Sewage RNA caught Univ of Arizona outbreak before it started: WaPo

The Washington Post on August 28 published an article about the University of Arizona’s sewage surveillance and how it caught a COVID-19 outbreak before it started. Like many other colleges, universities, and primary or secondary schools, the U of AZ has been dealing with the fall opening of school by closely watching its students as they moved into dorms.

One of their newer methods of surveillance: examining sewage from the dorm’s bathrooms for virus RNA. Previous research has shown that fragments of virus RNA can be detected in sewage outfalls even before people report symptoms or test positive for SARS-COV-2.

From the WaPo article:

When a wastewater sample from one dorm came back positive this week, the school quickly tested all 311 people who live and work there and found two asymptomatic students who tested positive. They were quickly quarantined.

“With this early detection, we jumped on it right away, tested those youngsters, and got them the appropriate isolation where they needed to be,” said Richard Carmona, a former U.S. surgeon general who is directing the school’s reentry task force, in a news conference.

Researchers around the world have been studying whether wastewater testing can effectively catch cases early to prevent covid-19 clusters. There are programs in Singapore, China, Spain, Canada and New Zealand, while in the United States, more than 170 wastewater facilities across 37 states are being tested. Earlier this month, officials in Britain announced testing at 44 water treatment facilities. The Netherlands has been collecting samples at 300 sewage treatment plants.

With colleges battling large outbreaks around the country, the University of Arizona — which is trying a mix of online and in-person courses — elected to test sewage from all 20 residence halls. Other schools are doing the same, including the University of California at San Diego and Syracuse University.

https://www.washingtonpost.com/nation/2020/08/28/arizona-coronavirus-wastewater-testing/

This technique– already proven at several large sewage facilities in the Netherlands– has the potential to surveil large or small groups of people and rapidly detect the excretion of virus RNA, even before symptoms appear in the affected population.

In the U of AZ case, we do not know if the two infected students were asymptomatic or presymptomatic, but it doesn’t matter for this surveillance technique. It can detect infections early, possibly even before nasopharyngeal swabs.