Global health leaders shift attention to new culprits that United Nations Secretary-General Ban Ki-moon calls "a public health emergency in slow motion": our bad habits like smoking, overeating and too little exercise.

What's killing us? For decades, global health leaders have focused on diseases that can spread — AIDS, tuberculosis, new flu bugs. They pushed for vaccines, better treatments and other ways to control germs that were only a plane ride away from seeding outbreaks anywhere in the world.

P.O.V.:

Do you agree with the shift in focus?

This time, germs aren't the target.

Next week, the UN General Assembly will hold its first summit on chronic diseases — cancer, diabetes and heart and lung disease.

Varied impacts worldwide

Europe and North America: These regions are paying the price of too much eating, too little exercise and smoking: heart disease and diabetes dominate. Cancers that are more prevalent with age — breast and prostate — reflect long life spans in these regions where treatment is widely available. In Eastern Europe and the former Soviet Union, lung cancer is the dominant cancer in men. Europe has the highest smoking prevalence in the world: 29 per cent.

Asia: Southeast Asia has the lowest rates of obesity in the world, even lower than Africa. Yet in China, where only 6 per cent of the population is obese, nearly four in 10 people have high blood pressure. China also has three times the death rate from respiratory diseases as the United States. Many areas also have high rates of infection with HPV, a sexually spread virus that can cause cervical cancer.

In India, the government has launched an aggressive diabetes and high blood pressure screening project. There are 51 million diabetics in India, the second-highest incidence in the world after China. Lung cancer is the most common type of cancer in India among men; in women, it's cervical cancer.

Central and South America: Cancer prevalence patterns largely resemble North America except that cervical cancer dominates among women in certain areas. Access to care is much poorer in many countries. Dr. Angel Sanchez, an International Cancer Corps volunteer for the American Society of Clinical Oncology, told of conditions at a hospital in Honduras, where there are more than 700 new cancer cases every year for two oncologists to handle.

Those account for nearly two-thirds of deaths worldwide, or about 36 million. In the United States, they kill nearly nine out of 10 people.

They have common risk factors, such as smoking and sedentary lifestyles, and many are preventable.

It's hard to fathom the suffering these maladies are causing in some parts of the world.

For example, until a few years ago Ethiopia had one cancer specialist, Dr. Bogale Solomon, for more than 80 million people.

"Now three more oncologists have joined," he said, and these four doctors struggle to treat patients in a country where cancer drugs and even painkillers are in short supply.

Anti-cancer drugs beyond reach

Wondu Bekele took his two-year-old son, Mathiwos, to that lone cancer centre in Addis Ababa when the boy developed leukemia.

The desperate father got advice from St. Jude Children's Research Hospital in the United States, procured chemotherapy drugs from India, and against all odds, got his son treated. Yet the little boy died because the hospital had no separate ward to protect him from catching disease from other patients. The father founded a cancer society in his son's name and will represent cancer groups at the UN meeting.

"Practically all cancer-related medicines are either nonexistent or beyond the reach of ordinary Ethiopians," he said. "We are struggling to make a difference here."

Advocates may be struggling to make a difference at the UN, too. Key officials have been unable to agree before the meeting on specific goals — reducing certain diseases or risk factors such as smoking by a specific amount and date. With the global economy in turmoil, finding money to meet any goals could be an even bigger hurdle.

"The timing is difficult with the economy the way it is, but it should not prevent us from setting goals," said Dr. Sidney Smith, who heads the World Heart Federation, an umbrella group of more than 200 organizations focused on heart disease.

"Many of the things we're proposing cost very little" and some, such as smoking cessation, even save money, said Smith, a cardiologist at the University of North Carolina at Chapel Hill.

"We're not talking about trying to find a new magic bullet. We're just talking about behaviour and cost-effective medicines" like Aspirin and generic blood pressure drugs that lower the risk of multiple diseases, he said.

This is only the second time the UN has taken up a health issue. The previous one in 2001 led to creation of the Global Fund to Fight AIDS, Tuberculosis and Malaria, with billions from governments and private groups such as the Bill & Melinda Gates Foundation.

Disease double burden

Now even rich nations are cash-strapped, and it's unclear whether private groups will step in. Asked whether the UN meeting would alter its focus, the Gates Foundation indicated it would not.

"Unfortunately, there is a lack of comparable investment in infectious diseases, which disproportionately affect the world's poorest," said a statement from the foundation. "Our priority will continue to be investing in cost-effective treatments that lead to maximum impact and fill in a gap where other resources are not invested."

Infectious diseases such as malaria and HIV, coupled with chronic diseases, pose a double burden, said Robert Geneau, a senior program specialist with the International Development Research Centre in Ottawa, who has worked in Tanzania, Senegal and Ivory Coast.

"One of the challenges I think that these countries are facing and the international community is facing is to find solutions to deal with this double burden," Geneau said. "The health-care system has to be strengthened."

For example in Malawi, when health-care workers who previously treated HIV and malaria realized that their patients also need care for diabetes and hypertension, specialists got together to develop integrated guidelines on caring for patients with all of these illnesses, Geneau said.

Rich cancer misconception

However, advocates say there are disparities in chronic diseases, too.

"The common belief that cancer is a problem of rich countries is a misconception," said Dr. Eduardo Cazap, president of the Union For International Cancer Control.

In Ghana, 23 million people are served by two oncology centres; the country has four cancer doctors and no specialist cancer nurses, said Dr. Allen Lichter, CEO of the American Society of Clinical Oncology, an organization of cancer specialists. The society has trained more than 2,000 doctors in developing countries on cancer care and plans to do more.

Africa also remains the only region in the world where infectious diseases, maternal-infant health problems and poor nutrition still kill more people than noncommunicable diseases do.

Worldwide, stroke and heart-related diseases account for nearly half of all noninfectious disease deaths — 17 million in 2008 alone,WHO says. Next is cancer (7.6 million deaths), followed by respiratory diseases such as emphysema (4.2 million). Diabetes caused 1.3 million deaths in 2008, but that's misleading — most diabetics die of cardiovascular causes.

The UN chose to focus on those four diseases and their common risk factors: tobacco use, alcohol abuse, unhealthy diets, physical inactivity and environmental carcinogens.

John Seffrin, CEO of the American Cancer Society, said the UN session must lead to specific goals and more money, or a chance to make a difference with these diseases may be lost for decades.

"This is our moment in the sun," he said. "A resolution alone is insufficient."

With files from CBC's Amina Zafar