Robert-Koch-Institut about SARS-CoV-2 - Characteristics of COVID-19, released 2020-04-10
Robert Koch Institut
1. Transmission routes
In the general population (social interaction)
The main transmission route in the population seems to be droplet infection. Theoretically, contact transfer is also possible. [...]
Contact transmission: Transmission through contaminated surfaces cannot be ruled out, especially in the immediate vicinity of the infected person (10), since reproductive SARS-CoV-2 viruses can be detected in the environment under certain circumstances (3) (see point “Tenacity”). PCR-positive stool samples (11-13) were also occasionally identified in COVID-19 patients. Viruses must be able to reproduce in order to be infected via stool. So far, this has been shown in a study, but the evidence was rarely found there (14).
21. tenacity; Inactivation of the virus on surfaces
Aerosols: In a study with experimentally produced aerosols enriched with SARS-CoV-2 viruses, reproductive viruses were detectable in aerosol for up to three hours (see point “Transmission routes”) (3).
Surfaces: In the same study, it was also investigated how long reproductive SARS-CoV-2 viruses can be detected on various inanimate surfaces: the amounts of detectable viruses decreased exponentially under all experimental conditions. Viruses could no longer be detected on copper after four hours and on cardboard after 24 hours, while these were detectable on stainless steel (up to 48 hours) and plastic (up to 72 hours) significantly longer. However, the viral load examined was relatively low in these studies. In comparison, SARS-CoV-1 viruses were also examined in this way and reported that the detection periods were similar to those of SARS-CoV-2 (3).
The different inactivation kinetics on different materials also correspond to previous experiences with human pathogenic coronaviruses, which remained capable of reproduction for up to six days (SARS-CoV-1) on inanimate surfaces such as metal, glass or plastic (70). Due to the structural similarity of SARS-CoV-1 and SARS-CoV-2, a similar tenacity is plausible for SARS-CoV-2. Another study found SARS-CoV-2-RNA on a wide variety of areas in the hospital room of a COVID-19 patient (however, reproductive viruses were not examined here) (9).
In principle, the reproductive capacity of viruses depends on many influencing factors, such as. B. from the ambient temperature and humidity (70-72).
3 van Doremalen N, Bushmaker T, Morris DH, Holbrook MG, Gamble A, Williamson BN, et al. Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1. The New England journal of medicine. 2020.
9 Ong SWX, Tan YK, Chia PY, Lee TH, Ng OT, Wong MSY, et al. Air, Surface Environmental, and Personal Protective Equipment Contamination by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) From a Symptomatic Patient. Jama. 2020.
10 European Centre for Disease Prevention and Control (ECDC). Factsheet for health professionals on Coronaviruses European Centre for Disease Prevention and Control; 2020 [Available from: https://www.ecdc.europa.eu/en/factsheet-health-professionals-coronaviruses].
14 Wang W, Xu Y, Gao R, Lu R, Han K, Wu G, et al. Detection of SARS-CoV-2 in Different Types of Clinical Specimens. Jama. 2020.
70 Rabenau HF, Cinatl J, Morgenstern B, Bauer G, Preiser W, Doerr HW. Stability and inactivation of SARS coronavirus. Med Microbiol Immunol. 2005;194(1-2):1-6.
71 Chan K, Peiris J, Lam S, Poon L, Yuen K, Seto W. The effects of temperature and relative humidity on the viability of the SARS coronavirus. Advances in virology. 2011;2011.
72 Casanova LM, Jeon S, Rutala WA, Weber DJ, Sobsey MD. Effects of Air Temperature and Relative Humidity on Coronavirus Survival on Surfaces. Applied and Environmental Microbiology. 2010;76(9):2712-7.