To date, there have been conflicting reports on the survivability of SARS-CoV-2 on fomite surfaces. This study, reported in Virology Journal, provides stability data under controlled temperature and 50 per cent relative humidity conditions.
Common surface types were inoculated with viral loads broadly equivalent to the highest titres excreted by infectious patients (3.38 × 105/10 µL) included polymer banknotes, de-monetised paper banknotes, brushed stainless steel, glass, vinyl and cotton cloth. All experiments were carried out in the dark at 20, 30 and 40oC, at various time points of 1 hour, 1, 2, 3, 4, and 7 days.
Decimal reduction time (D-values), temperature change required to achieve a 10-fold change in the D-value (Z-values) and half-lives were calculated.
Half-lives of between 1.7 and 2.7 days at 20 °C, were reported, which reduced to a few hours when the temperature was elevated to 40°C. Viable virus was isolated for up to 28 days at 20°C from common surfaces such as glass, stainless steel and both paper and polymer banknotes. Conversely, infectious virus survived less than 24 h at 40°C on some surfaces.
The report concludes that SARS-CoV-2 may remain infections for significantly longer periods than considered possible, and could inform increased risk mitigation procedures.