In a race against time to monitor the spread of the deadly strain of bird flu, H5N1, scientists at Tufts University's Cummings School of Veterinary Medicine are conducting extensive sampling efforts across various animal species. Led by virologist Jonathan Runstadler, the team at the Tufts Wildlife Clinic is working diligently to detect cases of H5N1 in wildlife that may otherwise go undetected.

The lab, part of a network of Centers of Excellence for Influenza Research and Response funded by the National Institutes of Health, tests a wide range of animals with the goal of identifying the virus in hosts that show no symptoms. This is crucial since the virus could potentially develop mutations that could enhance its ability to infect mammals, including humans.

Since H5N1 first emerged in the United States in 2022, the lab has screened approximately 10,000 bird samples and 2,500 mammal samples, including 1,000 from marine mammals. Although positive cases have been found in birds, no mammals have been identified as carrying the virus since the deaths of seals off the coast of Maine in the summer of 2022.

The lab's efforts extend beyond monitoring birds and marine mammals. Samples collected from various species including foxes, mountain lions, raccoons, and bears have also been tested, with the United States Department of Agriculture confirming over 200 cases of bird flu in mammals across the country.

One cause for concern is the potential for the virus to make its way into new animal hosts along the East Coast and throughout the country. To address this, Runstadler's team collaborates with partner organizations and receives samples from New England, Virginia, Florida, California, Alaska, and even Hawaii. These samples are carefully handled, packed in specialized containers with protective equipment, and shipped to the lab for analysis.

When a positive case is identified, the submitter is notified while the sample undergoes further confirmation at a USDA lab. Subsequent genetic sequencing is conducted either at the Runstadler lab or the Icahn School of Medicine at Mount Sinai in New York City. These sequences are then shared with global scientists through an online database, aiding in the understanding of the virus's evolution.

So far, one concerning mutation known as PB2 E627K has been detected in multiple mammal species, including seals, and even in a human case in Texas. While scientists emphasize the need for additional genetic changes to facilitate human-to-human transmission, ongoing surveillance and research are crucial to identifying any emerging patterns and gaining valuable insights.

The Tufts Wildlife Clinic's continuous efforts have positioned them as key contributors to the broader monitoring network for H5N1. Their dedication to wildlife surveillance and comprehensive sampling has provided invaluable data that aids in the understanding and control of the virus. As the world continues to grapple with the threat of H5N1, the work being done at Tufts University remains instrumental in safeguarding both animal and human health.