Rotterdam Zoo monkeypox outbreak

In 1964 there was an outbreak of mpox, then known as monkeypox, at Rotterdam Zoo, where two Central/South American giant anteaters were first identified with the disease. Until then, mpox was thought to occur only in primates. Housed in one large enclosure, the monkeypox virus subsequently spread to several orangutans, chimpanzees, gorillas, guenons, squirrel monkeys, macaques, marmosets and gibbons.

Unlike previous mpox outbreaks in laboratory monkeys, the outbreak in Rotterdam Zoo occurred in animals that were not for laboratory use, showed varying clinical presentations, and was particularly severe for orangutans. There were no reports of cases of transmission to humans.

In total, 11 of the 23 affected animals died, including six orangutans, the anteaters, three squirrel monkeys, the only one Asian gibbon and an American common marmoset. Several were complicated by fatal secondary bacterial infections.