Over 20 million South Africans have been screened for diseases since the launch of the HIV counselling and testing campaign (HCT), Deputy President Kgalema Motlanthe said on Thursday.

"The campaign has indeed been successful," he said in Pretoria at the launch of an HCT intensification campaign for public servants.

The intensification campaign -- aimed at the public sector -- forms part of Public Service Month, which runs from September 1 to 30.

HCT, which was launched in April 2010, is a government-led prevention and HIV testing promotion campaign, central to the National Strategic Plan on HIV and AIDS, sexual transmitted infections (STIs) and tuberculosis (TB).

Motlanthe said the government's goal was to ensure people were tested and screened at least once a year.

"As such, it is crucial that the government, as the leading partner in the drive for universal HCT programmes, leads by example."

It was, therefore, important for the government to step up its campaign within the public sector, ensuring each employee was encouraged to know their status.

Employees should encourage and support their relatives to do the same, and promote a healthy lifestyle.

Health Minister Aaron Motsoaledi said at the same event that the testing target of 49 percent of public servants, or 637,000, had not been reached by the end of March 2011.

These figures would have excluded employees of the state-owned enterprises and dependants of public servants.

To date only 18 percent of this target had been achieved through the departmental HCT campaigns.

"The HCT intensification launch event marks the beginning of a series of activities that will contribute to the attainment of the goal of getting 1.3 million public servants to test and know their status," the minister said.