By Ian Pepper, University of Arizona & WEST Center
Background: Wastewater Based Epidemiology (WBE) is a rapidly expanding new discipline formerly known as Sewage Surveillance. The concept behind WBE is that the concentration of specific microorganisms and/or chemicals in sewage is a reflection of the total inputs of these constituents from a given community. For SARS-CoV-2 and wastewater treatment plants, the concentration of Coronavirus in the sewage is a reflection of the total virus load resulting from the members of the community served by the plant. Critically important is the fact that the total virus load reflects viruses shed by infected individuals with symptoms, as well as infected individuals who are asymptomatic. Thus, assaying the sewage for the virus monitors a given community with one test, and answers the question: “Is the virus currently present in the community?” Previous studies with poliovirus indicate that as few as one infected person in 10,000 can be detected by WBE.
At the WEST Center, we are accepting sewage samples from WWTPs from around the U.S. and providing analyses for Coronavirus for a fee, to cover the costs. The approach to our testing is shown below.
Data analysis provides the following information.
- Quantitative data from multiple samples at a single WWTP over time determines if pandemic is increasing or decreasing
- Correlation of sewage concentrations of virus (gene copy) with the number of cases and deaths allows for future prediction of infection rates
- Determination of whether or not a community could/should return to work
- Future monitoring in the fall to determine if the pandemic is returning
- Can be used to evaluate the success (or lack thereof) of interventions such as social distancing
- Can compare the effects of different secondary treatment processes on virus removal
Additional Coronavirus Research Underway at the University of Arizona
1. Evaluation of Potential Risks from COVID-19 in Bioaerosols during WWT and from Sewers
- 60 bioaerosol samples are being collected from discrete points within WWTPs and sewer lines downstream of hospitals and where aerosols are likely to be generated during maintenance of sewer lines e.g. high pressure jetting of sewer lines
- Use of high volume sampling device (up to 200 L/minute) using dry filter air sampler allows large volumes of air to be sampled quickly
- Detection via RT-qPCR and subsequent cell culture if necessary
- Data used for exposure assessment and subsequent risk models to ensure health and safety of wastewater plant personnel
- Data also used to evaluate protection given by PPE and N.95 masks
2. Evaluation of Wastewater Treatment on COVID-19
ISSUE: Are biosolids a route of exposure to COVID-19?
- Conduct lab studies using miniature anaerobic digesters spiked with COVID-19 to evaluate whether Coronavirus can survive anaerobic digestion
- Previously successfully used to evaluate anaerobic digestion effects on Ebola virus surrogates
University of Arizona Student Re-Entry Plans for Fall 2020
Seven teams established:
- COVID-19 testing of humans (RT PCR)
- Antibody testing (Elisa IgG Antibody Test)
- Contact tracing (In person and app. Based)
- Isolation (segregated dorms or hotels
- Health Data Management and Communication (HIPAA and FERPA compliant data management)
- Thermometry (temperature measurement of individuals)
- Wastewater Based Epidemiology: Team Leader: Ian Pepper (Dormitory testing for early detection of in-house infections)
In Part 2: We will give you an overview of the data from all the projects. (Stay tuned)