Factors affecting stability and infectivity of SARS-CoV-2

Abstract

Background: In late 2019, a novel human coronavirus e severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) e emerged in Wuhan, China. This virus has caused a global pandemic involving more than 200 countries. SARS-CoV-2 is highly adapted to humans and readily transmits from person-to-person. Aim: To investigate the infectivity of SARS-CoV-2 under various environmental and pH conditions. The efficacies of various laboratory virus inactivation methods and home disinfectants against SARS-CoV-2 were investigated. Methods: The residual virus in dried form or in solution was titrated on to Vero E6 cells on days 0, 1, 3, 5 and 7 after incubation at different temperatures. Viral viability was determined after treatment with various disinfectants and pH solutions at room temperature (20e25 o C). Findings: SARS-CoV-2 was able to retain viability for 3e5 days in dried form or 7 days in solution at room temperature. SARS-CoV-2 could be detected under a wide range of pH conditions from pH 4 to pH 11 for several days, and for 1e2 days in stool at room temperature but lost 5 logs of infectivity. A variety of commonly used disinfectants and laboratory inactivation procedures were found to reduce viral viability effectively. Conclusion:This study demonstrated the stability of SARS-CoV-2 on environmental surfaces, and raises the possibility of faecaleoral transmission. Commonly used fixatives, nucleic acid extraction methods and heat inactivation were found to reduce viral infectivity significantly, which could ensure hospital and laboratory safety during the SARS-CoV-2 pandemic.

Microbicidal actives with virucidal efficacy against SARS-CoV-2 and other beta- and alpha-coronaviruses: implications for future emerging coronaviruses and other enveloped viruses

“…The data on the survival of SARS-CoV-2 on surfaces [14][15][16][17][18][19][20][21]41 , like previous data obtained for other coronaviruses [41][42][43][44][45][46][47][48][49] , demonstrate that viral persistence (survival) on HITES is dependent upon: 1) the type of surface, 2) the presence and type of organic matrix in which the virus is suspended at the time of deposition and drying upon the surface, and 3) time. The survival data for SARS-CoV-2 dried on surfaces (Table 1) indicate that the virus remains infectious longer on hard non-porous surfaces, such as plastic and stainless steel, than on wood or cardboard.…”

“…Zang et al 34 , upon being unable to recover infectious SARS-CoV-2 from RNA-positive human fecal samples, have argued that the virus is rapidly inactivated by simulated human colonic uid. This conclusion is not consistent, however, with the ndings of Xiao et al 32 or Zhang et al 33 , who were able to recover infectious SARS-CoV-2 from human feces reviewed in 35 , or with the reports of Liu et al 20 and Chan et al 21 that SARS-CoV-2 remains infectious for hours in human fecal suspensions. The conclusion is also not consistent with results obtained for other coronaviruses, such as SARS-CoV and MERS-CoV 35 .…”

“…Survival of SARS-CoV-2 on inanimate surfaces (prototypic HITES) and animate surfaces (swine skin). Several studies of the survival (persistence of infectivity) of SARS-CoV-2 experimentally dried on prototypic HITES, or added to human secretions/excretions or swine skin have been reported in the recent literature [14][15][16][17][18][19][20][21] . These studies have evaluated the recovery of infectious SARS-CoV-2 from hard non-porous surfaces (such as steel and glass), from relatively porous surfaces (such as wood and cardboard), or from skin or within bodily secretions/excretions.…”

“…Unfortunately, there are, to our knowledge, no data on the detection or persistence of infectious SARS-CoV-2 in wastewater, and this topic, therefore, remains a knowledge gap 35,39,40 . For the moment, on the basis of the reported survival of SARS-CoV-2 in human fecal suspensions and urine 20,21 , we assume the possibility of the contamination of wastewater streams with infectious SARS-CoV-2, and associated risk of virus dissemination through this route.…”

“…Temperature and relative humidity likely also play a role in the persistence of coronaviruses on HITES, although the data sets appearing in the literature speci cally for SARS-CoV-2 [14][15][16][17][18][19][20][21] have primarily evaluated survival under ambient conditions. For survival dependence on temperature, see references 17,19,21,41 .…”