Four million health workers are needed to combat the chronic shortage around the world, a report from the World Health Organization has warned

BBC News:

Fifty-seven countries have a serious shortage of health workers, affecting children's jabs, pregnancy care and access to treatment, it said.

Thirty-six of these countries are in sub-Saharan Africa.

The WHO's World Health Report 2006 said the shortage affected how diseases such as HIV/Aids could be tackled.

It says that at least 1.3 billion people worldwide lack access to the most basic healthcare, often because there is no health worker.

The burden is greatest in countries overwhelmed by poverty and disease where these health workers are needed most.

The report led to calls for Western countries to stop "poaching" healthcare staff from these countries.

Sub-Saharan Africa has 11% of the world's population and 24% of the global burden of disease but only 3% of the world's health workers.

A lack of personnel, combined with a lack of training and knowledge, is also a major obstacle for health systems as they attempt to respond effectively to chronic diseases and bird flu.

The WHO says life expectancies in the poorest countries are half of those in the richest nations.

UN: Shortage of health workers puts world at risk

Exodus of medics to West creates shortfall of four million

Sub-Saharan Africa suffers most from health worker shortages