superspreader event (a place with crowds where many people get infected with a disease)
“La presidenta de la Comunidad de Madrid, Isabel Díaz Ayuso, ha espetado a los grupos parlamentarios de la oposición que la manifestación del 8M, Día de la Mujer, fue «el mayor 'infectódromo' de España», con 120.000 personas.” — The president of the Community of Madrid, Isabel Díaz Ayuso, has snapped to the opposition parliamentary groups that the 8M demonstration, Women's Day, was "the largest superspreader event in Spain", with 120,000 people.
From infectar (“infect”) + -dromo. Formed by analogy with hipódromo, canódromo. Term coined by Isabel Díaz Ayuso, the president of the Community of Madrid, at the Assembly of Madrid on April 29, 2020 to criticize that the Government of Spain didn't ban the 2020 International Women's Day to prevent the spread of the coronavirus.