Off the Kuff Rotating Header Image

Lauren Stadler

A broader look at the Houston project to track COVID in wastewater

The DMN tells me things I did not know about my current favorite public works project.

The [Houston] health department is conducting the wastewater surveillance for COVID-19 in partnership with researchers at Rice University and Baylor College of Medicine. Wastewater testing cannot identify individual people who have COVID-19, but it can identify neighborhoods with particular virus variants or relatively high virus loads.

Dallas County is not participating in similar wastewater surveillance to track the virus, said Dr. Philip Huang, director of Dallas County Health and Human Services. He said he doesn’t know of any other organizations or municipalities in North Texas that are operating similar programs.

While Dallas County previously considered using wastewater surveillance, the price of creating such a system was too high. “It’s actually quite expensive to set that up,” Huang said.

“After the 10-week survey, [the water district] discontinued its participation in the study due to inconsistent data that required continuous interpretation by local and state public health officials,” said Kathleen Vaught, public relations specialist at the water district.

Public health experts have long used wastewater samples to track the growth and spread of bacteria and viruses, like the poliovirus.

The Centers for Disease Control and Prevention began discussing the use of the tool to study COVID-19 in February 2020.

By September of that same year, the CDC and the U.S. Department of Health and Human Services launched the National Wastewater Surveillance System, also known as NWSS, to help state, tribal and local health departments track and respond to COVID-19.

[…]

Houston is the only Texas city to participate in the NWSS, although that could change as the program grows in the next month, said NWSS team lead and CDC microbiologist Dr. Amy Kirby. Data taken from Houston wastewater samples is submitted to a national database tracking similar data from nearly 400 utilities across the country.

The University of California, Merced’s Naughton Lab created and maintains a dashboard, called COVIDPoops19, to track global wastewater testing for the virus.

I just want to say that learning of the existence of a dashboard called COVIDPoops19 has improved my life in ways I could not have imagined. You can zoom in on Houston in this dashboard and click on the various icons to learn more; clicking on the icon for Baylor College of Medicine led me to the actual Houston dashboard for this, which I had not seen before. If you play around with the slider, which shows you what the viral levels were for past weeks, you can see that the inflection point for this year was the week of June 21 – levels had been dropping through June 7, then you saw a few upticks on June 14, and on the 21st it was all increases, and it got worse for the next few weeks. We’re on more of an upward trend right now (December 6 is the most recent date), but there are increases and decreases in the various locations. I’m going to be bookmarking this page. Anyway, if you want to know more about this project, there you go.

Yes, omicron was found in the wastewater

In case you missed it.

Houston has detected the omicron variant of the virus that causes COVID-19 in eight of its wastewater treatment facilities, confirming the new strain is spreading in the city.

A Harris County resident was the first person in Texas to test positive for the variant Monday. She was fully vaccinated and did not report any recent travel history, officials have said.

City officials have been sampling wastewater facilities since last year, another metric to help the Health Department gauge the virus’s spread in Houston. People shed the virus through feces even if they are not symptomatic or have not tested positive, providing a truer picture than test results. It is also an early indicator, often presaging positivity rate and hospitalizations by weeks.

[…]

The city said the wastewater findings renew the need to get fully vaccinated and are cause for concern, but not panic.

“The Houston Health Department and Houston Water continue to do an exceptional job tracking the impact of the virus in our community,” Mayor Sylvester Turner said. “Vaccines help protect us, our loved ones, friends, and colleagues in the work environment. As the holidays approach, I encourage everyone to remain vigilant about their health and safety.”

See here and here for the background, and here for the Houston Health Department press release. I find it comforting to know that when all else fails, you can count on the wastewater treatment plants.

Our wastewater treatment plant is ready for omicron

One small bit of reassurance in these uncertain times.

The Houston Health Department is testing the city’s wastewater for the new COVID variant, omicron, which experts say could soon be found in the U.S.

The department tests the city’s wastewater weekly for COVID strains. The most recent samples collected the week of November 22 show no trace of the omicron variant, officials said.

“Although our team has not detected Omicron in Houston, we should anticipate it arriving, and the health department is prepared to scale its operations as needed to respond,” Houston Mayor Sylvester Turner said in a release. “In the meantime, I encourage eligible Houstonians to get fully vaccinated.”

Much is still unknown about the new variant, including if it’s more transmissible, deadly or more bypasses vaccines.

“While we await data to show the level of threat from Omicron, it’s important to remember that vaccination is our best tool to reduce cases, prevent serious illness and death, and slow the emergence of new variants,” Dr. David Persse, chief medical officer for the City of Houston said. “If you are not fully vaccinated or if you are eligible for a booster, please do it now to protect yourself, your family, and our community.”

