Environmental Surveillance for SARS-CoV-2 May Predict COVID-19 Cases

A recent study published in Comprehensive Environmental Science Reported that cases of coronavirus disease 2019 (COVID-19) can be predicted by environmental surveillance.

Individuals infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) shed viral particles. As a result, the viral genomic footprint remains in the environment. Viral genomes can persist for hours to days, depending on weather conditions and surface type. Environmental surveillance for pathogens is affordable, non-invasive, and can be performed in public places.

Environmental surveillance can therefore provide early warning of community transmission and disease outbreaks. Numerous studies have evaluated wastewater, air, and surface samples for the presence of SARS-CoV-2. Evidence suggests that SARS-CoV-2 levels in wastewater correlate with the incidence of COVID-19. Nevertheless, there are limited data to predict COVID-19 cases based on SARS-CoV-2 detection in the environment.

About research

This study evaluated SARS-CoV-2 detection in air, wastewater, and surface samples of student dormitories. His Y leg at the University of Miami’s Lakeside Village (YLV) student residence was selected. Wastewater from L is discharged to a designated maintenance hole (K). Researchers sampled dormitory surfaces, air, and wastewater (from K) from March 2, 2021 to May 28, 2021.

Only grab samples were collected during the first two weeks of the study. Both grabs and composite samples were then collected. Air pollution monitoring pumps with flow meters were installed in his two dormitory lobbies for air sampling. Swab samples from frequently touched surfaces (door handles, push rods, elevator buttons) were collected using sterile polyester swabs.

SARS-CoV-2 RNA was extracted from wastewater, air, and surface swab samples using the QuickRNA-viral 96 kit, followed by quantitative polymerase chain reaction (qPCR) analysis. Additionally, the student was randomly screened for her COVID-19 weekly. Air and ground sample data were aggregated and compared to wastewater sample data.

We calculated time-lag SARS-CoV-2 levels to assess whether virus detection in wastewater samples precedes COVID-19 case diagnosis. That is, if a case of COVID-19 was detected, the SARS-CoV-2 concentration of samples from the previous week was evaluated separately.

findings

There were 445 environment samples. 165 from air, 166 from surface and 114 from waste water. Grabs and composite samples were collected for 24 days. SARS-CoV-2 concentrations were below detection limits in grab samples when detected in composite samples for 4 days. Similarly, when SARS-CoV-2 was detected in the grab sample, it was below detection limits for 3 days in the composite sample.

The average SARS-CoV-2 concentration in the composite sample was slightly higher than in the grab sample, although not statistically significant. No significant difference was observed in SARS-CoV-2 was detected in 50 (30%) air samples with an average concentration of 14.8 genome copies (gc)/m2.³Virus was detected in 20% of surface swab samples, with an average concentration of 16.5 gc/m2.².

Half of the wastewater samples contained SARS-CoV-2 with an average concentration of 1390 gc/L. Detection of SARS-CoV-2 was consistent in all three sample types for his 36 days throughout the study. However, SARS-CoV-2, when found in wastewater, was often not detected in air/surface samples and vice versa. On average, two students in the dormitory were randomly tested for COVID-19 each day.

During the study, students were tested for COVID-19 for 44 days. A case of COVID-19 he was detected for 11 days. 1 case/day was detected in 9 days and 2 cases/day in 2 days. During this 11-day period, SARS-CoV-2 was detected in wastewater, surface, and air samples on days 7, 6, and 6, respectively. efficacy of The 1-day delay detection of SARS-CoV-2 in wastewater, surface, and air samples for predicting COVID-19 cases was 63.6%, 72.7%, and 90.9%, respectively.

This increased to 100% for air samples, 81.8% for surface samples, and 90.1% for wastewater samples 3 days before COVID-19 diagnosis. COVID-19 case prediction was better in aggregated environmental samples. For example, a predicted efficiency of 100% was recorded using 1-day delayed SARS-CoV-2 detection in aggregated wastewater and air samples.

Conclusion

In summary, this study supports that SARS-CoV-2 released from infected individuals can be detected in the environment. Virus detection in the sample suggests that her clinical case of COVID-19 in the dormitory can be predicted based on an appropriate time lag. Indeed, his 3-day late SARS-CoV-2 detection in wastewater was strongly correlated with a case diagnosis of COVID-19.

Additionally, air samples showed the highest efficiency in predicting COVID-19 cases. SARS-CoV-2 detection with a 1-day delay in air and wastewater or air and surface specimens predicted all cases. Therefore, environmental surveillance for SARS-CoV-2 is an effective tool for monitoring his COVID-19 in the community.