Only 45 per cent of the global blood supply is collected in developing countries, which are home to more than 80 per cent of the world's population, the World Health Organisation (WHO) said yesterday.

The figures are part of global information on blood safety and donations revealed to mark World Blood Donor Day 2007 yesterday.

The data, collected by the WHO in 2004 from 172 countries covering 95 per cent of the world's population, shows that out of 80 countries that have donation rates of less than 1 per cent of the population (fewer than 10 donations per 1,000 people), 79 are in developing regions.

"It is generally recommended that 1 to 3 per cent of the population give blood to meet a country's needs. The average number of blood donations per 1,000 population is 11 times higher in high-income countries than in low-income countries," the WHO said in a statement.

It said that while the need for blood is universal, there is a "major imbalance" between developing and industrialised countries in access to safe blood.

With the prevalence of HIV, hepatitis viruses and other blood-borne infections, it said such diseases are lowest among voluntary, unpaid donors.

However, while the 2004 data revealed some tangible improvements since 2001-2002, family/replacement donors and paid donors still remain a significant source of blood for transfusions in many developing countries.

Sixty countries reported an increase in the percentage of blood donated by unpaid donors, 41 countries maintained the same level, and 37 countries showed a decline in the percentage of donations from voluntary donors.

In 2002, 39 countries had achieved 100-per-cent voluntary blood donation, of which five were developing countries. By 2004, this had risen to 50.

On blood screening, the WHO recommends that, at a minimum, all blood for transfusion should be screened for HIV, hepatitis B, hepatitis C and syphilis.

However, complete and accurate data on the testing of donated blood are not available in the majority of developing countries, particularly in those where blood services are fragmented. Many do not yet have reliable systems for testing because of staff shortages, poor quality or irregular supplies of test kits, and

lack of basic laboratory systems.

Moreover, even the advanced technology used in many developed countries is unable to detect very recent infections and is not affordable or cost-effective in most developing countries.

"Forty-one out of 148 countries (28 per cent) that provided data on screening for transfusion-transmissible infections were not able to screen all donated blood for one or more of these infections," the WHO report said.