Sampling strategies for wastewater surveillance: Evaluating the variability of SARS-COV-2 RNA concentration in composite and grab samples

Correlation between SARS-CoV-2 RNA concentration in wastewater and COVID-19 cases in community: A systematic review and meta-analysis

“…The diurnal pattern of C RNA is likely related to the water usage pattern, where toilet use (a major source for SARS-CoV-2 entering sewers) more commonly occurs in the morning than other times ( Heaton et al, 1992 ). Furthermore, Augusto et al (2022) revealed that the C RNA from grab sampling at the peak shedding time (i.e. 8-10 am), reached a good agreement with the C RNA from 24 composite sampling, so did the correlation between C RNA and COVID-19 cases from both from grab and composite sampling results, over a 17 weeks monitoring.…”

“…Clear diurnal patterns of C RNA have been observed on consecutive days in WWTPs of different capacities (i.e. thousands to millions equivalent population) ( Augusto et al, 2022 , Bivins et al, 2021 , Curtis et al, 2020 , George et al, 2022 ). The diurnal pattern of C RNA is likely related to the water usage pattern, where toilet use (a major source for SARS-CoV-2 entering sewers) more commonly occurs in the morning than other times ( Heaton et al, 1992 ).…”

Investigation of Antibiotic Resistome in Hospital Wastewater during the COVID-19 Pandemic: Is the Initial Phase of the Pandemic Contributing to Antimicrobial Resistance?

“…In addition, sampling wastewater in the morning between 8 and 10 AM was previously reported in a separate study to exhibit relatively greater agreement with a composite of 24 h microbial profiles than at other sampling times. 17 All collected samples were stored at 4 °C for not more than 1 week on site at the hospitals before they were transported to the KAUST laboratory and processed immediately as described in section 2.2 . Daily transferal of samples from hospital to laboratory during the sampling period was not possible as Saudi Arabia imposed a strict movement restriction order at that time.…”

“…While the grab sampling approach only provides a snapshot view of the wastewater collected at that sampling time (9 AM), the limitation of this approach is alleviated in part by sampling over multiple days from April until July 2021. In addition, sampling wastewater in the morning between 8 and 10 AM was previously reported in a separate study to exhibit relatively greater agreement with a composite of 24 h microbial profiles than at other sampling times . All collected samples were stored at 4 °C for not more than 1 week on site at the hospitals before they were transported to the KAUST laboratory and processed immediately as described in section .…”

Wastewater-based epidemiology: A Brazilian SARS-COV-2 surveillance experience

“…In the sewer manholes and lift stations, a 4 h semi-composite sampling of 1000 mL (proportional to time) was carried out using the same automatic sampler. Semi-composite sampling was performed within a time interval (in this case, 4 h) lower than the standard of 24 h. Although it may not accurately represent the daily variation in sewage, it is an alternative for sampling sites which are difficult to access, such as sewer manholes, where it is not possible to maintain an automatic sampler for long periods [17] , [40] . The 1000 mL samples were divided into two aliquots of 40 mL and then stored at 4 °C for a maximum of 36 h. The remaining sample (920 mL) was used for physicochemical and RNA-sequencing analyses (not presented in this manuscript).…”