World citizen number 7 billion is less likely to die from infectious diseases like measles¹（麻疹） or even AIDS, and more likely to contract diabetes² or other non-communicable diseases (NCDs), as they are now the leading causes of deaths globally. 14th of November is official World Diabetes Day. In a world of 7 billion people with changing disease patterns, this day is more relevant than ever, according to external lecturer Siri Tellier from the Copenhagen School of Global Health at the University of Copenhagen.

"Our new world citizen number 7 billion is more likely to grow up in an urban setting, which increases his or her risk of getting diabetes, as well as chronic³ obstructive pulmonary disease (COPD慢性阻塞性肺病), cancer and heart disease," says Siri Tellier, who teaches demography⁴ and health in emergencies, while she also lectures on international perspectives on demographic challenges to Chinese university students in Beijing.

Global health challenges rapidly changing

World citizen number 7 billion, who was estimated to be born on 31 October, will face very different diseases than that of children born only a few decades ago. As the population of urban areas keeps growing, it rapidly changes the global health challenges.

"Until 2008, the majority of the world population lived in rural areas, but since then the majority has become urban, and most future population growth will happen in urban areas of developing countries. And one third of them, a little more than one billion, live in urban slums," says Siri Tellier.

A high proportion of people who move to cities are young adults, and this has several implications for health. Among them are the consequences of leaving their parents behind in rural areas.

"Aging parents can no longer depend on their adult children for care. They will often 'live with' chronic NCDs such as diabetes, and will need daily assistance. It's not just a question of the children sending them money from their new home in a big city -- who will care for the old people on a daily basis? The household size is shrinking. In rural areas it may be five, in urban areas only two. So in order to meet that challenge, new patterns of caring for older people will be needed," says Siri Tellier.