greatest challenge faced by public health officials in their efforts to get
a leg up on COVID-19 is that gaping window--between five days and as long as
two weeks--before an infected person begins presenting symptoms.
In the meantime,
the presymptomatic carrier--possibly a mask refusenik, possibly a
superspreader--becomes one more vector in the pandemic, until of course he
or she becomes an actual patient. It’s this lag between infection and
symptoms which has caught so many communities’ healthcare systems by nasty
surprise, as waves of folks who were fine yesterday but sick today converge
on ERs, clinics, or their primary care physicians.
Now, however, 1997
CHS graduate and virologist Dr. Doug Brackney may have found a way to close
this window somewhat: by sampling the primary sludge at wastewater treatment
plants and testing for the novel coronavirus.
discovered early on not only that the live coronavirus can be found in
patients’ feces but that its RNA can be too. At the time the lesson learned
was that fecal contamination could be a common vector of transmission, in
communities with poor sanitation or inadequate plumbing.
But Brackney and
his colleague Jordan Peccia, a professor of environmental engineering at
Yale University, wondered whether another lesson might be learned as well:
namely, whether the viral RNA could be detected in the primary sludge at
wastewater treatment plants, and if so whether a “community level
transmission” could be extrapolated from that viral presence.
Another way of
putting it: whether viral RNA concentrations in primary sludge could provide
an early warning of an impending outbreak in a community.
Peccia’s finding: that indeed they can.
Brackney is neither
an epidemiologist nor an environmental engineer. He’s a virologist who wrote
his dissertation at Colorado State University on the dengue virus, did a
post-doc at the University of New Mexico on the West Nile virus, and is now
studying virus-vectors--arthropods like mosquitoes, fleas, and ticks which
transmit pathogens to animals--as an associate scientist at the Connecticut
Agricultural Experiment Station. Then came C-19 and his team’s research,
like the work of a lot of other people, became temporarily non-essential.
“When the SARS
CoV-2 pandemic exploded, like most of society all labs were required to
cease work on current research projects except those studying SARS CoV-2,”
Brackney told the Chesterton Tribune. “I felt like I had a skill set
that could be useful in these times, so I reached out to a friend and
colleague at Yale University and asked if there was a way I could apply my
expertise and skills to help the research efforts. He put me in touch with
The result of their
collaboration: “SARS CoV-2 RNA concentrations in primary municipal sewer
sludge as a leading indicator of COVID-19 outbreak dynamics,” posted on May
22 by medRxiv.
The study worked
this way: between March 19 and May 1, Peccia’s lab collected and processed
samples of primary sludge--the solids which have settled out of raw
wastewater--from the treatment plant serving New Haven, Conn., a community
of around 200,000; Brackney performed diagnostics on the samples; and a team
of epidemiologists did the modeling.
The math in their
paper is way beyond the ability of a Chesterton Tribune reporter to
wrap his head around, but the result is straightforward: concentrations of
the novel coronavirus RNA in the primary sludge matched the epidemic curve
“perfectly,” Brackney said, but with one key difference, that those
concentrations began increasing seven days before the number of reported
C-19 cases did, and three days before the number of hospitalizations did.
That’s a full week
of lead time for local healthcare systems to batten their hatches and for
public health officials to make their dispositions. Also, as Brackney noted,
falling or rising concentrations of the viral RNA can be used “to inform
public health policies, such as lifting or imposing restrictions.”
Brackney does offer
a couple of caveats. For one thing, primary sludge testing “might not be
effective in rural areas where many homes have septic systems.” For another,
“this approach does require trained professionals to collect and collate the
data as well as specialized instrumentation.”
said, “this approach can easily be scaled up cheaply” and prove “a
cost-effective approach for surveillance of large populations.” He even
foresees--as a hack to the problem posed by the need for high-tech
instrumentation--a “statewide system where samples are sent to a centralized
lab and processed the same or next day.”
Their paper itself
suggests one more advantage of this surveillance method: it could be used
“to preempt community outbreak dynamics” especially in places where there is
limited clinical C-19 testing capacity.
Not every scientist
has the opportunity to participate in game-changing research of any kind.
Even fewer have the opportunity to level the playing field amid a public
health crisis of this magnitude. So Brackney is delighted to have had the
chance to play his role.
“This was a great
collaborative effort of numerous world experts in virology, epidemiology,
and environment engineering, and I am happy to have been able to contribute
to this potentially transformative approach for surveillance.”