Eleven more cases of listeriosis have been reported to the National Institute for Communicable Diseases (NICD), but no more deaths so far.

"No additional deaths have been reported since the last situation update [on March 8]," the NICD said on Thursday.

So far, 183 people have died of the food-borne disease outbreak and 978 cases have been reported since January 2017.

The NICD has been able to analyse data relating to some of the patients, in an effort to form a picture of who it was affecting the most.

On March 4, Health Minister Aaron Motsoaledi announced that an investigation into the outbreak had traced the ST6 strain of the listeria bacteria, believed to be behind the outbreak, to Tiger Brands's Enterprise factory in the Limpopo capital, Polokwane.

A national recall of Enterprise polonies, viennas, cold meats and chilled meat products was ordered and, by Monday, Tiger Brands had amassed and quarantined around 3 500 tons of the foods.

They are destined for incineration and staff are deep-cleaning the factory as local and international experts privately conduct investigations for the company to confirm the NICD's findings.

This was after the NICD had analysed swabs taken at the factory in Polokwane, after tracing the source of a food believed to have been consumed by a group of sick creche children, who are being treated at the Chris Hani-Baragwanath Hospital in Soweto, Gauteng.

Listeria monocytogenes were also found at Tiger Brands's Germiston plant, but it has not yet been confirmed that they were the ST6 strain.

Tiger Brands is not supplying any of these chilled meat products at present and has embarked on an extensive campaign to alert the public to return the products to retailers for a full refund, even if the packet has already been opened.

Rainbow Chicken Limited (RCL) has also recalled its polony as a precaution.

The NICD said in its latest bulletin that 748 of the known cases were reported in 2017, and 230 in 2018.

Of the cases they managed to get more information on:

- 532 of those affected were women (where gender was reported);
the ages of those affected ranged from birth to 92 years;
- 398 of the people who became ill were babies younger than 28 days;
- 96% of the affected babies became sick between birth and six days old;
- most cases have been reported from Gauteng (581), followed by the Western Cape (118) and then KwaZulu-Natal (70)
- 639 cases were diagnosed in public health facilities; and
- 342 were diagnosed in private health facilities.

The NICD added that cases were still expected to be reported up to four weeks or longer after the recall of the implicated foodstuffs, as the incubation period for listeriosis can be 21 days, with a reported maximum of 70 days.

"Health care workers are urged to continue with vigilance for new cases as persons who have consumed implicated processed meat products over the past few weeks may continue to present with listeriosis," said the NICD.

In the meantime, Cabinet extended its "heartfelt condolences" to the friends and families of those who lost their lives after contracting listeriosis, and wished those who were recuperating a speedy recovery.

Motsoaledi was also expected to meet representatives of the SA Nursing Council on Thursday.