Legionellose etter smitte fra fontenen på Youngstorget.

BACKGROUND: Most cases of legionellosis in Norway are acquired outside the country. This was a domestic case from an unusual source.

CASE PRESENTATION: A man in his thirties was admitted with pneumonia early in the summer. He developed respiratory failure before recovering. Cultures from his lower airways grew Legionella pneumophila serogroup 1. Samples from his home and workplace did not identify Legionella. On further questioning it was discovered that the patient regularly sat beside an outdoor fountain during his breaks from work. Samples from the fountain identified high numbers of L. pneumophila serogroup 1, sequence type 256. Full genome sequencing showed that isolates from the patient and fountain were identical. The fountain used recirculated water with small amounts of chlorine. High outdoor temperatures in Oslo may have facilitated growth of Legionella in the fountain.

INTERPRETATION: To our knowledge, this is the first published case of Legionella transmission from an outdoor fountain.