Indigenous people appear vulnerable to disease
Indigenous peoples, such as Aborigines and Native Americans, have low quality health which puts them at higher risk from swine flu, experts have warned.
There are around 400m people around the world who are classed as indigenous.
Australian researchers, writing in the Lancet, warn flu risk is increased because they are more likely to be malnourished and living in poverty.
One Aboriginal man has already died from swine flu, and Native Indians in Canada have seen many cases.
Established diseases are more common in indigenous populations, from skin infections to HIV/Aids.
Factors such as tobacco use, alcohol, drug use, physical inactivity, low intake of fruit and vegetables and high blood pressure increase health risks.
And the "Westernisation" of indigenous peoples, including their adoption of high-calorie, high-fat, high-salt diets, when combined with decreasing physical activity and genetic predisposition has increased the risk of conditions which were previously not a significant problem.
Children in indigenous communities often experience malnutrition, and poor living conditions and diarrhoeal diseases and respiratory infections are common.
Illness that can be prevented by vaccination, such as measles, mumps diphtheria and tetanus are also still rife.
Writing in the Lancet, Professor Michael Gracey, of Perth's Unity of First People of Australia (an Aboriginal research group) and Professor Malcolm King of the University of Alberta, Canada, said indigenous health shoulf be "a priority for action" by governments and non-governmental organisations.
"This is looming as an international public health catastrophe," they wrote.
Professor Gracey added: "The first Australian death from swine flu occurred very recently in a young desert-dwelling Aboriginal man.
"He had underlying medical conditions and his demise highlights the susceptibility of large numbers of Indigenous people to such infections.
"Many Aboriginal people died even in very remote parts of Australia during the great influenza pandemic of 1918."
The World Health Organization has already expressed concern over the progression of swine flu in indigenous groups.
In a speech on global health needs this week, WHO Director-General Margaret Chan said: "I firmly believe that this pandemic will reveal, in a highly visible, measurable, and tragic way, exactly what it means, in life-and-death terms, when health needs and health systems have been neglected, for decades, in large parts of the world."