Farms in Gauteng, North West and the Free State have been placed under precautionary quarantine following an outbreak of swine flu, the Department of Agriculture, Land Reform and Rural Development said on Friday.

Department spokesperson Reggie Ngcobo said the outbreak was first detected on a farm in Gauteng and that the provincial Veterinary Services had launched an investigation to identify any properties that could have had direct or indirect contact with the affected farm.

As a result, farms in North West and the Free State have also been placed under quarantine.

"The ASF- (African Swine Fever) negative status of these farms will be confirmed before the precautionary quarantine can be lifted. The source of the infection on the positive farm has not yet been identified, but it is believed that the infection was already on the farm from mid-December," Ngcobo added.

Ngcobo said the swine flu outbreak in the country started in 2019, but slowed down, with fewer new properties becoming infected since October 2022.

"Control measures are based on quarantine, and movement controls, with awareness, drives to highlight essential biosecurity measures to enable pig owners to prevent infection of their pigs. This outbreak of ASF on a farm with good biosecurity measures in place again illustrates that the virus is highly contagious," he said.

The department urged all pig farmers and pig keepers to only buy pigs directly from known healthy herds and to prevent contact between their pigs and other pigs or wildlife.

The department has also urged visitors not to go to areas where pigs are being kept.

"Anyone who has contact with pigs should wash their hands before and after handling the pigs; and before moving to other farms, one should ensure that they have thoroughly showered and to only use clean clothes, shoes, and equipment."