Most of us, after we flush the toilet, don’t think twice about our body waste. To us, it’s garbage. To epidemiologists, however, wastewater can provide valuable information about public health and help save lives.
History of Wastewater-Based Epidemiology
Wastewater-based epidemiology (WBE) is the analysis of wastewater to monitor public health. The term first emerged in 2001, when a study proposed the idea of analyzing wastewater in sewage-treatment facilities to determine the collective usage of illegal drugs within a community. At the time, this idea to bridge environmental and social sciences seemed radical, but there were clear advantages. Monitoring wastewater is a nonintrusive and relatively inexpensive way to obtain real-time data that accurately reflects community-wide drug usage while ensuring the anonymity of individuals.
In the nine months since the first cases of COVID-19 were noticed in Wuhan, China, the virus has spread around the globe and infected over 22 million people. As with all emerging infectious diseases, we often find ourselves with more questions than answers. However, through the tireless work of researchers, doctors and public health officials worldwide, we have learned a lot about the virus, how it spreads and how to contain it.
Remdesivir (RDV or GS-5734) was used in the treatment of the first case of the SARS-CoV-2 (formerly 2019-nCoV ) in the United States (1). RDV is not an approved drug in any country but has been requested by a number of agencies worldwide to help combat the SARS-CoV-2 virus (2). RDV is an adenine nucleotide monophosphate analog demonstrated to inhibit Ebola virus replication (3). RDV is bioactivated to the triphosphate form within cells and acts as an alternative substrate for the replication-necessary RNA dependent RNA polymerase (RdRp). Incorporation of the analog results in early termination of the primer extension product resulting in the inhibition.
Why all the interest in RDV as a treatment for SARS-CoV-2 ? Much of the interest in RDV is due to a series of studies performed by collaborating groups at the University of North Carolina Chapel Hill (Ralph S. Baric’s lab) and Vanderbilit University Medical Center (Mark R. Denison’s lab) in collaboration with Gilead Sciences.
Once the purview of virology researchers, the word “coronavirus” is now part of the vernacular in the mainstream media as reports of quarantined cruise ships (1) and makeshift hospitals (2) fill our online news feeds. While there is currently no approved anti-viral treatment for coronavirus infection (3), a team led by researchers from Vanderbilt University recently published work characterizing the anti-CoV activity of a compound, which they now plan to test against 2019-nCoV (4).
Developing New Therapeutics Against Coronaviruses
Coronaviruses (CoVs) are enveloped, single-stranded RNA viruses that exhibit cross-species transmission—the ability to spread quickly from one host (e.g., civet) to another (e.g., human). Scientists classify CoVs into four groups based on the nature of the spikes on their surface: alpha (α), beta (ß), gamma (γ) and delta (δ, 1). Only the alpha- and beta-CoVs can infect humans. Four coronaviruses commonly circulate within human populations: Human CoV 229E (HCoV229E), HCoVNL63, HCoVOC43, and HCoVHKU1. Three other CoVs have emerged as infectious agents, jumping from their normal animal host species to humans: SARS-CoV, MERS-CoV and most recently, 2019-nCoV (5).
A lot has happened since I first wrote about White-Nose Syndrome, the fungal disease that has devastated bat populations in North America. The disease, caused by the cold-loving fungus Geomyces destructans (now renamed Psuedogymnoascus destructans), has been identified in many more places, including most recently confirmed cases in Georgia, South Carolina, Illinois and Missouri in the United States and Prince Edward Island, Canada.
Controlling the spread of this disease is a tremendous problem, because as I indicated in a previous blog post, keeping a hardy fungus from spreading among a population of densely packed small animals in tiny, cold damp areas is not a simple task.