A new, highly lethal, highly contagious respiratory virus. The initial symptoms are similar to those of severe influenza (high fever, severe cough, difficulty breathing), and later are accompanied by rapid fibrosis of lung tissue (coughing up gray-black sputum and tissue fragments, hence the name "ash") and multiple organ failure. The incubation period is short (1-3 days), the onset is rapid, and the mortality rate is extremely high (initial estimate is >70%). It is mainly spread through droplets and aerosols, and is extremely powerful in closed and crowded places. There is a chain of transmission from asymptomatic infections in the early stage.
