Bird flu found in wastewater from 10 Texas cities through virome sequencing

The bird flu virus A(H5N1), which spread to livestock and infected 14 people this year, was detected using virome sequencing in the wastewater of 10 Texas cities by researchers from 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, H5N1 had not 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 locations, and 100 of 399 samples.

However, the abundance of H5N1 in wastewater samples collected over time did not correlate with flu-related hospitalizations over the same 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. Lack of clinical burden in humans and genomic information suggest that the source of the viral load found in wastewater during that period was of animal origin. But continued surveillance is crucial to monitor any evolutionary adaptations that could indicate the possibility of it jumping to humans, the researchers concluded.

The team detects viruses in wastewater using a viral probe capture kit that targets thousands of virus types or variants. As of May 2022, TEPHI has detected more than 400 human and animal viruses, several of which (SARS-CoV-2, influenza and mpox) are correlated with clinical case data in the population.