GENEVA - Heart ailments, infectious diseases and cancer remain the world's top three killers, the UN health agency said Monday.

Heart attacks and related problems are the top killer, claiming 29 per cent of people who die each year, the World Health Organization said in a report on the global burden of disease. In second place, infectious diseases lead to 16.2 per cent of worldwide deaths.

Cancer, in third, claims 12.6 per cent of global deaths, said the 146-page report, which is based on death registration data from 112 countries and estimates where reporting is incomplete.

The figures are from 2004, the most recent records available on a wide scale, officials from WHO said. But the rankings are unchanged since 1990 when WHO first did a global check.

Colin Mathers, WHO expert and lead author of the report, said he believed infectious diseases used to be the leading killer 20 to 40 years ago, but that he did not have statistics to back it up.

Some 58.8 million people died worldwide in 2004, most of them over 60, the report said. Nearly one in five deaths was a child under five.

The heart disease death rate was virtually unchanged from WHO's previous study on death causes, based on 2002 figures.

The rate for infectious diseases dropped from 2002, when they accounted for 19.1 of the world's deaths, partly because estimates for AIDS deaths were revised downward last year, said Mathers.

"Malaria deaths are also somewhat lower, and some of the other child causes have also come down a bit," Mathers said, adding that the number of deaths from measles has dropped thanks to wider use of vaccination.

Women die more often from heart disease than men. The rate for females is 31.5 per cent, and for males 26.8 per cent, the report said.

Mathers said the percentage for women was higher because there were more women living at older ages than men.

But in general, men are more affected by heart diseases, he said.

"Men in many parts of the world have a higher risk," he said, adding that they are more often overweight or obese, get insufficient physical activity and eat more fat and salt.

Filling out the top 12 causes of death are respiratory infections including pneumonia in fourth place, 7.2 per cent; respiratory diseases, including asthma and allergies, 6.9 per cent; accidental injuries and drownings, 6.6 per cent; newborn health problems, 5.4 per cent; digestive diseases, 3.5 per cent; suicide, murder and conflict, 2.8 per cent; neuropsychiatric disorders, 2.1 per cent; diabetes, 1.9 per cent; and maternal health problems related to pregnancy or birth 0.9 per cent.

Dr. Ties Boerma, who heads the agency's statistics department, said there is always a time delay in assembling such data from a number of countries.

"Countries have a backlog of two, three years in publicizing their own information," he said.

In countries where no death registration data are available, the figures are taken from research studies, which take a few years to get published, Boerma said.