Real-time sewage surveillance for SARS-CoV-2 in Dhaka, Bangladesh versus clinical COVID-19 surveillance: a longitudinal environmental surveillance study (December, 2019–December, 2021)

Interactive SARS-CoV-2 dashboard for real-time geospatial visualisation of sewage and clinical surveillance data from Dhaka, Bangladesh: a tool for public health situational awareness

“…Systematic sewage surveillance for SARS-CoV-2 has been employed by many governments as a complementary source of COVID-19 tracking and has been shown to capture the temporal dynamics of SARS-CoV-2, providing an early warning of increasing transmission 5–7. We have shown that sewage surveillance in Dhaka, Bangladesh, can act as an early warning indicator for COVID-19 cases up to 2 weeks in advance of large rises in COVID-19 cases and it provided evidence of persistent circulation of SARS-CoV-2 in areas with low access to clinical testing 8. Sewage surveillance can also capture both asymptomatic and symptomatic cases, while clinical surveillance largely captures symptomatic cases 6.…”

“…Sewage samples were collected weekly and tested for SARS-CoV-2 burden by icddr,b researchers by reverse transcriptase quantitative PCR. Estimates of viral load were then integrated into the dashboard within 5 days of sample collection 8…”

“…For example, at the beginning of the Delta wave in Dhaka, during the week of 27 December 2021 to 2 January 2022, the sewage viral load rose while the reported cases remained low (figure 4A). The sewage levels were ‘medium’ for most wards, while the case incidence was reported as zero or ‘low’ for all wards except ward 19, which has a high-income population and had access to a higher level of testing 8. Not until 3 weeks later, 24–30 January 2022, did the cases reach a substantially higher level and catch up with sewage levels (figure 4B), which supports the theory that sewage data can act as an early warning indicator for an impending rise in cases.…”

“… 5–7 We have shown that sewage surveillance in Dhaka, Bangladesh, can act as an early warning indicator for COVID-19 cases up to 2 weeks in advance of large rises in COVID-19 cases and it provided evidence of persistent circulation of SARS-CoV-2 in areas with low access to clinical testing. 8 Sewage surveillance can also capture both asymptomatic and symptomatic cases, while clinical surveillance largely captures symptomatic cases. 6 This is important for diseases such as COVID-19, where up to 40% of the infections are asymptomatic and many individuals go untested.…”

Is detection of enteropathogens and human or animal faecal markers in the environment associated with subsequent child enteric infections and growth: an individual participant data meta-analysis

“…Notably, however, our findings of infection with a pathogen following its detection in the environment indicate that environmental monitoring of pathogens can be a useful population-level surveillance tool, akin to wastewater-based epidemiology, which has been successfully used to monitor SARS-CoV-2 in various settings, including low-income countries. 42 A 2023 study in Kenya, Benin, and India found that detection of soil-transmitted helminths species in soil was strongly associated with infection with the same species and proposed soil-transmitted helminth monitoring in soil as a surveillance alternative to collecting stool samples from individuals. 43 Environmental sampling for specific pathogens is logistically simpler, less intrusive, and less time-consuming than collecting human biospecimens, especially when infection prevalence is low (eg, pathogen close to elimination).…”