Transmission Routes
Previous studies showed that corona virus can survived only 2 days in hospital wastewater and in dechlorinated tap water at 20° C [34]
WHO reported that COVID-19 has not been discovered in drinking-water fittings, and the risk to water supplies is low [35].Laboratory studies demonstrated that the water contaminated with feces of infected patients could promote the survival of the virus for days to weeks [36]. Besides transmitting by droplet, the oral-fecal route is considered as a crucial route to spread the virus. Earlier, SARA-CoV and MERS-CoV are proved to transmit by stools. Thus, it is possible to transmit SARS-CoV-2 via the fecal-oral route. Therefore, it is crucial to get rid of patients’ fecal in an exceedingly hygienic way. [37, 38]. Wei Luo et al; reported that there is no relationship between absolute humidity and transmission of COVID-19 [39].
Lately, one study showed that SARS-COV2 still in the aerosol for 3h ,72h on plastic, and for 48h on stainless steel, no viable SARS-COV2 was measured on copper and cardboard after 4h, 24h respectively[40].
In addition, the novel coronavirus stayed for up to seven days on the outer layer of a surgical mask and for two days on a cloth, but the virus was killed in three hours on printing paper like newspapers [41].
As for SARS-COV1 it had a half-life approximately 1.1 to 1.2 in aerosols, and no viable SARS-COV1 was measured after 8h on copper and cardboard ,therefore it was stayed up to 72h on plastic, and for 48h on stainless steel. Similar to SARS-COV2 in this surfaces. [40]
It still may be contagious for 2 h-9 days. however, this can be related to the temperature of the environment for instance 30°C to 40°C can decrease the period of presence. on the contrary, 4°C would raise the period of persistence to over than 28 days.[42]
Table (1): persistence of some strain of SARS-COV on some surfaces.