A critical shortage of doctors and nurses is causing unnecessary disease and death across much of the developing world as rich nations poach health-care workers.
Poorer nations such as Africa and Asia urgently need more than 4 million health professionals to fill medical shortages in 57 countries.
Shameful though it may be at least 1.3bn people have no access even to the most basic health care, often because there is no health worker and that burden is greatest in countries hardest hit by poverty and disease.
In its annual World Health Report (WHO) 2006, the agency says on average one in four doctors and one nurse in 20 trained in Africa is working in developed countries.
Some countries have been affected more than others, with 29 percent of Ghana's physicians and 34 percent of Zimbabwe's nurses working abroad says the WHO report.
In Canada, New Zealand, the United Kingdom and the United States, a quarter or more of all physicians had been imported from other countries.
Essential life-saving measures such as childhood vaccination, pregnancy and maternity care and treatment for HIV, malaria and tuberculosis are threatened by the shortage.
Lee Jong-wook WHO Director-General, says the shortage of health workers in the developing world is critical and threatens the U.N.'s Millennium Development Goals, which aims to halve poverty by 2015.
He says if action is not taken now, the millennium development goals will remain an empty promise.
He also says the spending on health must be increased and the supply of medicines and equipment needs to be improved.
The WHO says the worst-hit countries, which spend an average $33 per person per year on health care, need to boost their annual budgets to at least $43 per person within the next 20 years in order to tackle the crisis.
WHO Assistant Director-General Tim Evans says 57 countries across the globe are inhibited in providing essential life-saving interventions such as childhood immunisations.
The WHO report has highlighted the enormous inequities in the global health-care system, which threatens to worsen as rich countries attract doctors and nurses from poorer nations which bear the brunt of health crises like AIDS, malaria and tuberculosis.
The British-based Save the Children charity blames the International Monetary Fund (IMF), which it has accused of imposing spending restrictions on African governments which prevent them from investing in healthcare.
The charity says thousands of children across Africa continue to die every day from diarrhoea, malaria and measles, primarily because hospitals and clinics suffer from under-investment, migration of doctors and nurses, and crippling restrictions on spending imposed by the IMF.
Last year, a report by Save the Children and the charity Medact estimated that Britain had saved £65m in training costs for doctors and £38m for nurses it had taken from Ghana alone since 1999.