Biosolids Goes Viral - Redux

COVID-19 has shown that Life can change on a dime. Early last week I was deep in the weeds on phosphorus extraction. By the end of the week, I had returned to my TOPICs from four years ago, January 2016, Biosolids Goes Viral. It contains links to science articles that are still relevant today. I checked out WEF’s statement, “Current Priority: Coronavirus,” and is offering operator-relevant webinars. Yet, I am not convinced by our profession’s response to date to this new challenge.

In 2016, I glibly ended my essay with “Don’t Be Stupid” because I had discerned that humans unnecessarily engaged in risky behaviors. For our profession, riskiness is in our lack of response to the call for tracking viruses in biosolids.

I returned to Google Scholar and learned that coronavirus is not new to biosolids scientists. Our friends at University of Arizona, Drs. Ian Pepper and Chuck Gerba, are ahead of the curve with their 2008 paper Survival of Coronaviruses in Water and Wastewater, as they responded to concerns for those other previous coronavirus outbreaks – SARS and MERS. In that paper, several hopeful phrases include: “enveloped viruses [which is what coronavirus is] are less stable in the environment than nonenveloped viruses,” and “coronaviruses are more rapidly inactivated in water and wastewater at ambient temperatures.” But the larger message is not so sanguine, in that coronavirus is indeed present in biosolids, and those aspects of treatment that might influence its activity are not known.

Other reports give scope to how stupid we are about coronavirus. We have remained largely uninformed about biosolids-borne viruses, and the research effort over the past decade has been light. A 2010 paper out of Brazil, Detection of enteric viruses in sewage sludge and treated wastewater effluent, reported “this suggests that solids associated viruses in wastewater are protected from predation and inactivation. However, the coronaviruses were below the minimum detection limit after 3 days.” Reports out of Dr. Jordan Peccia’s lab at Yale were important but had little follow up by his lab or others. These include the 2011 paper Viral metagenome analysis to guide human pathogen monitoring in environmental samples, and the 2013 paper Identification of Viral Pathogen Diversity in Sewage Sludge by Metagenome Analysis. The 2016 paper Survivability, Partitioning, and Recovery of Enveloped Viruses in Untreated Municipal Wastewater pointed out that “[M]any of the devastating pandemics and outbreaks of the 20th and 21st centuries have involved enveloped viruses.. [h]owever, little is known about the presence and fate of enveloped viruses in municipal wastewater. EPA’s Threat and Consequence Assessment Division issued a report in 2018 Exposure Pathways to High-Consequence Pathogens in the Wastewater Collection and Treatment Systems, asserting: “Numerous respiratory viruses have been reported in feces, including respiratory syncytial virus, SARS coronavirus, adenovirus, and bocavirus… quantitative data that describe viable pathogen numbers in bodily fluids, especially feces, for many respiratory pathogens are scarce and/or highly uncertain.”

“Little is known”; “data… are scarce or highly uncertain”. We join the rest of the world in finding that COVID-19 is a wake-up call to support scholarship and science in wastewater and public health, because the cost of stupidity is high.

Here is TOPICs from January 2016.

Biosolids Goes Viral

Bacteria usually command front page, sort of the Donald of the microbe world. This week the Listeria bacteria powerfully disrupted Dole’s sale of bagged greens from Ohio (CDC: 1 Dead In Michigan From Listeria Linked To Dole Salads ), and several weeks back E coli shuttered Chipotle in various states, but particularly Oregon. 

But the more menacing of microbe stories this past week centered on viruses.

While Chipotle had its problem with E coli contamination, it also suffered from a virus, the norovirus, tied to unclean workers and food handling practices. Norovirus made ill a far larger number of patrons and workers than had E coli, not just in one locale, but in two, California and in Massachusetts (Chipotle’s Norovirus Outbreak Is Not A Typical Norovirus Outbreak ).

If you like this kind of stuff, you can’t beat the CDC reports of its investigations:  Vital Signs: Multistate Foodborne Outbreaks — United States, 2010–2014). (Hint: beware of organic alfalfa sprouts.) You can learn also of the viral causes of the over 100 million GI illnesses in the U.S. annually, particularly noroviruses and Norfolk-Like Viruses (NLVs).

Over the past two years, viruses clearly win the popular vote for health-scare. We had Ebola show its terrible rapid spread in 2014 into 2015. We in the wastewater industry have learned a bit about risks associated with discharge of human fluids to publicly owned sewers, and we have federal guidance to help us (Frequently Asked Questions (FAQs) on Interim Guidance for Managers and Workers Handling Untreated Sewage from Suspected or Confirmed Individuals with Ebola in the U.S.)  You  may have caught the news from WHO that “all known chains of transmission” of Ebola infections were closed (Latest Ebola outbreak over in Liberia; West Africa is at zero, but new flare-ups are likely to occur ). The next day the report came out that an Ebola case, an isolated one, had been reported. The world is not Ebola-free.

The latest viral scare, of course, is Zika. Zika is a mosquito-borne virus, like the better known West Nile Virus (WNV), but is scary for the horrifying birth defects and potentially debilitating paralysis. That it is not carried in animal, as is WNV in birds, will help limit Zika’s spread among humans in the United States.

