A new study looks at the spread of the novel coronavirus within the in-built environment. Unlike other studies which predominantly focus on the hospital setting, this new study centers on the typical home environment and considers the key factors that can aid the spread of the virus and the likelihood of someone developing COVID-19 symptoms.
The study is captured in the following research paper: “SARS-CoV-2 in environmental samples of quarantined households”. Readers should note that this study is a ‘pre-print’, meaning that it has yet to be peer reviewed.
In the study the authors undertake a an environmental surveillance within several households (21 households under quarantine conditions were randomly selected for this study). The outcome of the review is that while 60 percent of the people in this study (26 of all 43 tested adults) were found to have tested positive for the coronavirus it remained that none of the air samples collected showed any presence of the virus. Furthermore, very few of the fomites were positive either (fomites is a term for an infected surface material). While some surface samples were positive, there was no indication that the viral particles recovered had any viability (based on attempts to culture the isolated material).
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Where the virus was tested was within wastewater, a recovery that supports earlier studies into wastewater as a common indicator of the virus. Overall, the test samples showed:
All air samples were negative (15 samples);
10 of 66 wastewater samples were positive (15 percent);
Plus, 4 of 119 object samples were positive 3 percent).
The relatively high recovery of the SARS-CoV-2 virus in wastewater is proportional to the numbers of people who were found to be infected with the virus. By taking samples of wastewater, in relation to the transfer via human excreta, researchers can track for signs of the virus in relation to a specific locale. Wastewater samples are examined using techniques like viral RNA amplification.
The research concluded: “No statistically significant correlation between PCR-positive environmental samples and the extent of infection spread inside the household could be observed.” Further work is needed to assess how people become infected indoors. According to the researchers, the greatest focus should be with contaminated surfaces.
