Question

So are you saying the human disease actually isn't mild?

Answer 1

In some cases, certainly it isn't. It is important to note that the (H1N1) 2009 virus does cause severe infection in some people, including those who are otherwise healthy. While some fatal cases have been attributed to secondary bacterial infections or exacerbation of other health conditions, as is commonly seen in fatal cases of seasonal influenza in the elderly, an unusual feature of influenza A (H1N1) 2009 infection is severe viral pneumonitis, leading to acute respiratory distress syndrome, prolonged stays in intensive care units and extended use of mechanical ventilation or extracorporeal membrane oxygenation (ECMO) . It is unclear what predisposes some people to mild versus severe complications.