Keywords: Legionella; SARS-CoV-2; co-infection; cargo ships; medical evacuation EN Legionella SARS-CoV-2 co-infection cargo ships medical evacuation 1 4 4 09/13/23 20230701 NES 230701 Infectious diseases frequently occur in travellers on expedition ships, with an incidence rate of 3.5/1000 person-days.[1] Due to the confined, shared and crowded environment of ships, the risk of disease outbreak is significant, particularly for pathogens such as I Legionella i and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).[2],[3] Bacterial co-infection plays a substantial role in the prognosis of coronavirus disease 2019 (COVID-19), with reports demonstrating that patients infected with both I Legionella i and SARS-CoV-2 are more likely to require intensive care unit (ICU) admission and have a higher case fatality rate than without co-infection.[4] We recently encountered a case of severe pneumonia caused by I Legionella i and SARS-CoV-2 co-infection. Based on the results of WGS, there may be a high likelihood that I Legionella i infection occurred outside Japan, whereas SARS-CoV-2 infection transpired during the ship's port calls in Japan. [Extracted from the article]