Note that the omicron variant is already here in the US, and it’s just a matter of time before it’s detected everywhere. The wastewater tracking project here has been a big success, and since the latest variant is detectable via PCR testing, it’s no surprise that we’ll have this method to track it. Let’s please all do our part to keep it at a low level.

Yes, the wastewater is also pointing to a COVID surge

In case you were wondering.

There is more COVID-19 in the city’s wastewater system now than at any time in the pandemic, city officials said Wednesday, the latest warning that the virus is spreading at an unprecedented rate.

Dr. David Persse, the city’s health authority, said there is more than three times as much virus in the system as there was last July. The volume also is higher than in January, during the most recent spike. Persse said that wastewater data, a precursor to other data points, show the surge will only grow worse in the coming weeks.

“We are at a level of virus in the wastewater that we have never seen before,” Persse said. “The wastewater predicts what we’ll see in the positivity (rate) by two weeks, which predicts what we’ll see in hospitalizations by about two weeks.”

[…]

The findings came during a news conference in which the city announced it will partner with Harris County and up to 17 school districts to vaccinate students over 12 and their families every Saturday in August, an effort they are calling “Super Saturday.” The inoculations will occur in school buildings throughout the region.

Persse described the state of the surge in stark terms, pointing to dire situations in area hospitals and rising cases and hospitalizations. The Lyndon B. Johnson Hospital declared an “internal disaster” Sunday night amid a nursing shortage and an influx of patients, circumstances officials said are occurring in other area hospitals, as well.

Texas Medical Center CEO Bill McKeon earlier this week said the region is “headed for dark times,” and the hospital system has exceeded its base intensive care capacity, opening unused wards to care for new patients.

“If you are currently unvaccinated, you need to consider that you represent a potential danger to yourself, and others, and most particularly your own family,” Persse said. “If you are not vaccinated… your chances getting through this without having to become either vaccinated or infected, is essentially zero.”

Just over 64 percent of Houstonians over 12 have received their first dose of the vaccine, according to city data, and 54.3 percent are fully vaccinated. The numbers among youth residents are more paltry, though: 28.1 percent of 12-17-year-old Houston residents are fully vaccinated, and 38.5 percent have received their first dose.

“If your child is 12 or older, stop and get them the shot,” said Houston ISD Superintendent Millard House II. “Increasing vaccination rates among our communities will help ease the worries of our families and their children returning to school.”

This is another one from earlier in the month, as things were really starting to get bad. We are familiar with this project, and it has been a big success. I just wish it had better news for us, but this is where we are. Getting more of those 12-and-older kids vaccinated would make a big difference as well, so I hope that effort is successful. We’re on our own, so we’d better act accordingly.

The COVID wastewater tracking project has been a big success

This has been one of the best things to come out of this interminable and miserable COVID experience.

Lauren Stadler’s environmental engineering students always pose the same question at the beginning of a semester: “What happens to water in the toilet after you flush?”

Historically, humans have worked to quickly dispose and eradicate their own waste, which can carry diseases.

But an area’s waste creates a snapshot of who is there and what they’ve been exposed to, said Stadler, a wastewater engineer and environmental microbiologist at Rice University. She’s working with the Houston Health Department and Baylor College of Medicine’s TAILOR program to find SARS-CoV-2 in the city’s wastewater.

Stadler’s hunt has revealed variants in particular areas, heightening the city’s urgency to procure resources — COVID tests, informational meetings, advertising and now vaccine sites — in an effort to quash them before they proliferate.

“The beauty and challenge of wastewater is that it represents a pool of sample — we’ll never get an individual person’s SARS-CoV-2 strain, but a mixture of everyone in that population,” Stadler said. “We can find a population level of emergence of mutations that might be unique to Houston.”

[…]

Variant tracking has become an important part of the wastewater analysis process, Stadler said.

In February, the city and its research partners began seeing a quick emergence of the B.1.1.7 variant, which is now the dominant variant in the area. According to the Centers for Disease Control and Prevention, nearly 21,000 cases of the B.1.1.7 variant have been detected in nationwide.

Now that the team has gathered data and built a sustainable process, Stadler said they are using this information to forecast future pandemics. “Taking wastewater data, you can predict positivity rates and forecast infection burdens — it has this predictive power essentially. It’ll be very important to identify areas in the city experiencing increases in infection, and we can direct resources.”

The wastewater analysis team works with public works employees to collect weekly samples from nearly 200 sites across the city.

“I think they see this as a monitoring tool beyond the pandemic, and we see it as well,” Stadler said. “Hopefully, when SARS-CoV-2 is behind us, we will be able to monitor for an endemic virus, like flu. We can use wastewater monitoring to look for other viruses, bacterial pathogens and other pathogens of concern.”

See here and here for recent entries. I don’t have much to add, just my admiration for everyone involved and the knowledge they have gained. This was a simple and inexpensive innovation, and it will yield public health benefits for years to come. Kudos to all.