Researchers at UTHealth Houston and Baylor College of Medicine have detected the avian influenza A(H5N1) virus in the wastewater of 10 Texas cities using virome sequencing. This virus, which had spread to cattle and infected 14 people this year, was not detected in 1,337 previous samples until March 2024. However, from March to July of the same year, H5N1 was found in 10 cities, 22 sites, and 100 samples. Despite this, the abundance of the virus did not correlate with influenza-related hospitalizations, indicating a low risk to the public.
The virome sequencing protocol used by the research team can identify genetic changes in the virus that may suggest an adaptation to mammals, including humans. While the lack of clinical burden in humans and available genomic data pointed to an animal origin for the virus, continued surveillance is crucial to monitor any evolutionary adaptations that could indicate a potential risk of transmission to humans. The researchers concluded that the wastewater testing program established by UTHealth Houston and Baylor as part of the Texas Epidemic Public Health Institute (TEPHI) plays a vital role in monitoring such threats.
Lead authors of the study, which was published in the New England Journal of Medicine, include researchers from both institutions such as Michael J. Tisza, Blake Hanson, Eric Boerwinkle, and Anthony W. Maresso. The team uses a viral probe capture set to target thousands of viral species or variants and has detected over 400 human and animal viruses since 2022. Several of these viruses, such as SARS-CoV-2, influenza, and mpox, have shown correlations with clinical case data in the population, highlighting the importance of this type of surveillance.
Co-authors from UTHealth Houston and Baylor College of Medicine were also involved in the study, including Kristina Mena, Anna Gitter, Fuqing Wu, Janelle Rios, Jennifer Deegan, Justin Clark, Li Wang, Katelyn Payne, Matthew Ross, Sara Javornik Cregeen, Juwan Cormier, Vasanthi Avadhanula, Austen Terwilliger, Pedro Piedra, and Joseph Petrosino. John Balliew from the El Paso Water Utility also contributed as a co-author. By utilizing virome sequencing in wastewater samples, the team was able to identify the presence of H5N1 and other viruses, providing valuable data for public health monitoring and response efforts.
The research findings suggest that while H5N1 was detected in wastewater samples during a specific time frame, the risk of transmission to humans was deemed to be extremely low. The lack of correlation between the abundance of the virus in wastewater and influenza-related hospitalizations further supported this conclusion. The results underscore the importance of ongoing surveillance efforts through programs like TEPHI, which can help monitor potential threats and inform public health interventions to prevent the spread of infectious diseases.
Overall, the study highlights the value of virome sequencing in detecting the presence of potentially harmful viruses in wastewater and the importance of continued surveillance to monitor the evolution and adaptation of these viruses. By identifying and tracking viruses like H5N1, researchers can better understand the potential risks to public health and take proactive measures to prevent outbreaks and protect the population. Collaborative efforts between institutions like UTHealth Houston and Baylor College of Medicine, as well as involvement from public utilities like the El Paso Water Utility, demonstrate the interdisciplinary approach needed to address emerging infectious disease threats effectively.