Got questions? We've got answers... at least most of them.
Think of sampling waste from a sewage system as essentially “large-scale urinalysis.” Instead of testing one person at a time, wastewater surveillance looks at a specific population as a whole. Nearly 80% of households in the U.S. are served by municipal sewage collection systems. Countries all over the world are using this accessible and affordable technique to pinpoint virus hotspots in their community.
Our scientists work with your wastewater treatment plant operators to gather samples of untreated wastewater, and then analyze the samples. The near real-time results can provide public health officials with information about COVID-19 threats to a community.
Individuals spread COVID-19 every day without realizing it; either because they haven’t yet developed symptoms or because they never will. Even before a person is symptomatic, the SARS-CoV-2 virus is shed in feces. The presence of the virus shows even in those who are not exhibiting the traditional symptoms.
The data can serve as an early warning signal because the virus can be detected in effluent three to 10 days before the onset of symptoms. This gives your team the opportunity to swiftly launch mitigation strategies in order to decrease the health and economic costs to your community.
Early warnings can be particularly useful in monitoring high-risk facilities such as schools, nursing homes, prisons, food processing plants and universities – so you can quickly mobilize resources to the places that need attention the most.
As many as 81% of people infected with SARS-CoV-2 will shed viral RNA from their feces for approximately 30 to 40 days. Once in the wastewater, the viral RNA will be present and stable for about a week.
Using a patented technology using a patented technology that involves polymerase chain reaction (PCR) and mass spectrometry, our lab can detect anywhere between one infected person in 114, to one in 2 million. While this is a large range, the results depend on specific conditions on the ground, the number of virus particles being shed by individuals, water temperature and the amount of time particles spend in the pipes.
Wastewater surveillance is not a replacement for individual testing. Individual clinical testing pinpoints exactly who has the virus but depends on a number of factors: how willing is an individual to seek the test, and are the tests available and accessible? Everyone uses the toilet.
In addition, clinical testing has obstacles related to timing – an individual may test negative today, yet positive tomorrow. Obtaining results from individuals often takes longer than the results we can achieve with wastewater technology.
Wastewater results can provide a snapshot of the presence of the virus in buildings, neighborhoods, towns and cities. The results provide data source that is highly useful for public health decision-making.
Yes, we have been successful in identifying variants – often before they are detected by other means. According to the Centers for Disease Control, “many mutations do not affect the virus’s ability to spread or cause disease because they do not alter the major proteins involved in infection.” Wastewater surveillance can provide an important early warning signal.
Asking individuals about symptoms can be time-consuming and unreliable. Like any medical situation, some people are just not comfortable providing personal information. Sewage is available and not subject to interpretation. What you see is what you get.
To effectively address outbreaks of any infectious disease, we need systems that don’t rely on the actions of sick people.
There is no threat to individual privacy. Wastewater testing is non-invasive. Results cannot be connected to an individual or a single household because the process relies on aggregating sewage and data from households and businesses in the designated area. Civic and public health officials own the data, so they can determine how the data is shared.
Wastewater testing is inexpensive. For the cost of one nasal swab test, we can test an entire neighborhood.
Our research team will not only provide you with the data but will work with you to help plan interventions and monitor their success. The data is provided to you in a user-friendly dashboard that can be used in public presentations and on websites. The opportunity to detect a surge in the virus before it becomes detectable from individual clinical tests is particularly useful for deploying public health strategies.
The time from sample collection to getting the results is around 48 hours so we can get an idea of the increase in infections in your community. The rapid turnaround time can give policymakers a head-start so they can, if necessary, initiate lockdowns at the earliest stage to control the spread. It can also tell us when the disease is disappearing so that lockdown measures can be eased.
Many of our participating communities are generously sharing their experience with wastewater testing. For a look at how participating communities are using the data, visit Case Studies
According to the Centers for Disease Control, the National Wastewater Surveillance System is being implemented as a “portal for state, tribal, local, and territorial health departments to submit wastewater testing data into a national database for use in summarizing and interpreting data for public health action. Participation in a national database will ensure data comparability across jurisdictions.”
We know that low-income communities and communities of color are at greater risk for being diagnosed with COVID, often with reduced access to personal testing. Wastewater testing covers large swaths of territory, with no discrimination from one family to another.
As with the village of Guadalupe, Arizona, community leaders were able to identify an abundance of virus in an area populated by Hispanic families, enabling them to tailor mitigation strategies that would work best for these neighborhoods. Wastewater testing is an equalizer.
We can help you launch your project – and receive results quickly. Clinical testing can lag five to 11 days behind wastewater surveillance. Wastewater testing allows you to get in front of the virus fast. If your wastewater is treated prior to arriving at the plant, you may not be a candidate for wastewater testing. Contact us and a member of our team will be in touch with you within 24 hours to help you launch wastewater testing in your town.
Although we are all focused on COVID-19 at this time, there are many other threats to human health that can be identified with wastewater surveillance. Prior to the onset of the pandemic, our teams were working with communities to detect the presence of opioids. In addition to illicit drugs, wastewater surveillance can detect how a population is ingesting alcohol, nicotine, caffeine, antidepressants, stress hormones, viruses, bacteria and other toxic materials and pathogens.
Historically, wastewater testing has been effective in detecting outbreaks of norovirus, antibiotic-resistant bacteria, polio, and measles.
- Sewage testing over time can provide trend data that complements other surveillance data to inform public health decision making. However, at this time at this time, it is not possible to reliably and accurately predict the number of infecting individuals in a community.
- Wastewater surveillance at a treatment plant will not capture home on a septic-based system.
- Wastewater surveillance at a community treatment plan will not capture facilities served by decentralized systems such as prisons, universities or hospitals that treat their own waste.
- Low levels of infection in a community may not be captured by sewage surveillance. The lower limits of detection (i.e., the smallest number of people shedding the virus in stool that can still be detected by current testing methods) for sewage surveillance are not yet well understood. More data on fecal shedding by infected individuals over the course of disease are needed to better understand the limits of detection.
- Not all wastewater treatment plants are appropriate sites for surveillance given their operational logistics (e.g., if sewage is pre-treated before it reaches the plant).
The Centers for Disease Control are providing updates guidance and information as it becomes available. The links below will help you remain abreast of the latest information.
Sampling strategy: Where, how and what to sample https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/wastewater-surveillance/developing-a-wastewater-surveillance-sampling-strategy.html
Data reporting and analytics https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/wastewater-surveillance/data-reporting-analytics.html
Public health interpretation and use https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/wastewater-surveillance/public-health-interpretation.html
Targeted wastewater surveillance at facilities, institutions and workplaces