The avian influenza A(H5N1) virus, which has spread to livestock and infected 14 people this year, was detected by sequencing the virome in wastewater from 10 Texas cities by researchers at UTHealth Houston and Baylor College of Medicine. The virome is the collection of viruses in a sample, in this case a wastewater sample.
The information was published in the New England Journal of Medicine.
As of March 2024, no H5N1 had been detected in 1,337 wastewater samples analyzed by the team. But from March 4 to July 15 (the end of data collection for this article), H5N1 was detected in 10 of 10 cities, 22 of 23 sites, and 100 of 399 samples. However, the abundance of H5N1 in wastewater samples collected over time did not correlate with flu-related hospitalizations during the same time period, so the risk to the public was extremely low.
UTHealth Houston and Baylor established the wastewater testing program as part of the Texas Epidemic Public Health Institute (TEPHI).
The sequencing protocol used by the team can detect genetic changes that could indicate an adaptation of the virus to mammals, perhaps even humans. The lack of clinical burden in humans and genomic information suggested that the source of the viral load found in wastewater during that time period was from animal origins. But continued surveillance is critical to monitor any evolutionary adaptations that indicate the potential for it to jump to humans, the researchers concluded.
The senior authors of the journal letter were Michael J. Tisza, PhD, associate professor of molecular virology and microbiology at Baylor; Blake Hanson, PhD, associate professor in the Center for Infectious Diseases at the UTHealth Houston School of Public Health; Eric Boerwinkle, PhD, director of TEPHI and dean of the Kozmetsky Family Chair in Human Genetics and the M. David Low Chair in Public Health at the School of Public Health; and Anthony W. Maresso, PhD, holder of the Joseph L. Melnick Chair in Virology at Baylor. Boerwinkle and Hanson are also members of the UTHealth Houston Graduate School of Biomedical Sciences at the University of Texas MD Anderson Cancer Center.
The team detects viruses in wastewater using a set of viral capture probes targeting thousands of viral species or variants. Since May 2022, TEPHI has detected over 400 human and animal viruses, several of which (SARS-CoV-2, influenza and mpox) have been correlated with clinical case data in the population.
Co-authors of the UTHealth Houston letter include Kristina Mena, PhD, holder of the Jane Dale Owen Chair in Environmental Health Protection; Anna Gitter, PhD; Fuqing Wu, PhD; Janelle Rios, MPH, PhD; and Jennifer Deegan, MPAff. From Baylor College of Medicine: Justin Clark, PhD; Li Wang, MD, PhD; Katelyn Payne, BS, Matthew Ross, PhD; Sara Javornik Cregeen, PhD; Juwan Cormier, PhD; Vasanthi Avadhanula, PhD; Austen Terwilliger, PhD; Pedro Piedra, MD; Joseph Petrosino, PhD. John Balliew of El Paso Water Utility also was a co-author.