Were you one of the 53,000 attendees of the Anime NYC 2021 convention in New York City, or know someone who did? New York City authorities and Anime NYC organizers are urging every single attendee, exhibitor, artist, and staff member to get tested for COVID-19 — because one of the United States’ first confirmed cases of the new omicron variant was a man who attended the convention and likely caught it there (via Kotaku).

Omicron is the new coronavirus variant whose first known US case made the news only yesterday, but is now also identified in California, Minnesota, Colorado and New York State as well, less than a week after being classified by the World Health Organization. Several fully vaccinated people have tested positive. In a press conference today, New York governor Kathy Hochul said her state alone now has five confirmed omicron cases, and NYC mayor Bill de Blasio warned New Yorkers that they should assume there’s community spread. Hochul suggested that so far, all the US cases of the omicron variant have been minor, with very light symptoms; the man who attended Anime NYC has reportedly already recovered.

The man is from Minnesota; the Minnesota Department of Health says he had already been vaccinated, and developed mild symptoms the day after the convention. He hadn’t been outside the United States recently, according to The New York Times, suggesting he may have gotten it at the convention.

“Anyone who attended the AnimeNYC conference, especially anyone experiencing symptoms, should get tested immediately and take additional precautions including social distancing,” reads part of a statement from de Blasio. “I urge all New Yorkers to get vaccinated, wear a face mask while indoors and in public, and help our city beat this virus once and for all.”