JOHANNESBURG - Health officials say there is a possibility the source of the listeriosis outbreak may never be found.
The national health department is calling the outbreak the biggest on record.
To date, there have been 727 confirmed cases across South Africa with 61 reported deaths.
The disease is now classified as notifiable due to its rapid spread.
Health Minister Aaron Motsoaledi says tracing infected patients as well as the source is proving extremely difficult.