It was followed by the Northern Cape at 57 percent and the Eastern Cape at 48 percent, the SAIRR said in a statement on Thursday. The lowest vacancy rate was in North West, at 26 percent.

The SAIRR said South Africa had an overall vacancy rate of 56 percent for doctors in the public sector.

The vacancy rate refers to the proportion of total positions which are vacant.

The SAIRR said Limpopo also had the highest nurse vacancy rate at 68 percent, followed by the Eastern Cape, 67 percent, and the Free State, 47 percent. North West had the lowest rate at 12 percent.

South Africa had an overall nurse vacancy rate of 46 percent in the public sector.

The SAIRR said it calculated the figures using health department data on the number of public sector doctors and nurses, and the number of public sector doctor and nurse vacancies.

At the launch of the Human Resources for Health Strategy in October 2011, Health Minister Aaron Motsoaledi attributed the shortage of health professionals to a stagnation in their training and production, inequitable distribution between the public and private sectors, and emigration.

He said the department was working with health sciences faculties and colleges of medicine to increase the intake of medical students.

It had also entered into bilateral agreements with Cuba to train South African students in medicine, and was hiring retired health professionals to fill the vacancy gaps in the short-term.

SAIRR researcher Lerato Moloi said the high health professional vacancy rates were a worrying trend, given the proposed National Health Insurance (NHI) scheme and its objectives.

"The three focal points of the NHI scheme, as outlined by the [health department] are to ensure every South African has access to quality health services, to decrease the burden of disease, and to improve the overall performance of the health system.

"With such vacancy rates, these objectives seem unachievable," Moloi said.