This past week also witnessed another viral scare, an outbreak of avian flu in Indiana. The outbreak in Indiana was not the highly pathogenic avian influenza (NPAI) that resulted in loss last year of 48 million poultry and $3.3 billion, but a lesser pathogen.  Is there a risk to human health? We need to wait and see.

But we have increased viral risks from that great vector – stupid people. I found these two CDC reports of potential viral risks.  A New Jersey woman administered dozens of flu shots with the same unsanitary needle, and we had an NGO issue fraudulent rabies vaccine certificate to dogs imported to the U.S. from Egypt.

Stupid people seem to be the vector for water risks in Flint, Michigan., Yes, this is a lead issue, not a pathogen issue, but fundamentally the Flint story is about egregiously negligent government officials.  

Flint raises my biosolids guard.  With viruses emerging in prominence as world health issues, and with the failures of municipal utility management causing people serious harm, how can we in biosolids not pause to revisit our own responsibility for ensuring public health?  Are we sufficiently informed about connections between viruses in biosolids and human health risks, and do connect our choice of biosolids processes and practices to specific targets for viral pathogen reduction?  Are we witnessing a failure to advance the science behind biosolids pathogen and vector attraction reduction regulations? Have we ever witnessed biosolids folks doing stupid things? Yes, these are rhetorical questions.

If you haven’t reviewed the literature on viruses in biosolids over the past several years, you may not be aware of how rapidly our knowledge-base has increased about biosolids-borne viruses. 

Researchers have applied new DNA analytical tools to scan biosolids for a wide variety of virus types.  instead of focusing on a few potential indicator viruses, an array of viruses are measured.  The Yale University research team, headed by Dr. Jordan Peccia, in  Viral metagenome analysis to guide human pathogen monitoring in environmental samples, found “the RNA viruses parechovirus and coronavirus and the DNA virus herpesvirus were the most abundant human viruses in the biosolid sample tested here, [so that in the future we can] ensure that highly enriched and relevant pathogens are not neglected in exposure and risk assessments.” Their hope is that “as the costs of next-generation sequencing decrease, the pathogen diversity described by virus metagenomes will provide an unbiased guide for subsequent cell culture and quantitative pathogen analyses and ensures that highly enriched and relevant pathogens are not neglected in exposure and risk assessments.”

Treatment processes don’t necessarily serve as adequate barriers to all pathogens. For example, the Yale team, in  Survey of Wastewater Indicators and Human Pathogen Genomes in Biosolids Produced by Class A and Class B Stabilization Treatments, reported that in biosolids composting systems Legionella bacteria seemed to have the potential to proliferate during composting to thrive in biosolids composting processes.”  The authors also argued that “we can translate these infectious adenovirus concentrations in bulk biosolid samples to a downwind aerosol concentration using a previously described and calibrated aerosol transport model for respirable biosolid material at off-site locations.”

The Yale team’s results also offer ideas for improving regular monitoring of biosolids products.  The paper stated that in “…a cross section of biosolid samples (Fig. 1), male-specific coliphages appear to be a more stringent test of inactivation.  …pathogen concentrations for a given sample were more comparable to male-specific coliphage values; this result suggests that they would be more useful for documenting pathogen presence than fecal coliforms.”  In another recent journal article by this team, Identification of viral pathogen diversity in sewage sludge by metagenome analysis, the authors recommended that the industry should “consider a broader selection of viruses in environmental fate and transport studies, and importance of considering multiple human exposure routes to sewage sludge and wastewater.”

The EPA lab in Cincinnati has contributed recently to the evolving science of measuring viruses.  Eric Rhodes, head of the team at USEPA Cincinnati Labs, authored a recent article Determining Pathogen and Indicator Levels in Class B Municipal Organic Residuals Used for Land Application.  Dr Rhodes writes: “Overall, this study reveals that high concentrations of enteric pathogens (e.g., Cryptosporidium, Giardia, and HAdV) are present in biosolids throughout the United States. …. A more thorough analysis of the relationship between pathogenic HAdV and fecal indicator organisms is warranted. Nonetheless, these results reveal the potential risks associated with exposure to human adenovirus and protozoan pathogens present Class B treated biosolids.”

Research results that enumerate viral organism in biosolids provide inputs to new tools for assessing health risks and for decision making. A Swedish research team headed by Robin Harder published  Including Pathogen Risk in Life Cycle Assessment of Wastewater Management. 1. Estimating the Burden of Disease Associated with Pathogens , followed by Including Pathogen Risk in Life Cycle Assessment of Wastewater Management. Implications for Selecting the Functional Unit. This team conducted an evaluation “based on eight previous QMRA (quantitative microbial risk assessment) studies as well as parameter values taken from the literature. A total pathogen risk (expressed as burden of disease) on the order of 0.279 disability-adjusted life years (DALY) per year of operation was estimated for the model WWTS serving 287,600 persons and for the pathogens and exposure pathways included in this study.” 

Yes, a lot of new science and new assessments. This deserves our attention and, what is more, even in the absence of EPA funding, it deserves investment of our money. The pay back might be most keen in providing incentives for companies to evolve treatment technologies and for public agencies to institute best practices. The pay back is also in our pride when we well-serve our ratepayers and communities.  And, best of all, it may remind us Don't Be Stupid.