using a broad range of UVC wavelengths, and 222nm provided the best disinfection performance. Interestingly, 222 nm irradiation has been found to be safe for human exposure up to thresholds that are beyond effective for inactivating viruses. Therefore, applying UV light from KrCl* excimers in public spaces can effectively help reduce viral aerosol or surface transmissions.
Ultraviolet (UV) devices emitting UVC irradiation (200− 280 nm) have proven to be effective for virus disinfection, especially on surfaces and in air, due to their rapid effectiveness and limited to no material corrosion. Numerous studies of UV-induced inactivation focused on nonenveloped viruses. Little is known about UVC action on enveloped viruses across UVC wavelengths. In this study, we determined inactivation efficiencies of two coronaviruses (ssRNA) and an enveloped dsRNA bacteriophage surrogate in buffered aqueous solution (pH 7.4) using five commonly available UVC devices that uniquely emit light at different wavelengths spanning 222 nm emitting krypton chloride (KrCl*) excimers to 282 nm emitting UVC LEDs. Our results show that enveloped viruses can be effectively inactivated using UVC devices, among which the KrCl* excimer had the best disinfection performance (i.e., highest inactivation rate) for all three enveloped viruses. The coronaviruses exhibited similar sensitivities to UV irradiation across the UVC range, whereas the bacteriophage surrogate was much more resistant and exhibited significantly higher sensitivity to the Far UVC (<230 nm) irradiation. This study provides necessary information and guidance for using UVC devices for enveloped virus disinfection, which may help control virus transmission in public spaces during the ongoing COVID-19 pandemic and beyond.
The antiviral properties of zeolite (sodium aluminosilicate) powders amended with metal ions were assessed using human coronavirus 229E, feline infectious peritonitis virus (FIPV), and feline calicivirus F-9. Zeolites containing silver and silver/copper caused significant reductions of coronavirus 229E after 1 h in suspension. The silver/copper combination yielded a [5.13-log 10 reduction within 24 h. It was also the most effective ([3.18-log 10 ) against FIPV after 4 h. Other formulations were ineffective against FIPV. On plastic coupons with incorporated silver/ copper-zeolites, [1.7-log 10 and [3.8-log 10 reductions were achieved for coronavirus 229E and feline calicivirus within 24 h, respectively. Silver/copper zeolite reduced titers of all viruses tested, suggesting that it may be effective against related pathogens of interest [i.e., SARS coronavirus, other coronaviruses, human norovirus (calicivirus)]. Of note, it was effective against both enveloped and nonenveloped viruses. Metal-zeolites could therefore possibly be used in applications to reduce virus contamination of fomites and thus the spread of viral diseases.
Objectives To explore the symptom trajectory during the first 16 months of childhood leukemia treatment and any associations with the oxidative stress pathway measured by cerebral spinal fluid (CSF) concentration of oxidized phosphatidylcholine (PC), the predominant glycerophospholipid in the brain and cell membranes. Design Prospective longitudinal design. Sample and Setting Thirty-six children with newly diagnosed ALL between 2 years 9 months and 15 years of age at diagnosis 2 cancer centers in the Southwestern United States. Methods Symptoms were measured using the Memorial Symptom Assessment Scale at six specific time points during treatment. Biochemical changes in oxidative stress were measured by oxidized PC in the CSF. Main Research Variables Childhood cancer symptoms, oxidized PC. Results Significant differences were found in the number of symptoms experienced during the three phases of treatment. Symptom trajectory changes and influence of the oxidative stress pathway on symptom experiences were identified. Conclusions Symptoms experienced during treatment for childhood leukemia are associated with increased oxidative stress. Implications for Practice Children with leukemia experience symptoms throughout treatment. Physiologic measures indicate the influence of the oxidative stress on symptoms.
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