SARS-CoV-2 in environmental samples of quarantined households

Abstract

The role of environmental transmission of SARS-CoV-2 remains unclear. Particularly the close contact of persons living together or cohabitating in domestic quarantine could result in high risk for exposure to the virus within the households. Therefore, the aim of this study was to investigate the whereabouts of the virus and whether useful precautions to prevent the dissemination can be given. 21 households under quarantine conditions were randomly selected for this study. All persons living in each household were recorded in terms of age, sex and time of household quarantine. Throat swabs for analysis were obtained from all adult individuals and most of the children. Air, wastewater samples and surface swabs (commodities) were obtained and analysed by RT-PCR. Positive swabs were cultivated to analyse for viral infectivity. 26 of all 43 tested adults (60.47 %) tested positive by RT-PCR. All 15 air samples were PCR-negative. 10 of 66 wastewater samples were positive for SARS-CoV-2 (15.15 %) as well as 4 of 119 object samples (3.36 %). No statistically significant correlation between PCR-positive environmental samples and the extent of infection spread inside the household could be observed. No infectious virus could be isolated under cell culture conditions. As we cannot rule out transmission through surfaces, hygienic behavioural measures are important in the households of SARS-CoV-2 infected individuals to avoid potential transmission through surfaces. The role of the domestic environment, in particular the wastewater load in washbasins and showers, in the transmission of SARS CoV-2 should be further clarified.

Potential sources, modes of transmission and effectiveness of prevention measures against SARS-CoV-2

“…New findings from a COVID-19 cohort in Gangelt, Germany, and with cases in Italy provide data on the detection of infectious SARS-CoV-2 on surfaces. Although viral RNA was detected in 3.4% of 119 surface samples in 21 households of confirmed COVID-19-cases and on 7.7% of sampled surfaces around COVID-19-cases in Italy, infectious SARS-CoV-2 was not found in any sample [141,142]. Similar findings were described with SARS-CoV and influenza-virus.…”

Two metres or one: what is the evidence for physical distancing in covid-19?

“…23 Neither community study reported positive air samples, although one collected specimens up to 17 days after covid-19 carriers had left the room 25 and the other did not report time of sampling since cleaning or sampling distance from the infected person. 26 These negative studies thus fall substantially short of proving that airborne spread does not occur.…”

Detection of SARS-CoV-2 on contact surfaces within shared sanitation facilities and assessment of the potential risks for COVID-19 infections

“…When using sing a human adenovirus virus (HAdV), Verani et al, 52 found 135 out of 172 surfaces within toilet facilities in a health care setting to be contaminated. Contamination of contact surfaces outside the sanitation setting has been reported in hospitals 55,56,57,58 home settings 59,60,61 and public spaces 60 .…”