The United States’ Traveler-Based Genomic Surveillance (TGS) program has acquired more than one million volunteers to aid in the identification of infectious disease threats, according to the Centers for Disease Control and Prevention (CDC).

Volunteers provide nasal samples to the program upon travelling to the United States via plane. Those samples are used to rapidly detect infectious diseases and their variants. Currently, SARS-CoV-2 positivity has waned, but for those who test positive, variant XFG is the most common, followed by NB.1.8.1.

Additionally, the early detection of influenza H3N2 subclade K in the United States can be attributed to the program, CDC says.