What is the incubation period of hantavirus?

Hantavirus has one of the longer incubation periods among acute viral infections. Symptom onset usually occurs 14 to 28 days after exposure, but cases as short as 4 days and as long as 56 days have been documented. The variability reflects viral dose, host immune status, and route of exposure. Long incubation matters epidemiologically — by the time a person is diagnosed, the exposure event may be over a month in the past, making contact tracing difficult. For the 2026 MV Hondius outbreak, this is why the ship had already crossed the Atlantic before the index case was clinically recognized.