Examples of Covid policy based on wastewater surveillance.
August 15, 2024 7:01 AM Subscribe
In the US, we have a wastewater surveillance program. Many states give easy access to local levels and historical data, e.g. Illinois. I would like to see any examples of adaptive public health policy that is set to change based on current wastewater levels.
Ideally, I'd like to see examples of the form "When local wastewater samples show X gene copies per liter or greater, masks should be worn to mitigate further spread of Covid", or similar such guidelines on gatherings, air quality, etc. But the key here is that it's pegged to local wastewater data. Any type of govt source or NGO is fine. Scholarly sources are especially appreciated. If you want to give your own suggestion, please explain your reasoning and qualification in public health, epidemiology, or infectious disease dynamics. That is to say, I'm not looking for idle speculation here. Thanks!
Ideally, I'd like to see examples of the form "When local wastewater samples show X gene copies per liter or greater, masks should be worn to mitigate further spread of Covid", or similar such guidelines on gatherings, air quality, etc. But the key here is that it's pegged to local wastewater data. Any type of govt source or NGO is fine. Scholarly sources are especially appreciated. If you want to give your own suggestion, please explain your reasoning and qualification in public health, epidemiology, or infectious disease dynamics. That is to say, I'm not looking for idle speculation here. Thanks!
If you are looking for examples of where this is already a practice, you will have to look outside the US. AFAIK, no one in the US is implementing any recommendations for increased masking or other public safety precautions based on community spread of Covid-19.
As an example of how this might work, you can look at the NY State Health Dept's work on Polio: https://www.health.ny.gov/diseases/communicable/polio/wastewater.htm
They are using this information to guide vaccination drives more than anything else. There are large pockets of unvaccinated people in upstate NY.
posted by drossdragon at 11:11 AM on August 15 [1 favorite]
As an example of how this might work, you can look at the NY State Health Dept's work on Polio: https://www.health.ny.gov/diseases/communicable/polio/wastewater.htm
They are using this information to guide vaccination drives more than anything else. There are large pockets of unvaccinated people in upstate NY.
posted by drossdragon at 11:11 AM on August 15 [1 favorite]
One specific way they are used is by hospitals and medical systems to predict admissions due to covid, and thus staffing needs, up to 10 days in advance. This is helpful both on the upswing and the downswing of the curve.
I've heard hospital staffing type people talking about this, though unfortunately I can't remember or find a source like that. But here are a couple of sources that discuss the wastewater -> hospital admissions modeling, and the obvious use of that is to predict future staffing needs in hospitals.
* CDC:
* Sample research paper (you'll find lots more by searching google scholar): Wastewater surveillance provides 10-days forecasting of COVID-19 hospitalizations superior to cases and test positivity: A prediction study published in Infectious Disease Modeling:
Just for example one thing that is clear right now from the data is that we are right in the middle of a pretty big covid surge but currently in the U.S. the old covid vaccines are expired and the new ones aren't available yet. For example I'd like to get a booster right now because I can hide out for the next couple of weeks but then I've got a series of public things I must attend. Getting a booster right now would actually be optimal. But I'm having a hell of a time finding one.
Hopefully in the future they can avoid problems like that because they aren't just guessing about the covid surge right now, they have solid data due to wastewater testing. The past 3-4 weeks and the next 2-3 weeks are the time when you would definitely want vaccines available and they haven't been (and won't be - they're looking at September for wide availability).
So planning things like vaccine availability is one way the data can/should be used.
Another is getting a handle on what variants are current, growing, or waning in order to plan future vaccines to match variants as best they can. I know they use all available resources to determine which variants are active at any given time, not only wastewater testing. But wastewater testing is one of the most important, comprehensive, and accurate sources of that information. Just for example, here is a current look at the National Wastewater Surveillance System Covid-19 Variants in Wasterwater summary.
posted by flug at 12:41 PM on August 15 [2 favorites]
I've heard hospital staffing type people talking about this, though unfortunately I can't remember or find a source like that. But here are a couple of sources that discuss the wastewater -> hospital admissions modeling, and the obvious use of that is to predict future staffing needs in hospitals.
* CDC:
When people become infected with SARS-CoV-2, they usually shed the virus before they become sick enough to be hospitalized. In fact, the amount of virus shed in stool is highest around the time symptoms begin, whereas hospitalization often occurs one to two weeks after symptoms begin. In addition, hospital admissions can take a week or more to be reported to CDC, while wastewater testing data are often available within a week of the samples being collected.Though I note the CDC stopped publishing their wastewater forecasts in May 2024.
* Sample research paper (you'll find lots more by searching google scholar): Wastewater surveillance provides 10-days forecasting of COVID-19 hospitalizations superior to cases and test positivity: A prediction study published in Infectious Disease Modeling:
[T]he ten-day lead time is an important finding for public health officials because it can help with planning for predicted surges in new admissions and coordinate response efforts. . . . Advance notice can allow communities to respond accordingly and provides another data source of public health officials tracking the disease. . . .I know you're going to say this isn't being used to automatically trigger mask mandates or close schools or whatever. But things like adjusting the healthcare system so that it has sufficient capacity, but also not excess capacity (which wastes money, and a lot of it) is part of public health just as well as those other things. Most public health response happens behind the scenes and out of the public eye. And most of what is public is things like updates, information releases, warning, or recommendations - and these things are going to be informed by the sewage data, too.
The value of forecasting the decline of hospitalizations during a surge should not be underappreciated. These results also show the ability to predict new COVID-19 hospital admissions at multiple spatial aggregations (from the state level on down to the sampling point level).
The accuracy of statewide predictions in these analyses provide several public health benefits. First, wastewater surveillance for public health benefit does not require intense sampling frequencies – the majority of the data used here was from weekly sampling. Weekly sampling is much less burdensome on wastewater treatment plant operators who actually pull the sample. Second, our statewide models combined wastewater from different laboratories all using unique methods to quantify the amount of SARS-CoV-2 in wastewater. These results suggest that programs across jurisdictions might see benefit in combining data even if the methods differ. Third, the statewide estimate provides a concise message for policymakers. Aggregating community-level surveillance metrics into a statewide estimates resulted in accurate models and could benefit the decision-making process at larger geographic scales. . . .
Just for example one thing that is clear right now from the data is that we are right in the middle of a pretty big covid surge but currently in the U.S. the old covid vaccines are expired and the new ones aren't available yet. For example I'd like to get a booster right now because I can hide out for the next couple of weeks but then I've got a series of public things I must attend. Getting a booster right now would actually be optimal. But I'm having a hell of a time finding one.
Hopefully in the future they can avoid problems like that because they aren't just guessing about the covid surge right now, they have solid data due to wastewater testing. The past 3-4 weeks and the next 2-3 weeks are the time when you would definitely want vaccines available and they haven't been (and won't be - they're looking at September for wide availability).
So planning things like vaccine availability is one way the data can/should be used.
Another is getting a handle on what variants are current, growing, or waning in order to plan future vaccines to match variants as best they can. I know they use all available resources to determine which variants are active at any given time, not only wastewater testing. But wastewater testing is one of the most important, comprehensive, and accurate sources of that information. Just for example, here is a current look at the National Wastewater Surveillance System Covid-19 Variants in Wasterwater summary.
posted by flug at 12:41 PM on August 15 [2 favorites]
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COVID in wastewater | Public Health | County of Santa Clara: posted by graphweaver at 7:20 AM on August 15 [1 favorite]