Mortality patterns were in many cases similar to those associated with normal, seasonal flu. But the team observed: "Nevertheless two risk factors are noticeable: pregnancy and obesity."
But the conclusion that obesity may be a factor in some swine flu deaths opens up a new line of investigation for epidemiologists. Where an underlying disease was found to be present after someone had died of swine flu, in more than one in four cases the deceased had a metabolic condition – diabetes and/or obesity.
There has been a view that fatal cases involving the pandemic have tended to occur among the young, according to the team. And they found the average age of those who have died was 37. More than half of all deaths occurred among the 20- to 49-year-old age group. Overall, 12% of deaths occurred in cases aged 60 years or more.