We report 3 cases of Puumala virus infection in a family in Switzerland in January 2019. Clinical manifestations of the infection ranged from mild influenza-like illness to fatal disease. This cluster illustrates the wide range of clinical manifestations of Old World hantavirus infections and the challenge of diagnosing travel-related hemorrhagic fevers.
Keywords: Hantavirus pulmonary syndrome; Puumala virus; Russia; Switzerland; hantaviruses; multiple organ failure; neutralization test; viral zoonoses; viruses; zoonoses.